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Home My WebLink About921512.tiff Waste Services DEVELOPMENT CORPORATION February 7 , 1992 FEB 1 0 1992 Mr . Chuck Cunliffe C.] Director Weld County Planninn Weld County Department of Planning Services 915 10th Street Greeley, Colorado 80631 Dear Chuck: I am pleased to submit to Weld County the accompanying applications for the issuance of a certificate of designation and use by special review permit for the proposed East Weld Sanitary Landfill. It is my firm belief that the proposed Facility shall meet or exceed all applicable federal , state and local standards and requirements . Extensive planning, investigation and engineering have gone into the design and operations plan for the proposed Facility. Coupled with the operational experience and expertise of the applicant , these efforts will assure the Facility protects the public health, welfare and safety while meeting a fundamental community need. Toward expediting the comprehensive review of the proposed Facility, it is requested that the applications be referred to the Colorado Department of Health for their review, comment and recommendation as soon as possible . I look forward to the opportunity to work with you and your staff on this proposal and to the benefit I am sure we will realize during the course of your review. Please do not hesitate to contact me if you need any additional information to assist you. Thank you. Res ctfully, Brad Keirnes President CBK/kbc 921512 P.O. BOX 3365 • GREELEY, COLORADO 80633 • (303) 356-6600 920989 SOLID WASTE DISPOSAL SITES j 3 USE BY SPECIAL REVIEW APPLICATION U + �pp Department of Planning Services, 915 Tenth Street, Greeley, . oA B 40®31992 Phone - 356-4000 - Ext. 4400 Weld County Planning Case Number Date Received Application Checked By Mylar Plat Submitted Application Fee J ° S.m Receipt Number 1B/4-at?) Recording Fee Receipt Number TO BE COMPLETED BY APPLICANT: (please print or type, except for necessary signature) I (we) , the undersigned, hereby request a hearing before the Weld County Planning Commission and Weld County Board of County Commissioners concerning the proposed Use by Special Review Permit on the following described unincorporated area of Weld County, Colorado: See LEGAL DESCRIPTION OF SPECIAL REVIEW PERMIT AREA: Attachment Section T N, R W LEGAL DESCRIPTION of contiguous property owned which Special Review Permit is proposed: Section T N, R _W Property Address (if available) None PRESENT ZONE A OVERLAY ZONES None TOTAL ACREAGE 1676 PROPOSED LAND USE use by special review solid waste disposal site and facility EXISTING LAND USE Agricultural - grazing SURFACE FEE (PROPERTY OWNERS) OF AREA PROPOSED FOR THE USE BY SPECIAL REVIEW PERMIT: Name: Guttersen and Company, a Colorado Limited Partnership Address: P 0 Box 528 City: Kersey Zip: 80644 Home Telephone: 454-2880 Business Telephone: 784-5505 Name: Address : City: Zip: Home Telephone: Business Telephone: APPLICANT OR AUTHORIZED AGENT (if different than above) : Name: Waste Services Company Address: P 0 Box 3365 City: Greeley Zip: 80693 Home Telephone: 356-6600 Business Telephone: 356-6600 List the owner(s) and/or lessees of mineral rights on or under the subject properties of record. Name: See accompaning Affidavit Re: mineral ownership Address: City: Zip: Name: Address: City: Zip: — I hereby depose and state under the penalties of perjury that all statements , proposals and/or plans submitted with or contained within the application are true and correct to the best of my knowledge. COUNTY OF Weld ) STATE OF COLORADO ) / _ �'' l r. %r Iignature: 0 er or"Authorized Agent Subscribed and sworn to before me this ( 04- day of �7 -1Jkii-� 19 9(9) kanti A-0 —44G1r U B LI C My commission expires I UI I a'/I945 920989 - Industrial Cornplial ice 1746 Cole Blvd., Bldg. 21 #300 Golden, CO 80401 303/277-1400 FAX 303/277-1405 USE BY SPECIAL REVIEW PERMIT FOR THE EAST WELD SANITARY LANDFILL WELD COUNTY, COLORADO IC Project Number 2-3716 Prepared for: Waste Services Company P.O. Box 3365 Greeley, CO 80633 (303) 356-6600 Prepared by: Industrial Compliance 1746 Cole Boulevard Building 21, Suite 300 Golden, Colorado 80401 February 7, 1992 Dedicated to solving your environmental problems. 920989 A Subsidiary of SP Environmental Systems, Inc. S^s ' This document supplements the application by Waste Services Company for a Use by Special Review permit for the proposed East Weld Sanitary Landfill in unincorporated Weld County, Colorado. The information contained herein demonstrates that the proposed use satisfies or exceeds the requirements for a Use by Special Review in the Agricultural District as set forth in the Weld County Zoning Ordinance and Comprehensive Plan. Overview of Proposed Use: Waste Services Company proposes to construct and operate a sanitary landfill in eastern Weld County. The site will be known as the "East Weld Sanitary Landfill" (hereinafter called the "Facility"). The Facility will-be located approximately 5 miles north of Interstate- 76 off a private road that extends 3 1/2 miles north of Weld County Road 59. The Facility will be part of an integrated mine reclamation and waste management operation, including the inactive Keenesburg Open Pit Coal Mine and the existing Coors Ash Disposal Facility. The access road to the integrated operation has been constructed and maintained exclusively for the existing mine, the ash disposal site, and the future Facility. The Facility will serve the geographic region of Weld County known as the Southeast Service Area (SSA). The SSA consists of approximately 700 square miles and includes the Weld County communities of Ft. Lupton, Keenesburg, Prospect Valley, Roggen, Hudson and Lochbuie and the surrounding rural areas. In addition to this primary local service area the Facility will serve portions of the Denver metropolitan area, including the new Denver International Airport. Located within a local and regional service area, the Facility will function as part of a comprehensive solid waste management system consisting of collection, recycling, transfer and disposal. The Facility will receive for final disposal, the residual portion of the solid waste stream not recycled or reused at the points of generation, collection or transfer. As a sanitary landfill, the Facility will dispose of only non-hazardous solid waste which will be handled and disposed of in strict compliance with all federal, state and local laws and regulations. A complete description of the design and operation of the proposed Facility is contained in the formal Design and Operations Plan as part of the application for the Certificate of Designation submitted in conjunction herewith consistent with Section 45.4.1 of the Weld County Zoning Ordinance. WELD.USR 2/7/92 2 Revised 6/9/92 92O989 The proposed Facility by its location, design, construction and operation will provide a long- term capability for ensuring that local and regional solid waste management needs are met in an environmentally safe and economically feasible manner. Following is a comprehensive discussion of the ability of the proposed Facility to meet or exceed the standards and conditions for the approval by Weld County of the requested Use by Special Review. Toward facilitating the efficient review of this information, it is presented in a format that summarizes the specific Use by Special Review standard or condition and its reference, followed by a discussion of the related aspects of the proposed Facility. APPLICATION REQUIREMENTS: 1. A statement explaining how the proposal is consistent with the Weld County Comprehensive Plan. (Zoning Ord. - 24.7.1.1) The proposed Facility is consistent with the Weld County Comprehensive Plan and its environmental quality and natural resource goals and policies. The optimal location of the Facility in an isolated yet accessible area serves to minimize any potential for negative impacts on surrounding land uses and/or residents. The site is located in the Agricultural District in a vast area that is used predominantly for dryland grazing. The only other land uses within a 1-mile radius of the Facility are the inactive Keenesburg Coal Mine, the existing Coors Ash Disposal Facility, several high- voltage electrical transmission lines, and numerous oil and gas production sites. The former Keenesburg Town Landfill is 1 1/2 miles south of the facility. The topography of the area consists of undulating prairie marked by gentle ridges and knolls. The final topographic form of the Facility has been carefully designed to blend in with the elevation and features of the existing topography of the area. The scale of the proposed Facility consisting of approximately 700 acres of actual sanitary landfill area is properly understood in relation to the 976 acres of primary buffer area that surround it. Additionally, there is a 2964-acre controlled secondary buffer zone surrounding the parcel under consideration. The actual daily landfill working face itself will be approximately 1-acre in size. In addition to the contoured topographic form of the Facility and the use of numerous proven operational measures, the substantial primary and secondary buffer areas will further ensure WFI D.USR 2/7/92 3 Revised 6/9/92 that the scale of the Facility does not adversely impact surrounding land uses. The agricultural area in which the Facility is located is sparsely populated. There are no residences within 1 mile of the facility and only 1 residence within approximately 2 miles. Immediately northeast of the Facility is the inactive Keenesburg Coal Mine and existing Coors Ash Disposal Facility. These prior and existing uses have had an operational nature and intensity similar to the proposed Facility. They have demonstrated that such uses in the area do not adversely impact surrounding agricultural and other land uses. Access to the Facility will be from Weld County Road 59 onto and approximately to the end of a private 3 1/2-mile road. Weld County Road 59 was substantially upgraded and has been maintained to serve the heavy truck traffic to and from the coal mine and the ash disposal facility. The privately owned, constructed, and maintained asphalt road that extends north of Weld County Road 59 exists exclusively for these purposes. The traffic associated with the proposed Facility will be of a similar type and volume to that historically using this access route. Due to the substantial reduction in traffic resulting from the cessation of mining operations at the Keenesburg Coal Mine, the anticipated traffic associated with the Facility will not increase the potential for any adverse traffic impacts beyond historical levels. The potential for fugitive dust and any impacts therefrom will be mitigated at the Facility through a comprehensive dust abatement program including the watering or treatment of interior haul roads. The remote location of the Facility, its distance from residential structures and the use of properly fitted equipment will mitigate any potential for noise impacts. Visual impacts from the proposed Facility on adjacent properties and the public are mitigated by its remote location, the surrounding topography, the natural features incorporated into its final topographic form, the dust abatement program, the windblown debris program, and interim and final revegetation. The entrance to the Facility will be suitably landscaped to be compatible with the natural vegetation found in the area. The Facility will be fully secured by fencing, monitoring and restricted access. Its remote location and access from a 3 1/2 mile private road will assist in maintaining full security of the Facility. The Facility has been designed and will be constructed and operated to meet or exceed all WELD.USR 2/7/92 4 921999 applicable federal, state and local environmental standards and regulations. The Design and Operations Plan submitted in conjunction herewith extensively details the measures that will be taken to ensure this occurs. The Facility does not lie within an Important Wildlife Habitat Area as identified by the habitat area map prepared by the Weld County Department of Planning Services in cooperation with the State of Colorado Division of Wildlife contained in the Weld County Comprehensive Plan. The area around the Facility does not possess a habitat for fish. Other wildlife in the area are typical of a prairie environment and will not be significantly affected by the Facility as has been demonstrated by the experience of the adjacent coal mine and ash disposal sites. The Facility does not lie within a flood hazard or geologic hazard area as such are identified by the Weld County Zoning Ordinance or Comprehensive Plan. The Facility will be finally reclaimed through a comprehensive program of contouring, drainage management, cover placement and maintenance, and revegetation. The final topographic form will remain in an open space state while the buffer area around it will be available for original non-prime agricultural uses. Full practical and financial provision will be made to assure complete and proper post- closure maintenance and monitoring of the Facility in accordance with federal, state and local requirements. Waste Services Company in its extensive investigation and conceptualization of the Facility has carefully considered the environmental and economic feasibility of recycling and resource recovery and the role they realistically should play within the service area of the Facility. The result of this study has been a continued commitment to the ongoing promotion and practical implementation of various recycling and resource recovery alternatives within the comprehensive solid waste management system of which the Facility will be a part. Based on a broad knowledge of and varied experience in the recycling and resource recovery field, Waste Services Company believes that primary emphasis on waste reduction, reuse and recycling should be placed at the points of generation, collection and transfer, not final disposal. Practical, environmental and economic benefits of accomplishing recycling and resource recovery upstream of the final disposal point include cleaner, more recoverable and thus more recyclable products; a lower volume of materials transported to the final disposal point, resulting in fewer vehicle trips thus reducing fuel consumption, lessening the potential for traffic impacts and auto emissions; increased efficiency of both truck and rail shipment of recyclables to market; and increased economic feasibility of recycling and resource recovery. WELD.USR 2/7/92 5 920999 Significant proven recycling capabilities exist and are being expanded within both the local and regional service areas of the Facility. Curbside recycling programs have been implemented throughout the SSA and metropolitan Denver. Commercial recycling programs have expanded dramatically over the last three years and should continue as commodity markets allow. Additionally, recycling bins will be placed at the Facility entrance for the convenience of the public. The Facility will play a vital and complimentary role within the comprehensive solid waste management system of which it will be a part. By providing the necessary fundamental final disposal component, the Facility will enable the continued expansion, development and implementation of proven recycling and resource recovery alternatives within its intended service area. 2. A statement explaining how the proposal is consistent with the intent of the Agricultural District in which the Use will be located. (Zoning Ord. - 24.7.1.2) The Facility is located in the Agricultural District as required by the Weld County Zoning Ordinance. The Facility will be consistent with the intent of the district by additionally satisfying the applicable Use by Special Review standards and requirements for a solid waste disposal site and facility as set forth in the Weld County Zoning Ordinance and Comprehensive Plan. Furthermore, the planned end use of the Facility is to return it to agricultural or passive land uses. 3. A statement explaining how the proposed Facility will be compatible with the existing surrounding land uses. (Zoning Ord. - 24.7.1.3) The open space nature of the proposed Facility combined with the 3940-acre primary and secondary buffer areas around it, its isolated location and the proven operational methods to be employed will make the Facility fully compatible with the existing surrounding land uses. The existing surrounding agricultural use, i.e. grazing, and the mine reclamation and ash disposal facility will not be adversely affected by the proposed Facility. WELD.USR 2/7/92 6 Revised 6/9/92 920999 4. A statement explaining how the proposed Facility will be compatible with future development of the surrounding area as permitted by the existing zoning and with the future development as projected by the Comprehensive Plan or Master Plans of affected municipalities. (Zoning Ord. - 24.7.1.4) The area in which the Facility will be located is not included in the master plan of any municipality. Neither is it currently projected in the Comprehensive Plan of Weld County or otherwise reasonably assumed that the area will be zoned or permitted for Uses by Special Review other than agricultural or similar uses with which the Facility will be fully compatible. 5. A statement stating that the application complies with the Weld County Zoning Ordinance, Section 50, Overlay District Regulations if the proposal is located within the Overlay District Areas identified by maps officially adopted by Weld County. (Zoning Ord. - 24.7.1.5) The Facility does not lie within an Overlay District Area as identified by the maps officially adopted by Weld County. 6. A statement explaining what efforts have been made in locating the proposed Facility in the A-District to conserve productive agricultural land in the locational decision for the proposed Use. (Zoning Ord. - 24.7.1.6) The location of the Facility is in the Agricultural District as required. Its location conserves productive agricultural land by utilizing land that is considered by definition to be non-prime. The site was selected in part because it and the surrounding area are not irrigated or intensively farmed, but are non-prime. 7. A statement explaining there is adequate provision for the protection of the health, safety and welfare of the inhabitants of the Neighborhood and the County. (Zoning Ord. - 24.7.1.7) Careful and extensive consideration has been given to providing for the protection of the health, safety and welfare of the inhabitants of the neighborhood and county. The Facility will do so in part by being located, designed, constructed and operated in full compliance with all applicable environmental and other laws and regulations. The Facility Design and Operations Plan gives a detailed description of the extensive proven measures to be taken that will assure the protection of the environment at, above, beneath and around the Facility. This will result in the protection of the health, safety and welfare of WELD.USR 2/7/92 7 97tf989 the inhabitants of the neighborhood and the county. The Design and Operations Plan for the Facility will be reviewed by the Weld County and Colorado Departments of Health. Prior to the issuance by Weld County of the required permits for the Facility, it will have been found to meet or exceed all applicable federal, state and local environmental and public health standards and requirements. 8. Name, address, and telephone number of the applicant. (Zoning Ord. - 24.7.2.1) Waste Services Company attn: Brad Keirnes P.O. Box 3365 Greeley, CO 80633 (303) 356-6600 9. The name and address of the fee owner(s) of the property proposed for the Use by Special Review which are different than above. (Zoning Ord. - 24.7.2.2) Guttersen and Company Attention: Mike Guttersen P.O. Box 528 Kersey, Colorado 80644 10. The legal description of the property under consideration. (Zoning Ord. - 24.7.2.3) The legal description of the property under consideration is: A tract of land situated in Sections 2 and 3, Township 2 North, Range 64 West of the 6th Principle Meridian, and in Sections 26, 27, 34, and 35, Township 3 North, Range 64 West of the 6th Principle Meridian, County of Weld, State of Colorado, more particularly described as follows: Commencing at the northwest corner of said Section 26, a found no. 5 rebar with cap marked L.S. 10945; Thence south 0°15'23"east along the west line of the northwest one-quarter of said Section 26 a distance of 2052.67 feet to the true point of beginning, being a set 2 1/2 inch brass cap set in concrete, stamped L.S. 18472; thence along the boundary of the tract herein described for the following five (5) courses, the terminus of each course being marked by a set 2 1/2 inch brass cap set in concrete, stamped L.S. 18472: WELD.USR 2/7/92 8 920989 1) South 40°29'02" east a distance of 3566.38 feet. 2) South 00°00'00" west a distance of 9832.69 feet. 3) South 90°00'00" west a distance of 6071.64 feet. 4) North 00°00'00" west a distance of 12545.24 feet. 5) North 90°00'00" east a distance of 3756.22 feet to the true point of beginning, containing an area of 1676.5 acres, more or less. 11. The total acreage of the parcel under consideration. (Zoning Ord.- 24.7.2.4) The parcel under consideration comprises 1676 acres of which 700 acres will constitute actual sanitary landfill area and 976 acres will serve as primary buffer area. 12. A description of the existing land use of the parcel under consideration. (Zoning Ord. - 24.7.2.5) The existing land use of the parcel under consideration is grazing. 13. A description of the existing land USES of all properties ADJACENT to said parcel. (Zoning Ord.- 24.7.2.6) All properties adjacent to the Facility are used for grazing. 14. Present zone and overlay zones, if appropriate. (Zoning Ord. - 24.7.2.7) The present zoning of the parcel under consideration is agricultural. The northeasterly portion of the parcel will abut the Keenesburg Coal Mine and Coors Ash Disposal Facility for which Weld County previously issued Use by Special Review permits and a Certificate of Designation. 15. Signatures of the applicant and fee owner or their authorized legal agent. (Zoning Ord. - 24.7.2.8) Please see the accompanying grant of authority between the applicant and fee owner. WELD.USR 2/7/92 9 Revised 6/9/92 i 920989 16. A certified list of the names, addresses and corresponding Parcel Identification Number assigned by the Weld County Assessor of the owners of property (the surface estate) within five hundred (500) feet of the property subject to the application. If the list was assembled from the records of the Weld County Assessor, the applicant shall certify that such list was assembled within thirty (30) days of the application submission date. (Zoning Ord. - 24.7.2.9) Please see the accompanying affidavit and list of interest owners of surface estate within 500 feet of the parcel under consideration (Appendix D). 17. A certified list of the names and addresses of mineral owners and lessees of mineral owners on or under the parcel of land being considered. The source of such list shall be assembled from the records of the Weld County Clerk and Recorder, or from and an ownership update from a title or abstract company or an attorney, derived from such records. (Zoning Ord. - 24.7.2.10) Please see the accompanying affidavit and list of interest owners of the mineral and/or subsurface estate beneath the parcel under consideration (Appendix C). 18. A sign shall be posted as required giving public notice ten (10) days preceding the hearing date. (Zoning Ord. - 24.7.2.11) The applicant will post all signage as required by the Weld County Zoning Ordinance for giving public notice. 19. The type of USE for which the application is being made. (Zoning Ord. - 24.7.3.1) The type of use for which the application is being submitted is a solid waste disposal site and facility. 20. The proximity of the proposed USE to residential STRUCTURES. (Zoning Ord. - 24.7.3.2) The proposed Facility is approximately 2 miles from the nearest residential structure. The vicinity map submitted herewith identifies the location of any residential structures within 1/2 mile of the Facility as required. There are none. WELD.USR 2/7/92 10 9209 21. The number of shifts to be worked and the maximum number of employees. (Zoning Ord. - 24.7.3.3) The Facility will generally be operated Monday through Saturday for approximately 12 hours per day. This schedule is expected to require two partially overlapping work shifts and a maximum number of employees of 25. 22. The maximum number of users, patrons, members, buyers, or other visitors that the Use by Special Review facility is designed to accommodate at any one time. (Zoning Ord. - 24.7.3.4) The Facility will be designed to adequately accommodate approximately ten users at any one time. 23. The types and maximum numbers of animals to be concentrated on the site an any one time. (Zoning Ord. - 24.7.3.5) Animals are not intended nor will they be allowed to occupy active areas of the Facility. It is anticipated that inactive areas will continue to be utilized for livestock grazing by the current owner of the surface estate who is and will remain the predominant neighboring landowner. 24. The types and numbers of operating and processing equipment to be utilized. (Zoning Ord. - 24.7.3.6) The Facility will be part of an integrated operation including the reclamation of the inactive Keenesburg Coal Mine and the ongoing operation of the existing Coors Ash Disposal Facility. The integrated operation will generally require the following equipment: Equipment 1 Landfill Compactor 1 Scraper 1 Bulldozer 1 Motor Grader 1 Water Truck 2 Pickup/Service Trucks 1 Utility Tractor/Backhoe WELD.USR 2/7/92 11 25. The type, number, and USES of the proposed STRUCTURES to be erected. (Zoning Ord. - 24.7.3.7) The operation of the Facility will be supported by the major infrastructural capabilities existing at the adjacent mine and ash disposal facility. Those include all of the necessary utilities, maintenance facilities, administrative offices and a 3 1/2-mile long private asphalt access roadway. Detailed information about the facilities at the mine and ash disposal site is on file with Weld County under existing Use By Special Review permits and related building permits and approvals. The only structures to be erected will be a small self-contained, portable gatehouse and perimeter and interior fencing for security and for control of any windblown debris. Building permits will be obtained as required for these structures. 26. The type, size, weight, frequency of vehicular traffic and access routes that will be utilized. (Zoning Ord. - 24.7.3.8) It is expected that initial traffic volume will average 100 vehicles per operating day. This will generally consist of the following types of vehicles: 40 transfer tractor/trailer units 10 refuse collection trucks 50 other vehicles (cars, pickups, light trucks, etc.) The vehicle numbers and types may vary depending on changing conditions with the local and regional service areas of the facility. However, traffic and the potential for any impacts are not expected to significantly vary from historical levels. 27. Domestic sewage facilities. (Zoning Ord. - 24.7.3.9) Primary domestic sewage capabilities will be provided by those existing at the adjacent mine and ash disposal facility. Secondary service will be provided as needed by the use of portable toilets which will be properly serviced. WELD.USR 2/7/92 12 92098;3 28. The size of stockpile, storage, or waste areas to be utilized. (Zoning Ord. - 24.7.3.10) The Design and Operations Plan for the Facility describes the location and management of soil stockpiles. All soil stockpiles will be placed and maintained to minimize any potential for erosion and the growth of noxious weeds. 29. The method and time schedule of removal or disposal of debris, junk, and other wastes associated with the proposed USE. (Zoning Ord. - 24.7.3.11) The Facility will be kept in a clean and neat manner. Debris of any type will not be allowed to accumulate anywhere, including along fence lines. Periodic debris monitoring and removal, if necessary, will be performed. All wastes generated from the operation of the Facility will be properly classified and managed (recycled, reused or disposed of). 30. A time table showing the periods of time required for the construction of the operation. (Zoning Ord. - 24.7.3.12) It is intended that Facility construction will begin in mid-1993 and be completed by early 1994. 31. The proposed LANDSCAPING plans. (Zoning Ord.- 24.7.3.13) Due to the isolated location of the Facility from a 3 1/2 long private access road, landscaping will be limited to the area immediately around the entrance. Detailed landscaping plans will be submitted to the Department of Planning Services for comment prior to its installation. 32. The reclamation procedures to be employed as stages of the operation are phased out or upon cessation of the Use by Special Review activity. (Zoning Ord.- 24.7.3.14) One of the primary operational measures that will assure the capability of the Facility to conform with surrounding land uses will be to minimize the area of disturbance at any one time. The active working face of the Facility will be properly covered at the end of each operating day. All interim areas will be intermediately reclaimed by placing 1 foot of soil or equivalent cover over them. WELD.USR 2/7/92 13 920 - Areas that have been constructed to approved final topographic elevations and forms will be finally reclaimed through a combination of capping, covering and revegetation. A detailed description of the comprehensive reclamation program for the Facility is contained in the Design and Operations Plan. 33. A statement delineating the need for the proposed USE. (Zoning Ord: - 24.7.3.15 and 45.4.2) The Facility lies within and will primarily serve the geographic portion of Weld County known as the Southeast Service Area. The local area is one of four distinct service areas established as part of the regional solid waste management plan prepared for Weld County in 1979. That plan has been the foundation for the effective planning and provision for the solid waste management needs of Weld County for the past 12 years. The service areas concept it adopted is based on several factors which influence the determination of need. They include accessibility, current and projected population, and industrial growth. The concept of planned service regions with radii of approximately 15 miles, such as the Southeast Service Area, was affirmed by the recent report of the Regional Land Use Task Force. That report issued in October 1991, by a broad coalition of concerned private citizens and municipal and county officials from southern Weld and northern Adams Counties endorsed service areas of 16 miles or more in radius. The Facility is more than 20 miles from the nearest sanitary landfill, the central Weld Sanitary Landfill, and 30 miles from thenext nearest sites at Erie. Actual travel distances to these sites are significantly greater. The Southeast Service Area consisting of approximately 700 square miles was previously served by the Town of Keenesburg landfill. Since the closure of that landfill, the SSA has been without a convenient solid waste disposal site. It is anticipated that the existing need of the Southeast Service Area will significantly increase due to economic growth and development in the region resulting from the Denver International Airport. Secondarily, the Facility will serve the long-term regional needs of portions of the Denver metropolitan area. WELD.USR 2/7/92 14 920989 34. A description of the proposed fire protection measures. (Zoning Ord. - 24.7.3.16) Burning will not be conducted at the Facility. All incoming loads will be monitored for indications of burning and properly extinguished if necessary. All buildings and equipment will be fully equipped with appropriate fire protection devices. In the unlikely event a fire should occur at the active filling area of the Facility, it will be properly extinguished using proven operational methods. The applicant will coordinate its fire protection program in full cooperation with the Southeast Weld J+ district in which the Facility is located. 35. The type of storm water retention facilities associated with the proposed use. (Use by Special Review Procedural Guide - Solid Waste Disposal, page 3.) The purpose of the storm water retention facilities is to assure the increased runoff resulting from development does not harm the surrounding surface water features. Runoff resulting from this Facility development is not expected to significantly vary from historic runoff rates and is not expected to require the use of retention facilities. Additional surface water information is included in the Design and Operations Plan. ADDITIONAL REQUIRED INFORMATION AND DOCUMENTATION: 1. Proof that a water supply will be available which is adequate in terms of quantity, quality, and dependability. . Drinking water for the Facility will be imported. Water for other purposes will be supplied either by the existing well on the Coors Ash Disposal facility or by a new well, if installed. 2. Legal documentation that the applicant has or will obtain ownership of the property under consideration for the proposed Use by Special Review. Please see the accompanying memorandum of agreement between the applicant and the fee owner of the parcel under consideration and the assignment thereof (Appendices E and F). 3. A noise report, unless waived by the Department of Planning Services, documenting the methods to be utilized to meet the applicable noise standards. A noise report has been waived by the Department of Planning Services. Nevertheless, the WEI D.USR 2/7/92 15 9 '091gg Facility should not create any potential for adverse noise conditions due to its remote location, its distance from any residential structures, and the use and maintenance of properly fitted mufflers on all equipment. 4. A soil report of the site prepared by the Soil Conservation Service or soils engineer or scientist. In those instances when the soil report indicates the existence of moderate or severe soil limitations for the uses proposed, the applicant shall detail the methods to be employed to mitigate the limitations. The soils and surface and subsurface geology present at the Facility have been found to be suitable for the proposed use. All issues relating to the soils and their investigation are extensively addressed in the Design and Operations Plan submitted in conjunction herewith. 5. A completed Use by Special Review application form. Please see the accompanying completed form and grant of authority (Appendices A and D). 6. The required application review fee. Please find the accompanying application review fee. 7. The required Use by Special Review recording plat fee. Please find the accompanying recording plat fee. 8. The required Use by Special Review permit plan map consisting of: a. The vicinity map. The required vicinity map accompanies this application. b. The plot plan. The required plot plan accompanies this application. 9. Such additional information and supporting documentation as may be required by Weld County or subsequently submitted by the applicant. Please see the section entitled Post-submittal Additional Information and Documentation. Appendix G has been reserved for inclusion of additional information, as necessary. WELD.USR 2/7/92 16 3-10" , APPENDIX A USE BY SPECIAL REVIEW APPLICATION FORM. 920989sr- SOLID WASTE DISPOSAL SITES USE BY SPECIAL REVIEW APPLICATION Department of Planning Services, 915 Tenth Street. Greeley, Colorado 80631 Phone - 356.4000 - Ext. 4400 Case Number Date Received Application Checked By Mylar-Plat Submitted Application Fee Receipt Number Recording Fee Receipt Number JO Al COMPLETED DI APPLICANT: (please print or type, except for necessary signature) I (we), the undersigned, hereby request a hearing before the Weld County Planning Commission and Weld County Board of County Commissioners concerning the proposed Use by Special Review Permit on the following described unincorporated area of Weld County, Colorado: _ See LEGAL DESCRIPTION OF SPECIAL REVIEW PERMIT AREA: Attachment Section T N, R W LEGAL DESCRIPTION of contiguous property owned which Special Review Permit is proposed: Section T N, R W Property Address (if available) None PRESENT ZONE A OVERLAY ZONES None TOTAL ACREAGE 1676 PROPOSEDLANDUSE use by special review solid waste disposal site and facility EXISTINCLANDUSE Agricultural - grazing SURFACE ELL (PROPERTY OWNERS) OF ARLA PROPOSED E03 ICE LEL fl SPECIAL REVIEW PERMIT: • Name: Guttersen and Company, a Colorado Limited Partnership Address: P 0 Box 528 City: Kersey Zip: 80644 Home Telephone: 454-2880 Business Telephone: 7RA-scn5 Name: Address: City: Zip: Home Telephone: Business Telephone: • APPLICANT QR AUTHORIZED AGENT (if different than above) Name: Waste Services Company Address: P 0 Box 3365 City: Greeley Zip: RO6'7 Home Telephone: 356-6600 Business Telephone: 356-6600 List the owner(s) and/or lessees of mineral rights on or under the subject properties of record. Name: See accompanint Affidavit Re: mineral nwnerchin Address: City: Zip: Name: Address: City: Zip: I hereby depose and state under the penalties of perjury that all statements, proposals and/or plans submitted with or contained within the application are true and correct to the best of my knowledge. COUNTY OF Weld 1 STATE OF COLORADO ) / xignature: O ar ' Authorized t Subscribed and sworn to before me this day of �„-',�t(,lQ- 19 CO) 14tOlfl-(✓1 Q.f\ �'1 ,�I CCC NOTAme PUBLIC I U My commission expires I lI bG is 920989 APPENDIX B AFFIDAVIT AND LIST OF INTEREST OWNERS OF SURFACE ESTATE WITHIN 500 FEET 32:0333 SOLID WASTE DISPOSAL SITES AFFIDAVIT OF INTEREST OWNERS SURFACE ESTATE Commission expires Legal Description: See attachment STATE OF COLORADO ) ) SS COUNTY OF WELD THE UNDERSIGNED, being first duly sworn, states that to the best of his or her knowledge the attached list is a true and accurate list of the names , addresses, and the corresponding Parcel Identification Number assigned by the Weld County Assessor of the owners' of property (the surface estate) within five hundred feet of the property under consideration This list was compiled from the records of the Weld County Assessor, or an ownership update from a title or abstract company or attorney, derived from such records, or from the records of the Weld County Clerk and Recorder. The list compiled from the records of the Weld County Assessor shall have been assembled within thirty days of the application's submission date. y The foregoing instrument was subscribed and sworn to before me this It day Or .GG`,u,0 - , lA79 WITNESS my hand and official seal. be. ( ak Notary Public I( (J My Commission Expires: 1012 12 / /C-/G,f), 920_'83 • SOLID WASTE DISPOSAL SITES NAMES OF OWNERS OF PROPERTY WITHIN 500 -FEET Please print or type NAME ADDRESS, TOWN/CITY, ASSESSOR' S PARCEL STATE AND ZIP CODE IDENTIFICATION # Guttersen & Co. . P 0 Box 528. Kersey, CO 80644 130502000001 Guttersen & Co. , " 130503000007 Guttersen & Company, " 121526000010 Guttersen & Co. . " 121527000004 Guttersen & Co. , 121534000003 Guttersen & Company, 121535000008 Guttersen & Co. , 121535000009 920.;89 APPENDIX C AFFIDAVIT AND LIST OF INTEREST OWNERS OF THE MINERAL AND/OR SUBSURFACE ESTATE SOLID WASTE DISPOSAL SITES AFFIDAVIT OF INTEREST OWNERS MINERALS AND/OR SUBSURFACE ESTATE Legal Description: See Exhibit B attached STATE OF COLORADO } }ss. COUNTY OF WELD } THE UNDERSIGNED, being first duly sworn, states that to the best of his or her knowledge based upon research of the records of Transamerica Title by Crews and Zeren, Certified Professional Landmen, the attached list is a true and accurate list of the names and addresses of all mineral owners and lessees of mineral owners on or under the parcel of land. � .,��✓��If/ ter' The foregoing instrument was subscribed and sworn to before me this 0)+1- day of -A.LLGLh.Li, , 1992 . WITNESS my hand and official seal. My commission expires: IDll2q wc9, � y �� ll 'J'�'/� [SEAL] C`�/ Notary Publ ' c Exhibit B Owners of Mineral Owners and Mineral Lessees Sections 26, 27, 34 and 35, Township 3 North, Range 64 West, and Sections 2 and 3, Township 2 North, Range 64 West Union Pacific Railroad Company Transfuel Resources Co. 1416 Dodge Street P.O. Box 771089 Omaha, NE 68179 Houston, TX 77215-1089 Union Pacific Land Resources Don B. Sheffield Corporation 3741 Chevy Chase P.O. Box 7 Houston, TX 77019 Fort Worth, 1X 76101 Gibbs Petroleum Corporation Union Pacific Resources Company 11100 Kingsworthy P.O. Box 7 Houston, TX 77024 Fort Worth, TX 76101 Texas Petroleum Corp. Amoco Production Company P.O. Box 820008 P.O. Box 800 Dallas, TX 75382-0008 Denver, CO 80201 Alfred G. Heyde and Mary M. Ileyde HS Resources, Inc. Cord, AR 72524 535 Pacific Ave., Third Floor San Francisco, CA 94133 Gutterson and Company P.O. Box 528 SOCO Wattenberg Corporation Kersey, CO 80644 777 Main Street, Suite 2500 Fort Worth, TX 76102 Virginia S. Seldin and Bernice S. Frieder, Trustees Damson Investment Group, Inc. 1111 Race Street, Apr. 9-B 366 Madison Avenue Denver, CO 80206 New York, NY 10017 Dora L. Keyes and Coors Energy Company John T. Jacobs P.O. Box 467 c/o John T. Jacobs, Jr. Golden, CO 80401-0467 1940 South Freeman St. Oceanside, CA 92054 Aceite Energy Corporation 1905 Sherman Street Energy Minerals Corporation Suite 700 999 18th Street, Suite 3100 Denver, CO 80203 Denver, CO 80202-2431 Creek Cattle Company Sierra Energy Company P.O. Box 9354 6100 Neil Road 9:10389 Amarillo, TX 79105 Reno, NV 89520 APPENDIX D GRANT OF AUTHORITY 9ZO3f39 FROM KPROWSKY. WITWER 8 0L" SOURS 02.06. 1992 22 P. 3 R RDN IGR O`+`.; Y• WITVt' I OLD'HDUPV A i'• % • GRANT OB AUTHORITY Guttersen and company, a Colorado Limited Partnership hereby grants to C. Bradley keirnes, authority to execute a Use by Special Review Application and a Certificate of Designation Application to Weld County for the permitting of a solid waste disposal facility on the property owned by us as described in the attachment hereto, DATED 1492 Guttersen and Company, a Colorado Limited Partnership : gYt�l� artnor • . .......... .. ***END**. FEB 6 ' 92 14: 23 303 352 3165 PAGE . 003 320989 A TRACT OF LAND SITUATED IN SECTIONS 2 AND 3. TOWNSHIP 2 NORTH, RANGE 64 WEST OF THE 6TH PRINCIPAL MERIDIAN, AND IN SECTIONS 26, 27, 34 AND 35, TOWNSHIP 3 NORTH, RANGE 64 WEST OF THE 6TH PRINCIPAL MERIDIAN, COUNTY OF WELD, STATE OF COLORADO, MORE PARTICULARLY DESCRIBED AS FOLLOWS: COMMENCING AT THE NORTHWEST CORNER OF SAID SECTION 26, A FOUND N0. 5 REBAR WITH CAP MARKED L.S. 10945; 1HENCE SOUTH O'15'23" EAST ALONG THE WEST UNE OF THE NORTHWEST ONE-QUARTER OF SAID SECTION 26 A DIS-ACUCE CF 205267 FEET TO THE TRUE POINT OF BEGINNING, BEING A SET 21/2 INCH BRASS CAP SET IN CONCRETE, STAMPED L.S. 18472; THENCE ALONG THE BOUNDARY OF THE TRACT HEREIN DESCRIBED FOR THE FOLLOWING FIVE (5) COURSES, THE TERMINUS OF EACH COURSE BEING MARKED BY A SET 21/2 INCH BRASS CAP SET IN CONCRETE, STAMPED L.S. 18472: 1. SOUT-I 4029'02" EAST A DISTANCE OF 3566.38 FEET; 2. SOUTH 0'00'00' WEST A DISTANCE OF 9832.69 FEET; 3. SOUTH 90'00'00' WEST A DISTANCE OF' 607114 FEET; 4. NORTH 0'00'00" WEST A DISTANCE OF 12545.24 FEET; 5. NORTH 90'0000" EAST A DISTANCE OF 3756.22 FEET TO THE "TRUE POINT CF BEGINNING. CONTAINING AN AREA OF 1676.5 ACRES, MORE OR LESS. 920989 APPENDIX E OWNERSHIP MEMORANDUM OF AGREEMENT WELD.USR 2/7/92 21 sue- 920989 V. , FICA .Gvnu .17• wituiP I OLD/NEVRa $ I MEMORANDUM 07 AORSEHENT Agreement ("Memorandum") is by and between GutThis Memorandum of olorado Limited Partnership, ("Seller") and Oasts er icesComp by, Management of and Masts servites Development Corporation and Waste Colorado, Inc. ("Purchaser") . A. Seller and 8urchagsr have entered into a contact for iose desozi t for purchaser and Bale of certain lands, including datedlNovemberattached 9D1 is hereto roin called "Purchaser orated . Agreement" . B. pursuant to the terms and conditions of the Purchase Agreement, Purchaser ca Obtain eefsim letion of toit the eoproperty described in Exhibit "A" upon governmental authorisations and such as obtaining all roperty as solid waste disposal facility. permits for use of the prop Y �' —, 1992. DATED C---- WASTE SERVICES DEVELOPMENT CORPORATION cUTTERSEN AND COMPANY, A COLORADO LIMITED PARTNERSHIP By -� t WASTE MASAG T OF COLORADO, INC. By _ 411.14-..w . • . FEB 5 ' 52 14 : 23 ' 303 352 3165 PFIGE . 0L'Zpp 920989 EXHIBIT A A TRACT OF LAND SITUATED IN SECTIONS 2 AND 3. TOWNSHIP 2 NORTH, RANGE 64 WEST OF THE 6TH PRINCIPAL MERIDIAN, AND IN SECTIONS 26, 27. 34 AND 35. TOWNSHIP 3 NORTH. RANGE 64 WEST OF THE 6TH PRINCIPAL MERIDIAN, COUNTY OF WELD, STATE OF COLORADO, MORE PARTICULARLY DESCRIBED AS FOLLOWS: COMMENCNG AT THE NORTHWEST CORNER OF SAID SECTION 26, A FOUND NO. 5 REBAR WITH CAP MARKED -S. 10945: THENCE SOUTH 0'15'23" EAST ALONG THE WEST UNE OF THE NORTHWEST ONE-QUARTER OF SAID SECTION 26 A DISTANCE OF 2052.67 FEET TO THE TRUE POINT OF BEGINNING, BEING A SET 21/2 INCH BRASS CAP SET IN CONCRETE. STAMPED LS. 18472; THENCE ALONG THE BOUNDARY OF THE TRACT HEREIN DESCRIBED FOR THE FOLLOWING RYE (5) COURSES, THE TERMINUS OF EACH COURSE BEING MARKED BY A SET 21/2 INCH BRASS CAP SET IN CONCRETE. STAMPED L.S. 18472: 1. SOUTH 40'29'02" EAST A DISTANCE OF 3566.38 FEET; 2. SOUTH 0'00'06" WEST A DISTANCE OF 9832.69 FEET; 3. SOUTH 90'00'00" WEST A DISTANCE OF 6071.64 FEET; 4. NORTH 0"00'00' WEST A DISTANCE OF 12.545.24 FEET; 5. NORTH 90'OO'OD" EAST A DISTANCE OF 3756.22 FEET TO THE TRUE POINT CF BEGINNING, CONTAINING AN AREA OF 1676.5 ACRES, MORE OR LESS. 920989 APPENDIX F ASSIGNMENT WELD.USR 2/7/92 22 920999 ASSIGNMENT For good and valuable consideration Waste Services Development Corporation and Waste Management of Colorado, Inc. ("Assignors") do hereby transfer and assign to Waste Services Company all of our interest in and to that certain vacant land contract between Assignors as Purchaser, and Guttersen and Company as Seller, dated November 7, 1991. DATED this 5r4 day of Ac-dta gflY , 1992. WASTE SERVICES DEVELOP NT CORPORATION By( WASTE MANAGEMENT OF COLORADO, INC. By: ✓tom i 92O989 Austin Buckingham, Geologist, (303) 331-4846 Marion M. Galant, Community Relations Manager, 331-4855 (for immediate release) May 26, 1992 WELD COUNTY REQUESTS REVIEW OF EAST WELD SANITARY LANDFILL DENVER--The public is invited to submit written comments by July 31, 1992, on an application by the Waste Services Company, P.O. Box 3365, Greeley, CO, to operate a new sanitary landfill called the East Weld Sanitary Landfill facility. The landfill is located approximately 5 miles north of Interstate 76, off a private road that extends 3 1/2 miles north of Weld County Road 59. The proposed landfill will be located within part of Sections 2 and 3, Township 2N, Range 64W and part of Sections 26, 27, 34 and 35, Township 3N, Range 64W. The landfill will occupy 761 acres with more than 915 acres of primary buffer area around it. As required by state law, the application is has been sent to the Colorado Department of Health (CDH) for technical review. The Department's Hazardous Materials and Waste Management Division will review the application for any impact the facility may have on the environment and for compliance with the State's Solid Waste Disposal Sites and Facilities Act and Regulations. ll LI OI ---more--- MAY 2 9 1992 CY!e!d 02r*.n!3:17-in" 9;'0389 East Weld page 2 CDH professional staff will analyze site characteristics and the operation plan for the proposed facility, according to Austin Buckingham, geologist with the Division. Based upon a technical review of the application,the Health Department will provide Weld County and the applicant with a statement of findings as to whether the facility meets minimum requirements. If the Department issues a positive recommendation, the Weld County Commissioners may then complete the application review for approval or disapproval. Interested citizens may review the application during regular business hours through July 31, 1992, at the Weld County Health Dept., 1517 16th Ave. Court, Greeley, or at the Colorado Department of Health, 4210 E. 11th Ave., Room 351, Denver, CO. Written comments should be sent to Austin Buckingham, Colorado Department of Health, Hazardous Materials and Waste Management Division,4210 E. 11th Ave., Rm.351, Denver, CO 80220. For further information contact Austin Buckingham at (303) 331-4846. --30-- 9t;0389 Co1Aru� Rvv o,O l_k'hnu n, b. p—rs,s nrElnir p--- -t�ra- GREELEY/WELD May 21, 1992 • Weld County Board of Commissioners Centennial Building 915 10th Street Greeley,Colorado 80631 Dear Commissioners, At the May 20th meeting of the Greeley/Weld Economic Development Action Partnership (EDAP) Board of Directors, Brad Keirnes,President of Waste Services Development Corp.,presented his company's proposal to build a solid waste management facility in southeastern Weld County. The proposed facility will be state-of--the-art,implementing many technologies to protect the environment. The site chosen is unique and ideal for a landfill site. These considerations along with the fine reputation of the Keirnes family and the excellent history of Waste Services in Weld County give the proposed facility a strong foundation. Additionally,the economic development benefits of the project are considerable. The Town of Keenesburg,located just 5 miles from the site will benefit from the additional employment(10-20 jobs) and the attendant benefits of a strong local employer. On a broader scale,Weld County's ability to offer potential new industry a state-of-the-art regional solid waste management facility will be a tremendous boost to our current infrastructure system. At the meeting the EDAP Board voted unanimously to endorse the proposed landfill facility,based on the information provided to us by Waste Services Development Corporation. Please note that Weld County officials present at the meeting abstained from voting. We encourage the Weld County Board of Commissioners to approve Waste Service's application for a permit to construct the facility. Respectfull , Chairman cc: Brad Keirnes Lo Industrial Compliance 1746 Cole Blvd., Bldg. 21 #300 Golden, CO 80401 303'277-1400 FAX 303,277-1405 DESIGN AND OPERATIONS PLAN FOR THE EAST WELD SANITARY LANDFILL WELD COUNTY, COLORADO IC Project Number 2-3716 Prepared for: Waste Services Company P.O. Box 3365 Greeley, Colorado 80633 (303) 356-6600 Prepared by: Industrial Compliance 1746 Cole Boulevard Building 21, Suite 300 Golden, Colorado 80401 February 7, 1992 Revised: December 10, 1992 Dedicated to solving your-environmental problems. A Subsidiary of SP Environmental Systems.Inc. 'f"S = 920389 Industrial Compliance 1746 Cole Blvd.. Bldg. 21 #300 Golden, CO 80401 303:277-1400 FAX 303:277-1405 December 10, 1992 IC Project Number 2-3888 Board of Weld County Commissioners 915 10th Street Greeley, Colorado 80631 Dear Sirs/Madams: Enclosed are three copies of the Design and Operations Plan for the East Weld Sanitary Landfill (EWSL). The Design and Operations Plan has been revised as required by condition 7 of the Special Review Permit to incorporate all agreements that have resulted from State and County review. This letter is an outline to assist in review of the revised document and to verify that all of the appropriate conditions and agreements have been incorporated. This outline presents the responses and where the responses are found in the revised document to the following regulatory comment documents: Colorado Geologic Survey letter dated: April 7, 1992 Response letter from IC dated: May 15, 1992 Colorado Geologic Survey Concurrence dated: August 10, 1992 Colorado State Engineers Office letter dated: May 8, 1992 Response letter from IC dated: May 27, 1992 State Engineers Concurrence dated: September 10, 1992 CDH comment letter dated : July 22, 1992 Response letter from IC dated: July 28, 1992 CDH comment letter dated: August 4, 1992 Response letter from IC dated: August 5, 1992 CDH conditional approval recommendation letter dated: August 11, 1992 Response letter from IC dated: September 24, 1992 Weld County Resolution dated: October 14, 1992 Dedicated to solving your environmental problems. 4 �j�'� A Subsidiary of SP Environmental Systems,Inc. �1f^ eCn •�>O;'.3:JJ CDH RECOMMENDATION LETTER August 11. 1992 Recommendation 1 All health laws, standards, rules and regulation for the Department, Water Quality Control Commission, Air Pollution Control Commission and applicable zoning laws and ordinances shall be complied with. Revision: Page 2-1 (Section 2.1) has been revised to state that WSC will abide by all applicable laws, standards, rules, and regulations pertaining to landfill construction, operation and maintenance. Recommendation 2 If perched water conditions are encountered during excavation activities, the Division shall be notified within four working days. Contingency plans may be required by the Division. Revision: Section 5.3.1, page 5-3 has been revised to state that if perched water is encountered during excavation activities, the Division will be notified within four working days. The source and extent of the encountered perched zone will be evaluated and the Division will be informed of the findings. If necessary, contingency plans will be developed. Recommendation 3 - There was no recommendation 3 listed. Recommendation 4 A certification report shall be prepared by the Applicant and reviewed by the Division prior to commencing with landfilling in any cell. The report shall provide written evidence that the quality assurance plan was implemented and the construction was performed in conformance with the design criteria, the project plans and specification. Revision: Page 5-11, Section 5.3.3 has been revised to include the following wording: At least 30 days prior to the scheduled date to commence landfilling in any landfill module, a report detailing construction activities for that module will be submitted to the Division for review. The report will include evidence that construction was completed according to the approved plans, specifications, and design criteria. Recommendation 5 Plate 10 of the August 5, 1992 amendment to the application showed a number of temporary diversion structures. Please provide discussion and plans in the revised Design and Operations Plan as to how the phases will be filled, i.e., Will a phase be filled to ground surface prior to opening up another phase? Will several phases be operated concurrently and how will the temporary surface water diversion structures be coordinated with filling the phases? Please specify the storm event that the temporary diversion structures will be designed for and theconstruction specifications for the diversion structure (in plan view and cross section). Revision: Section 5.3.2 on page 5-5 has been revised to discuss the filling sequence in more detail. New Figures 5.1 through 5.5 have been added to illustrate the filling sequence. Page 2 920389 Plate 10 has been revised to show the placement and schedule of construction of the major temporary diversions structures. Section 5.3.5 on Page 5-13 has been revised to state that the temporary diversions structures shown on Plate 10 will be designed and constructed to control runoff from the 25-year 24-hour storm event. Each structure will be designed prior to construction of the appropriate cell or landfill module construction. The as-built report for the diversion structures will be submitted with the appropriate cell construction report. Recommendation 6 The Division would prefer if MW1 were retained as part of the background ground water monitoring network. Given the variety of lithologies encountered at the site, the range of ground water chemistries could best be evaluated with more than one well. If the MW series wells will be decommissioned, they should be decommissioned by overdrilling, removal of casing and grouting the well from total depth to the surface. Notification of the Division is requested. Revision: The existing ground-water monitoring wells have been added to Plate 14 along with a notation stating that MW-03 will be retained for inclusion in the permanent monitoring system network. As discussed in the IC response letter dated September 24, 1992, CDH intended that MW-03 be retained as an upgradient well, not MW-1 which is not in an upgradient position. Page 7-2, Section 7.1.2 has been revised to state that MW-03 will be retained as part of the permanent monitoring network for at least eight quarterly sampling events to establish background water quality. Once the chemical parameters in MW-03 and the proposed MW-11 have equilibrated, they will be compared as background wells and one may be abandoned if appropriate for statistical analysis. Page 4-29, Section 4.8.7, has also been revised to state that a statistical analysis program will be developed following establishment of background water quality. Recommendation 1 If the East Weld Sanitary Landfill chooses to accept friable asbestos waste in the future, a document detailing the friable asbestos waste handling and disposal procedures shall be developed by the applicant and submitted to the Division for review and approval. Revision: Section 2.2.3 on page 2-6 has been revised to state that prior to acceptance of any special waste, including friable asbestos, a special Waste Acceptance Plan will be developed detailing acceptance procedures, handling, and disposal procedures for each special waste. The Waste Acceptance Plan will have the concurrence of the Division prior to accepting any special waste for disposal. Recommendation 8 Within 60 days of approval for a Certificate of Designation from the Weld County Commissioners, the Design and Operations Plan shall be revised to incorporate all agreements and modifications that have resulted from Division and County review. The revised plan shall be submitted to the Division, the County and become part of the operating record to be maintained at the facility. Revision: This commitment to revise the Design and Operations Plan within 60 days of approval is not appropriate to include in the Plan and was not added. Page 3 9c099 CDH COMMENT LEI 1ER AUGUST 4. 1992 This comment letter asked for further information regarding the responses to the July 22, 1992 CDH comment letter. Those responses, including the additional information is addressed under the July 22, 1992 heading listed below. In addition, the August 4, 1992 letter reiterated WSC's commitment to maintain a minimum 15-foot separation between the base of the refuse and highest recorded water levels. This commitment is stated in Section 5.3.1, Page 5-3 of the text and on Plates 5 through 7. CDH COMMENT LETTER JULY 22. 1992 SITE CHARACTERIZATION Comment 1 Please provide a map showing the proximity of the nearby Coors coal mine with respect to the proposed landfill boundaries. Please provide discussion of the type of mining, depth of mining and future mining activities. Revision: Figure 2.2 has been revised to show the location of the historic Coors Coal Mine relative to the landfill. Section 2.2.2, Page 2-3 has also been revised to state that the historic mining operations consisted of a stripping operation to expose coal seams 65 to 100 feet below the ground surface. Comment 2 The text (page 2-3) states that a flood plain is located approximately 8000 feet to the east of the site. Figure 2.3 does not show the proximity of the proposed site to the FEMA flood plain. Revision: Figure 2.3 has been revised to show the location of the flood plain. Page 2.3, Section 2.2.2 has been revised to state that the flood plain is west of the site. Comment 3 It is assumed that MWI-MW3 are part of the monitoring program. Please clarify and show the locations on plate 14. Revision: See Recommendation 6 above Comment 4 Figure 3 is missing from Appendix D. Revision: Figure 3 is included in Appendix D. Comment 5 Figure 7 PZ-25 & figure 8 PZ-26 (of Appendix D) do not show the lignite water bearing zones discussed on page 4-22 of text. Revision: This comment asked for further clarification which has been added to Section 4.8.1.3, Page 4-21. Comment 6 How were the values for hydraulic gradient and porosity obtained (page 4-30). Revision: The source of the hydraulic gradient and porosity values have been added to the text on Page 4-28, Section 4.8.6. Page 4 92, 02789 Comment 7 How were the slug test 'h' values obtained for MW1-MW3, with a transducer or with a water level? Please provide the citation for the calculations used in determining hydraulic conductivity for wells MW1-MW3. Why were MW1- MW3 selected for monitor wells completions and no other wells? Did the sandstone units encountered in MW1 and MW2 produce water? What evidence is there to suggest that MW2 is confined and that MW1 & MW3 are unconfined. What zones are producing water in these wells? Since the slug test was performed over the screened interval, the permeability results are a composite. What conclusions are you drawing from this data? Revision: The "h" values were obtain with an electronic water level indicator and is noted on Page 4-9, Section 4.6.7. The hydraulic conductivity values were calculated by the Hvorslev method as stated on Page 4-9, Section 4.6.7. Further discussion of the water bearing intervals tapped by the monitor wells has been added to Sections 4.8.1.2 and 4.8.1.3, beginning on Page 4-18. Comment 8 Permeability from MW-2 was used to calculate the travel time. This permeability value is two orders of magnitude greater than MW1 and MW3. There is no evidence to suggest that this value is most representative of the subsurface materials. Using a range of permeability values would be appropriate here. The ground water in MW2 is defined as being under unconfined [sic], while MW1 and MW3 are defined as being under water table conditions (table 4.3). The majority of the ground water at the site is under water table conditions. Unconfined channel sands (page 4-22) have been documented beneath the site. A conservative evaluation of travel time should be calculated using the ranges of values and conditions at the site. Revision: The travel times have been revised as per the IC letter to the Colorado Geologic Survey. The revised travel times have been included on Page 4-24, Section 4.8.6. Comment 9 Can well location #11 and MW#1 be considered upgradient wells? Revision: See Recommendation 6 under the CDH recommendation letter dated August 11, 1992 listed above. Comment 10 The Division does not support the use of wet/dry wells in lieu of a saturated ground water monitoring program. Wet/dry wells should be used only under specific geologic conditions which are well known through site specific investigation. The ground water at the proposed site is ubiquitous, unconfined and shallow. Page 4.23 of the text states that 'Surface water infiltration is too slow to result in water ponding at the eolian sand-bedrock interface. Water continues to migrate horizontally and vertically downward through the fractures in the weathered and unweathered bedrock until the fractures and weathering effects have significantly decreased. Water continues to pond at that interval.' According to the data presented in the report, ground water zones were not identified in the eolian or weathered units. Ground water was found in bedrock Page 5 channel sands, lignite and fractured zones. Ground water monitor wells should be placed to target these saturated zones. Given that ground water was found in the majority of the bedrock wells and that the saturated intervals are often within 15 feet of the proposed base grades of the landfill, a saturated ground water monitoring system is entirely appropriate for the site. The Division does not believe that the subsurface conditions identified at the site lends itself to wet/dry monitoring. Wet/dry wells are the wells of last resort, if there are no other viable monitoring alternates. If the applicant wishes to implement some form of vadose monitoring, that would be considered optional and in addition to a ground water monitoring. Revision: Section 7.1.2 on Page 7-2 has been revised to clarify the proposed ground-water monitor well system. Comment 11 Point number 7 (on page 4-23 second sentence) is not an observation or fact, it is a hypothesis and is in contradiction to the conclusions made on that same page. Revision: Point number 7 (sic 8) on Page 4-21, Section 4.8.2, has been reworded to clarify the intention. Comment 12 Discussion of packer test failure and how this relates to the site characterization should be provided in the text. Revision: There were no packer test failures, which is clarified in the IC response letter dated July 28, 1992. The Design and Operations Plan has not been revised to reflect this clarification. Comment 13 Please supply the well logs for the nearby water wells identified on figure 4.5. Revision: The well logs for the nearby water wells is included in Appendix D and noted in Section 4.8.5, Page 4-24 DESIGN Comment 1 Plate 11 and the text should be revised to reflect the following design considerations: Revision: Plate 11 has been revised to reflect the following changes: a) The permeability of the compacted portion of the final cap is specified as less than or equal to 1x1O` cm/sec. The components of the cap have been revised to show 6-inches foundation layer, 18 inches of compacted clay material, 24- inches of unspecified root and frost protection layer, and 6-inch seedbed layer to support plant germination and growth. Section 8.1.1, page 8-1 has been revised to reflect this design. b) The permeability of the base liner has been specified on Plate 11 as ≤ lx1O cm/sec. and the permeability of the drainage layer has been specified as ≥ 2x1O2 cm/sec. The clay liner permeability requirement is stated on Page 5-5 of Page 6 L the text. Justification for the drainage layer permeability has been included in the text on Page 5-3, Section 5.3.1. c) The integration of the sump riser with the cap and liner has been included on Plate 11. d) Plate 11 has been revised to reflect the requested gravel specification. The gravel in the sump will consist of 1.5 to 3-inch rounded gravel material with ≤ 5-percent of the material passing a #200 sieve. e) A synthetic liner consisting of 60-mil HDPE has been added to the sump detail on Plate 11. Comment 2 The design and operations plan did not specify techniques for liner placement on the side slopes. Revision: Pages 5-5 and 5-11, Section 5.3.3 of the text states that the construction specifications will be developed prior to actual construction to develop real data that will be used during construction. The specifications will be submitted to CDH and Weld County for review. Comment 3 Atterburg limits and compaction density specifications were not provided in the design and operations plan. Revision: See comment 2 above. Compaction density specifications and Atterburg Limits have been added to the QA/QC document list on Page 5-11. Comment 4 The cross section are dated 1/30/92. Industrial Compliance continues to monitor water levels in the piezometers. The cross section should be revised to reflect the highest ground water table elevations measured to date. Based on the 1/30/91 cross sections, piezometers PZ-21, PZ-23, PZ-30 and PZ-37 encounter the ground water table at less than 15 feet below the designed base of waste in the landfill. The design base grade of the landfill should be revised to reflect the Division policy of a 15 foot separation distance between the waste and the highest recorded ground water table. Revision: Plates 5, 6, 7, 10, and 12 have been revised to reflect the highest water levels as of the October monitoring event. Revisions were not necessary to Plate 13. Comment 5 If alternative drainage media are used in lieu of a 12-inch drainage material (page 5-1), concurrence from the Division should be obtained prior to design modification. Other design modifications of similar nature should also receive prior approval by the Division. Revision: Plate 12 has been revised to state that the concurrence of the Division is necessary prior to any design changes. The text on Page 5-1 has also been revised to reflect this requirement. Comment 6 The text on page 5-3 should be revised to state that the liner will be built to a Page 7 920-17) permeability of less than or equal to 1x10° cm/sec. Perhaps this is the intended meaning of the language in the document, but absolute clarity is preferred. Revision: The permeability requirement for the clay liner has been added to Page 5-3. Comment 7 Please specify the acreage and the estimated life of each landfill phase. The slope on the liner ranges from 1% to 2%. The generally accepted and EPA standard (EPA/800/2-88/052) for slope on the liner is 2% combined with a drainage material of greater than or equal to 1*10-2 cm/sec. Please calculate the travel time of leac! ate movement to the sump using the proposed design and the EPA accepted design to show that the designs are equivalent. Revision: Table 5.1 on Page 5-2 has been added to detail individual phase life. Page 5- 3 of the text provides justification for the proposed design in light of the EPA recommended design. To establish equivalency with the EPA design, the drainage material permeability has been changed from a minimum of 1x1Q2 cm/sec. to 2x10-2 cm/sec. In addition, the HELP model in Appendix J has been revised to reflect the change in drainage material permeability as well as the change in cap design. Comment 8 Subtitle D states that the point of compliance shall be no more than 150 meters (492.12 feet) from the waste management unit boundary. The report has not clearly specified where the boundary for the certificate of designation will be. However, regardless of the location of the certificate of designation boundary, both gas monitoring wells and ground water monitoring wells should be located no more than 150 meters (492.12 feet) from the waste management unit boundary. It is the intention of the Division to adopt the Subtitle D, 150 meter point compliance distance in the revised State solid waste regulations. Revision: Plate 14 has been revised to move all monitor wells with the exception of MW- 03 to within 150 meters of the waste unit boundary. As agreed with the CDH, the methane monitor wells will remain at the property boundary. Comment 9 Placement of temporary surface water diversion structures during phase construction and operation should be specified. No permanent surface water control structures are planned. Is that intended? Please provide discussion regarding permanent surface water diversion control. Revision: Plate 10 has been revised to show locations of the major temporary diversion structures. The design criteria of these structures is discussed on Page 5-13. Comment 10 Please revise the HELP model based on site specific design parameters. Specifically, the parameters that require revision are the root zone depth, evaporative depth and permeability of the final cap. Revision: The HELP model in Appendix J has been revised to reflect the change in cap design and the change in the permeability of the drainage material. It also presents an evaluation for both open and closed phases. Page 8 '0 . 89 OPERATION Comment 1 The type, height and location of perimeter fence should be provided. Revision: Page 5-25, Section 5.4.2 has been revised to include perimeter fencing of 6 feet in height and constructed of utility mesh or equivalent materials. Comment 2 The text (page 2-6) states asbestos will be accepted. It is presumed that the applicant intends to accept only non-friable asbestos. Please clarify. Revision: Section 2.2.3, Page 2-6 states that a special waste acceptance document, having the concurrence of the Division, will be developed prior to accepting any special waste for disposal. Comment 3 Will the landfill obtain access to or the water rights for the wells located on the property? What is the source of water for liner construction and other landfill activities. According the page 6-2, the facility intends to rely on ponded run- off for water. Please document that this water source is adequate and reliable. Revision: Appendix 0 contains an estimate of water use and the available water from the Coors well. It also includes the approved permits for the construction of a new water well. Comment 4 The method for monitoring the wind conditions at the site has not been specified. Revision: Page 6-3, Section 6.2.1 states that an anemometer will be maintained at the facility for wind monitoring. Comment 5 Records which should be kept at the site, in addition to the those stated on page 6-2, are the approved design and operations plan, operational variances and the special waste acceptance plan (if one is developed). Revision: Page 6-2, Section 6.1.3 has been revised to include the Design and Operations Plan, Operational Variances, and Special Waste Acceptance Plan as records kept at the site. Comment 6 Statistical analysis of ground water data should be discussed in the design and operations plan. Revision: Section 7.1.2, Page 7-2, has been revised to state that an appropriate statistical method will be developed once chemical parameters of the monitor wells have equilibrated and background water quality can be established. Comment 7 Subtitle D and the revised State solid waste regulations will require notification to all airports within a five mile radius of the landfill site. Revision: There are no airports within a 5-mile radius of the site, so this comment was not addressed in the text. Page 9 gip 9c,QwUJ Comment 8 Post-closure inspections and maintenance should include repair of eroded areas, re-evaluation of proper surface water drainage and maintaining vegetation of the site. Revision: Page 8-3, Section 8.3, has been revised to include repair of all eroded areas, re- evaluation of those areas for proper surface water drainage and maintenance of vegetation as part of the post-closure inspection and maintenance program. Comment 9 Please specify the hazardous waste exclusion procedures-that will be implemented at the landfill. Revision: Page 6-5, Section 6.3, has been revised to include hazardous waste screening procedures to be implemented at the facility. COLORADO STATE ENGINEERS LE ITER May 8. 1992 This letter requested information on the anticipated water requirements at the facility, the available water from the existing Coors well, and permit applications for a new well if one was installed. Appendix O, called out on Page 6-2, of the Design and Operations Plan has been added which includes the requested information. COLORADO GEOLOGIC SURVEY LEI1'ER April 7, 1992 The Colorado Geologic Survey requested justification, or revised travel times, using more representative site specific data. Page 5-3, Section 5.3.1, of the text includes the revised travel time calculations. RESOLUTION - SITE SPECIFIC DEVELOPMENT PLAN Number 1 - No revisions necessary Number 2 - No revisions necessary Number 3 - No revisions necessary Number 4 - No revisions necessary Number 5 - Section 6.2.1 has been revised to reflect the wording of the resolution. Number 6 - No revision necessary - Number 7 - No revision necessary Number 8 - Page 7-1. Section7.1.1, has been revised to include the leachate analytical parameter_ Number 9 - No revision necessary Page 10 9p.., '53 Number 10 - Section 6.2.1, Page 6-3, has been revised to incorporate the requirements listed in Number 10. Number 11 - Section 6.2.3, Page 6-4 has been revised to reflect the off-site odor requirement. Number 12 - Section 6.2.4, Page 6-4 has been revised appropriately. Number 13 - No revision necessary Number 14 - Section 6.2.7, Page 6-5 has been revised to incorporate maximum permissible noise levels. Number 15 - Section 6.1.5, Page 6-3, has been revised appropriately. Number 16 - No revision necessary Number 17 - Appendix O, Water Need and Availability, has been added to the Plan. Number 18 - No revision necessary Number 19 - No revision necessary Number 20 - Section 6.1.3, Page 6-2 has been revised to incorporate these record keeping requirements. Number 21 - No revisions necessary Number 22 - No revision necessary Number 23 - Section 7.1.4, Page 7-10 has been revised to include the appropriate wording. Number 24 - No revision necessary Number 25 - No revision necessary Number 26 - No revision necessary Number 27 - No revision necessary Number 28 - No revision necessary Number 29 - No revision necessary Number 30 - No revision necessary Number 31 - No revision necessary Page 11 The Design and Operations Plan submitted herein has been revised to incorporate all agreements and modifications resulting from State, Referral Agency, and County review and will become a part of the operating record. Please call if you have any questions. Sincerely: INDUSTRIAL COMPLIANCE Reviewed by: Mark A. McMullen Curtis J. Ah ndsen Project Geologist Engineering Division Director cc: Mr. Leonard Butler, Waste Management of North America Mr. Roger Doak, Colorado Department of Health Page 12 920289 Industrial Compliance 1746 Cole Blvd., Bldg. 21 #300 Golden, CO 80401 303/277-1400 FAX 303/277-1405 December 10, 1992 Board of County Commissioners IC Project No. 2-3716 915 10th Street Greeley, Colorado 80631 Dear Sirs/Madams: This document is the detailed Design and Operations Plan for the proposed East Weld Sanitary Landfill. The facility will fulfill the solid waste management needs of the Southeast Service Area of Weld County and the surrounding region. The proposed facility emphasizes environmental safety and control at an geologically-suitable site. The Design and Operations Plan includes the following information: * Geologic and hydrogeologic characteristics of the site * Waste streams to be accepted * Design details for the filling area * Facility operational features * Facility monitoring * Site reclamation and post-closure care The facility is designed to meet the Weld County and State of Colorado solid waste requirements. Thank you for allowing us to submit this permit application. Sincerely, Reviewed By: INDUSTRIAL COMPLIANCE t Curtis J. Ahrendsen Michael H. Stewart, P.E., C.P.G. Director Technical Director Engineering Division c.09....111;949/4 ry CJA/ds zs 23004 - ;cum c7. r/�Fgn�y 0�\�`` Dedicated to solving your environmental problems. ////q nu/nu I`�'A y1,\10 P° Mi A Subsidiary of SP Environmental Systems.Inc. v � ss.E 9�y0 " TABLE OF CONTENTS PAGE 1.0 INTRODUCTION 1-1 2.0 GENERAL INFORMATION 2-1 2.1 Facility Need 2-1 2.2 General Description 2-1 2.2.1 Location 2-1 2.2.2 Location Criteria 2-3 2.2.3 Acceptable Waste Streams 2-6 2.2.4 Landfill Design 2-8 2.2.5 Filling 2-8 2.2.6 Final Cover 2-8 2.2.7 Site Access 2-8 2.3 Zoning and Land Use 2-9 3.0 SITE DESCRIPTION 3-1 3.1 Existing Site Topography 3-1 3.2 Surface Water Drainage 3-1 3.3 Climatology 3-5 4.0 SITE GEOLOGY AND HYDROGEOLOGY 4-1 4.1 Geologic Overview 4-1 4.2 Hydrologic Overview 4-4 4.3 Economic Geology 4-5 4.4 Potential Geologic Hazards 4-5 4.5 Site Description 4-5 4.6 Field Investigation and Methodology 4-6 4.6.1 Soil Borings 4-6 4.6.2 Piezometer Installations 4-7 4.6.3 Ground-Monitor Well Installations 4-7 4.6.4 Ground-Water Sampling 4-8 4.6.5 Test Pits 4-8 I 920.jg.9 TABLE OF CONTENTS (Cont.) 4.6.6 Collection of Representative Site Materials for Geotechnical Testing 4-8 4.6.7 Slug-Test Permeability Testing 4-9 4.6.8 Packer Test Permeability 4-9 4.7 Site Geology 4-10 4.7.1 Surficial Materials 4-10 4.7.2 Weathered Bedrock Materials 4-12 4.7.3 Bedrock Materials 4-12 4.7.4 Geotechnical Properties of On-Site Materials 4-13 4.8 Site Hydrogeological Characteristics 4-14 4.8.1 Ground-Water Occurrence and Distribution 4-14 4.8.1.1 Ground-Water Occurrence in the Eolian Sands 4-14 4.8.1.2 Ground-Water Occurrence in the Weathered Bedrock 4-18 4.8.1.3 Ground-Water Occurrence in the Bedrock Materials 4-18 4.8.2 Summary of Hydrogeologic System 4-21 4.8.3 Fate of Ground Water 4-22 4.8.4 Aquifer Characteristics 4-22 4.8.4.1 Permeability 4-22 4.8.4.2 Storage Coefficient 4-22 4.8.5 Wells Within A 1-Mile Radius of the Site 4-24 4.8.6 Travel Time Calculations 4-24 4.8.7 Ground-Water Quality 4-29 4.8.8 Ground-Water Monitoring Network 4-30 5.0 FACILITY CONFIGURATION 5-1 5.1 Waste Characteristics, Site Area and Volumes 5-1 5.2 Site Life 5-1 5.3 Disposal Area Design 5-3 II 9;10283 TABLE OF CONTENTS (Cont.) 5.3.1 Fill Area Design and Excavation 5-3 5.3.2 Phasing and Refuse Filling 5 4 5.3.3 Liner Construction 5 5 5.3.4 Materials Selection and Quantities 5-11 5.3.5 Surface Water Control 5-11 5.3.6 Pre-operational Activities 5-24 5.4 Support Facilities 5-24 5.4.1 Landfill Access 5-24 5.4.2 Site Fencing 5-25 5.4.3 Resource Recovery 5-25 6.0 FACILITY OPERATIONS 6-1 6.1 Site Management 6-1 6.1.1 Operations Schedule 6-1 6.1.2 Equipment and Personnel Requirements 6-1 6.1.3 Control and Record Keeping 6-2 6.1.4 Safety Control 6-2 6.1.5 Water and Sanitary Requirements 6-2 6.2 Control of Nuisance Conditions 6-3 6.2.1 Litter Control 6-3 6.2.2 Vector Control Cr4 6.2.3 Odor Control 6-4 6.2.4 Dust Control 6-4 6.2.5 Fire Control 6-4 6.2.6 Landfill Gas Control 6-5 6.2.7 Noise 6-5 6.3 Hazardous Waste Screening Prortdures 6-5 7.0 SITE MONITORING 7-1 7.1 Environmental Monitoring 7-1 7.1.1 Landfill Liquids Detection and Monitoring 7-1 7.1.2 Groundwater Monitoring 7-2 7.1.2.1 Monitoring System Installation 7-3 7.1.2.2 Monitor Well Construction 7-3 7.1.3 Landfill Gas Monitoring 7-4 7.1.4 Environmental Monitoring Results 7-7 III i 970,1'39 TABLE OF CONTENTS (Cont.) 8.0 CLOSURE AND POST-CLOSURE 8-1 8.1 Reclamation and Revegetation 8-1 8.1.1 Final Cap Design 8-1 8.1.2 Revegetation 8-1 8.2 Post-Closure Monitoring 8-3 8.3 Post-Closure Inspections and Maintenance 8-3 8.4 Post-Closure Land Use 8-3 9.0 REFERENCES 9-1 IV 320389 TABLE OF CONTENTS (Cont.) LIST OF FIGURES FIGURE 2.1 SITE LOCATION MAP 2-2 FIGURE 2.2 SITE VICINITY MAP 2-4 FIGURE 2.3 FLOOD PLAIN MAP 2-5 FIGURE 2.4 SITE AQUIFER RECHARGE AREAS 2-7 FIGURE 3.1 SITE LOCATION, LAYOUT, AND TOPOGRAPHY 3-2 FIGURE 3.2 SURFACE WATER WITHIN 2-MILES OF SITE 3-3 FIGURE 3.3 SITE DRAINAGE PA 11 ERNS 3-4 FIGURE 3.4 WIND ROSE MAP 3-6 FIGURE 4.1 GEOLOGIC MAP OF SITE 4-2 FIGURE 4.2 STRATIGRAPHIC SECTION 4-3 FIGURE 4.3 SITE SOIL MAP 4-11 FIGURE 4.4 CONCEPTUAL SUBSURFACE MODEL 4-19 FIGURE 4.5 WATER WELLS WITHIN 1-MILE OF SITE 4-26 FIGURE 5.1 INITIAL FILLING MODULE 5-6 FIGURE 5.2 SECOND FILLING MODULE. . . 5-7 FIGURE 5.3 THIRD FILLING MODULE 5-8 FIGURE 5.4 FOURTH FILLING MODULE. . 5-9 FIGURE 5.5 FIFTH FILLING MODULE . 5-10 FIGURE 5.6 TYPICAL GRASS-LINED CHANNEL SECTION 5-19 FIGURE 5.7 TYPICAL DIVERSION BERM SECTION 5-20 FIGURE 5.8 STRAW DIKEJSEDIMENT TRAP 5-21 FIGURE 5.9 STRAW BALE DIKES 5-22 FIGURE 5.10 SEDIMENT TRAPS 5-23 FIGURE 7.1 TYPICAL GROUND-WATER MONITORING WELL 7-5 FIGURE 7.2 TYPICAL UNSATURATED INTERVAL DETECTION WELL 7-6 FIGURE 7.3 TYPICAL LANDFILL GAS PROBE 7-8 LIST OF TABLES TABLE 4.1 GEOTECHNICAL RESULTS OF ON-SITE MATERIALS 4-15 TABLE 4.2 ZONES OF PIEZOMETER COMPLETION 4-19 TABLE 4.3 PACKER AND SLUG TEST PERMEABILITY RESULTS 4-23 TABLE 4.4 PERMITTED WATER WELLS WITHIN A 1-MILE RADIUS OF PROPOSED SITE 4-25 TABLE 5.1 INDIVIDUAL PHASE VOLUMES .5-2 TABLE 5.2.1 COMPARISON OF PRE- AND POST-CONSTRUCTION DRAINAGE WITHIN FILL LIMITS 5-14 TABLE 5.2.2 COMPARISON OF PRE- AND POST-CONSTRUCTION DRAINAGE DOWNSTREAM OF FILL LIMITS 5-16 TABLE 7.1 GROUND-WATER MONITORING PARAMETERS AND FREQUENCY 7-9 TABLE 8.1 BULK SEED RATES 8-2 V 97,089 TABLE OF CONTENTS (Cont.) APPENDICES APPENDIX A OWNERSHIP MEMORANDUM OF AGREEMENT APPENDIX B CLIMATE INFORMATION APPENDIX C FIELD BORING LOGS APPENDIX D LITHOLOGIC LOGS & COMPLETION LOGS APPENDIX E GEOTECHNICAL RESULTS APPENDIX F WATER LEVEL DATA APPENDIX G PERMEABILITY CALCULATIONS APPENDIX H WATER QUALITY RESULTS APPENDIX I SOIL BALANCE CALCULATIONS APPENDIX J HELP MODEL CALCULATIONS APPENDIX K SURFACE WATER RUNOFF CALCULATIONS APPENDIX L SOIL LOSS CALCULATIONS APPENDIX M EMERGENCY CONTACT PHONE NUMBERS APPENDIX N SOIL CONSERVATION SERVICE REVEGETATION LETTER APPENDIX O WATER AVAILABILITY AND WELL PERMIT LIST OF PLATES PLATE 1 COVER SHEET PLATE 2 EXISTING 2 FT. TOPOGRAPHY PLATE 3 BOUNDARY SURVEY PLATE 4 BORING AND CROSS-SECTION LOCATION MAP PLATE 5 GEOLOGIC CROSS-SECTIONS A-A' AND B-B' PLATE 6 GEOLOGIC CROSS-SECTIONS C-C' AND D-D' PLATE 7 GEOLOGIC CROSS-SECTIONS E-E', F-F', AND G-G' PLATE 8 BEDROCK CONTOUR MAP PLATE 9 GROUND-WATER CONTOUR MAP PLATE 10 TOP OF DRAINAGE LAYER, LANDFILL LIQUID COLLECTION, PHASING, AND VOLUME CALCULATIONS PLATE 11 DESIGN DETAILS PLATE 12 ENGINEERING CROSS-SECTIONS A-A', B-B', AND C-C' PLATE 13 ENGINEERING CROSS-SECTIONS D-D', E-E', AND F-F' PLATE 14 FINAL CONTOUR AND PROPOSED MONITORING WELL LOCATIONS PLATE 15 PRE-CONSTRUCTION DRAINAGE MAP PLATE 16 POST-CONSTRUCTION DRAINAGE MAP VI 9 ).:83 1.0 INTRODUCTION This Design and Operations Plan and associated documents is for the proposed V%aste Services Company (WSC), East Weld Sanitary Landfill (EWSL) serving southeastern Weld and the surrounding region. The proposed landfill is located approximately 5 miles north of Interstate- 76 off Weld County Road 59. The site is situated on approximately 1676 acres accessible by a combination of private, county, and state highway systems. The submittal of the Design and Operations Plan is a result of intensive site studies and technical plan development. The applicant, WSC, is familiar with the area and has made an extensive effort to select and develop a site which will provide a necessary service to the county and region in an environmentally and socially acceptable manner. An ownership memorandum of agreement is included as Appendix A. The applicant's company name, address, and phone number are: Waste Services Company attn: Brad Keirnes P.O. Box 3365 Greeley, Colorado 80633 (303) 356-6600 Information used to develop the plan was primarily derived from site specific field investigations and from IC's experience with sanitary landfill design and operations in Colorado. Other sources of information are referenced in Section 9.0. The procedures outlined in this Design and Operations Plan meet or exceed current solid waste management practices in Colorado and satisfies the requirements of the Colorado Department of Health (CDH) Solid Waste Regulations. The major sections of the report are as follows: * General Information * Site Description * Site Geology and Hydrogeology * Facility Design and Configuration * Facility Operation * Site Monitoring * Closure and Post Closure In addition, detailed drawings are included and referenced in the document to show the methods proposed to meet the requirements of the Colo.ado Solid Waste Regulations for development of an environmentally sound landfill. Plate 1 is a cover sheet introducing the remaining drawings. The results of the investigations and studies indicate that the site can be developed, operated and closed in a manner consistent with current and anticipated environmental standards and regulations. This includes the Subtitle D Regulations outlined under the Resource Conservation and Recovery Act (RCRA) as published in the October 9, 1991 Federal Register. RCRA Subtitle D provides a minimum national criteria for the design, operation, and maintenance of municipal solid waste landfills. The criteria for the proposed EWSL have 1-1 920._'39 incorporated these rules with the exisiting State requirements to ensure an environmentally sound facility. As a result, the facility is designed and will be constricted to meet the performance standards of Subtitle D. 1-2 920239 2.0 GENERAL INFORMATION 2.1 Facility Need The need to achieve a high level of environmental protection during solid waste disposal operations has resulted in stricter landfill engineering and operational regulations. As a result, landfills require much more extensive effort to site, design, permit, construct, operate, monitor, and close. This situation is likely to cause many regions to either close existing landfills or operate landfills that are not in compliance with existing regulations. WSC proposes constructing and operating the EWSL to serve the long-term needs of southeastern Weld County and the surrounding region (Figure 2.1). This facility will provide the region with the fundamental final disposal component at a landfill in compliance with the parameters of the CDH Solid Waste Regulations. Southeastern Weld County has been without a convenient sanitary landfill since the closure of the town of Keenesburg landfill. The existing need of the area is expected to increase due to economic growth and development resulting in part form the new Denver International Airport. The facility will be part of an integrated mine reclamation and waste management operation, including the inactive Keenesburg Open Pit Coal Mine and the existing Coors Ash Disposal Facility. The access road to the integrated operation has been constructed and maintained exclusively for the existing mine, the ash disposal site, and the future facility. The proposed EWSL is consistent with the Weld County Comprehensive Plan and its environmental quality and natural resource goals and policies. The optimal location of the Facility in an isolated yet accessible area serves to minimize any potential for negative impacts on surrounding land uses and/or residents. WSC will abide by all applicable laws, standards, rules, and regulations pertaining to landfill construction, operation and maintenance. 2.2 General Description 2.2.1 Location The proposed site, consisting of 1676 acres is situated in a remote arca in southeastern Weld County. Of this acreage, approximately 700 acres are included within the landfill footprint and another 976 acres consist of the primary buffer zone. Additionally, WSC will control a secondary buffer zone consisting of approximately 2964 acres. In total, the operator will have ownership of approximately 4640 acres that include and surround the site in the following sections: Township 3 North, Range 64 West; Section 27, Section 34, Section 35, West 1/2 and Southeast 1/4 of Section 26 Township 2 North, Range 64 West; Section 2, Section 3, Section 10, and South 1/2 of Section 11 2-1 9fr'7,0233 cn CO _I O O Po O l z O O n$e n 6 cn Q J e.•' 11 O Q O Pi ..s o o o ■ z a w 4,11' b 6 £ 1. a c� S s O O ei it c5 e -- O ,n w N N 4 h a ti C IZ? — oF7- .mg 2 1$„„b^ a iv d Y n) x E y '°° � J (�..a. ..' li pa f/:'i ;' m sg �11 I IE Vo, £� / n ^"Y cy- ;,l N'h�• fI. �.. Los lcr¢¢k (.' r o/_. c 1 r 7I ,0° t ) ,, ;.. f. *'-' I i' _ N. II: l'HI /I I I) rte' ,)ii € a �o fiRma 01 I (/- A,_ ' 'Ntii ✓ 1 . t o. v- A _L. /4' pew( 4 y,o 9,, ' ,r, a / �� ir te' \ 1--1 I i. A [p i irmstiorm ----'---- 1 _ -✓g)-' ¶ I/- _ 9]g �► a: clifittli,i iiiiiiiiiiiiii , ,-.Th----_,i,- - , *Ilm 00. 7 ,1-0141fal Altr-Vgaind'gs,`,_._.,.!: _.° _ F,'''''' 7,,.,i F. 4016--Millir‘ iii, lAilligii. Paghlrgall01111 i,40.,"! - - -''. 2 ''nta"44541 billiriliMrSibilAkil 4-''�� ,°.�_!a:,.. ►.Viii. Al\ ', I ( 3r. AIlli I ,„Ti. eimphimpu1 V 11•.�A J ' I5000 °Foto Oril � I■Pi �l► ■�. • MI Its 1e� /Vin,°cm r -Neal_'\ mil-krilwomma- tilllitaitElli-- -\\*Illik-klailmvall'i - lireibiliDditirlits9dollia - F ,F]1 iZ' � ,1 7�Rir a�Y rn -p +1 o -"'Plirn IMValtr3Mia .4,4 alm was �:1� ` , :' ► �1✓1,417,11,,.., -��o ? � .E�.JI[3! e1��i Ham 10 7:r" � till'Vatier .M1 - erel,... ...--.;,1•MS.A.--T------_riii- --C-',"..1 vim _air. EuleprAstiffra,,,,ti siiiii. tjw�� xawlavl o ..a Wall I ��j I � Fri®i�[I�L�� 1 y j■� r 1.t� l ftti]111 �'f � � -M1 E, 49 Maw ; _ .r �. � ��EMS rsital tl W'a�s i wriih iii'haw.. � O, ri N C O�� gil �a i`l�; - 4 �.'`_ i atintitlierfaltA ,,� jMM , o jai ,�� .,_ L!, : ;.;; DAIEgataPilhaatritaikm&41,IlitilitletliiiikoteM1 `y1 ra The Coors Coal Mine and Ash Disposal facility is located approximately 1.5 miles east of the proposed landfill location (Figure 2.2). Mining consisted of a stripping operation to expose coal seams 65 to 100 feet below ground surface. The mining activities have permanently ceased and the facility is now operated under an approved Design and Operations Plan as the Coors Ash Disposal Facility. The site is approximately 5 miles north of Interstate 76 on Weld County Road 59. Access to the facility will be from Weld County Road 59 onto and approximately to the end of a private 3 1/2-mile road. Weld County Road 59 was substantially upgraded and has been maintained to serve the heavy truck traffic to and from the coal mine and the ash disposal facility. The privately owned, constructed, and maintained asphalt road that extends north of Weld County Road 59 exists exclusively for these purposes. The legal description of the primary buffer property is included on the plan sheets. Plate 1 shows the proposed site and its boundaries. The site boundary and surrounding area is also shown on Plate 1. There are no residences within approximately 2 miles of the proposed facility. 2.2.2 Location Criteria Following a comprehensive site selection effort, an initial assessment of the selected landfill location was conducted prior to beginning any formalized site characterization. The site location study followed criteria outlined in the CDH Solid Waste Regulations and the Subtitle D requirements. The location criteria are described in this section. Flood Plain Information The proposed landfill site is not located within a 100-year flood plain according Federal Emergency Management Agency (FEMA) flood insurance rate maps. Therefore, the landfill will not restrict the flow or reduce the temporary storage capacity of the 100-year tood. The floodplain closest to the site is approximately 8000 feet to the west. (Figure 2.3) Additionally, a portion of the Weld County Comprehensive Plan is devoted to impacts of development within floodplains. Flood plains have not been mapped within the portion of property proposed for incorporation as a landfill according to a January, 1973 map. Proximity to Airports There are no airports located within 10,000 feet of the proposed site. Wetlands According to the Soil Survey of Weld County, Southern Part, no wetlands are present on site. The only evidence of surface water on the site are intermittent streams and draws. There is an intermittent, unnamed stream located approximately 2500 feet south west of the proposed site. Surface water systems at the site are more fully described in other portions of this permit application. 2-3 920283 01 Co ti22 ! 1'�tI 'E17IIL1ItVL4ii '4 -K2 wP, Olg O C 0 eves*; f.1 1 L- 9. 6S V SS • • I w 1 II Nowt ZI .......H yi..._ .pl w tti Pn 11 p ( I z • F - O ,� E rI ° g cee M469� _.. �._ __-_- fie', y 1 a o e 01_I ,'�� l i ai °� i z� r f, r : >6Y °ro _ srds*— [84 1 6r� �� GB9 ec O o II 015 moil):7 3 f �,J o sp 8 _ ■ • Z o J/F 0 asero'Rwe \� 1� 3 s m b Li L 284ih(Iflr�x 6 0 p U n e ; .. A , • . II II —_ It It ItII If ne FilAreaii II. — C. II \\ • • I Primary Buller Aria a tons c �Flootl Plain Y .. - �.�, '-/I_"- - =J — —ter "..'~j' ~ " It Secondaryl]Buffer Zone I I Y • \ 11 L • 11 II Tom _ ;; — — ; 'EXPLANATION OF ZONE DESIGNATIONS ZONE EXPLANATION • A Areas of 100-year flood; base flood elevations and flood hazard factors not determined. •• AD Areas of loo-year shallow flooding where depths re between one (I)and three(3)feet;average depths • of inundation are shown,but no flood hazard factorsii are determined. AN Arses of 100-year shallow flooding where depths \ T re between one (1) an `d three (3) feet;base flood 0 1 2G MILES a elevations are shown, but no flood hazard factors arc determined. AlA]0 Areas of 100-year flood; base flood of ovations and • flood hazard fact0yesrn b APPROX. SCALE A» Areas of 100-year nooa to be protected by nooa protection system under eo actorson; base floodelevations and flood hazard factors not determined. GENERATED BY FIRM (FLOOD INSURANCE RATE MAF) B Areas between limits or the 10o-year flood and SOO- COMMUNITY PANEL NUMBER 080266 0900C year flood;or certain areas subject ra 100-year flood- ing m; cont with ributing an nsage less isoLess than of e square .. INDUSTRIAL COMPLIANCE tie;or areas protected by levees from the base flood. 1746 COLE BLVD. (Medium shading) — BLDG. 21 SUITE 300 c Areas of minimal flooding.(No shading) GOLDEN. COLORADO 80401 O Areas of undetermined, but possible,-flood hazards. • OPyear coastal flood with velocity V Areas of I (wane FIGURE 2.3 action);base flood elevations and flood hazard factors not nesermined. VI-V30 Areas of 100-year coiner flood with velocity (wave FLOOD PLAIN MAP action);base flood u.va lions and flood narvd factor, determined. ra.v. WASTE SERVICES COMPANY ALT: SANITARY LANDFILL .,r-l.<—Mrs 2-3716 Iar unardrro REV. 07/92 a„r„, r ... INDUSTRIAL COMPLIANCE cow,- r-W,H,T. tp—w*'Pr Sr,L..P, 1nj Naa,e. 2;716E23 9 '(339 Fault Areas The nearest fault to the site is approximately 24 miles east of the site, and it is classified with an age of displacement in the Quaternary Period, which includes the Pleistocene and Holocene Epochs. Seismic Impact Zones A USGS map of horizontal velocities (percent g) in rock with 90 percent probability of not being expected in 250 years was used to determine if the site is suitable (USGS Open File Report 82-1033), as recommended in Subtitle D. According to this map, the site is not located in a seismic impact zone. Unstable Areas Based on site reconnaissance and document reviews, there is no evidence of unstable areas such as landslides on the site. Colorado Landslide Hazard Mitigation Plan categorizes the area encompassing the site as having a low potential for landslides. Ground-Water Management Districts The site is not within any of the ground-water basins or ground-water management districts designated by the Colorado State Engineer, Water Resources Division. The Lost Creek basin is the closest designated basin and management district to the site. It is located approximately 3 miles southeast of the site. AAquifers According to a map of Weld County Aquifer Recharge Zones, the site is located outside of any alluvial recharge areas. A portion of this map showing the site is reproduced as Figure 2.4. Section 4 presents more complete information regarding aquifers in the site vicinity. 2.2.3 Acceptable Waste Streams The proposed site will receive municipal and commercial nonhazardous solid waste including, but not limited to, bulky waste, demolition and construction waste, soil, rock, concrete, and related inert solids that are relatively insoluble in water. Special waste, as defined by the State will also be accepted. These wastes include, but are not limited to, friable and non-friable asbestos, bulk tires or other bulk materials, dried sludges, and biomedical wastes which require special handling and disposal procedures. Prior to acceptance of any special wastes, including friable asbestos, a special Waste Acceptance Plan will be developed detailing the acceptance procedures, handling, and disposal procedures for each special waste. The Waste Acceptance Plan will have the concurrence of the Division prior to accepting any special waste for disposal. 2-6 92;0:133 c} '�, r. ./77.101.±, ♦ ht 1' ♦see t yr r / !. I/;4 "w I�ig$ , / .. p_ . . u .. S'�;e r Div-ire it[� I �/I,e'•W - 4'0v % e I 1 �/� a eeip.-� i•�1 Allen 7 r�/I%w'ie�✓•� t./ jae4:, ice_ o 'newt'? q e r ,� 7� ta �� iU_4 �4��j�•I�i•.,.. rise ellEirMisA'_ J%///Y/.'// m IF iaII 0 4nr %w. �� - 'sass�i�:' - •_ice.. ter.. v �.� r r%/ I )" i ••! j/a J //i/I / I/•7j Syr/j s1 — =ti k 4'R►=" //an/ . .;::%//P/t/✓' {' •-+�,�� %;� ;fir I v� . Q M1 in��., 0 4` -•�•V/�;'I • • ,�! � :% f' y�y r bed '=;' . _�..�fr . aiii .,-am�:• •..49 d '4�•��'� .� / •/ 694 ,, - ars_ .�1' r 04�AO li %Y 1.\ I mw.nL/e i Ni-kI �V�< i \ '"4/4, �' % ,a0. . \, \ `� Mona A• r' �-•'�•-+ � �% �� I • \\ .. `469„I °... , j,9ke i v lea it r , ni i 'yj�1 -_ - r 66 �� I laN°*Pt1W / .a ��\ 3. -, % i '1 \\ ?If lo„), ri, prei (,\,... ' ,,,, ..,k \\\ t Isa6C� hi- . a) . .•oe �`/i/j lillt I di,1 % f �r. SITE LOCATIOIV1'�j no a . ', �I Mi 195 //L a /�1 /�� its;1 \ tI,.., Keene . a iii 1 �,10so►. - ,4y ,�a0R�Al, Iii r . • r n6 r Ali e%LII t, , r-' IV' r fry4r i .r �� _ 1/4 �il%/J/p.2.snau>i a '• ♦ '♦II.4 ran / Y ` 1 pp '; • 8 __ .•ter_ ,�j1�` .soe �� %tiii� ; 744, iiefi ,x.960 ; %'J1 �� 1 I j a 4- '/� ' �•'�i�. \I �nw.•eri�iR' I ' .nd�1� : — t !.c r I \ ,.'/ � ` "cr I \ • r.,�l ��%ll!, !��!irr `� F4 Fir r..m i ) 1 ca&.4ch:1 I VSi - l t' 4:0444. . ',''• r\i lI I `9/' . u w 30' . ..w I INDUSTRIAL COMPLIANCE _ 1746 COLE BLVD. BLDG. 21 SUITE 300 GOLDEN. COLORADO 80401 FIGURE 2: 4 N SITE AQUIFER RECHARGE AREAS 0 2.5 5 MILES WASTE SERVICES COMPANY SANITARY LANDFILL APPROX. SCALE .1<oxcr. 01 /30/92 "mar NO. 2-3716 I. aon6nm Fr INDUSTRIAL COMPLIANCE mow a-W.H.T. IM.Kww ar. J.L.P. I » rIC2-3 920233 The facility will not dispose of hazardous wastes as defined by Federal or State regulations or bulk liquid wastes. EWSL will further maintain policies and practices to prevent the receipt of any small quantity generator waste as defined by the Resource Conservation and Recovery Act (RCRA) in 40 CFR Part 260 and 261 although it is exempted by RCRA. 2.2.4 Landfill Design The proposed landfill incorporates the following environmentally protective features: • A soil liner consisting of 3-feet of compacted cohesive soils constructed over the base of the facility and an adequate area for a borrow source on-site, if necessary. * A landfill liquids collection system consisting of a permeable drainage material, a synthetic lined sump, and removal systems. * Landfill gas monitoring and venting system. * Ground-water monitoring system. * A compacted soil cap for closure of the completed portions of the landfill. 2.2.5 Filling The area of disturbance will be minimized as practicable. Generally, filling will be accomplished using the area ramp and fill method. This includes excavating and lining the active area, placing and compacting refuse in controlled lifts, and covering the refuse on a daily basis. Filling procedures for various waste streams are more fully outlined in subsequent sections of this document. 2.2.6 Final Cover Competed portions of the landfill will be closed using a final cover system consisting of an initial 0.5 foot foundation layer overlain by a minimum of 1.5 feet of compacted cohesive soil, and 2-feet of unspecified root and frost protection layer. Revegetation will be completed with a minimum of 0.5 feet of topsoil to support growth. The area will be revegetated to return the site to its natural, environmentally suitable condition. Completed portions of the fill will be reclaimed as filling areas reach final grades to minimize the size of the disturbed areas. 2.2.7 Site Access The site is accessible on all-weather roads from an existing 3 1/2 mile long private paved road, Weld County Road 59 and Interstate 76. General access to the site is shown on Figure 2.1. Access for refuse vehicles within the facility will be by all-weather roads to the working face of the landfill. The EWSL operator will properly maintain on-site roads at all times including mitigating dust when necessary. 2-8 9Z0289 2.3 Zoning and Land Use Zoning in the area of the landfill is for agricultural use and is in the A District. According to the We'd County Zoning Ordinance, solid waste disposal facilities are acceptable and require a Use by Special Review (USR) in these districts. Additionally, solid waste facilities require a Certificate of Designation approved by the Weld County Board of Commissioners using the CDH Solid Waste Regulations as a guide. The proposed landfill meets the criteria of the regulations. 2-9 92O3s9 3.0 SITE DESCRIPTION 3.1 Existing Site Topography The existing site topography and facility layout is shown on Plate 1. The slopes are relatively gentle across the site and typically range from 0.4 percent to 12.5 percent. The highest existing elevation of the filling area, located at the southern end, is approximately 4930 feet above sea level. The lowest point is located at the northern end of the filling area and is at an elevation of 4884 feet. This equates to an overall slope of approximately 0.6 percent. The filling area runs longitudinally from south to north and laterally from the center of the filling area to the east and the west. The location was selected to minimize surface water runon and to maximize use of the best geologic features within the boundaries of the property and adapt the final form of the landfill to the existing topography. The topography of the vicinity is shown on Figure 3.1. The surrounding topography is similar in grade and elevations rise east and south of the site to offer visual screening of the operations from the Keenesburg and Interstate-76 area. The fact that the proposed facility is isolated significantly enhances its suitability for development as a landfill from an aesthetic standpoint. 3.2 Surface Water Drainage The site is located in an area that limits surface water drainage to the site. Run-on is not expected to occur to the filling area. The surface water features within 2-miles of the site are also shown in Figure 3.2. Surface water originating on the site generally flows to the east and west (Figure 3.3). There are no intermittent streams mapped on the property according to the United States Geological Survey (USGS) 7.5 minute topographic maps. This appears appropriate because of the relatively gentle slopes across the site. Small depressions are located within the filling area of the site that appear to have been man- made, possibly for stock-watering purposes. These depressions will be removed during the landfill development. 3-1 9202,83 r !T4441 �B ZS I 0) 1 o0ace F,:oz r� _ IA\fT su a� L )N bZ "CZ ZZ �1 U_ U t 6i �� 1 wo W 5§ Z 7Z �••. ='h ZZ FtH?x t ��eFBn �- ._ -._ x.._166 -..�_ W O WI r §` .760 i,1 V m - h Ii } oase _ c I' • o• 1.Belle • C _ pa I O0 ZT Z- 1:44 f�. -� . OL 8 Tl w rw Lo < '1'1;1: � B�IuuouiM W • d :::" LL i ' iI -�881 la r,..L,S;,," —.r-- [I t j. J G w • < . II 1 IIII \ Yd el o y mil: .. V Bisa > 41� Aft' '' I4.ss :i \ I.r 'ileM Ie fPeo W �l E li•• C7 i •I..0 7. ter B Ol �I; I• 61 f I CC vo • O' er ...175 J �-- 6 1 m t i El ce o o w Be— eBBe eoee 5eI U s E 4�wBUM C 4 ceB. E !n o 0 3 CC CC o 5 6 — w CP co o c� I } �` uct O I e _ agar*we N o 4 3 i -go,9 t - Brea 84,1,4,/ jr L43- D w R. o C m a Cl) U �. V w w I O 0 om0�4 1n L. OmFo J '21°5°U w' Eonw N N 8 Z a I- o- o - nQ Q o m _ W z ¢so LL I- >._, t- Q < w}43S • `^Qmo w ,-t- , -t= o Nz<'' _ Q �N 9 c3. 111111 ig 7 II 1 I( 8CI I ET El: F------- 7,1- bL _ 9ZC c' R f — _ o_ .I N I r w 1 c I II � ---Z-1 El — 01 F 5 0 I I If 1 114 "" -. CO 1 s. L I I 1in - a I. i r. r - I a«I ° I' inn' I 02 -Y£sl I 9E 9E 5£J I m EEE EE a ZE rfp.,, 4 1`r - i. I'IAp I LL 1477.--7.7 0£ 90 150 LZ 9Z 6Z f w I 33 I, I ‘ 61I ♦ bZ ',bZ EZ ZZ 10 OZ «..„ ."`., \ ' - II I 91 EI96^`fI EI j 51 91 I4 /_ 'iT_—. l- ,.•.� —--./------ —_ I 2 a I[ CPO O G t Ut2 £ ii:: A yC N §.atilt W w > u a I ii.,, U.,o J o U 16 rt 1- !li � Z96_b 96, T 7 /064 0464 - NI EI N h O F .._.-,.....r.._. iiiii0:00I ;I w 4 / , Ib6b , o R.,/sin It M auoZ�Jajifl9 ciepuoo 46 vN, }F[ y4 { ► ` z i , £9a4 19Lab 9&9 - 4 A.PVMii g 989 ,) BM 6L8t 5£ b� ' (l i 1 ea4 9994 ..406+ illillSit'— , u _ I, <99, 0s8 Q 8989�� - >W8 il ZZBbi IlaM de BnIN L 3.3 Climatology Climatology information was obtained from The Colorado Climate Center located at the Colorado State University. While information specific to Keenesbur€ was not available, climate data was gathered specific to Denver, Fort Lupton, Byers, Brighton, Greeley, and Fort Morgan and is included in Appendix B. The climate of the area in the vicinity of the proposed landfill is generally similar to that of Fort Lupton. It is characterized by low relative humidity, light to moderate winds, mild temperatures,and light precipitation (NOAA, 1990). Brighton is the nearest city with comprehensive climate data. The average annual mean temperature is 49.9 degrees. Monthly mean maximum temperatures range from a low of 42 degrees in January to a high of 89.5 degrees in July. Monthly mean minimum temperatures range from a low of 13.7 degrees in January to a high of 56.8 degrees in July. Monthly mean average temperatures range from a low of 27.9 degrees in January to a high of 73.2 in July. Annual precipitation avenges 14.28 inches. This is compiled from data since 1973. The wettest month is May with an average of 2.97 inches of precipitation. The month with the least precipitation is February with an average of 0.41 inches. The maximum precipitation in a month is 5.7 inches in May and the minimum is .01 inches in September. Wind data is taken from information collected at Stapleton Airport during the period from 1949 to 1990. Annual average wind speed for this period is 8.7 miles per hour (mph). Monthly averages range from a high of 10.1 mph in April to a low of 7.9 mph in October. The prevailing wind direction is southerly. Figure 3.4 shows a wind rose map from Stapleton data. 3-5 9Z0:'S3 H \ CALM) 0 \\2 s \ zo NW NE to \ W E SE SW mph I-T 8.12 13-18 19-24 25-38 39+ Annual Wind Rose • INDUSTRIAL COMPLIANCE 1748 Nil COLE BLVD. BLDG. 21 SUITE 300 GOLDEN: COLORADO 80401 FIGURE 3.4 WIND ROSE MAP UN WASTE SERVICES COMPANY mw.or. SANITARY LANDFILL .„CUE,„d 2-3716 Inn 01 /30/92 02,011.0711 Mt INDUSTRIAL COMPLIANCE ni u.W.H.T. I ArausieD„r J•L.P. I ns„wc FIG3-3 320359 4.0 GEOLOGY AND HYDROGEOLOGY 4.1 Geologic Overview The site is situated on the northeast flank of the Denver Ground-Water Basin which extends from Greeley in the north to Colorado Springs in the South and from the Front Range in the west to near Limon in the east. The greater Denver Basin including the Denver Ground Water Basin, can be traced on contour maps of the top of the Precambrian Basement and extends north into southeastern Wyoming and southwestern Nebraska. The deepest portion of the Basin is beneath the city of Denver where the Precambrian exists approximately 7000- feet below sea level. Both the Denver Basin and the Front Range Uplift are a result of orogenic movements of the earths crust which began in the late Cretaceous and continued into the Miocene (75 million years to 15 million years ago). The basin forms a bowl in which the bedrock formations dip steeply to the east on the west side of the basin adjacent to the Front Range. The bedrock formations on the north, south, and east flanks of the basin dip gently toward the center of the basin beneath Denver. Figure 4.1 is a regional geologic map of the area surrounding the site. The bedrock materials beneath the site range in age from Precambrian to the late Cretaceous Laramie Formation. Figure 4.2 is a generalized stratigraphic section. Bedrock formations above the Laramie are not present at the site; however, the site is mantled by wind-blown Quaternary eolian sands. The Cretaceous Pierre Shale lies conformably on top of the Niobrara Formation and is generally considered to be the base of the Regional Denver Basin Aquifer system due to its thickness (8,000 feet in some areas) and its minimal permeability. Only the Formations above the Pierre Shale will be discussed here. Immediately above the Pierre Shale is the Fox Hills Sandstone. The Fox Hills Sandstone represents a transitional phase between the underlying, predominantly marine sediments and the overlying predominantly continental sediments. The Fox Hills is a tan, cross-bedded sandstone grading downward into a brown, fine-grain, silty sandstone interbedded with shale. The thickness of the Fox Hills Sandstone ranges from 300 to and 500 feet. The contact between the Pierre and the Fox Hills is transitional. The Laramie Formation rests conformably on top of the Fox Hills. In some areas of investigation, the contact between the Fox Hills and the Laramie appers to be transitional. The Laramie Formation is continental in origin with the sediments deposited in brackish or fresh-water fluvial environments. The Formation typically consist of interbedded gray shales, clays, claystones, lignites, and sandstones. The lignite or coal units represent brackish or stagnant backwater deposits with significant volumes of organic deposits. The clays and claystones were deposited in backwaters or inter-channel waters that were fairly- well drained. 4-1 9 U.`:33 Alj Fa'1 arnesv le / � \J n'arns,p / arY/ .� KI _`� ` j tT ± : �'' G est r — 7,1.1k tlit.1� ��I r_. ne,a' �� IF!. � � � � � ATION }'' 111 I i',11, .43;--..4 Svat:tt'":"frit . e 1 i— f . . i i Afri ir .i f,. ,e9 r 1 ,r,...- is i 4e Sic, p ^" / 'l' l o-" �4±!' s pf _go $I /�c)pi�; cle F:"" 3.? k'. LEGEND Oa = MODERN ALLUVIUM—Includes Piney Creek Alluvium and younger deposits Qg = GRAVELS AND ALLUVIUMS (PINEDALE AND BULL LAKE AGE)—Includes Broadway and Louviers Alluviums Qe = EOLIAN DEPOSITES—Includes dune sand and silt and Peoria Loess Tkdl = DENVER FORMATION OR LOWER PART OF DAWS0N ARKOSE—Arkosic sandstone, shale, mudstone, conglomerate, and local coal beds Qgo = Older Gravels and Alluviums (Pre—Bull Lake Age); Includes Slocum, Verdos, Rocky Flats, and Nuss baum—Alluviums in the east, and Florida Bridgetimber. and Bayfield Gravels in the South—west. KI = Laramie Formation—Shale, Claystone, Sandstone, and major coal beds. Kf = Fox Hills Sandstone—Tan, Cross—bedded Sandstone with innerbedded marine shales. Tkda = Denver and Arapahoe Formations—Sandstone, Mudstone, Claystone, and conglomerate. INDUSTRIAL COMPLIANCE 174 COLE BLVD. BLDG. 21 SUITE 300 GOLDEN, COLORADO 80401 FIGURE 41 COLORADO 5 10 MILES GEOLOGIC MAP OF SITE APPROX. SCALE wimp WASTE SERVICES COMPANY reoxar SANITARY LANDFILLPROEM 01/30/92 .n ow INDUSTRIAL C0M6 PLIANCE DRAM er.W.H.T. I OPPROVED ,n M.A.M. InE WI& FIG4-1 920L39 Age Unit Thickness Lithologic Description Quaternary Qe 5'-40' EOLIAN DEPOSITS: Includes dune sand and silt and Peoria Loess. Cretaceous Kl 300'-400' I ARAMTE FORMATION: claystone, shale, and sandstone, light gray to brown. Kfh 50' FOX HILLS FORMATION: silty sandstone with interbedded shales, gray to brown. Kp 6000'+ PIERRE SHALE: shale, sandy shale, and some sandstone/siltstone lenses near the top, brown to dark gray-brown, friable. Kn 350' NIOBRARA FORMATION: calcareous shale and limestone, gray to grayish-yellow. Kcg 450' CARLILE SHALE: silty claystone and siltstone, olive-gray, GREENHORN LIMESTONE: limestone, claystone, and siltstone, gray, GRANEROS SHALE: siltstone and claystone, dark gray. Kd 230' DAKOTA GROUP: sandstone siltstone, carbonaceous shale, and conglomerate near the base, light to dark gray. Jurassic Jmr 380' MORRISON AND RALSTON CREEK FORMATION: shale, claystone, sandstone, and some thin limestone beds, varied colors. Je 50' ENTRADA FORMATION: sandstone, light brown to gray. TR TRPI 470' LYKINS FORMATION: shale, siltstone, and limestone, red to red- brown. " Penn P1 230' LYONS SANDSTONE: sandstone, orange to pink to gray. Penn PPf 900' FOUNTAIN FORMATION: sandstone, siltstone, and conglomerate, with thin shale beds, red-brown. PC — — Undifferentiated Precambrian igneous rocks. nINDUSTRIAL COMPLIANCE 1746 COLE BLVD. BLDG. 21 SUITE 300 GOLDEN. COLORADO 80401 FIGURE 4.2 STRATIGRAPHIC SECTION a, ,. WASTE SERVICES COMPANY ,,,,c SANITARY LANDFILL ��, PROJECT NW GINFIL,m,,.2-371 6 01 /30/92 INDUS'RIAL COMIIPLI N orww„ ,nW,H.T. I ApPROVEDe+: M.A.M. Incwaif: FlG4-2 9z® ^99 The sands and sandstones represent ancient stream-channel deposits. They tend to be represented by cleaner, coarser sands near the center of the channel and grade outward to finer grain sands and silts. The individual lithic units are characteristically lenticular and laterally discontinuous in nature and are thus difficult to correlate over distance. The bedrock unit immediately underlying the surficial materials at the proposed landfill site is the upper Laramie. The Laramie Formation is generally divided into an upper and lower member. The lower Laramie is distinguished from the upper Laramie by the presence of lenticular coal beds. The uppermost coal bed defines the top of the lower Laramie. Review of geologic and hydrogeologic data from the adjacent inactive Keenseburg Coal Mine indicates that the lower Laramie is approximately 280-feet thick in the area of the site while the upper Laramie ranges from 60 to 180 feet thick. Above the Laramie, the site is mantled by Quaternary windblown eolian sands, except for the far northwestern corner which is covered with mixed outwash deposits. The thickness of these sands across the site ranges from 5 feet to over 30 feet and the sands are lithologirally consistent. They are very-fine-to-fine-grained with little or no clay. Near the ground surface they contain varying amounts of silt but grade downward to a generally-siltier phase. The bedrock formations dip gently to the southwest (1 to 3 degrees) toward the center of the basin. The upper limit of competent bedrock beneath the site is controlled by, and generally minors the northwest dipping surface topography. 4.2 Hydrogeologic Overview The site is not located within any ground-water management districts designated by the Colorado State Engineers Office. The four major bedrock aquifers existing in the Denver Basin, from oldest to youngest, are the Laramie-Fox Hills, the Arapahoe, the Denver, and the Dawson. The Pierre Shale which underlies the Fox Hills is considered to be the base of the major Denver Basin Aquifer system due to its thickness (8,000 feet in some areas) and its low permeability. The Dawson, Denver, and Arapahoe Aquifers outcrop south and thus are not present beneath the site. The Fox Hills and sands of the lower Laramie Formation are commonly grouped together as one system. The resulting Laramie-Fox Hills (LF) Aquifer represents the only regional bedrock aquifer system beneath the site. Data from the Keenseburg Coal Mine Study indicate that the top of the Laramie-Fox Hills Aquifer is 280 feet below the ground surface. This data is consistent with data obtained from maps of the Laramie-Fox Hills Aquifer published by The Colorado Division of Water Resources (Vanslyke and others, 1988) that show the top of the Laramie-Fox Hills Aquifer to be approximately 330 feet below the ground surface at this site. Comparison of the contour maps structured on top and on the base of the Aquifer indicate that it is approximately 300-feet thick beneath the site. Water in the LF Aquifer is generally classified as a sodium bicarbonate type. Review of the water wells apparently completed into the LF Aquifer within two miles of the site indicate that the majority of the wells supply water for livestock purposes. 4-4 920.1.'33 The Potentiometric Surface Map of Laramie-Fox Hills Aquifer (Robson and others, 1978) indicates a regional flow direction in the aquifer to the north northeast where discharge most likely occurs into the alluvial aquifers of the South Platte River or its tributaries. 4.3 Economic Geology The Denver Basin is generally known for its oil and gas reserves. The vast majority of these reserves are produced from sands in the early-Cretaceous Dakota Group with minor amounts produced from the mid-Cretaceous Niobrara Formation and the late-Cretaceous, lower-Pierre Formation. There is significant gas production to the west, north, and east of the site although no evidence of production in the immediate vicinity of the site exists. Oil is produced in the Prospect Valley area approximately 8-miles southeast of the site. Significant thicknesses of coal are known to exist in the lower Laramie Formation but their value is economically dependant on grade and overburden thickness. The adjacent inactive Keenseburg Coal Mine operation (currently under reclamation) exists approximately 1.5- miles east of the northeast boundary of the site. No economic thicknesses of coal were found in the intervals penetrated during the site-specific drilling program. 4.4 Potential Geologic Hazards The closest fault experiencing displacement during Holocene time is approximately 24 miles east of the site. It is classified with an age of displacement during the Quaternary Period. The site is not located in a seismic impact zone. A seismic impact zone is defined as an area having a 10 percent or greater probability that the maximum expected acceleration in hard rock, expressed as a percentage of the earth's gravitational pull, will exceed 0.10g. USGS Open File Report 82-1033 indicates that the maximum horizontal acceleration expected in the rock in the area surrounding the site, within a 250 year period, is approximately 0.07g. The site is not located in a geologically unstable area. The Colorado Landslide Hazard Mitigation Plan categorizes the area encompassing the site as having a low potential for landslides. The terrain is nearly-level to moderately-sloping plains overlain by sandy soils. The surface soils consist of moderately-to-excessively-draining sands with a low shrink- swell potential. Furthermore, once site excavation begins, side slope grades will be maintained in a fashion that alleviates any stability problems. There are no geomorphological features on site such as caverns or karst topography which could present stability problems. The relationship of the site to flood plains is discussed in Section 2.3.1 of this document. 4.5 Site Description The site is located in an area of generally low topographic relief on slightly-to-moderately- undulating plains. Vegetation is moderate and typical of the fairly-dry Colorado plains. There are no significant depressions found on the site. 4-5 The site straddles a mildly-undulating northwest-southeast trending ridge. The highest portion of this ridge exists in the southern portions of the proposed fill area at an elevation of 4930-feet MSL (mean sea level). From here the ridge slopes downward to the northern limits of the proposed filling area at an approximate 1-percent grade to an elevation of approximately 4867-feet MSL. The eastern and western flanks fall off at approximately 1.4 to 2-percent grades. This ridge forms a surface-water divide. The east flank dips toward Ennis draw approximately 1.75 miles to the east of the site while the west flank dips toward Box Elder Creek approximately 2 miles west of the site. 4.6 Field Investigation and Methodology IC conducted a detailed field investigation to assess the site-specific geologic and hydrogeologic conditions. The data accumulated during this field program was used to verify the suitability of the site for potential use as a municipal solid waste sanitary landfill and to assist in the design of an environmentally-sound facility that would meet all applicable Federal and State regulations. Components of the field program included soil borings, piezometer installations, ground- water monitor well installations, ground-water sampling, test pits, geotechnical materials testing, slug-out permeability tests, and packer permeability tests. Each of these components is discussed below. Findings and conclusions are discussed in later sections of this document. 4.6.1 Soil Borings A total of 50 soil borings were advanced at the site at the locations shown on Plate 4 to characterize the hydrology and subsurface materials. The soil borings on the logs were designated with either an "SB" label for a soil Boring, a "PZ" label for a piezometer or "PK" for packer test. All "SB" borings were converted to a "PZ" designation for map labeling purposes. The portion of the site proposed for filling was evaluated by 36 soil borings. The location of the borings was determined by topographic and areal coverage considerations that permitted the generation of cross sections which depict the site geological and hydrogeologic conditions. Each boring was surveyed for ground-level elevation and horizontal coordinates to facilitate correlation of subsurface features. The cross-section locations are illustrated in Plate 4 and the actual cross-sections are included on Plates 5, 6, and 7. The majority of the borings were advanced with a CME-55 drill rig using 6 or 8-inch outside-diameter hollow-stem auger and continuous-core equipment. The continuous-core equipment was used from the ground surface to the total depth of the boring to allowing detailed examination of the entire thickness of strata penetrated. The core was laid out in the proper orientation next to each boring to allow additional examination and to assist in correlation with other borings. A soil boring log detailing the boring location, drilling and sampling method, the lithology, well or piezometer completion data, and other pertinent information was completed during drilling for each boring advanced at the site. Copies of the soil boring logs are included in Appendix C. Graphic lithologic logs are included in Appendix D. 4-6 Nine borings were nested next to other borings and completed as piezometers as discussed below to gather additional hydrogeological information. In the case of nested borings, where the initial boring was drilled with continuous core equipment and the lithology known, the second boring was advanced with 4-inch diameter solid stem auger to a predetermined depth and no continuous core was collected. 4.6.2 Piezometer Installations Of the 50 borings, 44 were completed as piezometers to asses ground-water conditions beneath the site. All piezometers are designated with a "PZ" label corresponding to the label of the boring (ie. soil boring SB-1 became piezometer PZ-1). The piezometers consisted of 1-inch-diameter, Schedule-40, PVC pipe joined with glue joint couplings. A specific interval of the pipe was hand slotted to allow infiltration of ground water from the water bearing intervals into the pipe. The pipe was placed in the boring and the annular space surrounding the pipe was backfilled with clean sand from the base of the boring up to a specific depth. A bentonite seal was placed on top of the sand to isolate the zone of interest from shallower zones and surface infiltration. The remainder of the boring was then backfilled to the ground surface with cuttings. In some instances, a bentonite seal was also placed at the surface to further minimize potential surface infiltration. Piezometer completions are illustrated in Appendix D. The piezometers were checked periodically with an electronic water-level indicator to detect the presence of and measure elevations of ground water. Some of the piezometers (PZ-27, PZ-28, PZ-30, PZ-32, PZ-33, PZ-35, PZ-36, PZ-37, PZ-38, PZ-39) were paired with initial piezometers to evaluate if the detected water existed under confined conditions. Piezometer PZ-34 was completed with two piezometers (dual completed) in the same hole to monitor distinct intervals. Each piezometer was surveyed for horizontal coordinates and elevation at ground level and at the top of the pipe. For consistency, water levels were measured from the top of the pipe rather than from ground level. A barb-wire fence was installed around each piezometer to protect it from damage. 4.6.3 Ground-Water Monitor Well Installations Three ground-water monitor wells were installed at the site. The wells were completed as follows: 1) The boring was advanced using 8-inch outside diameter hollow-stem auger. Continuous cores were collected. 2) Two-inch diameter, flush joint, thread-coupled, Schedule-40 PVC pipe was placed to the total depth of the boring inside the hollow stem auger. The bottom 10 or 20 feet of pipe consisted of 0.02 inch factory-slotted PVC screen. 3) The annular space around the pipe was backfilled through the hollow-stem auger from the bottom to approximately 3 feet above the screened interval with a graded, 10-20 silica sand. 4-7 4) A 3-foot bentonite seal was placed above the sand pack to isolate the zone of interest from shallow infiltration. 5) A cement grout was placed from top of the bentonite seal to the ground surface. 6) A steel protective cover with a locking cap was installed over the well to protect it from damage and prevent unauthorized access. A barb wire fence was placed around each monitor well to prevent access and damage. Specific monitor well construction information is included in Appendix D. 4.6.4 Ground-Water Sampling Each of the three ground-water monitoring wells (MW-01, MW-02, and MW-03) was developed and sampled to gather data on ground-water quality. Prior to sampling, the water level in each well was checked and the volume of ground water contained in the well was calculated. The wells were purged and sampled with a bottom-loading PVC bailer. Each well was sampled with a dedicated bailer and bailing rope to prevent cross-contamination between samples. Other equipment that came into contact with the ground-water samples was decontaminated with deionized water before beginning sampling and between wells. Each of the three wells bailed dry prior to the extraction of three full volumes. Parameters of pH, specific conductivity, and temperature were monitored through the purging process following the extraction of each volume of water. Following sufficient recharge, ground water was extracted with the bailer and poured into prepared sample bottles. Ground water to be used for dissolved metals analysis was filtered in the field with a 0.45-micron filter prior to placing it in the sample bottle. The samples were immediately put in a cooler, kept cool, and delivered to the laboratory within 24-hours of collection. Ground water analytical results, field data and chain of custody forms are included in Appendix H. 4.6.5 Test Pits A total of 13 test pits were excavated across the site to evaluate the suitability of the surficial sands for use as drainage material. The depths of the test pits varied upon the material encountered but were a maximum of approximately 15 feet deep. The pits were completed with a backhoe and samples of the sand believed to possess the best potential for drainage use were collected for laboratory analysis. Selected samples were submitted for grain-size analysis, percent passing the #200 sieve, and permeability testing. Locations of the test pits are shown on Plate 4. 4.6.6 Collection of Representative Site Materials for Geotechnical Testing Representative soil and bedrock materials were collected during the field program and submitted for laboratory analysis to evaluate their suitability for use in landfill construction. The locations of borings and test pits where samples were collected are shown on Plate 4. Representative samples included: 4-8 1) The surficial sand collected from test pits as described above submitted for grain size analysis and permeability analysis. 2) Relatively-undisturbed samples of the surficial sands, weathered bedrock, and competent bedrock materials submitted for natural moisture and in-place permeability analysis. 3) Samples of weathered and competent bedrock materials submitted to define natural and recompacted characteristics including grain size and consolidation analysis, Atterberg Limits, Optimum Moisture and Maximum Density Analysis. Relatively-undisturbed samples were collected in brass liners in a California-Barrel Sampler. The California-Barrel Sampler was driven into the material with a 140-pound hammer falling approximately 30-inches. The number of blows of the hammer and corresponding penetration were recorded on the boring logs. The samples to be submitted were left undisturbed in the brass liners and sealed for delivery to the laboratory to prevent moisture loss. The remaining samples were collected from the continuous core samples and/or the auger cuttings. 4.6.7 Slug-Test Permeability Testing Permeability testing was conducted in each of the three ground-water monitoring wells shown on Plate 4. Prior to initiating the test, the static water level was measured in the well. A 5 foot long by 1.25-inch internal-diameter PVC bailer was lowered into the well and allowed to fill to capacity. The bailer was then rapidly withdrawn and the water level indicator lowered into the hole. The water level was measured at specific time intervals with an electronic water level probe as the well recovered and the rise in water level was plotted against time using the method developed by Hvorslev to determine the permeability of the water bearing interval in centimeters per second. Results of the slug testing are in Section 4.8.3. 4.6.8 Packer Test Permeability Six of the 50 borings were used to evaluate the permeability of in-situ materials by the packer test method. Borings used for packer testing are designated by "PK" and shown on Plate 4. One packer test was conducted in each of the six borings. Each of the three material categories (surficial sand, weathered bedrock, and the competent bedrock) were evaluated by two packer tests. Results of the Packer testing are in Section 4.8.3. To complete this testing, a 4-inch diameter borehole was drilled with solid-stem auger. Following completion of the boring to total depth, the augers were withdrawn from the boring and a packer attached to hollow piping was lowered down the borehole and inflated with compressed air at the top of the interval to be tested. The hollow piping extended from the surface down the borehole and through the middle of the packer. The piping was open beneath the packer to allow the interval between the base of the packer and the bottom of the hole to be filled with water. At the surface, the piping was attached to a manifold with a pressure gauge and flow meter which were connected to a water tank. The hole above the packer was filled with water to visually check if leakage around the packer was occurring 4-9 920339 during the test. The test interval below the packer was filled with water prior to beginning the test and the initial flow meter reading was recorded. Water was then pumped at constant pressure through the hollow pipe into the test interval and the volume of water accepted by the tested interval versus the elapsed time was recorded. When sufficient data was obtained through pumping at a specific pressure, the pressure was increased by 5 pounds per square inch (psi) and held constant while the rate of infiltration was recorded. All tests were initiated at 10 psi pumping pressure and generally were increased in 5 psi increments. 4.7 Site Geology Materials encountered at the site during the site-specific boring program can be divided into three basic types. The uppermost type consists of windblown eolian sands. Below the eolian sand exists varying thicknesses of weathered Laramie Formation bedrock materials which consist of clays containing slight-to-moderate amounts of fine sands and silts. Beneath the weathered bedrock are more competent, less weathered bedrock clays and claystones of the upper Laramie Formation. For the purposes of this discussion, and the associated maps, the top of bedrock was chosen as the upper limit of the competent bedrock as defined by stiffness and degree of weathering. Boring logs are included in Appendix C and lithologic logs are included in Appendix D. Cross-sections produced from boring and water level data are included on Plates 5, 6, and 7. The sections show present topography, static water levels, construction depths and lithology across the site. 4.7.1 Surficial Materials The site is mantled by eolian sands ranging in thickness from 5-feet at PZ-11 to 36-feet at PZ-15. All soil borings with the exception of PZ-10 and PK-6 (a packer test hole) penetrated the entire thickness of eolian sands. The average thickness of the eolian sand across the site is 17 feet. The eolian sands were uniformly very-fine-to-fine grained, round to subround, and slightly-to-moderately silty at the surface. They commonly graded downward to a more silty material occasionally containing minor amounts of clay. Occasional lime cement (caliche) deposits were observed although no extensive cementation was observed in the surficial sands. The eolian sands originate from windblown alluvial sources located in nearby stream valleys with deposition thicknesses and grain size dependant upon wind direction and energy. Soils in Colorado (including the vicinity of the site) have been mapped by the U.S. Soil Conservation Services (SCS, 1980); however, the SCS states that the available soils information is highly generalized and may not accurately reflect local variations of the existing conditions. Moreover, this information is only relevant to a maximum depth of 60 inches. The SCS distinguishes four soil types across the site (Figure 4.3). Roughly 98-percent of the site soils consist of Osgood and Valent sands. The remaining approximately 2-percent of the site is covered with Olney loamy sand which exists in the far northwest corner. The Osgood sand (0 to 3 percent slopes) is a deep, well-drained soil on smooth plains that forms in eolian sands. The surface layer in the Osgood sand is typically grayish brown sand about 22-inches thick. The subsoil and substratum is a brown to light-brown loamy sand or 4-10 920339 I \ � - \ w \ 9 \......\ e 9, \ 1 99 \ >0 9 69 ., 34 35 ,0 49 1 J0 7, 49 _ H 1 v l B 4 \ i Y r V o' 00 10 • I ct....,..\.,, - _ GENERATED FROM SOIL SURVEY OF WELD COUNTY (SOUTHERN PART) SHEET NUMBER 24. / LEGEND INDUSTRIAL COMPLIANCE 44 = OLNEY LOAMY SAND 1-3% SLOPES 1718 COLE BLVD. iii49 = OSGOOD SAND 0-3% SLOPES BLDG. 21 SUITE 300 69 = VALENT SAND 0-3% SLOPES GLDEN. COLORADO 80101 70 = VALENT SAND 3-99. SLOPES FIGURE 4.3 \ SITE SOIL MAP N 0 1/2 1 MILE ,,,,,,. WASTE SERVICES COMPANY I I moKcc SANITARY LAN ILL I i APPROX. SCALE Mr met 2-3716 Ian a, 01 /30/92 a„E,,,mf,, INDUSTRIAL COMPLIANCE BRAVII4 OMW.H T. IMPROVED rn J.L.P I9uHAW: FIGS-3 92;0239 sandy loam which correlates to the silty sand observed during the drilling program. Permeability is moderately rapid and available water capacity is moderate. Surface runoff is very slow and the erosion potential is low. Two classes of Valent sands are found on the site (0 to 3-percent slopes and 3 to 9-percent slopes). Both types are deep, excessively-drained soils formed in eolian deposits. The surface layer and underlying layers are a brown sand with no mention of increased loams or silts with depth. Both of these soils include small areas of caliche within 40 inches of the surface that were observed during the drilling program and described on the boring logs as white lime or caliche cementation. The permeability is rapid and the available water capacity is moderate in each of these soils. The surface runoff is slow and the erosion hazard low in each of these soils. The Olney loamy sand covers a small portion of northwest portion of the site. The Olney loamy sand is listed as a deep, well-drained soil formed in mixed outwash deposits. Generally, the term outwash is associated with glacial deposits, but it is assumed that outwash as it is used here refers to fluvial type deposits. The surface layer is grayish brown loamy sand about 9-inches thick. The subsoil is yellowish-brown sandy clay loam about 15- inches thick and the substratum is listed as a very pale brown, calcareous, fine sandy loam. The permeability and available water capacity are moderate. Surface runoff is slow and the erosion hazard is low. 4.7.2 Weathered Bedrock Materials Weathered bedrock materials were encountered immediately below the eolian sands across the site. A total of 38 borings penetrated the full thickness of the weathered bedrock. Thicknesses of the weathered bedrock varied greatly and ranged from 1-foot thick in PZ-16 to 25-feet thick in PZ-8 and PZ-9. Generally, the thickest intervals of weathered bedrock occurred in very-slight depression features such as exist around PZ-8 and PZ-9. The observed weathered bedrock materials were predominantly brown to red-brown and brown, soft to firm, moderately-plastic clays with highly variable sand and silt content. Occasionally the sand content was sufficient to classify the material as a clayey sand. Minor amounts of gravel were observed in the weathered bedrock clays of a few borings such as PZ-8, PZ-9 and PZ-12. Much of the weathered bedrock clays were oxidized and caliche deposits were common. 4.7.3 Bedrock Materials Materials of the upper Laramie Formation represent the bedrock in the interval evaluated beneath the entire site. Although thin intervals within this bedrock unit exhibit vertically- limited signs of weathering, it is distinguished from the weathered bedrock discussed above by the degree of weathering. The top of the competent bedrock materials, hereafter referred to as bedrock, is shown on the bedrock contour map on Plate 8 and was defined as the point where the weathering decreased sufficiently for the clays to remain predominantly gray in color and become very firm to hard. As expected, the top of bedrock generally mirrors the topography and exhibits the same prominent ridge, or nose, with a high point in the southern end of the site dipping to the northwest and with the flanks dropping off to the west and east. 4-12 920239 A total of 38 borings penetrated at least 10 feet of the bedrock with the average penetrated thickness being 35 feet. The lithology of the bedrock consisted primarily of gray clays and claystones with the thin, discontinuous silty and sandy intervals characteristic of the Laramie Formation. Most borings contained vertically-limited zones of chemical and physical alteration expressed as oxidized zones or limonite concretions, on the order of 2-inches thick. These zones are believed to be representative of previous erosional surfaces and were observed to be horizontally oriented. Lignitic deposits generally less than 6-inches thick were also common throughout the site. The majority of the borings penetrating the claystone bedrock exhibited moderate-to-high degrees of horizontally-and-vertically oriented fracturing. These fractures probably originated from stress relief during unloading periods and enhanced through weathering. All observed fracturing was associated with oxidation. Some evidence of possibly random- oriented fracturing was observed, as in PZ-20 at 45 feet in which 45 to 60-degree fractures were described. The upper 50 feet of bedrock generally contained a fairly high degree of fracturing which decreased with depth. Borings which penetrated a greater thickness of bedrock such as PZ-31 and PZ-34 indicated that the degree of fracturing decreased significantly between 100 and 110-feet below ground surface. Most fracturing observed in the boring program indicated preferential horizontal orientation with possible randomly oriented vertical fracturing. While most of the borings contained varying thicknesses of sandy clay intervals representative of overbank deposits, 6 borings (PZ-3, 8, 12, 14, 25, and 29) contained a significant thickness of water-bearing gray sands. All of these sands were very-fine to fine- grained and silty or clayey near the top and graded downward to materials containing less silt and increasing in grain size. These sands represent meandering channel sands which bisect the interchannel clays, silts, and lignites. Evidence that these sands represent channel environments is best illustrated on Cross-Sections D-D' on Plate 6 and B-B' on Plate 5. One of the thickest sections (22-feet) of saturated channel sand seen was in SB-29 on Cross- Section D-D'. This sand was penetrated at an elevation of 4834-feet MSL. Soil Boring SB- 24 is located approximately 450-feet east of SB-29 and reached an elevation of 4828-feet MSL. SB-24 did not penetrate the channel sand, indicating the laterally discontinuous pattern of the channel sands. Borings PZ-3 and PZ-14 (Plate 5) encountered approximately 5 feet of saturated channel sand. Boring PZ-15 which is located between PZ-3 and PZ-14 did not encounter this sand although a sandier clay interval was observed at approximately the stratigraphically-equivalent interval. This sandy clay interval probably represents channel margin or levee deposits. Borings PZ-7 and PZ-31, adjacent to PZ-14 and PZ-3 respectively, did not encounter any sandier interval at the stratigraphically-equivalent depth. 4.7.4 Geotechnical Properties of On-Site Materials Samples were collected during the site specific investigation to assess the characteristics of in-situ materials as well as to assess the materials available for use in landfill construction components such as low-permeability liners and drainage layers. Representative samples of the eolian sands were collected to evaluate its suitability for use as a drainage material. Samples of the weathered and unweathered bedrock were collected to assess the potential for their use in low-permeability soil liners. In addition, relatively-undisturbed samples of the sand, weathered bedrock, and bedrock were collected to evaluate the in-situ vertical permeabilities of on-site materials. Sample collection methods are described in Section 4-13 920"39 4.6.6. Table 4.1 lists the location and depths of these samples as well as the laboratory results. A complete copy of the geotechnical results is included in Appendix E. Analysis of the properties of the weathered and unweathered bedrock beneath the site indicate they can be used to construct a low-permeability liner system which will meet both Federal and State requirements for sanitary landfills. As discussed in Section 5.2.3, a test pad will be constructed using potential liner material. Actual construction and material specifications will be developed using the results of this test pad study. The permeability of the eolian sand indicates that it would not be suitable for use in a drainage system without some modification to the sand or the proposed design itself. 4.8 Site Hydrogeological Characteristics A total of 44 soil borings were completed as piezometers to characterize the ground-water regime beneath the site. Detailed individual completions along with corresponding lithologies are shown Appendix C. Piezometer installations can be divided into three general categories: 1) Piezometers completed to monitor only the levels of ground water present within the bedrock materials; 2) Piezometers completed to monitor only the levels of ground water present in the eolian sands and weathered bedrock materials; and 3) Piezometers completed to monitor ground water present in the bedrock and all overlying weathered bedrock and eolian sands. Table 4.2 lists all the piezometers, the zones monitored and other pertinent information. The water levels in the piezometers were measured following completion and periodically thereafter to obtain dynamic and static- water elevation information. The information is tabulated in Appendix F. 4.8.1 Ground-Water Occurrence and Distribution 4.8.1.1 Ground-Water Occurrence in the Eolian Sands Ground water was not present in the eolian sands within the area of investigation. The most likely location for ground water in the eolian sands would be at the permeability discontinuity between the sand and the underlying weathered bedrock materials. All of the piezometers in Table 4.2 listed as being sand completions or completed across the entire bedrock, weathered bedrock, and sand intervals are completed in a fashion to detect ground water at this potential permeability discontinuity. Although some boring logs, such as PZ- 23, described potential water-bearing intervals within the sands, all of these piezometers are either dry or have static water levels below the base of the sands (see PZ-27). PZ-37A, which is adjacent to PZ-23, was completed specifically to determine if the potential water bearing zone observed in PZ-23 at 17.2-feet would actually produce water. PZ-37A has remained dry for over 2 weeks. 4-14 90:.)33 U, e L o O U O O 8 m b b --• - -b K K C)) K K K p O\ N (-4 <t v 2 Ea) o N I 6 c -O. - - y y TA cc en c ee n. �' o 0 o 0 o •Q5.Q O •C w w w K K XXX W EW v a) U U U \o N N II .. A U a a x • O Zccd N O p� v) 4 7 F. .~-. .--i O.-. tS .E+ y h U CIDO g .J O\ In O\ O CO O In M ..s 2 • F e ,a N N v v i .-: \o O o M O_: o oa iF N en a In en N en 11, h- F 2' a R r is R N In N en �_ N., .C.1 �.., M [� V t1 •.•, O\ en 00 y. Z N In N en V` 0; a, M O\ N o0 V N V' v'1 '�Y tn.. N..._ O M O O\ r'— •- 4 N •--' — G a - M M N N E C ti u U N eaPio II V 'O C y 00 b 4 O\ 00 . 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N a 0 U _I V Vi Ct t Id 0 i1/� r�.fi 0 VD N r O\ \C Cn 00r. N N NN N N N N N i E.- a a s a a a a a ;, /\ J O h N N y h y N c, 0 L. 4. .-. 4. I.. W 4- �.. - N L., w w w L. 4- c d 0 O 00 00000 a Ca ID O\ O .r N r <t 'n ON 0 N f+1 <t In coN 0O O' C ,,' ^ O\ — — N N N N N N N ch c? c? M cn cM c7 c 7 M cn cj O ❑ N N N N N N N N N N N N N N N N N N N N N 0 O a a a aa. aaaaaaaaaaaaaaaa z 920233 4.8.1.2 Ground-Water Occurrence in the Weathered Bedrock With the possible exception of MW-03 described below, ground water does not appear to be present within the weathered bedrock unit in the area of investigation. Within the weathered bedrock, ground water could occur within distinct higher-permeability zones or at the permeability discontinuity at the bedrock/weathered bedrock interface. All of the piezometers appropriate for monitoring the eolian sand as described above are completed across the entire weathered bedrock interval with the exception of PZ-10 which was terminated within the eolian sand. Monitor Well MW-03 is completed across the lower portion of the weathered-bedrock interval. This interval was generally sandier in this boring than in others and the weathered/unweathered contact is somewhate ambiguous. The lithology equivalent to the static water level in MW-03 was described as containing iron stained fractures, indicating movement of ground water. Because this well is on relatively high ground, the ground water in MW-03 is less likely to exist under confined conditions than wells tapping ground water at lower elevations. It is believed that the iron stained fracturing observed is yielding ground water to the well under water table conditions. Besides MW-03, the only piezometers or wells with a static water level above the top of the competent bedrock unit are monitor well MW-02 and nearby PZ-13. The top of the interval monitored in MW-02 (base of the bentonite seal) is approximately 4-feet below the top of the bedrock and the static water level is approximately 9-feet above this level (See Appendix D). This information indicates that the source of this ground water is within the bedrock unit and exists under confined conditions. 4.8.1.3 Ground-Water Occurrence in the Bedrock Materials With the possible exception of MW-03 described above, all ground water existing beneath the site is in the competent bedrock materials. The majority of the ground water exists under water table conditions although it is locally confined, particularly along the western flank of the ridge (MW-02, PZ-12, and PZ-19 Deep). Plate 9 is a ground-water contour map illustrating the generally northwestern flow direction of ground water beneath the site. A more westerly component is evident in the southwest portion of the site. Figure 4.4 is a conceptual model of the subsurface conditions in an east-west direction across the site. It shows the relationship of the lithology and proposed excavation to the ground-water table with potential migration pathways should a release occur. 4-18 92;0339 RIDGE TOP UNSATURATED-INTERVAL ncrcr'nnM 1"'RL ` - . PILL BOUNDARY MONITOR WELL rAPPROX.500 FEET JI SAND EXCAVATION 1 \ WEATHERED BEDROCK UNWEATHERED BEDROCK ----------------------- I-------------------- witINDUSTRIAL 17466 COLE BLVD. BLDG. 21 SUITE 300 GOLDEN, COLORADO 60401 LEGEND FIGURE 4,4 -.---) -POTFMIAL MIGRATION PATHWAYS CONCEPTUAL SUBSURFACE MODEL o„>,,, WASTE SERVICES COMPANY eROX-C1) SANITARY LANDFILL KOrriF„ 2-3716 I^.r :� 2/7/92 Gacvro l BY. INDUSTRIAL COMPLIANCE I SAVED 23716F7.I 920283 All of the borings listed in Table 4.2 as bedrock completions or as completions across all three intervals are completed in a fashion to detect the presence of ground water in the bedrock. Ground water is present in every piezometer completed into the bedrock with the exception of PZ-2, PZ-5, PZ-33, and PZ-34A. PZ-2, PZ-5 and PZ-34A penetrate only the upper 2 feet of the bedrock. PZ-33 was drilled approximately 15 feet from PZ-11 to determine if the ground water present in PZ-11 existed under confined conditions. PZ-33 penetrated 25 feet of bedrock and remains dry. The saturated intervals within the bedrock materials contain both horizontal and vertical zones of enhanced permeability (fractures, paleo-erosional surfaces, lignitic zones, and sandy intervals) within the low permeability clays and claystones. There is vertical ground water movement within these clays and claystones but they yield water very slowly relative to the enhanced permeability zones. For examples, the majority of ground water in MW-01 comes from a lignitic zone at 26-feet below ground surface (bgs), a sandy interval at 39-feet bgs. and the wet sand at 41-feet bgs. The ground water tapped in MW-02 appears to originate predominantly from a fractured interval at approximately 43-feet bgs. The ground water in MW-03 appears to originate predominantly from the fractured silty clays at 40-feet bgs, as well as a wet ironstone observed at approximately 45-feet bgs, and a wet sand lense at approximately 50-feet bgs. Much of the ground water detected in the bedrock interval beneath the site exists in fractures. Both horizontal and vertical fracturing were commonly observed in every boring penetrating the bedrock with the exception of SB-4 (PZ-4), SB-8 (PZ-8), and PZ- 2. In addition, much of the observed fracturing occurred near the top of the bedrock/weathered bedrock contact as seen in PZ-16 and SB-7 (PZ-7). Oxidation along the fracture faces was common. In many cases, the fractures were filled with gypsum or calcite as seen in SB-21 at a depth of 23 feet and 40 feet, SB-23 at 43 feet, and SB-26 at 45 feet. Water occurrence in fractures was readily observed during drilling in many borings such as MW-03 at 45 feet, PZ-07 at 53 feet, and PZ-11 at 45 feet. In many piezometers, static ground water levels correspond to fracture intervals that were described as only slightly moist during drilling. Evidence of water present in fractures described as slightly moist can be seen in the comparison of PZ-16 and its nested well PZ- 36. Piezometer PZ-16 was drilled to a total depth of 61 feet. The only potentially water bearing intervals observed in PZ-16 were a slightly moist iron stained fracture at a depth of 32 feet below ground surface (4856.97-feet MSL) and a moist sandy clay at a depth of 44- feet below ground surface (4844.97-feet MSL). Static water level in PZ-16 is 33-feet below ground surface (4855.97-feet MSL), closely corresponding to the observed fracture. To determine if the ground water present in PZ-16 originated from the fracture under water table conditions, rather than from the moist sand under confining pressure, PZ-36 was drilled approximately 7 feet away from PZ-16 to a depth of 42-feet below ground surface (4846.69-feet MSL). PZ-36 contains water, verifying the presence of ground water in the fracture. Six borings (PZ-3, PZ-8, PZ-12, PZ-14, PZ-25, PZ-29) intersected water-bearing channel sands. These borings are located randomly across the site. The thickness of the water bearing channel sands that were penetrated ranged from 2 feet in PZ-14 to approximately 22 feet in PZ-8 and PZ-29. Ground water in the sands appears to be confined in PZ-12, and PZ-14. PZ-19 and PZ-22 also intersected siltier sands representative of water bearing 4-20 920383 channel margin environments. Ground water was also present in zones of oxidation representing ancient erosional surfaces (PZ-16 at 33 feet), sandy clays representing near channel and overbank deposits (PZ-17 at 37 feet and PZ-20 at 41 feet) and thin lignitic zones (PZ-25 at 56 feet and PZ-26 at 32 feet). These lignitic zones are laterally discontinuous and are considered modifiers to the predominant claystone lithology. 4.8.2 Summary of the Hydrogeologic System An understanding of the hydrogeological system beneath the site is crucial in order to design a landfill ground-water monitoring network that will provide timely detection should a failure of the design components occur. Figure 4.4 above presents a conceptual model of the subsurface conditions beneath the site. Review of the data acquired during the field program yields the following significant observations: 1) The site is mantled by highly-permeable, homogenous Quaternary eolian sands. No permeability discontinuities such as stratified clays were observed within the sands. 2) The highly-permeable Quaternary sands rest on Cretaceous bedrock materials of significantly lower permeability creating a permeability discontinuity at the Quaternary/Cretaceous interface (eolian/sand interface). 3) Ground water is not present along the permeability discontinuity at the Quaternary/Cretaceous interface. 4) The uppermost saturated zone occurs at approximately the same interval within the unweathered bedrock across the site. 5) The degree of fracturing decreases approximately 70 to 80 feet into the bedrock. 6) With one exception, all borings placed into the bedrock materials intercepted ground water. 7) The resulting ground-water contour map shows no significant anomalies and closely mimics the topography. 8) There are no well-defined surface drainages in the study area. If there were any defined surface drainages in the study area, they would be more likely to be underlain by ground water flowing along the sand/bedrock interface, which would likely be relatively shallow and could significantly effect the design or even the suitability of the site. Considering the above observations, the following conclusions can be drawn concerning the hydrogeological system beneath the site: 4-21 920289 1) Surface water infiltration is too slow to result in water ponding at the eolian sand- bedrock interface. 2) Water continues to migrate horizontally and vertically downward through the fractures in the weathered and unweathered bedrock until the fractures and weathering effects have significantly decreased. Water begins to pond at that interval. 3) Over geologic time water slowly migrates laterally to form a near continuous ground- water system that can be effectively monitored as detailed in Section 7.0. 4.8.3 Fate of Ground Water The generally northwest-to-western flow directions and northerly-dipping topography makes it likely that the ground water eventually discharges either into the alluvial aquifers associated with the South Platte River, or Box Elder Creek which eventually discharges into the South Platte River north of the site. 4.8.4 Aquifer Characteristics 4.8.4.1 Permeability Table 4.3 summarizes the permeability results of the packer and slug tests conducted at the site. The methods used to conduct these tests are detailed in Sections 4.6.7 and 4.6.8. The locations of these tests are shown on Plate 4. Actual data and calculations are included in Appendix G. Six packer tests were conducted to gather horizontal permeability data in the unsaturated intervals in the eolian sand, the weathered bedrock materials, and in the competent bedrock. Horizontal permeability data was gathered from the saturated intervals in each of the three monitor wells by slug testing using the slug-out method. 4.8.4.2 Storage Coefficient Storage coefficient calculations are not appropriate to apply to a strictly fracture-controlled system due to its almost non-existent storage capacity. 4-22 9�L0�1�3 TABLE 4.3 PACKER AND SLUG TEST PERMEABILITY RESULTS Packer Tests Boring Number Interval Tested (Zone) Permeability PK-1 38.5-51 feet (Bedrock) No Take PK-2 38.5-50 feet (Bedrock) No Take PK-3 18.5-30 feet (Weathered Bdrk) 2 x 10-6 cm/sec PK-4 10.5-21 feet (Sand) 1.7 x 10' cm/sec PK-5 13.5-21 feet (Weathered Bdrk) No Take effi PK-6 14.5-26 feet (Sand) 1.6 x 10' cm/sec No Take = Formation did not accept any water for duration of test, permeability is very low but cannot be quantified Slug Tests Well Number Zone Conditions Permeability MW-01 Bedrock Water Table 3.2 x 10' cm/sec MW-02 Bedrock Confined 8.6 x 10-6 cm/sec MW-03 Weathered Water Table 8.7 x 10' cm/sec Permeability determined through rising head test by slug-out method 9201:39 Typical storage coefficient values for materials felt to be representative of the sandy clays and sands observed at the site were derived from the USGS Water-Supply Paper 1662-D, Specific Yield- Compilation of Specific Yields for Various Materials. Storage coefficient values are approximately equal to the Specific Yield in unconfined aquifers. Typical values listed in the USGS paper of materials represented on site are: 1 to 4-percent Clays, moderately silty with minor amounts of very fine grain sands such as seen in the overbank and channel margin deposits on site 5 to 15-percent Sand, very fine grain, moderately silty and very slightly clayey. This value is probably representative of the channel deposits observed on site, although it may be slightly lower than the actual value in the cleaner sands 4.8.5 Wells Within a 1-Mile Radius of the Site The Colorado Division of Water Resources was contacted for a list of permitted water wells in the vicinity of the proposed site. Table 4.4 is a list of the wells within a 1-mile radius of the proposed site. No information was available where blanks exist in the table. As can be seen, all wells listed are used for livestock. Figure 4.5 is a map depicting the location of these wells relative to the site. All available well logs were obtained from the Office of the State Engineer and are included in Appendix D. 4.8.6 Travel Time Calculations The permitted well listed in Table 4.4 in Section 35 may be located in or near-the east boundary of the landfill footprint. Once located, this well may be abandoned if it compromises the effectiveness of the environmental safeguards incorporated into the landfill design. The nearest well downgradient of the site is approximately .8 miles west of the proposed fill boundary and located between the site and Box Elder Creek. Travel time was calculated for any liquids to breach the lining system and travel to the well. The following pathways and assumptions were used in this calculation: 1) Landfill liquids would travel vertically through the three foot clay liner that has a permeability of lx1O' cm/sec. 4-24 920:S3 • OD 'b o 0 71)1 o - v c C' N U en y 4 � L 2cr -4q 7 aW • 0 P. 3• 0 C M vo v t W C7. F G-4 z • 0 a• c < 3 3 3 x a x r. z z z Z Hrn H EA 2 w 3 w 3 w it cn c ft cina 0 O a) cd II II 9 u II 97©_.--n V, o LI W N Ill 0 Z m H m Q O n N. n o mO Umco r EH A oa � -- .: Q triIr. Z 4 Z ¢Olvz N O ccCL- w.. giito LLJ = o J , 4 H (-1=IO I ---- i O (n U Z J p q Z= Ol c 1 J cr E gS i I E— I wQ� I € I w �F n� - or:. F— Zs. N 2 4 - _ — I i—N . o _ _ _ - T • • ! .\l r E�.--' _ / EEE t 0 / C ; _ I CI V 1 . to • I C\ O ."wry II i V A m 1. e I I (I) . _ to _ r Q of a i I I -Y e a I 2c — .^ SE �i9E I EE I I � I ; LL Q I {I � -�, r R v I I 1 Wi 1 - .u. I .u.' § I� -e L .I i. r _ _ - 1 .J - 1 ,�. I 2 C I o 1 3 r>�, w \� � II N C LJ L \EZ c • 1 9w0:.'�3 2) The liquid would continue to travel vertically downward 15 feet through unsaturated bedrock materials and be intercepted by ground water traveling west. The actual unsaturated thickness of bedrock material directly upgradient of the well is greater than 15 feet, so 15 feet is a conservative value. Vertical permeability of the unsaturated bedrock materials was estimated. 3) The landfill liquid would then migrate laterally through saturated bedrock materials at a gradient (derived from Plate 9) until intercepting the well. A horizontal permeability value through the saturated bedrock of 8.6x10` was used. This permeability was derived from slug test data from MW-02 which is located near the western fill boundary. These three components are calculated separately as follows: 1) Vertical Migration Through 3-foot Thick Clay Liner Unsaturated Flow Conditions Assumptions: T = Travel time through unsaturated materials Zo = Flow Path Length in unsaturated materials @ = Effective porosity (0.1 claystone, 0.2 silty sand) qu = Volume of infiltrated liquid. Also equal to unsaturated vertical hydraulic conductivity (estimated to be 1 x 10-8 cm/sec from test data) Ks = Saturated vertical hydraulic conductivity (1 x 10-' cm/sec) n = Brooks-Corey parameter (n = 4) Therefore: T (q� 1-1/exic fn) T = (3 ft)(0.1)(30.48 cm/ft) (1x10- **3/4)(1x10'**1/4) T = 5.14 x 10"8 sec = 16.3 yrs 2) Vertical Travel Time through 15-foot Thick Native Clay Unsaturated Flow Conditions Assume: Zo = 15 feet @ = 0.15 qu -= 1x1021cm/s Ks = 1 x 10` cm/s n = 4 T = (qu 1-1/o) o) T = (15 ft)�0.15)(30.48 cm/ft) (1x10 **3/4)(1x10'**1/4) T = 3.86 x 10-8 sec = 12.23 yrs 4-27 3) Horizontal Travel Time Through Saturated Materials For the following calculation, hydraulic gradient was determined from the ground- water contour map (Plate 9). Porosity was estimated at 25%, or 0.25, based on the moderately consolidated sandstone typical of the water bearing unit observed at the site. Assuming Darcy's Law is valid for this flow system, and using an average permeability value of 1.6 x 10` cm/sec. derived from slug test data of MW-1 and MW-2. Q=KiA or V= Ki /4' where: V = velocity (cm/s) i = gradient (unitless number) K = Horizontal hydraulic conductivity (cm/s) ¢ = estimated at .25 V = K i / 45 V = (1.6 x 10` cm/sec) (0.018) / 0.25 V = 1.2 x 10-5 cm/sec The nearest well is estimated to be approximately 4224 feet from the edge of the landfill footprint. The estimated travel time to this well with flow in material of the same hydraulic conductivity: Velocity = Distance/Time Time = Distance/Velocity T = 4224 ft (6 x 10-5 cm/sec)(ft/30.48 cm) T = 1.1 x 1010 sec T = 340 years through saturated materials Adding travel time: 16 years travel time through clay liner 12 years travel time through unsaturated materials 340 years travel time through saturated materials to well Total —370 years total travel time for liquids that might breach the lining system and travel to the nearest well 4-28 920 39 4.8.7 Ground-Water Quality This section discusses the representative ground-water quality of the site. Three ground- water monitoring wells (MW-1, MW-2, and MW-3) were installed along the southwestern portion of the site to provide permanent ground-water sampling points. The locations of these monitoring wells are shown on Plate 15. These monitoring wells were sampled on December 9, 1991. The field and laboratory results for these wells are discussed below. At this time there is an insufficient amount of ground-water analytical data from the site to specify an appropriate statistical analysis program for ground-water monitoring at the landfill. After eight quarters of background ground-water monitoring are completed, the data will be reviewed and an appropriate statistical analysis method will be specified. This program will concur with State regulations regarding statistical analysis methods of ground- water monitoring results for solid waste disposal facilities. Field parameters, such as pH and specific conductance, and temperature were measured at each monitoring well. The field parameter results are presented in Appendix H and discussed below. * Ground-water pH ranged from 7.00 to 7.14 Ph units. * Specific conductance, which is an indicator of ionized species, ranged from 4,247.5 to 9,130 umhos/cm. * Temperature ranged from 10.7° to 12.2° celsius. The ground-water samples collected from monitoring wells MW-1, MW-2, and MW-3 were analyzed at the laboratory for the organic and inorganic suite of parameters outlined in Table 7.1. The analytical results are presented in Appendix H and significant findings are summarized below: * No volatile organic compounds (VOCs) were identified above the laboratory detection limits in any of the wells. * Total Organic Halogen (TOX) ranged between 5 and 10.5 ug/1. * Total Organic Carbon (TOC) ranged between 5 and 5.9 mg/l. * Total dissolved solids (TDS) was calculated on the basis of the specific conductance measurements, as outlined in Driscoll, (1986). The specific conductance was multiplied by a conservative factor of 0.65 to obtain a reasonable estimate of TDS. The TDS measurements ranged from 2,763 to 5,935. The TDS measurements exceeded the Secondary Drinking Water Standards (SDWS) of 500 mg/1 for all wells. * Sulfate concentrations range from 2680 to 5160 mg/l. Sulfate concentrations exceed the SDWS of 250 mg/1 for all wells. * Nitrate concentrations range from 1 to 16 mg/1. Nitrate concentrations in MW-2 at 11 mg/1 and MW-3 at 16 mg/1 exceed the Primary Drinking Water Standards 4-29 320339 (PDWS) of 10 mg/1. • Chloride concentrations in MW-1 at 264 mg/1 and MW-2 at 450 mg/1, exceed the SDWS of 250 mg/I. * Alkalinity (bicarbonate) ranged from 293 to 521 mg/1, which is indicative of very hard water. * The water chemistry-type can be characterized as sodium-sulfate. Waters can be classified for suitability for irrigation by their conductivity (salinity) and the sodium absorption ratio (SAR), a parameter that is calculated based upon the concentrations of sodium, magnesium, and calcium. The ground water exhibits a salinity classification of C4 (very-high-salinity water) for MW-3. The U.S. Department of Agriculture (USDA) classification states that C4 type water is not suitable for irrigation under ordinary conditions. The salinity values for MW-1 and MW-2 fall beyond the limits of the USDA classification diagram due to the high conductivity. The ground water from MW-3 had a sodium classification of S1 (low-sodium water), which can be used with little danger on nearly all soil. The ground water from MW-1 and MW-2 had a sodium classification of S3 (high-sodium water), which may be harmful to most soils. The sodium hazard is also increased if the water contains a high concentration of bicarbonate ions. As the soil solution becomes more concentrated there is a tendency for calcium and magnesium to precipitate as carbonates and for the relative proportion of sodium to be increased as a consequence. A final ground-water potential use is stock watering. McKee and Wolf (1963) report that stock can tolerate TDS concentrations up to 10,000 mg/1, however, for the State of Colorado, TDS as high as 2,500 mg/1 is considered acceptable for stock. They also state that the upper limit for livestock lies between 1,000 mg/1 for sulfate and 2,000 mg/1 for sodium. Based on this criteria, the ground water may not be suitable for livestock watering. The ground-water results shows several constituents that exceed the PDWS and SDWS. Therefore, the shallow water that occurs at the site is considered to be of poor quality and generally unsuited for domestic use. In addition, the shallow ground water in the vicinity of the site is generally unsuitable for irrigation purposes and may not be suitable for livestock watering. 4.8.8 Ground-Water Monitoring Network Details of the ground-water monitor system are outlined in Section 7.0 of this document. The ground-water monitoring system consists of 20 ground water monitor wells installed around the perimeter of the fill area and is designed to effectively monitor the downgradient saturated materials and provide upgradient background-water quality data. In addition, unsaturated interval detection wells will be installed to monitor intervals above the saturated zone that could potential transmit landfill liquids should a failure of the liner system occur. 4-30 5.0 FACILITY CONFIGURATION 5.1 Waste Characteristics, Site Area and Volumes Only solid non-hazardous waste will be accepted at this facility. WSC will own approximately 4640 acres. Seven hundred acres of this will be used as the filling area. The remaining property surrounding the fill area is to be used a buffer system (Plate 1). The primary boundary, the filling area, the waste to be placed into it, and the ancillary operations as discussed throughout this report, are the only activities under current consideration that would be regulated by the Certificate of Designation issued by Weld County under the authority of the State Solid Waste Act. The site was selected because of its hydraulic isolation from alluvial ground-water and overburden thickness that permits economic excavation to clays for use in the liner and cover. The geologic and hydrogeologic conditions, topography, and relative isolation from populated areas make this an ideal site for this type of facility. A total of approximately 78,790,000 cubic yards (CY) of airspace will be included in the landfill development. This total includes approximately 63,030,000 CY of actual refuse filling space (assuming 4:1 refuse to soil ratio). A total of approximately 20,500,000 CY of material will be excavated from the fill area. Approximately 6,410,000 CY of this will be useable as liner and cap which is in excess of an estimated 5,650,00 CY needed for these uses (Appendix I). The remaining volume will be used as topsoil and unspecified material for cap construction, protective cover, intermediate cover, and daily cover. Additionally, there is sufficient acreage and material available within the primary buffer area as borrow to excavate useable cohesive materials for liner and cap if necessary. The drainage material will meet a permeability specification instead of a thickness specification. If a sand blanket is used, approximately 1,050,000 CY of drainage material will be necessary on the base of the fill area. This type of drainage material will be obtained from an off-site source or processed from existing on-site material, if feasible. Concurrence from the CDH will be obtained prior to all modifications of the approved design. 5.2 Site Life The site will initially take in approximately 3,000 cubic yards of refuse per day with ar: annual growth rate of 3% per year. In year 10 of landfilling operations, it is anticipated that the daily intake will increase to 8,000 cubic yards per day and that the 3% arm'ial growth rate will continue through the closure of the facility. Utilizing these assumptions and a gate yardage to in-place yardage conversion factor of 1.5, the total site life will be approximately 33 years. This estimated site life is based upon current estimates of the economic growth and development within the facility service area. The acreage and estimated life of each landfill phase is presented in Table 5.1. 5-1 9; 0�j33 TABLE 5.1 Maximum Surface Approximate Estimated Phase Area (Acres) Airspace (CY) Life (Years) 1 49 5,285,000 3.0 2 91 7,017,000 3.5 3 120 14,083,000 7.5 4 146 5,941,000 3.0 5 167 14,269,000 7.5 6 127 16.435.000 $I TOTAL 700 63,030,000 33.0 5-2 9L0. 33 5.3 Disposal Area Design The landfill development design is shown in the plates included with this document. The objective of the plan is to show graphically the various landfill details and filling plans. Plates are referred to within this section as they are applicable. 5.3.1 Fill Area Design, and Excavation The base of the landfill will be excavated to include six phases. The base grade is configured for the installation of 17 independent landfill liquid collection systems, within the overall landfill footprint, as shown in Plate 10. Water levels in the piezometers have been measured monthly since installation. Appendix F includes these measurements and the highest recorded water levels through October 1992. This comprises 10 months of measurements and the water levels have stabilized. As per CDH guidance, the landfill has been designed to maintain a minimum of 15-foot separation between the highest recorded water levels and the base of refuse. The initial area (Phase 1) will drain to the three sumps in the northeastern part of the fill area. Phase 2 will drain to the sumps in the northern part of the fill area. Phases 3 and 4 will both drain to the eastern part of the fill area. Phases 5 and 6 will drain to the western edge of the fill area. Each phase is separated by a access road which will be lined when no longer in use. Plate 10 presents the phasing sequence. If perched water is encountered during excavation activities, the Division will be notified within four working days. The source and extent of the encountered perched zone will be evaluated and the Division will be informed of the findings. If necessary, contingency plans will be developed. The entire landfill, including the base and sidewalls, will be underlain by 3-feet of soil recompacted to a maximum permeability of 1x10-7 cm/sec. The liner grades are configured so that landfill liquids, if any, will drain freely to the respective gravel-lined sump. Access roads with in the footprint of the landfill will be removed prior to filling in those areas. Liner will then be placed to the grades established in this report. The landfill liquid collection system consists of a drainage layer on the liner. The drainage layer will have a permeability specification of 2 x 1O2 cm/sec or greater. Plate 10 shows the top of drainage layer elevations. Currently, this plan assumes the use of 12 inches of a suitably-performing sand blanket however, alternative synthetic drainage net material which meets the permeability specifications may also be considered following CDH approval. The leachate collection system (minimum 1 percent bottom slopes with a drainage layer of 2x1O2 cm/sec permeability) was compared with the EPA recommended design of a minimum 2 percent slope along the base with a drainage layer of 1x1O2 cm/sec. permeability. This was done to compare the travel times of landfill liquids through the drainage layer as designed with those of the EPA recommended design. Assuming Darcy's flow relationship is valid for this system, a comparison was made between the unit flow rates (unit travel 2 time) for a 2 percent slope with lx10 cm/sec drainage material (EPA recommended design) and a 1 percent slope with 2x1O2 cm/sec drainage material (proposed design). Considering that the unit travel times are inversely proportional to the permeability and gradient variables, doubling one variable while keeping the other variable constant, will result in halving the travel time. Each of the above cases was calculated as shown below. 5-3 3 0239 EPA Recommended unit travel time Assuming: 1) 2 percent base grade 2) hydraulic conductivity of 1x1(12 cm/sec. Average velocity = Ki where: K=1x1O2 cm/sec. i=0.02 Average velocity (unit travel) = 0.0002 cm/sec. Design unit travel time Assuming: 1) 1 percent base grade 2) hydraulic conductivity of 2x1O2 cm/sec. Average velocity=Ki where: K=2x1O2 cm/sec i=0.01 Average velocity (unit travel) = 0.0002 cm/sec. These results show that the travel time for the two designs are equivalent. In addition, the designs are also equivalent in the performance criteria specified in Subtitle D of requiring that less than one foot of landfill liquid head be maintained over the liner at all times. The HELP Model (Hydrologic Evaluation of Landfill Performance, Version 2) was run using site-specific parameters to ensure that the landfill liquid collection system would efficiently drain liquids to the gravel lined sump for monitoring and/or removal. The HELP model indicates the maximum daily depth of leachate on the liner is 0.9 inches, well within the 12 inches maximum specified in the Subtitle D requirements. The HELP Model is presented in Appendix J. A 12-inch, Schedule 80, PVC riser pipe, will extend from the base of each sump to the surface and will provide access for monitoring and/or removal of any liquids that accumulates in the sump. The riser pipe will be overlain by 2-foot of unspecified fill to protect against breakage. Plate 11 presents details of the system. 5.3.2 Phasing and Refuse Filling Filling will begin in the northwest end of Phase 1, progressing to the southeast. Following the filling of Phase 1, the subsequent landfill areas will typically be developed in the order they are numbered in this document. Variations of this filling sequence may be made by the landfill General Manager depending on site specific conditions encountered. Filling will typically progress with refuse being placed in loose 2-foot_layers and compacted to form refuse lifts generally ranging from 10 to 15 feet in thickness. The landfill operator will decide whether to unload refuse at the top or bottom of the working face and either push up or down. The direction will change according to the conditions encountered at the site. 5-4 9?02239 At the close of each working day, 6 inches of daily soil, or an alternative daily cover material, will be placed over the exposed refuse. When a lift is completed, the next lift will be subsequently placed on top of it until the phase is completed. At least 1-foot of soil or other suitable material will be placed over disposal areas left temporarily unused, but not closed, for periods longer than one month. This intermediate cover may be necessary when reaching the end of a filling phase as well. When possible, the intermediate cover will be removed and reused for daily cover prior to resuming filling in that area. Because of the size of the phases, filling will occur in only a portion of each phase at any one time. The actual size of the active area will depend on the volume of incoming refuse, weather, and operational considerations. In general, the currently active portion will be filled as high as practical within the following limitations: 1) Where possible, exterior slopes (those on the outside of the permitted fill area boundary) will be maintained at final grade elevations as shown on Plate 14. In no case will exterior slopes be allowed steeper than those shown on the approved design plans. 2) Interior (temporary) slopes will be maintained at a maximum slope of 3:1. The general filling sequence can best be shown by illustration. Figures 5.1 thorugh 5.5 illustrate a typical filling sequence that will be followed. Actual refuse volumes and operational considerations may modify this plan somewhat. Filling will commence in one portion of a phase until the above conditions can no longer be maintained. Generally, this means that an area will be filled to some level above the existing ground surface but not to final elevations. Filling will then commence in an adjacent area up to an elevation approximately equal to the initial area. At this point, if the top of the fill is of sufficient working area, filling may again be conducted above the initial filling area, within the above limitations. 5.3.3 Liner Construction The entire landfill will be underlain by a compacted soil liner with a minimum 3-foot thickness. The weathered bedrock and bedrock from the Laramie Formation underlying the site are typically appropriate for use as liner materials (see Section 4, Geology/Hydrogeology). Estimates based upon the test borings installed at the site indicate that approximately 6,410,000 CY of weathered bedrock and bedrock is present. The final site configuration is shown on Plate 15. Additional liner and cap materials that meet the outlined specifications for construction could be excavated from a borrow area located within the WSDC property if necessary. The placement of the soil liners at the landfill will meet stringent requirements to ensure proper material and proper compaction techniques are used during liner construction. The liner will be built to a permeability of 1 x 10- cm/sec or less and specifications for its placement will be predetermined by the construction of a test fill. 5-5 0 § \ \ \ ; n,c, \#b"� - — : §c: • / >-Z _ % » < -< § • + (/ ) p 2 0_ <— �/ ` / o% § i ? - gz o . \ QUI- \ g %S=/ | ! e . . •• _ .0 CC 6/2j. • • h- in • \6 , !\ • • �� ) § � ; , a • § | | § ; � C . S 5 \) cc • ;y \ 0>- \ \\ • , do cc \\ \ \• \ \ tai 41 0 / ( D 9g..,17:0_1;39 N w W O NT Ng- cn a 0 N 0� N wW -J 0. Mq (NJ is CC Q U Uyti�Q. J� J I- > "1[Wy 1/2O Ll- & z 0 F NZ Na ZZ 0V .1 w W W al Q� 8Z , a o z��Utr) oQ a a F U z o a , zwzo O • is, O0 UQ ON 11 m Q Yew �� Q ; e J o�••. 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W W ZO XO XO p w Isla- w W O O J Q W Q c Z 7 W J L J d H at O 3 I— < Z 30 iliti • • vY' W N O (N I 0 2 a • \ a� CY C7 N 00 N Lail 0. 00 N W p;WC JCn CC V•-1ti0 J0 H V�yO LT_ CJ 0 L1.1 Z C' .tat kin I-4 ‹. 8Z 0 w c9 CO, o = ar aJ a w-`o ` Q Z.-R1U O1 Q_ CC D CC , U z O 00O Id V Fx-, WZ U �� C w C~z. U� Q i g rn-w O ` >0 I x WOO Zo ` z LUJCOV1 g OOU Z CJ LULU -1 Z JO w. Vl?�ricH ZctJ W W O LEJ�F— ZS LT.<C. \o�� (nQN o Z m t ri L O m 5 a cc 3 3 II�•�♦� W J cTo m o ILI ...♦, JJ JJw-re w �� O o o=II` xo w o0 H 0` W C7 C7 CC CCZ W Z JCOJJ J_J W D J_0 W O Ou tlMO O 0F-N HZ` Z.- ZN 41 HIr I---CC Z OO W WO O WW W 0 J 0 W Q Q OC W Z 0 J L- a - Dl- 0 I- < 7 9201.;39 The purpose of test fill is to develop real data that will be the most useful during liner placement. Prior to beginning construction of the test pad, a work plan will be prepared and submitted for review to Weld County and CDH. The work plan will outline details related to the pad construction including: * Number and thickness of lifts * Dimensions of pad * Testing parameters for soils prior to placement * Testing procedures following test pad construction The results of the testing program will be used to prepare a liner specification plan, including Quality Assurance/Quality Control procedures, necessary to build a liner within the landfill meeting the permeability specifications. Portions of the QA/QC plan will include: * Frequency and location of field testing points * Types of field testing required * Types of laboratory tests to conduct * Surveying requirements * Lift thickness * As-built preparation * Notification requirements * Atterburg limits * Compaction density specifications The specifications will be submitted to CDH and the Weld County Health Department for review and approval before construction of the liner begins. At least 30 days prior to the scheduled date to commence landfilling in any landfill module, a report detailing construction activities for that module will be submitted to the Division for review. The report will include evidence that construction was completed according to the approved plans, specifications, and design criteria. 5.3.4 Materials Selection and Quantities Based upon the information discussed in Section 4, the soils underlying the site are appropriate for use in liner construction. The soil materials will be excavated, segregated and stockpiled for use in the liner and final cover. The material will be selected prior to liner placement during excavation and construction of the test fill mentioned in Section 5.2.3. 5.3.5 Surface Water Control As discussed in Section 3 (Topography), the proposed East Weld Sanitary Landfill is located along the top of the drainage divide between Ennis Draw (to the east) and Box Elder Creek (to the west). The drainage divide for these two basins runs north and south approximately through the eastern third of the propeny (Plate 16). Using a 1 inch = 400 feet two-foot contour interval map, 18 small drainage basins were delineated within the limits of excavation and fill for the landfill. These smaller basins drain to five larger basins, which 5-11 in turn drain to Ennis Draw and Box Elder Creek. The larger drainage basins were delineated using a 1 inch = 2,000 feet map. Calculations for estimating peak and total flows from the site, including computer program output, are included in Appendix K. For convenience, pre-construction drainage basins have been defined as follows; * Within the limits of fill, drainage basins are numbered with Arabic numerals, starting with drainage basin 1 in the northwest corner of the property and proceeding counterclockwise. * Where the small drainage basins extend beyond the limits of fill, the basins are numbered using roman numerals, e.g., pre-construction basins 1 and 18 below the limits of fill are numbered as I and XVIII. * Basins I through VIII and XVIII drain to the west to Box Elder Creek. Basins I and XVIII extend to Box Elder Creek. Basins II through VIII drain to basin BE-1 and then to Box Elder Creek. * Basins IX through XII drain to basin ED-1, and then to Ennis Draw. Basins XIII through XVII drain to basin ED-2 and then to Ennis Draw. Information compiled by the United States Department of Agriculture, Soil Conservation Service (SCS) was used to estimate the impact of constructing a landfill on surface water systems, and the requirements for minimizing the impacts to the surface water system. Except for soils in the central portion of Drainage Basin I, all soils at the site are classified by the Soil Conservation Service as Osgood or Valent soils. These soils are deep and well- drained very sandy soils which have the lowest, or Type A, runoff potential. Approximately 35 percent of the soils in Drainage Area I (below the limits of fill) are classified as Olney soils which have a Type B or slightly higher runoff potential. The surface vegetative cover can be classified as semiarid rangeland. Using SCS estimates, the Curve Number (CN - a measure of the runoff potential) for all existing land except within Drainage Basin I is 55. The CN for Drainage Basin I is in the Vicinity of the Proposed Site estimated to be approximately 63. After construction, drainage within the limits of the fill area will be slightly changed, in areal extent, in volume and in peak flow. The changes to drainage include the following. * The drainage divide within the property between Ennis Draw and Box Elder Creek will be shifted slightly towards the west. The shift will reduce the area draining to Box Elder Creek from within the property by approximately 70 acres. The area within the property draining to Ennis Draw will be increased by the same amount. The size of the small drainage basins within the limits of fill also will be different. As can be seen by comparing Plate 16 (Pre-Construction Drainage) and Plate 17 (Post-Construction) some of the drainages are increased in size and others are decreased (also see Table 5.2.1). 5-12 920 :33 * Topsoil similar to native soil will be replaced on the final cover over the i.indfill. The low permeability compacted cohesive soils beneath the topsoil will reduce infiltration, however, this will increase the amount of runoff. The replaced soil is expected to be similar to a hydrologic type C soil. The top of the landfill will be replanted with a grass mixture and managed to prevent over-grazing. Based on SCS guidelines, the combination of vegetative cover and soil type is expected to have a CN of approximately 63. The changes in peak and total flow as a result of construction of the landfill were calculated using the TR55 computer model (developed by the SCS). * Table 5.2.1 shows the pre-construction and post-construction size and 10-year and 100-year peak and total flows from drainage basins within the limits of fill. As can be seen from this Table, both the peak and total flow from drainages within the limits of fill generally are increased. All drainage will exit the fill area and the site at the same points as before construction. * Table 5.2.2 shows the pre-construction and post-construction 100-year peak and total flows for the larger drainage basins downstream of the site. As can be seen from this Table, the changes to both the peak and total flows are relatively small, except for Basin ED-1. The total change in flows should be less than one percent of the total flow in both Ennis Draw and Box Elder Creek. The effect of construction will be a slight increase in the amount of water which runs off from the property (and is available to downstream users) by approximately 15 percent. Because the peak flows also are increased, especially for the on-site basins and basin ED-1 (see Tables 5.2.1 and 5.2.2), construction of erosion controls or small basins to reduce peak flows may be necessary. The need for such controls will be examined as construction of the landfill progresses. There are no known structures, including ponds, culverts, bridges, roads or railroads downgradient of the site which could be affected by the slightly increased peak and total flows from the site. The site does not receive any surface water run-on from off-site locations (see Plate 16, Pre- Construction Drainage). Within the site, however, runoff may need to be diverted around active working areas using temporary diversion structures. Temporary diversions will include both ditches and berms. The berms will be built along the uphill side of the cells to divert water into ditches, or where drainageways are intersected to divert flow into ditches. All temporary diversion structures shown on Plate 10 will be designed to safely control the flow from the 24-hour, 25-year storm event from the upgradient drainage area and will be constructed according to the schedule listed on Plate 10. Documentation for the construction of each of the structures shown on Plate 10, including design specifications and as-built diagrams, will be included in the appropriate cell construction report. An example of where such temporary diversions may be necessary is the northwest corner of the fill area. Filling will begin in this area of the property, and the first cell to be opened will intersect the flow of drainage basin IA (see Plates 10 and 16). Upgradient of the first cell to be built, a small berm will be built along the uphill side of this cell and across the drainageway for basin lA to divert water into a ditch which will route runoff southward to the crainageway for basin 1B. All diverted flows will be released into existing drainages to rejoin the natural drainage system. Temporary ditches typically will be 11 to 12 feet wide at the base, with three 5-13 9(.:133_.: 9 C OO 00 ' i v-. 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As much as possible, ditches will be designed with a flow velocity of less than four feet per second (4 fps); where higher flow velocities are necessary as a result of topography, erosion and sediment may be controlled using riprap and sediment control measure such as described below. Temporary berms typically will be constructed with 11 to 12 feet wide tops, 3:1 side slopes, and with a minimum of 0.5 feet of freeboard above the design flow depth on the upgradient side of the berm (Figure 5.7). As the landfill progresses, the temporary diversions will be removed and others will be built. Locations of the temporary diversions are left to the discretion o the landfill operator. Surface-water diversion and siltation structures other than those shown on Plate 10 may be required throughout the life of the landfill. These other diversion structures are very temporary in nature and will be constructed as illustrated in Figures 5.8 through 5.10. The actual locations and time frames for these structures depends on actual refuse volumes and landfill configuration (ie. current available fill area, current construction activities, etc.) and is difficult to ascertain at the present time. In addition, measures will be taken to ensure that any water which falls on within the cell is diverted away from the working face, and water which contacts the working face is not allowed to leave the working area. These objectives will be achieved in the following ways: * Minimizing the size of the working face. * Constructing temporary diversions within the cell to route the run-off around or away from the working face. * Constructing temporary diversions to route runoff from the working face to temporary or permanent sumps for collection and proper handling. The cover over the landfill has been constructed with relatively flat (less than 15 percent) side slopes. The rate of erosion from such a cover is expected to be very low as shown in the Revised Universal Soil Loss Equation (RUSLE)included in Appendix L. Permanent sediment control measures are not expected to be necessary. Temporary sediment control measures are expected to be necessary to minimize the amount of sediment which is transported offsite. These temporary measures could be necessary downgradient of areas where preliminary work for opening a cell is being done (topsoil removal and initial excavation) or of newly reclaimed portions of the cover. Temporary sediment control measures could include small triangular ditches along the downgradient side of stripping or newly reclaimed areas to collect runoff from these areas and route it to straw-bale dikes, small sediment traps or silt fences (Figures 5.8, 5.9, and 5.10) which will be constructed in drainageways. All potentially sediment-laden runoff will be routed through sediment controls before it is released to rejoin the natural drainage system. As reclamation progresses and the surface of the cover stabilizes, the temporary sediment control measures will be removed and others will be built. Locations of the temporary measures are left to the discretion of the landfill operator. Temporary diversions will be built during the progressing landfill development. The diversions will be constructed to route water away from the working face on the undisturbed areas on the uphill side of the working face. As the landfill progresses, these berms will be removed and others will be built. Locations of the temporary diversions are left to the discretion of the landfill operator. 5-18 920._;'33 Grass - Lined Channel Freeboard 1. ...-- 100 Width ININDUSTRIAL COMPLIANCE COLE BLVD. BLDG . Z1 SUITE 300 GOLDEN. COLORADO 80401 FIGURE 5.6 TYPICAL GRASS—LINED CHANNEL SECTION n.,,,. WASTE SERVICES COMPANY PROJECT' SANITARY LANDFILL ,,o. 2-3716 [A,TE ,,,4 01/30_/92 ,,„,4„„ „ INDUSTRIAL COMPLIANCE oxwmw erW.H.T. (.P.m e,+ J.L.P. I FILE war.: FlG5-2 92i 39 12 foot top width 1 foot freeboard 3 Height as necessary Existing Ground INDUSTRIAL COMPLIANCE f746 COLE BLVD. BLDG. 21 SUITE 300 GOLDEN. COLORADO 60401 FIGURE 5.7 TYPICAL DIVERSION BERM SECTION . WASTE SERVICES COMPANY rRoiacr. SANITARY LANDFILL man=tom 2-3716 Sr INDUSTRIAL COMPLIANCE 01 / 0/92 NOT TO SCALE W.H.T LL P I Par POMP FIG5� ' Excavate, if necessary, lot ---n`. •Hoene . J Flow Earth embankment. Flow.. 4. 4, •"..`ti �• • .` :"'i>,joowidth/J _�. . �sv '../i//. Yev • ,, F Cutaway to show straw • -T • "-� �`\%. bale core • ```• Stone ••�' `(4%. :a, Length (ft.) " __ TI1i!i;!!, ll'I...,• 6 X drainage area (ac.)..—I__' 1 rtt�in ll f .i i �.:—,z - 24.1, n: 6" min..jl t 6,.i l llilpl'ii'�:��,P:_a;i:--;.:-I- —c:— 7li.:.lill .ii!illllll.jl • rl' i.ilil!I!'�.iail�_.a _ ___u_'s__..__� Ts'1'i...il9j�lt l!��i111i Extend•core into J earth embankment. • Elevation NOTE—Drawings show straw bales used for sore. Bales are anchored as per Standard and Specifications for Straw Bale Dike.Other Materials (e.g., timber or concrete block) may also be used for core Firmly anchor all core material to grouhd. Construction Specifications 1. Area under embankment shall be cleared,grubbed and stripped of any vegetation and root mat.The pool arca shall be cleared. 2. The fill material for the embankment shall be free of roots or other woody vegetation as well as over- sized stones,rocks,organic material or other objectionable material.The embankment shall be com- pacted by traversing with equipment while it is being constructed. 3. Sediment shall be removed and trap restored to its original dimensions when the sediment has accv- mulaad to one-half the design depth of the trap. Removed sediment shall be deposited in a suitable area and in such a manner that it will not erode. 4.The structure shall be inspected after each rain and repairs made as needed. 5. Construction operations shall be carried out in such a manner that erosion and water pollution is minimized. 6. The structure shall be removed and the area stabilized when the drainage area has been properly stabilized. 7. All cut and fill slopes shall be 2:1 or flatter. B. The crushed stone used in the outlet shall be MHSA size No.23 or AASHTO M43,Size No. 2 or 244 or equivalent.Gravel meeting the above gradation may be used if crushed stone is not available. Crusher run is not acceptable. INDUSTRIAL COMPLIANCE /_—_- 1746 COLE BLVD. BLDG. 21 SUITE 300 GOLDEN. COLORADO 80401 • FIGURE 5.8 STRAW DIKE / SEDIMENT TRAP aeon. WASTE SERVICES COMPANY SANIIARY LANDFILL MUFTI tap. 2-3716 LATE 01 /30/92 gpteaga, We INDUSTRIAL COMPLI NCE� Mate, Ern\ALFI J ImpFtcwo gr J.L.P. n,E( was FIGS--4 ac tttt 11 t Flow-y .0JI i1 tr illl�t (�,,__ ( hI irflt 1 a/rer "A% " \4" vertical face Embedding detail Angle first stake toward v_ •; .I - previously.laid bale �! rL<i `• /r rr/ff.; � Flow-y //�e.111 Y7 �� i _ �rF • • a Wire or nylon :� 4 -� bound bales // !• /_::ars placed on the b ,r/liTir/5/.-15.-:'-' �% ' .% contour fiitl (r1 IN�ilfir, If II (I4i(0 I1 Is1•, ., • _� , steel pickets, or Yll ifil1 4M t I' -_ 2" : 2" stakes 1 )/2' to 2' _ `' tilt I� � in ground • ' • Anchoring detail Construction Specifications • 1. Bales shall be placed in a row with ends tightly abutting the adjacent bales. 2. Each bale shall be embedded in the soil a minimum of 4". 3. Bales shall be securely anchored in place by stakes or re-bars driven through the bales. The first stake in each bale shall be angled toward previously laid bale to force bales together. 4. Inspection shall be frequent and repair or replacement shall be made promptly as needed. B. Bales shall be removed when they have served their usefulness so as not to block or impede storm flow or drainage. miINDUSTRIAL COMPLIANCE 1746 COLE BLVD. BLDG. 21 SUITE 300 GOLDEN, COLORADO 80401 FIGURE 5.9 STRAW BALE DIKES o. . WASTE SERVICES COMPANY mum SANITARY LANDFILL reoiazT ho- 2-3716 Ina 01/30/92 tsrxRawpm. INDUSI RIAL COMPLIA oww ecW,H.T. J.L.P. Ira; roue F1G5-5 92 0239 I vA i . .. . .... • Flow • Dike Flow .•.`` .`':'�.,,, ,.... ,1. •.f.Flow .� :.` ':' . . ,. . ...� ,.' •' ':..; .. ms`s=:y ;'.: �''}:..: embankment , c.≤: : ;q;. • 4' toP width ' •••-✓ • • � � 2:1 slope <zr outlet .��_...:•:: ::.:. ;:: Dike if requird To divert water . 2:1 or(latter . . ::. :. \\\\ Width Ift.) _ Section A-A ' 6 X drainage area lac.) Outlet section Excavated earth outlet sediment trap Embankment earth outlet sediment trap Construction Specifications ' 1. . Area under embankment shall be cleared, grubbed and stripped of any vegetation and root mat. The pool area shall be cleared.. 2. The fill material for the embankment shall be free of roots or other woody vegetation as well as oversized stones,rocks,organic material, or other objectionable material.The embankment • shall be compacted by traversing with equipment while it is being constructed. 3. Sediment shall be removed and trap restored to its original dimensions when the sediment has accumulated To one-half the design depth of the trap. Removed sediment shall be deposited in a suitable area and in such a manner that it will not erode. 4. The structure shall be inspected after each rain and repairs made as needed. 5. Construction operations shall be carried out-in such a manner that erosion and-water pollution are minimized. 6. The structure shall be removed and area stabilized when the drainage area has been properly stabilized. 7. All cut and fill slopes shall be 2:1 or flatter. 8. Outlet crest elevation shall be ae.Jeast 1 foot below the top of the embankment. INDUSTRIAL COMPLIANCE 1746 COLE BLVD. BLDG. 21 SUITE 300 GOLDEN. COLORADO 80401 FIGURE 5. 10 SEDIMENT TRAPS mom WASTE SERVICES COMPANY r7roact.T SANITARY LANDFILL MIAMI ago- 2-3716 Iwo mum rtm 01 /30/92 tea= Ms INDUSTRIAL COMPLIANCE �avw erW.H.T. leFts n en cI.L,P, Irnc nva: FlGs—e Complete perimeter ditches are not necessary because: 1) potential runon to area during filling can be controlled during operation by the limited sections; and 2) the majority of the water will leave the filled site as overland flow. Each ditch will be constructed during the excavation of the phase that it drains. The ditches will be trapezoidal, 11-feet wide, 3-feet deep, and have 3 horizontal to 1 vertical side slopes. Runoff calculations for these ditches are included in Appendix K. 5.3.6 Pre-operational Activities Prior to placement of refuse in the first phase of the landfill, various activities will be completed including: * Obtain all the necessary regulatory permits * Construction of a test fill and completion of a construction specification plan reviewed and approved by Weld County Health Department and CDH * Excavate and segregate the topsoil, liner and cover material for the first area. * Place and certify the initial portion of the liner. * Install the initial ground-water monitoring wells. * Sample monitor wells for background water chemistry information. * Construct permanent and temporary run-on control structures as needed for the first filling area. * Construct perimeter fences. * Improve or, if necessary, construct interior access roads. 5.4 Support Facilities The site layout is presented on Plate 1. Access to the entrance facility will be from I-76 to Weld County Road 59. From the end of Weld County Road 59, an existing private paved road will remain in use as access to the facility entrance. Local and required access to the support facilities will continue on the paved private road. Buildings at the existing Coors Ash Disposal facility located immediately east of the site will be used as the support facilities. Support facilities will consist of an administrative office, maintenance building, and equipment yard. 5.4.1 Landfill Access Access into the landfill area will be from two all-weather roads. The first, for refuse collection vehicles, will be constructed to the landfill area from the entrance facility. The second, for landfill operations equipment, will be constructed from the support facilities to the landfill area. 5-24 920'1;39 Temporary roads will be built to allow convenient passage of two-way traffic into the disposal area and the working face. Temporary directional devices will be used to control traffic to and from the working face. These devices may include: * Pylons * Barricades * Signs * Temporary fences 5.4.2 Site Fencing Unauthorized access to the landfill facility will be prevented by permanent site fencing around the perimeter of the primary property boundary. The fence will be, at a minimum, 6 feet in height and constructed of utility mesh or equivalent materials. Temporary fencing/screening will also be used at the working face to control windblown debris and, in some cases, to direct traffic. 5.4.3 Resource Recovery Resource recovery activities in the Rocky Mountain Region have been attempted using both methane gas recovery and recycling. Methane gas recovery has not been widely practiced in this region because the amount of methane generated in the relatively shallow landfills has not proven to be economical. If recovery of the gas becomes economically viable in the future, the operator will consider development of this resource. The second type of resource recovery involves separating recyclable materials from the refuse. National experience indicates that economical recovery of recyclable materials generally requires separation of the recoverable items at the point of generation or collection. The landfill operator will place recycling bins at the entry to the landfill but will not assume the responsibility to separate the recoverable items at the working face or at the gate. The operator will review the feasibility of sorting the waste brought into the landfill as markets for recoverable materials further develop. Various proven recycling capabilities do already exist within the local and regional service areas of the facility. 5-25 6.0 FACILITY OPERATION 6.1 Site Management 6.1.1 Operations Schedule The proposed EWSL will initially be open for operation during the daylight hours. Generally, these hours are 6:00 a.m. to 6:30 p.m. Monday through Saturday. Use during other periods will be by appointment only. Notification of changes in the operational hours will generally be posted on the entry gate at least 2 weeks prior to a change. The facility will generally be closed on Thanksgiving, Christmas, New Years Day, Memorial Day, Fourth of July, and Labor Day. 6.1.2 Equipment and Personnel Requirements The following personnel and equipment will typically be available at the site: Personnel: 1 General Manager 1 Environmental Engineer 3 Equipment Operators 2 Laborer/Spotters (as needed) 1 Mechanic 2 Ticket Takers Equipment: 1 Landfill Compactor 1 Scraper 1 Bulldozers 1 Motor Grader 1 Water Truck 2 Pickup/Service Truck 1 Utility Tractor/Backhoe All personnel will be trained in safe and proper landfill operating F-ocedures. 6-1 3.0:0._;`33 6.1.3 Control and Record Keeping • A system of records will be maintained at the landfill office during the life of the landfill. Incoming waste verification and record keeping will be performed by gate attendants. These attendants will be trained to be familiar with the types of wastes allowed at the facility and will deny access to vehicles carrying unacceptable waste streams. Accurate records will be kept of gate receipt volumes. In addition, results of all of the monitoring and inspection activities discussed in Sections 7.0 and 8.0 will be retained for inspection by authorized regulatory officials during normal business hours. At a minimum, the site operator wiil keep the following records on site and available for review: 1) Volume and types of incoming refuse 2) Results of wind, gas and water quality monitoring 3) Any special waste accepted within the bounds of the Certificate of Designation. 4) Construe ion QA/QC documentation 5) Approved Design and Operations Plan 6) Operational variances 7) Special Waste Acceptance Plan 8) Inspections for hazardous wastes and PCB's (if applicable) 9) Quarterly operation inspection reports completed by the Weld County Environmental Protection Services Division 6.1.4 Safety Control Safety control at the facility is the responsibility of the site General Manager. Normal safety precautions will be observed while people are near or are operating the landfill equipment. Employees at the site will be trained in first aid techniques. A well-stocked first aid kit will be kept in the landfill office at all times. Emergency telephone numbers will be prominently posted in the landfill office. Posted telephone numbers will include local police and fire departments, the nearest hospital facility, and the Colorado State Department of Health. The local fire districts in which the site is located is the Keenesburg Fire Protection District. The nearest hospital to the site is the Greeley Hospital. 6.1.5 Water and Sanitary Requirements Both potable and non-potable water is required for site operation. Water for both needs is available at the facility operations area either from the existing Coors well, or a new permitted well. Estimated water usage, availability, and permit for a new well is included in Appendix O. Water may be required for compaction of soil liners and covers and for dust control. The quantity of water will vary depending upon the type of activity being conducted at the site and the moisture content of the liner materials. If water is available from ponded runoff from unfilled and permanently closed areas it may also be used for on-site activities. 6-2 901' 39 Sanitary needs of employees will be met through the provision of permanent washroom facilities at the maintenance facility served by individual sewage disposal systems installed according to County Regulations.. Additionally, portable facilities will be placed near the landfill office and/or the working portion of the landfill for employee and customer needs. 6.2 Control of Nuisance Conditions 6.2.1 Litter Control Windy days will occur at the landfill, and measures will be implemented as necessary to minimize windblown debris. An anemometer will be maintained at the facility for wind monitoring. The following operational measures will be employed at the site: 1) Application and maintenance of a minimum 6-inch cover following the placement of each refuse lift and at the end of each day. Also, cover will be placed on refuse as soon as possible on days when wind is a noticeable problem. 2) The maximum size of the working face shall not exceed 150 feet in width and 14 feet in vertical depth at any time and a litter screen will be placed on the downwind side when accepting waste. Any increase in width or height must be approved by the Weld County Environmental Protection Services Division (WCEPSD). The size of the working face may be reduced during windy periods and oriented to take advantage of prevailing wind directions. The size of working face shall be reduced to 100 feet in width while accepting waste after dark. 3) The working face shall be enclosed on the downwind side(s) with a litter screen while accepting waste. A six-foot litter and access control fence shall be maintained areound the Special Review Permit area. 4) Operations will cease during periods when high winds are present. High winds are defined as sustained winds of 40 miles per hour or greater, or gusts of 55 mile per hour or greater that are expected to persist for one hour or longer as defined by the National Weather Service. 5) The access route south from the office and maintenance area cosisting of portion of Weld County road 59, 18, and 57 1/2 to the I-76 interchange, and the perimeter of the Special Review Permit area shall be patrolled daily for litter. Any debris found outside the working face shall be picked up within 24 hours of discovery. The manager shall respond to requests for picking up debris within 24 hours of notification by the WCESPD. 6) All loads of refuse brought on-site without being secured or covered will be charged twice the regular disposal rate. In the event that litter escapes from the working face for any reason, it will be collected and returned to the working face by site personnel and, if required, additional temporary labor. The operator will make every reasonable attempt to satisfy the concerns of the surrounding private property owners with respect to cleanup and removal of any blown litter. A telephone number will be provided to neighboring landowners. 6-3 Blowing refuse may come from vehicles transporting materials to the facility for disposal. To minimize this type of littering, the operator will maintain a fee schedule that will penalize all uncovered loads which come to the site. The penalty for bringing an uncovered load to the landfill will be twice the normal disposal fee. 6.2.2 Vector Control Disease and nuisance vectors are controlled by expeditious compaction and application of daily cover to minimize food and harborage. If, in the unlikely event additional vector control is required, the services of a professional exterminator will be obtained by the site General Manager. 6.2.3 Odor Control Odors at sanitary landfills may result from a variety of sources usually contained in the incoming refuse. Application of daily cover as described in this plan, will effectively minimize landfill odors. Additionally, grading and maintenance of the site to promote postive runoff will minimize surface water ponding. Implemetation of the landfill liquid monitoring and management system will reduce the potential for odors to emanate from the landfilling activities. Odors detected off-site shall not equal or exceed the level of 15:1 dilution threshold, as measured pursuant to Regulation 2 of the Colorado Air Pollution Control Regulations. The remote location and size of primary and secondary buffer areas will provide ample opportunity to ensure that odors do not affect residences. 6.2.4 Dust Control Dust and particulate matter originating from winds, vehicular traffic and operational equipment are controlled by the site General Manager. Long-term access roads will be covered with gravel to minimize dust generation. During dry periods the operator will have the option of using water or other applicable dust suppressants to minimize the amount of dust generated on the temporary access roads. Applications of these materials will be made whenever deemed necessary by the landfill supervisor. The landfill operator will be required to obtain a dust emissions permit from the Colorado Department of Health prior to beginning operations at the site. The facility operator shall implement a plan for controling fugitive dust as approved by the WCEPSD. The operator will reve^etate closed areas to minimize areal dust generation according to the closure plan presented in Section 8. 6.2.5 Fire Control No burning of waste will be permitted at the landfill site. Personnel working at the face will be specifically trained to detect potential fire problems to ensure that no spontaneously combustible materials are placed in the fill. If a fire occurs in the refuse, it will be extinguished by excavating and removing the burning refuse and covering it with soil. A water truck will also be on-site and can be used for extinguishing fires. In addition, all equipment operators will keep fire extinguishers on their machines to control small fires that 6-4 9T;CL'33 do not require excavation and covering. The Keenesburg Fire District will be contacted prior to the onset of operations. District personnel will be shown all operations, and the location fire fighting equipment and access gates. Landfill personnel will cooperate during any routine inspections and will comply with all reasonable requests that District personnel may make. 6.2.6 Landfill Gas Control The landfill is designed to have all filling on a compacted soil liner above the water table minimizing landfill gas generation. Migration of landfill gas below the natural ground surface will be minimal because of the low permeability of the bottom and side materials. Landfill gas monitoring procedures are discussed in Section 7.3. If gas migration needs to be controlled, an active or passive system will be installed. 6.2.7 Noise The maximum permissible noise level shall not exceed the industrial limit of 80 dB(A), as measured according to Section 25-12-102, Colorado Revised Statutes. 6.3 Hazardous Waste Screening Procedures Hazardous waste screening procedures at the East Weld Sanitary Landfill will include but not be limited to: * Training of appropriate facility personnel to recognize regulated hazardous and PCB wastes, * Random inspections by qualified personnel of incoming loads, and, * Notification of CDH if a regulated hazardous or PCB waste is discovered at the facility. In addition to the training of gate attendants, personnel at the working face will also be trained to recognize regulated hazardous and PCB waste. 6-5 92" 239 7.0 SITE MONITORING 7.1 Environmental Monitoring 7.1.1 Landfill Liquids Detection and Monitoring Little or no landfill liquids are expected to be generated by the facility. This is a result of the following: * Lack of ground water that can migrate into the in-place waste. HELP Model calculations are presented in Appendix J. * Procedures to prohibit disposal of liquid wastes or sludges. * Surface water controls directing runon away from the working face. * Maintenance of a relatively small working face. * Placement of daily cover to prevent precipitation from entering the compacted refuse. * The low annual precipitation rate (approximately 14 inches per year) will keep the total moisture content of the incoming and in-place refuse relatively low. If any liquid is produced, it will be detected at the sump locations shown on Plate 10. The landfill liquid monitoring system for each sump will consist of a 12-inch diameter, PVC Schedule 80 riser pipe that will extend from the base of the sump to the surface beyond the filling area. Plate 11 shows details of the landfill liquid collection system. The riser and collection pipe will be placed into the sump base and will bend to extend horizontally along the sump base. The riser pipe will extend to the surface where it will have a locking well protector. There will be a minimum of 3 feet of compacted soil beneath the sump base and the riser pipe on the sidewalls of the landfill. The liquids removal system will be constructed at the time each landfill cell is initially opened and lined. Clean gravel will be placed in the sump with a minimum of 12 inches of sand or equivalent drainage material placed over the gravel. Sand or equivalent drainage material will also be placed over the entire liner, excluding side slopes, to promote drainage to the sumps and also protect the soil liner from exposure degradation. The landfill liquid collection system will be monitored on a quarterly basis at the collection sump. Any liquids encountered will be sampled and analyzed to determine proper methods of discharge, disposal or treatment. Leachate will be monitored for the following parameters at a minimum: * Total Organic Halides (TOX) * Total Phenols * Biochemical Oxygen Demand (BOD) * Specific Conductivity * Total Petroleum Hydrocarbons (TPH) * pH 7-1 I - _ All analyses required by any discharge permits will be completed as part of the monitoring program. 7.1.2 Ground-Water Monitoring Ground water beneath the site will be monitored at 20 locatons around the landfill for eight quarters and semi-annually thereafter as an additional assurance and a back-up to the landfill liquid detection monitoring described in Section 7.1.1. The proposed well locations are shown on Plate 14. The existing monitor wells MW-01 and MW-02 will not be part of the permanent monitoring program. The locations and sampling intervals are selected in a manner that will: * Provide representative background data on the natural waters. * Intercept the ground water along flow paths directly in-line and down-gradient from the landfill. * Monitor the waters nearest to the surface that would be the first impacted if a release were to occur. * Monitor the saturated channel sands observed during the site specific field investigation. * Monitor the unsaturated intervals above the saturated intervals. Ground-water monitor well MW-03 will be retained as part of the background monitoring network for at least eight quarterly sampling events to gather background water quality data. Proposed monitor well MW-11 shown on Plate 14 is also in a position to remain as an up- gradient well for the life of the site. MW-11 will be installed and sampled on a quarterly basis following issuance of the Certificate of Designation. Once the chemical parameters have equilibrated in all ground water monitoring wells and background water-quality has been established, an appropriate statistical method will be chosen and applied to the results of the quarterly ground-water monitoring. Depending on the statistical method used, only one background monitor well may be required. The ground-water chemistry of monitor wells MW-3 and MW-11 will be compared, and if similar, one well may be abandoned. If the analytical results indicate two different chemistries, it may be appropriate to retain both wells. Abandonment of any ground-water monitor wells will be conducted according to applicable State guidelines and to the stipulations outlined above. The Division will be notified if the applicant intends to abandon any ground-water monitor wells. The Certificate of Designation boundary will be the primary property boundary. The point of compliance distance for ground-water monitoring is a maximum of 150 meters from the waste unit boundary. 7-2 9R_e_'39 7.1.2.1 Monitoring System Installation The monitoring system consists of cluster wells in 18 locations because of the lack of water in the upper eolian formation and the underlying confined conditions. Monitor wells MW- 03 and MW-11 are in a postion to remain upgradient for the life of the landfill, so these locations will not contain a wet/dry well. The well cluster includes 2-inch monitor wells tapping the ground water and an unsaturated-interval detection well which will monitor the unsaturated interval above the interval tapped by the monitor well. Eighteen of the 20 proposed well locations will consist of both a wet well completed in the saturated interval and a wet/dry well completed across the unsaturated interval and a wet/dry well completed across the unsaturated interval above the ground water table. The wet/dry wells will generally be completed to tap the eolian sand/weathered bedrock and/or the weathered/unweathered bedrock interface. The exact interval tapped by each wet/dry well will be determined in the field and dependent on the location specific geology. Should a wet/dry well ever contain water, the source of the water will be evaluated and the need for a permanent monitor well will be examined. This combination of unsaturated interval wells and wet/dry wells will provide optimum detection in the event of a release. There will be a total of 20 monitoring points. The wells at each monitoring point will be installed to coincide with the opening of the landfill modules in a phased manner. Well points 1 through 10 will be installed prior to beginning any landfilling in Phase 1. Of these, wells 1 through 9 will be considered down-gradient and wells 10 and 3 are upgradient. Well points 11, 12, and 13 are also considered upgradient wells and will be installed as subsequent Phases are constructed. The remaining wells 14 through 20, are downgradient and will be installed as subsequent Phases are constructed. Well points 5 and 18 will be located to tap the channel sands observed in piezometers PZ-8 and PZ-12 respectively. As noted earlier, each well point includes one well and one unsaturated-interval detection well. 7.1.2.2 Monitor Well Construction The monitoring system will include both wet wells and unsaturated-interval detection wells. Monitor Well Construction Monitor wells will be constructed of 2-inch, flush threaded, factory-slotted, Schedule 40 PVC monitor pipe unless hydrogeologic conditions dictate a modification of the typical construction parameters. Screen size is dependent on the soil characteristics at the site. Generally, a .010 or .020 inch factory slotted well screen will be used and placed 2-feet above the equilibrated water level to allow for seasonal fluctuations in the ground water. This will also allow for measurement of free product, if applicable. The well screen will extend to the contact point of the confined aquifer and extend above the equilibrated water level. Locking steel protectors will be placed on each well. Each well will be installed 7-3 3;.::0'_'33 according to accepted protocols. Figure 7.1 shows a schematic of a typical ground-water monitoring well construction. Unsaturated-Interval Detection Wells The unsaturated-interval detection well will typically be completed at a depth coinciding with the top of the interval monitored in the monitor well and will cross the sand/clay contact. They will have a perforated interval reaching to within 10 feet of the land surface. Construction of the unsaturated-interval detection wells will consist of 1-inch diameter glue joint. PVC casing, placed in 6-inch diameter borings. The PVC will be drilled or hand- slotted to within 10 feet of the ground surface. The annular space will be gravel packed to approximately 1 foot above the slotted interval of the PVC. The remaining annular space will be backfilled with dry bentonite. Figure 7.2 is a typical well construction diagram. Glue joint PVC is acceptable for use because of the nature of the monitoring efforts in these wells. The unsaturated-interval detection well will only be used as a measure of the presence or absence of ground water. The site characterization program showed there to be a lack of water in the upper sand zone necessitating a varied approach to monitoring the site. The use of this type of well facilitates the monitoring process. If, during installation of the unsaturated interval detection wells, water is encountered, a determination will be made whether to complete the well as a ground-water monitor well. CDH will be notified of this change. The monitor wells containing water will be sampled and the results of the water quality analyses will be submitted to CDH and Weld County. The samples will be analyzed for the parameters and frequencies outlined in Table 7.1. As previously noted, the initial background monitoring will include the first eight quarters of analytical data, the post- background semi-annual monitoring is the normal sampling and analysis frequency during the operational life of the site, the post-background annual detection monitoring includes events during the initial 5 years following closure, and the post-background 5 year detection monitoring includes the remainder of the post-closure period. The operator will make reasonable changes as necessary if CDH and Weld County would like to amend the sampling parameter list during the life of the site. The operator also reserves the right to add parameters to the list as is appropriate. 7.1.3 Landfill Gas Monitoring Landfill gas monitoring will be performed semi-annually. The site is remote from any development that may be impacted by landfill gas generation. Approximately 35 landfill gas probes will be installed surrounding the site at the property boundary. In accordance with Subtitle D, methane gas concentration will be monitored in the vents and will not exceed the LEL at the property boundary. The landfill gas measurement probes will typically be placed on 1000 foot centers and be completed to a depth 10 feet beneath the base of the excavated portion of the landfill nearest the probe location. They will have a perforated interval reaching to within 10 feet of the land surface. Construction of the probes will consist of 1-inch diameter glue joint, PVC casing, placed in 7-4 920L,39 I _ _ au-face •Er.• schedule 10 PVC P1Pe :tom' '...• {cyc y\ bskf111 ad craft wV' :tiA :Ei3EE JL !Xt JM -- r bento-1e plug ... 7 vale- the slotted scedde 19 -:— _ sad peck PVC PtPe i . well base cap INDUSTRIAL COIANCE 1746 COLE EWD.MPL BLDG. 21 SUITE 300 GOLDEN, COLORADO 80401 FIGURE 7. 1 TYPICAL GROUND-WATER MONITORING WELL WASTE S •VICES COMPANY • flt0Kt, SANI A Y LANDFILL /7/92 yam. p INDUSTRIAL COMPLIANCE CS.\we„W.H.T. er, M.A.M. I yvra 2371EI:7.1 9'20239 LOCKING STEEL PROTECTOR PVC CAP GROUND SURFACE BENTONITE/GROUT ONI E/GROUT 3 MIXTURE BLANK 1' PVC PIPE %:; .. . :;t__. BENTONITE PLUG Cf .a v? ,,:'. f r= - • - == 1' PERFORATED • ' PVC PIPE (SCH 40) VARIABLE =- • -- -;-7-.--...-4-.?".;-.;- PEA GRAVEL T ===== • MIN 6' • INDUSTRIAL COMPLIANCE 1746 17x6 COLE BLVD. BLDG. 21 SUITE 300 GOLDEN, COLORADO 804C I FIGURE 7.2 TYPICAL UNSATURATED-INTERVAL DETECTION WELL - WASTE SERVICES COMPANY -, SAM I ARY LANDEILL ,,,, 2-3/I6 Infi.crn perm 2/7/92 GR T,. . INDUSTRIAL COMPLIANCE ro.... - VJ.H.T, I.—o.,m... M.A.M. l!..,./En 23716:7.1 - 3:2:{1.1'33 4-inch to 6-inch diameter borings. The annular space will be gravel packed to approximately 1 foot above the slotted interval of the PVC. The remaining annular space will be backfilled with dry bentonite. Figure 7.3 is a typical landfill gas probe construction diagram. Glue joint PVC is acceptable for use because of the nature of the monitoring efforts in these probes. The probes will be monitored each quarter for pressure, combustible gas concentrations and the presence of water. All monitoring results will be submitted to Weld County and CDH. 7.1.4 Environmental Monitoring Results Monitoring results for the landfill liquids detection and ground-water monitoring programs will be interpreted and the results will determine whether any additional requirements are necessary. The interpretations will be based on the following: * Landfill Liquid Detection: The climatological information indicates that there will probably not be landfill liquids generated in the base of the refuse from surface percolation. It is possible, however, that liquids will be found in the detection system during the period the landfill is being developed. If necessary, the operator will arrange for disposal of the liquids. * Ground-Water Monitoring: The ground-water monitoring system will include a minimum of eight sampling events. The data will be used as background information for analytical and statistical interpretation during the life of the site. During subsequent monitoring of the site, the analytical results will be statistically tested to determine whether significant variance in the data has occurred. If, the detection system shows there to be liquids present following the placement of the first lift or the ground-water monitoring exhibits a statistical variance, the landfill operator will notify both CDH and Weld County within 5 working days of verification of the information. The operator will also request a meeting with both parties to discuss the results and interpretation. If necessary, confirmation monitoring and analysis will be completed. If an environmental problem is confirmed, the operator will have 30 days to evaluate the problem and propose a remediation plan to the State and County. The plan will include specific actions and a time schedule required to correct the situation. The plan will be implemented immediately upon approval by CDH and Weld County. It is understood that construction operations and ongoing monitoring of the facility may yield information that was previously unknown and change the current concept of the site hydrogeology and geology. If at any time during the operating life or post-closure period of the facility, information is obtained that changes the currently held concept of the site sufficiently to require a change in the design, operations, or monitoring program, the Division will be notified and consulted. It is also understood that future regulatory changes may become binding and result in design, operational, or monitoring modifications. 7-7 9:7,0239 • LOCKING STEEL PROTECTOR PVC CAP GROUND SURFACE 3, \ ` BENTONITE/GROUT MIXTURE • BLANK 1' PVC PIPE 2 >. : ;:• BENTONITE PLUG tr4' ✓t; rs == . L7.: 7L7L71' PERFORATED `=` PVC PIPE (SCH 42) VARIABLE __ : • == .7 7 PEA GRAVEL r __-_= MIN 6' iwINDUSTRIAL COMPLIANCE 1746 COLE BLVD. BLDG.21 SUITE 300 GOLDEN, COLOPADO 50401 FIGURE 73 TYPICAL LANDFILL GAS PROBE n,„. WAS I E SERVICES COMPANY SANI I ARY LANDHLL HE--n, 2-8/ 16 k - m 1/7/92 CAP.TED... INDUSTRIAL COMPLIANCE ' v»+c W.H.T. I...•ow.P.. M.A.M. Isaca 23716=7.3 9,10: 39 TABLE 7.1 - GROUND-WATER MONITORING PARAMETERS AND FREQUENCY INITIAL BACKGROUND MONITORING-(EIGHT OUARTERSI Water Quality Field Parameters pH Specific Conductance Temperature Depth to water from ground surface Elevation of ground water Anions Cations Organics Other Sulfate Magnesium TOC+ Nitrate/Nitrite as N Bicarbonate Calcium TOX• Ammonia as N Carbonate Potassium VOC @# Chloride Sodium Cation-Anion balance Metals(dissolved) Pesticides/Radionuclides Arsenic Endrin Barium Lindane Cadmium Toxaphene Chromium 2-4,D Iron 2,4,5,TP-Silvex Lead Methoxychlor Manganese Gross Alpha Mercury Gross Beta Selenium Radium(2261228) Silver POST BACKGROUND SEMI-ANNUAL DETECTION MONITORING Water Quality Field Parameters pH Specific Conductance Temperature Depth to water from ground surface Elevation of ground water Anions Cations Organics Other Sulfate Magnesium TOC + Nitrate/Nitrite as N Bicarbonate Calcium TOX • Ammonia as N Carbonate Potassium VOC eg Chloride Sodium Cation-Anion balance 7-9 POST BACKGROUND ANNUAL DETECTION MONITORING Water Quality Field Parameters pH Specific Conductance Temperature Depth to water front ground surface Elevation of ground water Anions Cations Organics Other Sulfate Magnesium TOC + Nitrate/Nitrite as N Bicarbonate Calcium TOX • Ammonia as N Carbonate Potassium VOC @//' Chloride Sodium Cation-Anion balance Metals(dissolved) Arsenic Iron Mercury Barium Lead Selenium Cadmium Manganese Silver Chromium POST BACKGROUND FIVE YEAR DETECTION MONITORING Water Quality Field Parameters pH Specific Conductance Temperature Depth to water from ground surface Elevation from ground water Anions Cations Organics Other Sulfate Magnesium TOC + Nitrate/Nitrite as N Bicarbonate Calcium TOX • Ammonia as N Carbonate Potassium VOC @I Chloride Sodium Cation-Anion balance Metals (dissolved) Pesticides/Radionuclides Arsenic Endrin Barium Lindane Cadmium Tozaphene + EPA method 9060 Chromium 2-4,D • EPA method 9020 Iron 2,4,5,TP-Silver (Ground water samples only) Lead Methozychlor @ EPA method 624 Manganese Gross Alpha (Ground water samples only) Mercury Gross Beta K May be required Selenium Radium(226/228) Silver 7-10 92(1.'239 8.0 CLOSURE AND POST-CLOSURE 8.1 Reclamation and Revegetation The EWSL will be opened, developed and closed in phases. When filling in an area reaches its final contours it will be covered and reclaimed as the subsequent area is excavated and readied for filling. The top 8 to 12 inches of topsoil will be stripped and stockpiled for reclaiming the closed portion of the landfi'l. The location of the stockpiles is left to the discretion of the General Manager. The stockpiles will be posted as such and will be revegetated to minimize erosion and to increase the organic content of the soils. 8.1.1 Final Cap Design The final cap will include the following at a minimum: * a 6" foundation layer immediately above the refuse to provide a suitable foundation for the construction of the barrier layer, * 18-inches of compacted soil with a specified permeability of 1x10 cm/sec or less to serve as a barrier layer, * 24-inch unspecified root and frost protection layer, and * 6-inch seedbed layer to support plant germination and growth. The total thickness of the cover will be at least 4.5 feet. All but the topsoil will be placed as soon as possible after the filled area reaches its final contours. The topsoil will be placed immediately prior to seeding. The subsoil surface will be disced with a plow or sin. :ar implement to ensure there is proper binding of the topsoil to the subsoil, and that ali large rocks and debris are removed prior to seeding. Soil analyses will be done to determine the proper fertilizer requirements for supporting the species to be planted. When fertilizers or soil amendments are required they will be applied immediately before or after seeding. 8.1.2 Revegetation The seeding and revegetation portion of the Design and Operations Plan is taken from recommendations supplied by the Soil Conservation Service (SCS). The SCS was contacted and their recommendations are included as Appendix N. Seed should be planted using a drill to reduce the amount of seed used. Table 8.1, showing bulk seed rates, assumes the use of a drill but if broadcast seeding is to be done, the amount of seed used must be doubled. Following seeding of the topsoil the seed should be protected by spreading and crimping mulch into the soil at least 4 inches. It is recommended that approximately 3000-4000 pounds per acre is applied and that a weed-free, native grass hay be used as the mulch material. 8-1 920:'39 TABLE 8.1 - BULK SEED RATES PLS/ACRE % SPECKS TOTAL PLS SPECIES la 100% IN MIX PER ACRE Prairie Sandreed 6.5 30 2.0 Sand Bluestem 16.0 20 3.2 Switchgrass 6.5 25 1.1 Western 16.0 10 1.6 Wheatgrass Yl. Indiangr. 10.0 15 1.5 The PLS notation in the table refers to Pure Live Seed. 8-2 3033 8.2 Post-Closure Monitoring Following completion of filling at the landfill, a post-closure period of 30 years will begin in order to ensure that the site remains environmentally secure. Ground-water wells will be sampled on a semi-annual basis during the post-closure period. The water analyses will be identical to those conducted during the life of the site. Any variance in analytical results will require the operator to take the proposed action described in Section 7.1.4. The landfill gas probes will be monitored on the same frequency as the water wells. 8.3 Post-Closure Inspections and Maintenance Post-closure maintenance should not be necessary for the completed landfill; however, refuse settlement may occur even though it's potential will be minimized by compaction techniques. Inspections to determine whether settlement has occurred will be completed following closure of the site. In areas where settlement has occurred, the operator will bring the contours back to grade to reduce the possibility of ponding water on the site. Post-closure inspections and maintenance will also include the repair of eroded areas, re- evaluation of those areas for proper surface water drainage, and maintenance of vegetation on site. 8.4 Post-Closure Land Use The proposed landfill site is currently in an area zoned for agricultural use. Future land use following closure of the site will be determined by the land owner and Weld County. Development of a landfill does not preclude use of the land although certain limitations must be expected. The areas that remained unfilled could easily be developed for a variety uses. The site can ultimately be used for grazing land upon completion of development. 8-3 920 39 9.0 REFERENCES Costa, John E. and Bilodeau, Sally W., August 1982, Geology of Denver, Colorado, U.S.A; Colorado Geological Survey, Department of Natural Resources, V. XIX, No. 3. Emmons, Cross, Whitman, and Eldridge, 1896, Geology of the Denver Basin: U.S. Geol. Survey Monograph 27. Hansen, Wallace R., Crosby, Eleanor J., 1982, Environmental geology of the Front Range Urban Corridor and vicinity, Colorado: U.S. Geol. Survey, Professional Paper 1230 Haun, J. D., 1967, Structural geology of the Denver Basin-regional setting of the Denver Earthquakes, pt. A: Colorado School of Mines Quarterly, v. 63, no. 1. Hunt, C. B., 1954, Pleistocene and Recent deposits in the Denver area: U.S. Geol. Survey Bulletin 996-C. Johnson, A.I., 1976, Specific Yield- Compilation of Specific Yields for Various Materials, Geological Survey Water-Supply Paper 1662-D, U.S. Department of the Interior, Prepared in Cooperation with the CAlifornia Department of Water Resources. LeRoy, L.W., 1946, Stratigraphy of the Golden-Morrison Area, Jefferson County, Colorado: Quarterly of the Colorado School of Mines, V. 41, Number 2. Lohman, S. W., 1979, Ground-Water Hydraulics: U.S. Geol. Survey Professional Paper 708. McWhorter, D. B. and Ortiz, N. November 1978, Water Resources and Impact Evaluation for a Proposed Mining Site - Weld County, Colorado; Submitted to Adolph Coors Company, Golden, Colorado. Robinson, W. D., 1986, The Solid Waste Handbook, a practical guide: New York, John Wiley and Sons. Robson, S. G., Zawistowski, Stanley, and Romero, J. C., 1981, Geologic Structure, Hydrology, and Water Quality of the Laramie-Fox Hills Aquifer in the Denver Basin, Colorado: U.S. Geol. Survey, Atlas HA-650, Sheet 3. Robson, S. G., and Romero, J. C., 1981, Geologic structure, hydrology, and water quality of the Denver Aquifer in the Denver Basin, Colorado: U.S. Geol. Survey, Atlas HA-646, Sheet 2. Robson, S. G., and Romero, J. C., 1981, Geologic structure, hydrology, and water quality of the Dawson Aquifer in the Denver Basin, Colorado: U.S. Geol. Survey, Atlas HA-643, Sheet 2. Soil Survey of Weld County, Colorado, Southern Port; United States Department of Agriculture, Soil Conservation Service. 9-1 920239 Tchobanoglous, George, Theisen, Hilary, and Eliassen, Rolf, 1977, Solid wastes, engineering principles and management issues. U.S. Environmetal Protection Agency, Office of Solid Waste and Emergency Response, March 1986, Design, construction and evaluation of clay liners for waste management facilities: Draft Technical Resource Document for Public Comment, chapter 4, Clay- Chemical Interactions and Soil Permeability. VanSlyke, G., Romero, J., Moravec, G., and Wacinski, A; March 1988; Geologic Structure, Sandstone/Siltstone Isolith, and J oration of Non-Tributary Ground Water for the Laramie-Fox Hills Aquifer, Denver, Colorado; Colorado Division of Water Resources, Denver Basin Atlas No. 4, DBA-4. Wright-McLaughlin Engineers, 1969 (revised 1984), Urban storm drainage criteria manual, v. 1 and 2. 9-2 3r vL°33 APPENDIX A MEMORANDUM OF AGREEMENT 32®." 33 Y• , F10M KPPOu..1 :. u11uE►. 4 OLOIMEU►6 J L MEMORANDUM or AORABKENT Agreement ("Memorandum") is by and between This Memorandum of olorado Limited Partnership, ("Seller") and Masts and company, Management of and Masts sezviaee Development Corporation and Waste Kanaq Colorado, Inc, ("Purchaser") . A. Seller end Purchaser have entered into s contract for purchaser and Sale of certain lands, including those described in Exhibit 1 91 ie h i hereto eren caledPurchase incorporated la" r The controot, dated November 7 , Agreement" . B. Pursuant to the terms and conditions of the Purchase Agreement, t Exhibit oisatisfa fee ction oft certaie to n conditions e described in Exhibit "A" upon overnmontal authorizations and such as obtaining all noptrtarga a solid waste disposal facility. permits for use of the P-oP y ,�`t' _, 1992. DATED _�-- •- 14ASTt SERVICES DEVELOPMENT CORPORATION ( /17 r;y7/ GUTTERGEN AND COMPANY, A COLORADO LIKTTED PARTNERSHIP • By ) / r r� WASTE MANAG�T OF COLORADO, INC. • ' • . FEB 6 ' 82 14 : 23 303 352 3165 PR617 . 002 920 '39 EXHIBIT A A TRACT OF LAND SITUATED IN SECTIONS 2 AND 3, TOWNSHIP 2 NORTH, RANGE 64 WEST OF THE 6TH PRINCIPAL MERIDIAN, AND IN SECTIONS 26. 27. 34 AND 35, TOWNSHIP 3 NORTH, RANGE 64 WEST OF THE 6TH PRINCIPAL MERIDIAN, COUNTY OF WELD, STATE OF' COLORADO, MORE PARTICULARLY DESCRIBED AS FOLLOWS: COMMENCING AT THE NORTHWEST CORNER OF SAID SECTION 26, A FOUND NO. 5 REBAR WITH CAP MARKED L.S. 10945: 1NENCE SOUTH O'15'23' EAST ALONG THE WEST LINE OF THE NORTHWEST ONE-QUARTER OF SAID SECTION 26 A DISTANCE OF 205267 FEET TO THE TRUE POINT OF BEGINNING, BEING A SET 21/2 INCH BRASS CAP SET IN CONCRETE. STAMPED LS. 18472: THENCE ALONG THE BOUNDARY OF THE TRACT HEREIN DESCRIBED FOR THE FOLLOWNG FIVE (5) COURSES, THE TERMINUS OF EACH COURSE BEING MARKED BY A SET 21/2 INCH BRASS CAP SET IN CONCRETE, STAMPED L.& 18472: 1. SOUTH 4029'02" EAST A DISTANCE OF 3566.38 FEET; 2. SOUTH 0'00'00' WEST A DISTANCE OF 9832.69 FEET; 3. SOUTH 90'00'00" WEST A DISTANCE OF 6071.f.4 FEET; 4. NORTH 0'00'00' WEST A DISTANCE OF 12..545.24 FEET; 5. NORTH 90'00'00" EAST A DISTANCE OF 3755.22 FEET TO THE TRUE POINT CF BEGINNING, CONTAINING AN AREA OF 1676.5 ACRES, MORE OR LESS. APPENDIX B CLIMATOLOGY 920.:`33 • SUMMARY OF MONTHLY CLIMATIC DATA FOR BRIGHTON COLORADO FOR YEARS 1973-1990 SUBSTATION NO. 50950 DIVISION 4 LATITUDE - 40 0 LONGITUDE - 104 49 ELEVATION - 4980 FEET JAN FEB MAR APR MAY JUN JUL AUG SEP 0CT NOV DEC ANN MONTHLY MEAN MAXIMUM TEMP (F) AVE. 42.0 47.2 55.3 64.3 72.4 84.3 89.5 86.4 79.3 68.2 52.3 43.7 65.2 MAX. 54.1 55.7 63.7 72.5 78.4 89.1 91.6 90.4 83.9 72.5 59.7 55.7 67.6 YEAR 1986 1976 1986 1981 1974 1990 1980 1985 1977 1975 1981 1980 1981 MIN. 30.6 32.9 49.0 55.2 66.9 77.5 88.1 84.1 75.0 58.2 40.5 28.5 62.4 YEAR 1979 1989 1983 1983 1983 1983 1985 1981 1985 1984 1985 1983 1983 YEARS OF RECORD 17. 17. 17. 17. 17. 16. 15. 17. 16. 17. 17. 18. 14. MONTHLY MEAN MINIMUM TEMP (F) AVE. 13.7 18.7 25.5 33.5 42.5 51.8 56.8 54.5 45.8 34.7 23.2 15.3 34.6 MAX. 23.5 24.5 32.0 38.3 46.4 56.3 58.7 58.5 51.0 37.0 26.9 24.8 37.2 YEAR 1986 1987 1986 1981 1987 1988 1985 1983 1990 1988 1990 1980 1986 MIN. 3.0 10.0 21.3 28.3 39.1 47.7 54.9 50.2 40.7 30.6 16.7 3.4 32.7 YEAR 1979 1989 1976 1975 1983 1975 1979 1974 1974 1976 1979 1983 1975 YEARS OF RECORD 17. 17. 17. 17. 17. 16. 15. 17. 16. 17. 17. 18. 14. MONTHLY MEAN AVERAGE TEMP (F) AVE. 27.9 33.0 40.5 48.9 57.5 68.1 73.2 70.5 62.6 51.5 37.8 29.5 49.9 MAX. 38.8 39.3 47.9 55.4 61.2 71.9 74.9 73.8 66.1 53.7 43.0 40.3 52.1 YEAR 1986 1976 1986 1981 1974 1990 1980 1983 1990 1988 1981 1980 1986 MIN. 16.8 21.5 36.5 42.5 53.0 63.4 71.9 67.3 58.2 45.7 29.5 16.0 48.4 YEAR 1979 1989 1980 1984 1983 1983 1975 1974 1974 1984 1985 1983 1979 YEARS OF RECORD 17. 17. 17. 17. 17. 16. 15. 17. 16. 17. 17. 18. 14. DEGREE DAYS (BASE 65F) AVE. 1145.3 897.5 753.8 477.8 238.4 40.5 1.1 6.2 119.8 414.3 810.2 1093.2 6049.1 MAX. 1486 1214 881 668 369 110 5 21 215 594 1057 1519 6612 YEAR 1979 1989 1980 1984 1983 1983 1987 1987 1974 1984 1985 1983 1983 MIN. 806 740 526 287 141 0 0 0 37 343 654 761 5241 YEAR 1986 1976 1986 1981 1977 1977 1989+ 1989+ 1981 1988 1981 1980 1986 YEARS OF RECORD 17. 17. 17. 17. 17. 16. 15. 17. 16. 17. 17. 18. 14. NO DAYS MAX TEMP GTR OR EC) 9OF AVE. 0.0 0.0 0.0 0.1 0.5 9.3 16.7 10.2 3.8 0.0 0.0 0.0 40.1 MAX. 0 0 0 1 3 16 23 19 9 0 0 0 61 YEAR 1974 1974 1974 1989 1989 1980 1980 1985 1978 1973 1973 1973 1980 MIN. 0 0 0 0 0 4 12 5 0 0 0 0 30 YEAR 1990+ 1990+ 1990+ 1990+ 1990+ 1983 1986 1976+ 1986 1990+ 1990+ 1990+ 1986 YEARS OF RECORD 17. 17. 17. 17. 17. 16. 15. 17. 16. 17. 17. 18. 14. NO DAYS MAX TEMP LESS OR EQ 32F AVE. 7.3 4.2 1.6 0.3 0.0 0.0 0.0 0.0 0.0 0.1 2.5 5.9 23.6 MAX. 19 11 5 3 0 0 0 0 0 1 10 15 37 YEAR 1979 1989 1989 1983 1974 1974 1974 1974 1974 1984 1985 1983 1978 MIN. 0 0 0 0 0 0 0 0 0 0 0 1 9 YEAR 1986 1977 1986+ 1990+ 1990+ 1990+ 1989+ 1990+ 1990+ 1990+ 1990+ 1976 1986 YEARS OF RECORD 17. 17. 17. 17. 17. 16. 15. 17. 16. 17. 17. 18. 14. NO DAYS MIN TEMP LESS OR ED 32F AVE. 30.5 26.7 25.9 12.7 2.0 0.0 0.0 0.0 1.5 11.9 25.8 30.1 167.9 MAX. 31 29 31 24 7 0 0 0 6 18 30 31 194 YEAR 1988+ 1984+ 1984 1984 1979 1974 1974 1974 1985 1980+ 1979 1988+ 1984 MIN. 29 20 18 5 0 0 0 0 0 7 22 27 142 YEAR 1975+ 1986 1986 1985+ 1987+ 1990+ 1989+ 1990+ 1990+ 1990 1987 1980 1986 YEARS OF RECORD 17. 17. 17. 17. 17. 16. 15. 17. 16. 17. 17. 18. 14. NO DAYS MIN TEMP LESS OR EQ 0 F AVE. 4.7 2.2 0.5 0.1 0.0 0.0 0.0 0.0 0.0 0.0 0.6 3.8 12.1 MAX. 15 8 3 1 0 0 0 0 0 0 3 12 26 YEAR 1979 1989 1976 1975 1974 1974 1974 1974 1974 1973 1979 1983 1979 MIN. 0 0 0 0 0 0 0 0 0 0 0 0 2 YEAR 1990+ 1987+ 1990+ 1990+ 1990+ 1990+ 1989+ 1990+ 1990+ 1990+ 1990+ 1984+ 1986 YEARS OF RECORD 17. 17. 17. 17. 17. 16. 15. 17. 16. 17. 17. 18. 14. HIGHEST TEMPERATURE (F) TEMP 74 77 82 90 94 101 103 101 97 87 81 74 YEAR AND DAY198226 198625 198630 198921 198923 199029 198908 198006 199013 199005+199025 198017 YEARS OF RECORD 17. 17. 17. 17. 17. 16. 15. 17. 16. 17. 17. 18. LOWEST TEMPERATURE (F) TEMP -22 -24 -8 -8 22 35 46 41 19 15 -7 -26 YEAR AND DAY198418 198905 197606+197502 197807 197511 198713 197819 198529 198930+197627 199022 YEARS OF RECORD 17. 17. 17. 17. 17. 16. 15. 17. 16. 17. 17. 18. PREPARED BY: COLORADO CLIMATE CENTER, DEPT. OF ATMOSPHERIC SCIENCE, COLORADO STATE UNIV. FT. COLLINS, CO 80523, (303)491-8545 SUMMARY OF MONTHLY CLIMATIC DATA FOR BRIGHTON COLORADO FOR YEARS 1973-1990 SUBSTATION NO. 50950 DIVISION 4 LATITUDE - 40 0 LONGITUDE - 104 49 ELEVATION - 4980 FEET JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC ANN MONTHLY PRECIPITATION (IN) AVE. 0.45 0.41 1.29 1.61 2.97 1.75 1.46 1.40 0.87 0.79 0.80 0.63 14.28 MAX. 1.23 1.48 5.25 4.01 5.70 3.48 4.76 3.24 2.33 3.35 1.96 2.09 19.75 YEAR 1989 1987 1990 1986 1987 1983 1977 1979 1989 1984 1983 1973 1983 MIN. 0.10 0.10 0.22 0.32 0.14 0.09 0.31 0.16 0.01 0.02 0.10 0.08 9.97 YEAR 1983 1982 1982 1982 1974 1990 1988 1985 1978 1988 1984 1980 1988 YEARS OF RECORD 17. 17. 17. 17. 17. 16. 15. 17. 16. 17. 18. 18. 15. GREATEST DAILY PRECIP (IN) AMOUNT 0.66 0.60 2.12 2.26 2.73 2.27 2.25 1.26 0.96 1.18 0.77 1.37 YEAR AND DAY199020 198720 199006 198603 198213 197908 197721 197513 198909 197822 198715 197324 YEARS OF RECORD 17. 17. 17. 17. 17. 16. 15. 17. 16. 17. 17. 18. MONTHLY SNOWFALL (IN) AVE. 6.0 4.8 9.2 6.5 1.8 0.0 0.0 0.0 0.6 2.0 7.1 7.4 46.7 MAX. 13.2 8.2 22.1 17.0 11.1 0.0 0.0 0.0 6.4 8.7 19.6 20.7 78.3 YEAR 1989 1990 1983 1974 1979 1974 1974 1974 1985 1984 1979 1973 1979 MIN. 1:0 1.2 1.1 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.9 0.3 32.4 YEAR 1983 1982 1986 1985 1990+ 1990+ 1989+ 1990+ 1990+ 1988+ 1982 1980 1988 YEARS OF RECORD 17. 17. 17. 17. 17. 16. 15. 17. 16. 17. 16. 18. 13. GRIST DEPTH SNOW ON GRND IN MON (IN) 15 5 7 13 4 0 0 0 6 5 18 16 YEAR AND DAY198301 198906+198831+198604 198317+ 0 0 0 198529 198416 198328 198227 YEARS OF RECORD 17. 16. 14. 15. 15. 15. 15. 17. 14. 15. 15. 17. NO DAYS PRECIP GTR OR EQ 0.1 IN AVE. 1.5 1.5 3.6 3.8 4.9 3.6 3.1 3.1 2.8 2.2 2.9 1.6 35.2 MAX. 4 3 7 6 8 6 5 7 6 5 7 4 44 YEAR 1985 1987+ 1990+ 1983+ 1982+ 1977 1983+ 1984 1989+ 1974 1983 1973 1983 MIN. 0 0 1 1 1 0 1 1 0 0 0 0 26 YEAR 1983 1982+ 1982+ 1988+ 1974 1990 1987 1985+ 1978+ 1988+ 1976 1990+ 1988 YEARS OF RECORD 17. 17. 17. 17. 17. 16. 15. 17. 16. 17. 17. 18. 14. NO DAYS PRECIP GTR OR EQ 0.5 IN AVE. 0.1 0.1 0.5 0.9 2.1 1.1 0.7 0.8 0.4 0.5 0.4 0.2 7.9 MAX. 1 1 2 2 5 3 2 3 2 4 1 2 14 YEAR 1990+ 1987 1990+ 1986+ 1987 1987 1985+ 1979 1989 1984 1990+ 1982 1987 MIN. 0 0 0 0 0 0 0 -0 0 0 0 0 4 YEAR 1989+ 1990+ 1989+ 1990+ 1984+ 1990+ 1988+ 1988+ 1986+ 1990+ 1989+ 1990+ 1976 YEARS OF RECORD 17. 17. 17. 17. 17. 16. 15. 17. 16. 17. 17. 18. 14. NO DAYS PRECIP-OTR OR EQ 1.0 IN AVE. 0.0 0.0 0.2 0.1 0.7 0.4 0.4 0.3 0.0 0.1 0.0 0.1 2.2 MAX. 0 0 2 2 2 2 2 1 0 1 0 1 5 YEAR 1974 1974 1990 1986 1988+ 1983 1983+ 1987+ 1974 1984+ 1973 1973 1983 MIN. 0 0 0 0 0 0 0 0 0 0 0 0 0 YEAR 1990+ 1990+ 1989+ 1990+ 1990+ 1990+ 1989+ 1990+ 1990+ 1990+ 1990+ 1990+ 1980 YEARS OF RECORD 17. 17. 17. 17. 17. 16. 15. 17. 16. 17. 17. 18. 14. NUMBER OF DAYS WITH HAIL AVE. 0.0 0.0 0.0 0.0 0.1 0.1 0.1 0.2 0.0 0.0 0.0 0.0 0.5 MAX. 0 0 0 0 1 1 1 2 0 0 0 0 3 YEAR 1974 1974 1974 1974 1980 1980 1980 1981 1974 1973 1973 1973 1980 MIN. 0 0 0 0 0 0 0 0 0 0 0 0 0 YEAR 1981+ 1981+ 1981+ 1981+ 1979+ 1979+ 1981+ 1980+ 1981+ 1981+ 1981+ 1981+ 1979+ YEARS OF RECORD 8. 8. 8. 8. 7. 7. 8. 8. 8. 9. 8. 9. 6. ** NOTE : MANY WEATHER STATIONS DO NOT RECORD ALL HAIL OCCURRENCES. THEREFORE THESE DATA MAY NOT BE REPRESENTATIVE. NO. OF DAYS WITH SNOW ON GROUND AVE. 15.0 7.6 4.6 2.5 0.4 0.0 0.0 0.0 0.1 0.7 6.3 11.5 51.8 (GTR OR EQ 1 INCH ON GROUND) MAX. 31 22 11 7 2 0 0 0 1 4 22 31 92 YEAR 1988+ 1989 1983 1974 1983+ 1974 1974 1974 1985 1984 1985 1983 1983 MIN. 1 0 0 0 0 0 0 0 0 0 0 0 25 YEAR 1977 1982 1982 1990+ 1990+ 1990+ 1989+ 1990+ 1990+ 1988+ 1982+ 1980 1976 YEARS OF RECORD 17. 17. 16. 17. 17. 16. 15. 17. 16. 17. 17. 17. 12. PREPARED BY: COLORADO CLIMATE CENTER, DEPT. OF ATMOSPHERIC SCIENCE, COLORADO STATE UNIV. FT. COLLINS, CO 80523, (303)491.8545 SUMMARY OF MONTHLY CLIMATIC DATA FOR GREELEY COLORADO FOR YEARS 1931-1967 SUBSTATION NO. 53546 DIVISION 4 LATITUDE - 40 25 LONGITUDE - 104 41 ELEVATION - 4650 FEET JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC ANN MONTHLY MEAN MAXIMUM TEMP (F) AVE. 39.7 43.7 50.4 62.0 72.0 83.0 90.9 88.3 79.3 67.9 51.5 42.8 64.3 MAX. 51.2 58.7 59.5 71.1 83.2 90.1 97.6 97.3 86.0 74.5 64.5 51.3 70.4 YEAR 1934 1954 1946 1946 1934 1933 1936 1934 1948 1963+ 1949 1933 1934 MIN. 21.5 31.2 41.5 52.6 61.5 75.3 84.3 83.7 66.0 58.6 42.6 30.7 61.3 YEAR 1937 1942 1958 1957 1935 1951 1958 1963 1965 1959 1955+ 1932 1951 YEARS OF RECORD 36. 37. 36. 36. 36. 36. 36. 36. 36. 36. 35. 36. 34. MONTHLY MEAN MINIMUM TEMP (F) AVE. 7.9 13.7 21.2 32.4 42.7 51.3 56.7 54.5 44.3 32.5 19.4 12.1 32.3 MAX. 16.8 21.0 28.4 38.2 48.2 55.3 60.7 59.0 50.8 39.3 26.1 18.6 34.2 YEAR 1965 1963 1938 1943 1958 1956 1966 1934 1963 1963 1949 1933 1958 MIN. -10.5 -0.5 11.8 25.8 38.3 47.6 53.7 51.0 37.3 25.3 11.3 -2.9 29.8 YEAR 1937 1942 1932 1953 1953+ 1935 1952 1950 1945+ 1952 1952 1932 1932 YEARS OF RECORD 36. 37. 36. 36. 36. 36. 36. 36. 36. 36. 35. 36. 34. MONTHLY MEAN AVERAGE TEMP (F) AVE. 23.8 28.7 35.8 47.2 57.3 67.2 73.8 71.4 61.8 50.2 35.4 27.5 48.3 MAX. 33.2 39.5 43.2 54.6 64.6 72.7 77.1 78.2 66.1 56.9 45.3 35.0 52.0 YEAR 1934 1954 1946 1946 1934 1956 1966 1934 1948 1963 1949 1933 1934 MIN. 5.5 15.4 27.4 40.8 49.9 62.1 69.9 68.8 53.2 45.0 28.2 13.9 46.2 YEAR 1937 1942 1932 1953 1935 1951 1950 1956+ 1965 1959 1952 1932 1942 YEARS OF RECORD 36. 37. 36. 36. 36. 36. 36. 36. 36. 36. 35. 36. 34. DEGREE DAYS (BASE 65F) AVE. 1308.8 1033.3 925.4 539.9 213.9 53.8 2.3 12.3 162.8 430.2 889.4 1134.8 6744.3 MAX. 1653 1317 1140 696 331 115 9 40 352 613 1033 1315 7335 TEAR 1963 1956 1965 1957 1957 1955 1961 1964 1965 1959 1955 1963 1955 MIN. 981 807 741 427 140 3 0 0 55 244 751 981 6325 YEAR 1965 1963 1966 1962 1963 1956 1966+ 1961+ 1963 1963 1962 1957 1963 YEARS OF RECORD 12. 13. 12. 12. 12. 12. 12. 12. 12. 12. 10. 12. 10. NO DAYS MAX TEMP GTR OR EQ 9OF AVE. 0.0 0.0 0.0 0.0 1.1 8.3 18.1 12.7 4.0 0.0 0.0 0.0 45.4 MAX. 0 0 0 0 6 18 26 23 13 0 0 0 68 YEAR 1948 1948 1948 1948 1964 1956 1955+ 1949 1948 1948 1948 1948 1948 MIN. 0 0 0 0 0 1 5 4 0 0 0 0 27 YEAR 1967+ 1967+ 1966+ 1966+ 1965+ 1965+ 1958 1963+ 1965+ 1966+ 1966+ 1966+ 1951 YEARS OF RECORD 18. 19. 18. 18. 18. 19. 19. 19. 19. 18. 17. 18. 16. NO DAYS MAX TEMP LESS OR EQ 32F AVE. 10.4 6.1 3.7 0.5 0.1 0.0 0.0 0.0 0.0 0.1 3.2 6.3 31.5 MAX. 22 14 9 3 1 0 0 0 0 1 9 12 52 YEAR 1949 1955+ 1965 1959 1954 1948 1948 1948 1948 1961+ 1952 1961+ 1955 MIN. 0 0 0 0 0 0 0 0 0 0 0 0 19 YEAR 1965 1954 1961+ 1965+ 1966+ 1966+ 1966+ 1966+ 1966+ 1966+ 1949+ 1957 1953 YEARS OF RECORD 17. 19. 19. 18. 18. 18. 18. 18. 18. 18. 17. 16. 13. NO DAYS MIN TEMP LESS OR EQ 32F AVE. 31.0 28.0 29.1 14.5 1.9 0.1 0.0 0.0 1.6 14.8 29.0 30.9 181.4 MAX. 31 29 31 22 8 1 0 0 5 28 30 31 197 YEAR 1948 1964+ 1965+ 1953 1953 1954 1948 1948 1965 1952 1961+ 1965+ 1952 MIN. 31 26 26 10 0 0 0 0 0 1 27 30 157 YEAR 1967+ 1951 1963+ 1965 1963+ 1966+ 1966+ 1966+ 1966+ 1963 1964+ 1955+ 1963 YEARS OF RECORD 18. 20. 19. 19. 19. 18. 18. 18. 18. 17. 17. 17. 14. NO DAYS MIN TEMP LESS OR RI 0 F AVE. 8.1 3.2 1.5 0.1 0:D 0.0 0.0 0.0 0.0 0.0 0.9 3.1 16.8 MAX. 21 10 6 1 0 0 0 0 0 0 6 7 37 YEAR 1955 1956+ 1960+ 1957 1948 1948 1948 1948 1948 1948 1952 1961 1955 MIN. 0 0 0 0 0 0 0 0 0 0 0 0 5 YEAR 1965 1967+ 1966+ 1966+ 1966+ 1966+ 1966+ 1966+ 1966+ 1966+ 1966+ 1959+ 1953 YEARS OF RECORD 18. 20. 19. 18. 18. 18. 18. 18. 18. 18. 18. 14. 13. HIGHEST TEMPERATURE (F) TEMP 70 77 82 86 96 106 107 105 99 90 82 75 YEAR AND DAY194321+193227 194630 193825 194226+195424 193623 193801 195401+194706+193406+193911 YEARS OF RECORD 37. 37. 36. 36. 36. 36. 36. 36. 36. 35. 36. 35. LOWEST TEMPERATURE (F) TEMP -36 -39 -30 -2 23 31 40 39 23 8 -18 -30 YEAR AND DAY194205 195101 193212 194503 195402+194713 195208+196428+194527+193531 195227 193212 YEARS OF RECORD 35. 37. 36. 36. 36. 36. 36. 36. 36. 34. 35. 36. PRFD&RED BY: COLORADO CLIMATE CENTER, DEPT. OF ATMOSPHERIC SCIENCE, COLORADO STATE-UNIV. FT. COLLINS, CO 80523, (303)491-8545 SUMMARY OF MONTHLY CLIMATIC DATA FOR GREELEY COLORADO FOR YEARS 1931-1967 SUBSTATION NO. 53546 DIVISION 4 LATITUDE - 40 25 LONGITUDE - 104 41 ELEVATION - 4650 FEET JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC ANN MONTHLY PRECIPITATION (IN) AVE. 0.33 0.33 0.71 1.33 2.41 1.63 1.27 0.94 1.00 0.78 0.36 0.31 11.42 MAX. 1.22 1.18 2.65 4.32 5.79 3.99 3.73 3.77 3.61 2.95 2.06 1.50 18.68 YEAR 1948 1942 1961 1944 1935 1962 1961 1956 1966 1947 1946 1937 1961 MIN. 0.00 0.00 0.12 0.09 0.12 0.00 0.06 0.05 0.00 0.00 0.00 -1).00 5.65 YEAR 1966+ 1954 1966+ 1955 1963 1933 1966 1949 1953+ 1956+ 1965+ 1957+ 1954 YEARS OF RECORD 37. 37. 36. 36. 36. 36. 36. 36. 36. 36. 36. 36. 36. GREATEST DAILY PRECIP (IN) AMOUNT 0.43 0.42 0.83 1.50 1.80 2.68 1.31 1.83 1.60 0.94 0.49 0.58 YEAR AND DAY194826 195811 196128 195702 196430 196230 196101 196319 196321 196019 195511 195812 YEARS OF RECORD 20. 20. 19. 19. 18. 19. 19. 18. 19. 19. 19. 18. MONTHLY SNOWFALL (IN) AVE. 4.6 4.8 7.7 4.3 0.1 0.0 0.0 0.0 0.2 0.9 3.7 3.9 32.7 MAX. 16.0 12.0 18.0 27.5 1.0 0.0 0.0 0.0 4.0 9.5 21.5 13.5 52.7 YEAR 1949 1942 1959 1945 1943+ 1931 1931 1931 1959+ 1942 1946 1941 1944 MIN. 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 16.0 YEAR 1966+ 1963+ 1946+ 1965+ 1966+ 1966+ 1966+ 1966+ 1966+ 1966+ 1965+ 1959+ 1933 YEARS OF RECORD 29. 28. 24. 29. 35. 36. 36. 36. 36. 34. 27. 27. 18. GRTST DEPTH SNOW ON GRND IN MON (IN) 9 6 18 14 0 0 0 0 0 2 10 12 YEAR AND DAY194904 196029+195926 195312 -0 0 0 0 0 195106 195620 195813 YEARS OF RECORD 8. 10. 11. 11. 18. 19. 19. 19. 18. 18. 9. 7. NO DAYS PRECIP GTR OR EO 0.1 IN AVE. 2.0 1.7 3.3 3.5 6.4 4.7 3.9 3.5 3.0 2.3 2.1 1.6 39.4 MAX. 7 5 8 9 14 11 9 7 7 8 6 6 77 YEAR 1951+ 1948 1948 1953+ 1952 1949 1951 1951 1961 1959 1952 1951 1951 MIN. _0 0 0 -0 0 1 M 0 0 0 0 0 21 YEAR 1966+ 1967+ 1962 1962+ 1963 1956 1966 1960+ 1953 1956 1965+ 1964+ 1964+ YEARS OF RECORD 20. 20. 18. 19. 18. 19. 19. 18. 19. 19. 19. 18. 16. NO DAYS PRECIP GTR OR al 0.5 IN AVE. 0.2 0.0 0.3 0.6 1.9 1.2 0.7 0.5 0.8 0.5 0.0 0.1 6.6 MAX. 2 0 2 2 5 4 2 2 4 2 0 1 19 YEAR 1948 1948 1959+ 1952+ 1949 1949 1965+ 1963 1961 1960+ 1948 1958 1949 MIN. 0 0 0 0 0 0 0 0 0 0 0 0 2 YEAR 1967+ 1967+ 1966+ 1965+ 1966+ 1964+ 1966+ 1966+ 1962+ 1966+ 1966+ 1966+ 1954 YEARS OF RECORD 19. 19. 17. 18. 17. 18. 18. 17. 18. 18. 18. 18. 16. NO DAYS PRECIP GTR OR EO 1.0 IN AVE. 0.0 0.0 0:0 0.2 0.4 0.4 0.1 0.1 0.2 0.0 0.0 0.0 1.3 MAX. 0 0 0 1 2 2 1 1 2 0 0 0 3 YEAR 1948 1948 1948 1964+ 1961+ 1965 1965+ 1963+ 1966 1948 1948 1948 1966+ MIN. 0 0 0 0 -0 0 0 0 0 0 0 0 0 YEAR 1967+ 1967+ 1966+ 1966+ 1966+ 1964+ 1966+ 1966+ 1965+ 1966+ 1966+ 1966+ 1960+ YEARS OF RECORD 19. 19. 18. 19. 19. 19. 18. 17. 18. 18. 18. 18. 17. NUMBER OF DAYS WITH HAIL AVE. 0.0 0.0 0.0 0.0 0.1 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.1 MAX. 0 0 0 0 1 0 0 0 0 0 0 0 1 YEAR 1956 1956 1956 1956 1956 1956 1956 1956 1956 1956 1956 1956 1956 MIN. 0 0 0 0 0 0 0 0 0 0 0 0 0 YEAR 1967+ 1967+ 1966+ 1966+ 1966+ 1966+ 1966+ 1966+ 1966+ 1966+ 1966+ 1965+ 1965+ YEARS OF RECORD 12. 12. 11. 11. 11. 11. 11. 11. 11. 11. 11. 10. 10. ** NOTE : MANY WEATHER STATIONS DO NOT RECORD ALL HAIL OCCURRENCES. THEREFORE THESE DATA MAY NOT 8E-REPRESENTATIVE. NO. OF DAYS WITH SNOW ON GROUND AVE. 0.0 0.0 99.9 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 99.9 99.9 (GTR OR EQ 1 INCH ON GROUND) MAX. 0 0 999 0 0 0 0 0 0 0 -D 999 999 YEAR 1964 1963 0 1963 1963 1963 1963 1963 1963 1963 1965 0 0 MIN. 0 0 999 0 0 0 0 0 0 0 0 999 999 YEAR 1966+ 1963 0 1963 1966+ 1966+ 1966+ 1966+ 1966+ 1966+ 1965 0 0 YEARS OF RECORD 2. 1. 0. 1. 4. 4. 4. 4. 4. 4. 1. 0. 0. PREPARED BY: COLORADO CLIMATE CENTER, DEPT. OF ATMOSPHERIC-SCIENCE, COLORADO STATE UNIV. FT. COLLINS, CO 80523, (303)491-8545 9Z0:1'39 SUMMARY OF MONTHLY CLIMATIC DATAFOR GREELEY UNC COLORADO FOR YEARS 1967-1990 SUBSTATION NO. 53553 DIVISION 4 LATITUDE - 40 25 LONGITUDE - 104 42 ELEVATION - 4720 FEET JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC ANN MONTHLY MEAN MAXIMUM TEMP (F) AVE. 40.7 46.7 54.6 63.9 72.3 83.3 89.0 86.9 78.4 66.2 50.8 41.4 64.5 MAX. 48.8 57.2 63.6 70.6 79.3 89.6 92.0 90.7 85.1 72.9 58.3 53.9 68.2 YEAR 1981 1970 1972 1981 1974 1977 1980 1969 1977 1975 1981 1980 1977 MIN. 27.1 33.0 47.4 54.9 66.3 75.9 84.2 83.6 72.4 53.7 38.7 26.3 61.9 YEAR 1979 1989 1980 1984+ 1983 1967 1990 1981 1985 1969 1985 1983 1985 YEARS OF RECORD 23. 23. 24. 24. 24. 24. 24. 24. 24. 24. 24. 24. 23. MONTHLY MEAN MINIMUM TEMP (F) AVE. 13.7 19.1 25.9 34.2 43.4 52.5 57.7 55.4 45.9 34.7 23.9 15.2 35.2 MAX. 19.8 24.5 30.8 39.2 47.1 56.7 60.0 59.5 51.6 38.8 27.8 23.0 37.3 YEAR 1983 1987 1986 1981 1977 1988 1980 1983 1990 1973 1981 1980 1981 MIN. 4.6 9.9 20.2 27.4 39.8 49.1 56.0 50.7 42.0 29.7 15.8 6.0 33;0 YEAR 1979 1989 1969 1968 1968 1982 1967 1967 1971 1969 1985 1983 1985 YEARS OF-RECORD 23. 23. 24. 24. 24. 24. 24. 24. 24. 24. 24. 24. 23. MONTHLY MEAN AVERAGE TEMP (F) AVE. 27.2 32.9 40.3 49.1 57.9 68.0 73.4 71.2 62.2 50.5 37.4 28.3 49.9 MAX. 33.7 39.3 47.1 54.9 62.9 73.1 76.0 75.1 66.7 55.2 43.1 38.5 52.4 YEAR 1981 1970 1986 1981 1974 1977 1980 1983 1990+ 1973 1981 1980 1977 MIN. 15.9 21.5 34.6 42.5 53.2 62.6 70.5 67.5 58.1 41.7 27.3 16.2 47.5 YEAR 1979 1989 1969 1983 1983 1967 1990 1967 1971 1969 1985 1983 1985 YEARS OF RECORD 23. 23. 24. 24. 24. 24. 24. 24. 24. 24. 24. 24. 23. DEGREE DAYS (BASE 65F) AVE. 1165.4 901.0 758.1 472.6 230.0 44.7 3.9 6.5 123.4 443.7 822.2 1130.9 6098.0 MAX. 1514 1215 935 669 366 113 25 26 244 716 1125 1509 6870 YEAR 1979 1989 1969 1983 1983 1983 1972 1979 1985 1969 1985 1983 1985 MIN. 964 714 545 304 97 0 0 0 22 297 651 816 5356 YEAR 1981 1970 1986 1981 1977 1977 1986+ 1986+ 1969 1973 1981 1980 1981 YEARS OF RECORD 23. 23. 24. 24. 24. 24. 24. 24. 24. 24. 24. 24. 23. NO DAYS MAX TEMP GTR OR EQ 90F AVE. 0.0 0.0 0.0 -0.0 0.7 8.7 15.8 12.0 2.7 0.0 0.0 0.0 41.5 MAX. 0 0 -0 1 4 18 24 25 8 0 0 0 59 YEAR 1968 1968 1967 -1989 1969 1977 1980 1983 1983 1967 1967 1967 1980 MIN. 0 0 0 0 0 0 8 5 0 0 0 0 31 YEAR 1990+ 1990+ 1990+ 1990+ 1990+ 1967 1990 1974+ 1986+ 1990+ 1990+ 1990+ 1968 YEARS OF RECORD 23. 23. 24. 24. 24. 24. 23. 24. 24. 24. 24. 24. 22. NO DAYS MAX TEMP LESS OR ED 32F AVE. 7.9 3.6 1.7 0.2 0.0 0.0 0.0 0.0 0.0 0.2 2.6 6.7 22.8 MAX. 22 10 5 2 0 0 0 0 1 2 12 18 46 YEAR 1979 1989+ 1989+ 1973 1967 1967 1967 1967 1985 1969 1985 1983 1978 MIN. 1 0 0 0 0 0 0 0 0 0 0 1 9 YEAR 1990+ 1983+ 1986+ 1990+ 1990+ 1990+ 1990+ 1990+ 1990+ 1990+ 1989+ 1976 1977 YEARS OF RECORD 23. 23. 24. 24. 24. 24. 24. 24. 24. 24. 24. 24. 23. NO DAYS MIN TEMP LESS OR EQ 32F AVE. 30.5 27.2 25.5 12.0 1.5 0.0 0.0 0.0 1.3 12.0 25.7 30.3 165.7 MAX. 31 29 30 24 5 0 -D 0 7 20 30 31 183 YEAR 1990+ 1984+ 1980+ 1968 1967 1967 1967 1967 1985 1969 1979 1990+ 1984 MIN. 28 24 19 3 0 0 0 0 0 3 19 28 146 YEAR 1970 1971 1989+ 1969 1987+ 1990+ 1990+ 1990+ 1990+ 1974+ 1987 1987+ 1974 YEARS OF RECORD 23. 23. 24. 24. 24. 24. 24. 24. 24. 24. 24. 24. 23. NO DAYS MIN TEMP LESS OR EQ 0 F AVE. 4.2 1.5 0.2 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.4 3.1 9.5 MAX. 12 8 2 1 0 0 0 0 0 0 2 13 21 YEAR 1979 1989 1989+ 1975 1967 1967 1967 1967 1967 1967 1985+ 1983 1979 MIN. 0 0 0 0 0 0 0 0 0 0 0 0 2 YEAR 1990+ 1988+ 1990+ 1990+ 1990+ 1990+ 1990+ 1990+ 1990+ 1990+ 1990+ 1984+ 1970+ YEARS OF RECORD 23. 23. 24. 24. 24. 24. 24. 24. 24. 24. 24. 24. 23. HIGHEST TEMPERATURE (F) TEMP 74 76 81 90 95 103 103 102 99 89 79 75 YEAR AND DAY198226 198625 198630 198921 198929 199029 198908+197506 199013 197907 198007 198017 YEARS OF RECORD 23. 23. 24. 24. 24. 24. 24. 24. 24. 24. 24. 24. LOWEST TEMPERATURE (F) TEMP -25 -20 -4 -3 25 35 42 41 17 5 -7 -24 YEAR AND DAY198418 198905 197606 197502 198312 197511 197130 196831 -198530 196914 197229 198922 YEARS OF RECORD 23. 23. 24. 24. 24. 24. 24. 24. 24. 24. 24. 24. PREPARED BY: COLORADO CLIMATE CENTER, DEPT. OF ATMOSPHERIC SCIENCE, COLORADO STATE UNIV. FT. COLLINS, CO 80523, (303)491-8545 9?0,.., 39 SUMMARY OF MONTHLY CLIMATIC DATA FOR GREELEY UNC COLORADO FOR YEARS 1967-1990 SUBSTATION NO. 53553 DIVISION 4 LATITUDE - 40 25 LONGITUDE - 104 42 ELEVATION - 4720 FEET JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC ANN MONTHLY PRECIPITATION (IN) AVE. -0.49 0.36 1.19 1.73 2.70 1.85 1.42 1.08 1.11 0.97 0.82 0.51 14.23 MAX. 1.44 1.52 4.13 3.41 5.36 3.68 3.41 3.89 3.36 4.46 2.29 1.11 22.17 YEAR 1980 1987 1990 1983 1981 1983 1989 1979 1971 1969 1983 1979 1979 MIN. 0.02 0.00 0.09 0.18 0.10 0.21 0.28 0.12 0.00 O:D3 0.02 0.00 8.44 YEAR 1975 1977 1978 1982 1974 1990 1972 1973 1978 1988 1989+ 1974 1968 YEARS OF RECORD 23. 23. 24. 24. 24. 24. 24. 24. -24. 24. 24. 24. 23. GREATEST DAILY PRECIP (IN) AMOUNT 0.67 0.79 1.91 1.74 2.94 3.20 2.30 1.65 1.68 1.93 1.22 0.75 YEAR AND DAY198928 198726 199005 197122 197529 197408 198929 197910 197117 197822 197920 197927 YEARS OF RECORD 23. 23. 24. 24. 24. 24. 24. 24. 24. 24. 24. 24. MONTHLY SNOWFALL (IN) AVE. 5.9 -4.2 8.0 6.4 1.1 0.0 0.0 -0.0 0.7 3.5 8.1 6.L 42.8 MAX. 16.3 13.2 17.0 16.5 6.0 0.0 0.0 0.0 9.0 37.3 23.5 13:8 68.7 YEAR 1980 1987 1988 1984 1983+ 1967 1967 1967 1971 1969 1983 1975 1983 MIN. 0.3 0.0 0.3 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 17.4 YEAR 1968 1977 1978 1976+ 1990+ 1990+ 1990+ 1990+ 1990+ 1988+ 1989 1974 1976 YEARS OF RECORD 22. 22. 22. 20. 24. 24. -24. 24. 24. 21. 22. 20. 17. GRTST DEPTH SNOW ON GRND IN MON (IN) 12 9 30 9 6 0 0 0 5 17 16 13 YEAR AND DAY197103 0 197423 198420 197806 0 0 0 198529 196912 198327 0 YEARS OF RECORD 21. 21. 22. 22. 23. 24. 24. 24. 23. 21. 20. 18. NO DAYS PRECIP GTR OR EC, 0.1 IN AVE. 1.5 1.2 3.3 3.9 5.8 4.4 3.3 2.8 2.9 2.5 2.4 1.8 35.3 MAX. 6 5 7 8 12 11 6 6 6 8 6 4 49 YEAR 1980 1984 1980 1973 1987 1967 1982+ 1979 1985+ 1969 1987+ 1988+ 1987 MIN. 0 0 0 1 0 1 1 0 0 0 0 0 23 YEAR 1983+ 1985+ 1986+ 1982 1974 1990+ 1979+ 1973 1984+ 1988+ 1989+ 1976+ 1974 YEARS OF RECORD 23. 23. 24. 24. 24. 24. 24. 24. 24. 24. 24. 24. 23. NO DAYS PRECIP-4TR OR EO 0.5 IN AVE. 0.2 0.1 0.5 1.3 1.7 1.0 0.7 0.6 0.6 0.5 0.3 0.2 7.7 MAX. 2 2 2 3 5 3 2 2 2 4 2 1 13 YEAR 1973 1987 1990+ 1975 1981 1983 1989+ 1989+ 1971+ 1969 1972 1985+ 1969 MIN. 0 0 0 0 0 0 0 0 0 0 0 0 2 YEAR 1987+ 1990+ 1989+ 1990+ 1985+ 1990+ 1990+ 1987+ 1987+ 1990+ 1990+ 1990+ 1968 YEARS OF RECORD 23. 23. 24. 24. 24. 24. 24. 24. 24. 24. 24. 24. 23. NO DAYS PRECIP GTR OR EO 1.0 IN AVE. 0.0 0.0 0.1 0:2 0.5 0.4 0.2 0.1 0.2 0.2 0.1 0.0 2.1 MAX. 0 0 1 1 2 2 2 2 1 2 1 0 7 YEAR 1968 1968 1990+ 1984+ 1983+ 1983 1989 1979 1982+ 1969 1983+ 1967 1983 MIN. 0 0 0 0 0 0 0 0 0 0 0 0 0 YEAR 1990+ 1990+ 1989+ 1990+ 1990+ 1990+ 1990+ 1990+ 1990+ 1990+ 1990+ 1990+ 1987+ YEARS OF RECORD 23. 23. 24. 24. 24. 24. 24. 24. 24. 24. 24. 24. 23. NUMBER OF DAYS WITH HAIL AVE. 0.0 0.0 0.1 0.3 1.3 1.1 0.5 0.1 0.1 0.1 0.0 0.0 3.4 MAX. 0 0 1 2 3 -4 2 1 1 1 0 0 5 YEAR 1968 1968 1975 1968 1972+ 1967 1976 1979+ 1976 1971 1967 1967 1981+ MIN. 0 0 0 0 0 0 0 0 0 0 0 0 1 YEAR 1981+ 1981+ 1981+ 1981+ 1979+ 1980+ 1980+ 1981+ 1981+ 1981+ 1981+ 1981+ 1974+ YEARS OF RECORD 14. 14. 15. 15. 15. 15. 15. 15. 15. 15. 15. 15. 14. ** NOTE : MANY WEATHER STATIONS DO NOT RECORD ALL HAIL OCCURRENCES. THEREFORE THESE DATA MAY NOT BE REPRESENTATIVE. NO. OF DAYS WITH SNOW ON GROUND AVE. 14.8 7.7 4.8 1.8 0.3 0.0 0.0 0.0 0.2 1.0 5.8 14.4 53.8 (GTR OR EO 1 INCH ON GROUND) MAX. 31 22 10 9 3 0 0 0 - 3 9 21 31 92 YEAR 1988 1989+ 1979 1983 1979 1967 1967 1967 1985 1969 1985 1985+ 1985 MIN. 0 0 0 0 0 0 0 0 0 0 1 0 13 YEAR 1983+ 1983+ 1978 1990+ 1990+ 1990+ 1990+ 1990+ 1990+ 1990+ 1989+ 1976+ 1977 YEARS OF RECORD 22. 20. 21. 21. 24. 24. 24. 24. 23. 22. 19. 20. 15. PREPARED BY: COLORADO CLIMATE CENTER, DEPT. OF ATMOSPHERIC SCIENCE, COLORADO STATE UNIV. FT. COLLINS, CO 80523, (303)491-8545 9 :0_ 33 SUMMARY OFMONTHLY CLIMATIC DATA FOR FORT MORGAN COLORADO FOR YEARS 1931-1990 SUBSTATION NO. 53038 DIVISION 4 LATITUDE - 40 15 LONGITUDE - 103 48 ELEVATION - 4320 FEET JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC ANN MONTHLY MEAN MAXIMUM TEMP (F) AVE. 38.8 44.0 51.6 62.6 71.8 82.9 89.9 87.3 78.3 67.5 51.6 41.7 64.0 MAX. 49.8 58.5 62.3 71.0 79.2 90.3 94.2 93.6 84.4 75.6 63.6 51.5 67.9 YEAR 1934 1954 1986 1946 1934 1956 1964+ 1983 1977 1950 1949 1980 1934 MIN. 20.5 27.1 39.8 52.6 60.0 74.4 84.1 81.8 66.3 52.8 38.5 24.7 60.4 YEAR 1937 1942 1958 1957 1935 1945 1958 1933 1965 1969 1985 1983 1942 YEARS OF RECORD 60. 60. 60. 60. 60. 60. 60. 60. 60. 60. 60. 60. 60. MONTHLY MEAN MINIMUM TEMP (F) AVE. 9.2 15.3 23.2 33.9 44.2 53.6 59.2 57.0 46.9 34.4 21.5 12.7 34.3 MAX. 18.5 23.6 28.4 40.8 49.4 58.6 63.2 63.4 53.2 41.2 27.4 20.5 37.4 YEAR 1983 1954 1940 1943 1958 1988 1966 1983 1963 1963 1949 1980 1981 MIN. -11.5 -0.1 13.3 28.3 39.1 48.7 54.6 53.0 40.8 29.0 13.7 -0.6 31.1 YEAR 1937 1942 1932 1933 1950 1951 1950 1953 1934 1969 1985 1932 1937 YEARS OF RECORD 60. 60. 60. 60. 60. 60. 60. 60. 60. 60. 60. 60. 60. MONTHLY MEAN AVERAGE TEMP (F) AVE. 24.0 29.7 37.4 48.3 58.0 68.3 74.6 72.2 62.6 51.0 36.6 27.2 49.2 MAX. 33.5 41.1 44.9 55.6 62.9 73.9 78.1 78.5 67.8 58.2 -45.5 36.0 52.1 YEAR 1934 1954 1986 1946 1963 1956 1966 1983 1990 1963 9949 1980 1981 MIN. 4.5 13.5 27.7 42.0 50.0 62.2 70.4 69.0 54.0 40.9 26.1 13.1 46.4 YEAR 1937 1942 1965 1957 1935 1951+ 1958+ 1946 1965 1969 1985 1983 1937 YEARS OF RECORD 60. 60. 60. 60. 60. 60. 60. 60. 60. 60. 60. 60. 60. DEGREE DAYS (BASE 65F) AVE. 1270.6 963.9 842.2 499.5 222.8 46.6 4.2 9.7 134.7 434.2 846.0 1170.8 6442.3 MAX. 1640 1264 1150 685 370 108 42 39 335 743 1160 1597 7095 YEAR 1963 1956 1965 1957 1967 1983 1972 1968 1965 1969 1985 1983 1985 MIN. 993 0 613 291 98 0 0 0 37 212 650 894 5441 YEAR 1981 1957 1986 1981 1977 1977 1989+ 1984+ 1981 1963 1981 1980 1981 YEARS OF RECORD 37. 37. 37. 36. 36. 36. 36. 36. 36. 36. 36. 36. 36. NO DAYS MAX TEMP-OTR OR EO 90F AVE. 0.0 0.0 0.0 0.0 1.0 9.0 18.1 13.9 4.3 0.1 0.0 0.0 46.7 MAX. 0 0 0 1 6 18 28 27 11 1 0 0 68 YEAR 1948 1948 1948 1989+ 1964 1980+ 1963 1983 1983 1989+ 1948 1948 1980 MIN. 0 0 0 0 0 0 5 5 0 0 0 0 20 YEAR 1990+ 1990+ 1990+ 1990+ 1990+ 1967 1958 1965+ 1986+ 1990+ 1990+ 1990+ 1965 YEARS OF RECORD 42. -42. 42. 42. 42. 43. 43. 43. 43. 42. 42. 42. -42. NO DAYS MAX TEMP LESS OR E032F AVE. 9.5 5.0 3.4 0.5 0.0 0.0 0.0 0.0 0.0 0.2 3.0 7.0 29.0 MAX. 22 12 10 3 0 0 0 0 1 3 17 20 50 YEAR 1979+ 1948 1958 1973+ 1948 1948 1948 1948 1985 1969 1985 1983 1985 MIN. 0 0 0 0 0 0 0 0 0 0 0 0 13 YEAR 1965 1983+ 1986+ 1987+ 1990+ 1990+ 1990+ 1990+ 1990+ 1990+ 1989+ 1959+ 1981 YEARS OF RECORD 43. 42. 43. 42. 42. 42. 42. 42. 42. 42. 43. 43. 41. NO DAYS MIN TEMP LESS OR EO 32F AVE. 31.0 27.3 27.3 12.5 1.3 0.0 0.0 0.0 1.0 12.9 27.7 30.9 171.9 MAX. 31 29 31 22 4 0 0 0 8 26 30 31 192 YEAR 1948 1988+ 1973+ 1956 1978+ 1948 1948 1948 1985 1985 1979+ 1990+ 1970 MIN. 31 0 18 5 0 0 0 0 0 0 20 30 144 YEAR 1990+ 1957 1989 1981+ 1987+ 1990+ 1990+ 1990+ 1990+ 1963 1987 1983+ 1957 YEARS OF RECORD 43. 43. 43. 43. 43. 42. 42. 42. 42. 43. 43. 43. 42. NO DAYS MIN TEMP LESS OR EO 0 F AVE. 7.2 3.0 0.8 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.7 3.9 15.6 MAX. 20 10 6 1 0 0 0 0 0 0 6 14 34 YEAR 1963+ 1948 1948 1975 1948 1948 1948 1948 1948 1948 1952 1983 1948 MIN. 0 0 0 0 0 0 0 0 0 0 0 0 4 YEAR 1989+ 1987+ 1990+ 1990+ 1990+ 1990+ 1990+ 1990+ 1990+ 1990+ 1990+ 1984+ 1970 YEARS OF RECORD 43. 42. 43. 42. 42. 42. 42. 42. 42. 42. 43. 43. -41. HIGHEST TEMPERATURE (F) TEMP 75 75 85 90 96 105 107 105 102 92 85 84 YEAR AND DAY198227 198626+196329+198922+198930 199028 198910+193801 198501 198001 194115 194102 YEARS OF RECORD 60. 60. 60. 60. 60. 60. 60. 60. 60. 60. 60. 60. LOWEST TEMPERATURE (F) TEMP -35 -41 -27 -1 23 32 42 40 11 5 -19 -30 YEAR AND DAY194205 195101 193212 197502 195402 194712+197130+196428+198530 196915 195010 193212 YEARS OF RECORD 60. 60. 59. 60. 60. 60. 60. 60. 60. 60. 60. 60. PREPARED BY: COLORADO CLIMATE CENTER, DEPT. OF ATMOSPHERIC SCIENCE, COLORADO STATE UNIV. FT. COLLINS, CO 80523, (303)491-8545 SUMMARY OF MONTHLY CLIMATIC DATA FOR FORT MORGAN COLORADO FOR YEARS 1931.1990 SUBSTATION NO. 53038 DIVISION 4 LATITUDE - 40 15 LONGITUDE - 103 48 ELEVATION - 4320 FEET JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC ANN MONTHLY PRECIPITATION (IN) AVE. 0.27 0.21 0.70 1.35 2.61 1.94 1.78 1.44 1.16 0.70 0.37 0.28 12.76 MAX. 0.99 0.81 2.66 4.09 6.53 4.04 6.70 5.06 4.67 4.57 1.32 0.78 18.86 YEAR 1945 1953 1990 1935 1967 1958 1956 1946 1973 1942 1944 1933 1990 MIN. 0.00 0.00 0.00 0.03 0.26 0.05 0.25 0.00 . 0.00 0.00 0.00 0.00 5.15 YEAR 1983+ 1979+ 1985 1955 1974 1952 1935 1947 1943 1980+ 1984+ 1981+ 1939 YEARS OF RECORD 60. 60. 60. 60. 60. 60. 60. 60. 60. 60. 60. 59. 59. GREATEST DAILY PRECIP (IN) AMOUNT 0.57 0.59 1.43 1.36 2.59 2.13 4.60 1.73 2.33 1.22 0.71 0.61 YEAR AND DAY199020 195008 198305 197325 198725 196608 195631 195405 197308 198405 197921 198225 YEARS OF RECORD 40. 41. 43. 41. 43. 42. 43. 43. 42. 43. 43. 42. MONTHLY SNOWFALL (IN) AVE. 5.0 3.4 6.7 3.1 0.3 0.0 0.0 0.0 0.4 0.9 3.3 4.3 28.2 MAX. 14.5 12.0 20.5 15.0 6.0 0.0 0.0 0.0 10.5 17.0 20.5 15.0 54.5 YEAR 1984 1931 1974 1935 1957 1931 1931 1931 1936 1969 1983 1987 1984 MIN. 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 7.8 YEAR 1986+ 1987+ 1989+ 1990+ 1990+ 1990+ 1990+ 1990+ 1990+ 1989+ 1989+ 1981+ 1986 YEARS OF RECORD 52. 50. 44. 52. 57. 60. 60. 60. 58. 58. 52. 47. 34. GRTST DEPTH SNOW ON GRND IN MON (IN) 11 3 7 12 1 0 0 0 0 3 10 8 YEAR AND DAY198820+198811+195926+195703 196807+ 0 0 0 0 196614 197201 198511 YEARS OF RECORD 19. 16. .18. 26. 40. 43. 43. 43. 41. 33. 26. 19. NO DAYS PRECIP GTR OR ED 0.1 IN AVE. 1.3 0.9 2.4 3.7 6.2 4.9 4.3 4.0 3.1 2.0 1.6 1.4 36.5 MAX. 6 6 10 12 18 12 10 11 10 7 8 6 74 YEAR 1949 1953 1949 1953 1952 1967 1951 1952 1950 1986 1952 1948 1952 MIN. 0 0 0 0 1 1 1 0 0 0 0 0 16 YEAR 1987+ 1990+ 1989+ 1965+ 1974 1959+ 1971+ 1985+ 1981+ 1988+ 1989+ 1990+ 1964 YEARS OF RECORD 41. -42. 42. 41. 43. 42. 43. 43. 43. 43. 43. 42. 37. NO DAYS PRECIP GTR OR ED 0.5 IN AVE. 0.1 0.0 0.3 0.8 1.9 1.6 1.2 1.0 0.8 0.4 0.1 0.0 7.9 MAX. 1 0 2 3 6 5 4 3 4 4 1 1 17 YEAR 1990+ 1948 1990+ 1983+ 1967 1949 1965 1990+ 1973 1969 1990+ 1982 1948 MIN. 0 0 0 0 0 0 0 0 0 0 0 0 3 YEAR 1989+ 1990+ 1989+ 1990+ 1989+ 1988+ 1988+ 1988+ 1990+ 1990+ 1989+ 1990+ 1988 YEARS OF RECORD 42. 42. 42. 42. 42. 42. 42. 42. 42. 41. 42. 41. 40. NO DAYS PRECIP GTR OR EC 1.0 IN AVE. 0.0 0.0 0.1 0.1 0.5 0.3 0.3 0.2 0.1 0.0 0.0 0.0 1.6 MAX. 0 0 1 1 2 2 3 1 1 1 0 0 5 YEAR 1948 1948 1990+ 1973+ 1975+ 1970 1965 1990+ 1989+ 1984+ 1948 1948 1965 MIN. 0 0 0 0 0 0 0 0 0 0 0 0 0 YEAR 1990+ 1990+ 1989+ 1990+ 1990+ 1990+ 1989+ 1988+ 1990+ 1990+ 1990+ 1990+ 1980+ YEARS OF RECORD 42. 42. 42. 42. 42. 42. 42. 42. 42. 42. 42. 41. 41. NUMBER OF DAYS WITH HAIL AVE. 0.0 0.0 0.0 0.0 0.3 0.2 0.2 0.0 0.1 0.0 0.0 0.0 0.9 MAX. 0 0 0 1 2 2 2 1 2 1 0 0 5 YEAR 1956 1956 1956 1974 1961 1958 1962 1958 1973 1971 1956 1956 1958 MIN. 0 0 0 0 0 0 0 0 0 0 0 0 0 YEAR 1981+ 1981+ 1981+ 1981+ 1981+ 1981+ 1981+ 1981+ 1981+ 1981+ 1981+ 1981+ 1981+ YEARS OF RECORD 26. 26. 26. 26. 26. 26. 26. 26. 26. 26. 25. 26. 25. " NOTE : MANY WEATHER STATIONS DO NOT RECORD ALL HAIL OCCURRENCES. THEREFORE THESE DATA MAY NOT BE REPRESENTATIVE. NO. OF DAYS WITH SNOW ON GROUND AVE. 0.6 1.2 1.1 0.0 0.1 0.0 0.0 0.0 0.0 0.1 0.6 1.5 5.0 (GTR OR EO 1 INCH ON GROUND) MAX. 3 3 4 0 1 0 0 0 0 1 9 14 7 YEAR 1965 1986+ 1982+ 1963 1968+ 1963 1963 1963 1963 1990+ 1985 1985 1988 MIN. 0 0 0 0 0 0 0 0 0 0 0 0 3 YEAR 1990+ 1990+ 1990+ 1990+ 1990+ 1990+ 1990+ 1990+ 1990+ 1989+ 1990+ 1987+ 1986 YEARS OF RECORD 11. 13. 14. 18. 26. 28. 28. 28. 27. 26. 16. 13. 2. PREPARED BY: COLORADO CLIMATE CENTER, DEPT. OF ATMOSPHERIC SCIENCE, COLORADO STATE UNIV. FT.-COLLINS, CO 80523, (303)491-8545 3: OI 33 SUMMARY OF MONTHLY CLIMATIC DATA FOR BYERS 5 ENE COLORADO FOR YEARS 1931-1990 SUBSTATION NO. 51179 DIVISION 4 LATITUDE - 39 45 LONGITUDE - 104 8 ELEVATION - 5100 FEET JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC ANN MONTHLY MEAN MAXIMUM TEMP (F) AVE. 42.3 46.2 52.4 62.6 71.7 83.4 90.2 88.0 79.4 68.0 53.0 44.6 65.2 MAX. 54.7 59.2 62.4 70.7 78.7 92.4 94.6 93.2 85.9 77.6 64.9 55.8 69.8 YEAR 1986 1954 1986 1954 1963 1956 1939 1937 1948 1950 1949 1980 1954 MIN. 28.9 34.2 42.6 53.0 58.3 74.0 84.6 83.9 70.6 52.5 38.5 26.4 61.4 YEAR 1979 1942 1965 1944 1935 1967 1967 1967+ 1965 1969 1972 1983 1983 YEARS OF RECORD 59. 59. 59. 60. 60. 59. 60. 60. 60. 60. 60. 60. 56. MONTHLY MEAN MINIMUM TEMP (F) AVE. 12.9 17.0 22.8 31.8 41.5 50.3 56.3 54.8 46.1 34.8 22.5 15.4 33.9 MAX. 23.4 26.6 28.7 38.2 48.3 55.5 60.3 58.9 52.7 43.4 29.8 24.3 37.1 YEAR 1953 1954 1986 1943 1934 1956 1933 1932 1963 1963 1949 1933 1934 MIN. -4.4 5.6 13.8 24.6 34.5 45.3 52.5 50.1 39.7 27.1 13.2 1.5 29.5 YEAR 1937 1936 1965 1975 1975 1975 1972 1974 1974 1969 1979 1983 1975 YEARS OF RECORD 59. 59. 59. 60. 60. 59. 60. 60. 60. 60. 60. 60. 56. MONTHLY MEAN AVERAGE TEMP (F) AVE. 27.6 31.6 37.6 47.2 56.6 66.8 73.3 71.4 62.8 51.4 37.8 30.0 49.5 MAX. 38.1 42.9 45.6 54.2 61.7 74.0 77.0 75.8 68.7 59.0 47.4 39.0 53.2 YEAR 1986 1954 1986 1946 1958 1956 1954 1937 1948 1950 1949 1980 1954 MIN. 12.4 20.1 28.2 40.8 48.4 60.6 69.7 67.3 55.7 39.8 26.4 14.0 46.7 YEAR 1937 1942 1965 1945 1935 1945 1950 1967 1965 1969 1972 1983 1973 YEARS OF RECORD 59. 59. 59. 60. 60. 59. 60. 60. 60. 60. 60. 60. 56. DEGREE DAYS (BASE 65F) AVE. 1161.5 940.0 847.2 535.0 262.8 60.3 4.7 8.8 132.9 434.9 828.0 1103.8 6320.7 MAX. 1560 1199 1132 719 400 153 31 30 300 774 1150 1577 7100 YEAR 1979 1960 1965 1983 1975 1969 1972 1956 1965 1969 1972 1983 1983 MIN. 824 613 596 341 135 0 0 0 18 214 620 800 5160 YEAR 1986 1954 1986 1954 1958 1977+ 1989+ 1988+ 1963 1963 1965 1980 1954 YEARS OF RECORD 39. 40. 39. 40. 40. 39. 40. 40. 40. 40. 40. 40. 37. NO DAYS MAX TEMP GTR OR EQ 90F AVE. 0.0 0.0 0.0 0.0 0.8 9.0 17.9 13.6 4.1 0.0 0.0 0.0 46.1 MAX. 0 0 0 1 6 19 28 22 11 1 0 0 74 YEAR 1948 1948 1948 1989 1964 1956 1955 1962+ 1956 1967+ 1949 1948 1954 MIN. 0 0 0 0 0 0 8 4 0 0 0 0 18 YEAR 1990+ 1990+ 1990+ 1990+ 1990+ 1967 1967+ 1963 1986+ 1990+ 1990+ 1990+ 1967 YEARS OF RECORD 41. 42. 41. 42. 42. 42. 43. 43. 43. 42. 41. 42. 38. NO DAYS MAX TEMP LESS OR EQ 32F AVE. 7.2 3.9 2.3 0.2 0.0 0.0 0.0 0.0 0.0 0.1 2.3 4.9 21.1 MAX. 19 11 7 3 0 0 0 0 1 1 12 16 38 YEAR 1979 1989 1969+ 1983 1948 1948 1948 1948 1985 1986+ 1985 1983 1983 MIN. 0 0 0 0 0 0 0 0 0 0 0 0 8 YEAR 1986+ 1977+ 1986+ 1990+ 1990+ 1990+ 1990+ 1990+ 1990+ 1990+ 1989+ 1970+ 1981+ YEARS OF RECORD 41. 42. 42. 42. 42. 41. 42. 42. 42. 42. 42. 43. 37. NO DAYS MIN TEMP LESS OR EO 32F AVE. 30.5 27.1 28.0 17.0 3.5 0.1 0.0 0.0 1.6 12.6 26.3 30.2 177.8 MAX. 31 29 31 25 12 2 0 0 7 26 30 31 209 YEAR 1988+ 1988+ 1980+ 1975+ 1975 1951 1948 1948 1985+ 1969 1979+ 1990+ 1975 MIN. 27 22 23 9 0 0 0 0 0 0 19 26 153 YEAR 1950 1962+ 1989+ 1986+ 1987+ 1990+ 1990+ 1990+ 1990+ 1948 1953 1955 1963 YEARS OF RECORD 42. 43. 42. 42. 43. 41. 42. 42. 42. 43. 41. 43. 37. NO DAYS MIN TEMP LESS OR EO 0 F AVE. 5.7 2.5 1.1 0.1 0.0 0.0 0.0 0.0 0.0 0.0 0.7 3.3 13.5 MAX. 18 9 7 1 0 0 0 0 0 0 4 14 33 YEAR 1979 1982 1965 1983+ 1948 1948 1948 1948 1948 1948 1979+ 1983 1979 MIN. 0 0 0 0 0 0 0 0 0 0 0 0 1 YEAR 1986+ 1987+ 1990+ 1990+ 1990+ 1990+ 1990+ 1990+ 1990+ 1990+ 1990+ 1980+ 1953 YEARS OF RECORD 41. 42. 42. 42. 42. 41. 42. 42. 42. 42. 42. 43. 37. HIGHEST TEMPERATURE (F) TEMP 74 76 85 92 97 106 105 104 99 90 80 76 YEAR AND DAY198630 193520 196328 198921 198928 195423 199001+193801 195402 196703+197808+198027 YEARS OF RECORD 60. 59. 59. 60. 60. 59. 60. 60. 59. 59. 59. 60. LOWEST TEMPERATURE (F) TEMP -32 -36 -16 -9 20 29 38 37 10 1 -19 -33 YEAR AND DAY198418 193608 194302+197502 197807+195102 197130 196421+198530 196914 195516 198922 YEARS OF RECORD 59. 59. 59. 60. 60. 60. 60. 60. 58. 58. 59. 60. PP"`RED BY: COLORADO CLIMATE CENTER, DEPT. OF ATMOSPHERIC SCIENCE, COLORADO STATE UNIV. FT. COLLINS, CO 80523, (303)491-8545 9F ,o,: ?9 • SUMMARY OF MONTHLY CLIMATIC DATA FOR BYERS 5 ENE COLORADO FOR YEARS 1931-1990 SUBSTATION NO. 51179 DIVISION 4 LATITUDE - 39 45 LONGITUDE - 104 8 ELEVATION - 5100 FEET JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC ANN MONTHLY PRECIPITATION (IN) AVE. 0.43 0.42 0.96 1.61 2.66 1.89 2.08 1.63 1.31 0.76 0.61 0.41 14.81 MAX. 1.39 1.60 3.34 5.24 6.06 8.01 5.17 5.93 5.67 4.22 2.74 1.60 23.76 YEAR 1942 1934 1981 1938 1975 1965 1985 1951 1938 1969 1972 1973 1969 MIN. 0.00 0.00 0.13 0.28 0.17 0.10 0.44 0.01 0.00 0.00 0.00 0.00 6.31 YEAR 1983+ 1973+ 1982 1956 1974 1956 1939 1960 1978 1988+ 1965 1980 1954 YEARS OF:RECORD 60. 60. 60. 60. 60. 60. 60. 60. 60. 60. 60. 59. 59. GREATEST DAILY PRECIP (IN) AMOUNT 0.68 0.56 1.30 2.02 3.91 3.02 3.24 4.02 4.01 1.37 1.66 0.67 YEAR ANO DAY196208 198411 198104 195702 197306 196516 198519 195103 196602 196614 197201 197324 YEARS OF RECORD 40. 42. 39. 43. 41. 43. 43. 43. 42. 42. 42. 39. MONTHLY SNOWFALL (IN) AVE. 6.9 5.9 10.2 6.2 0.7 0:0 0.0 0.0 0.9 2.7 6.1 5.9 47.0 MAX. 18.0 20.0 32.0 35.2 7.0 0.5 0.0 0.0 18.0 38.0 29.5 20.0 83:0 YEAR 1965 1934 1981 1935 1950 1937 1931 1931 1936 1969 1946 1982 1959 MIN. 0.0 0.0 0.5 0.0 0.0 0.0 0.0 0.0 0.0 -0.0 0.0 0.0 23.0 YEAR 1983+ 1973+ 1986 1985+ 1990+ 1990+ 1990+ 1990+ 1990+ 1988+ 1988+ 1980+ 1943 YEARS OF RECORD 52. 55. 50. 55. 56. 60. 60. 59. 59. 57. 53. 54. 43. GRIST DEPTH SNOW ON GRND IN MON (IN) 12 13 13 14 4 0 0 0 9 14 15 18 YEAR AND DAY 0 0 197923 198422 197301 0 0 0 197117 196912+198327+198225 YEARS OF RECORD 31. 32. 30. 30. 36. 43. 43. 42. 40. 34. 32. 34. NO DAYS PRECIP-GTR OR EQ 0.1 IN AVE. 1.7 1.7 3.4 3.8 5.8 4.7 5.5 4.3 3.1 2.0 2.2 1.5 40.8 MAX. 7 5 10 9 15 13 11 11 9 7 7 5 78 YEAR 1951 1952 1952 1957+ 1949 1949 1951 1951 1950 1969 1952 1960 1951 MIN. 0 0 0 1 1 0 2 -0 0 0 0 0 24 YEAR 1984+ 1990+ 1978+ 1982+ 1974+ 1956 1978+ 1960+ 1983+ 1988+ 1981+ 1990+ 1977+ YEARS OF RECORD 41. 42. 40. 43. 40. 43. 43. 42. 43. 42. 41. 41. 34. NO DAYS PRECIP GTR OR EO 0.5 IN AVE. 0.1 0.0 0.4 0:8 1.9 1.2 1.3 1.0 0.8 0.5 0.2 0.1 8.6 MAX. 1 1 4 3 5 6 5 3 5 5 -2 2 21 YEAR 1990+ 1984 1949 1984+ 1957 1949 1958 1984+ 1963 1969 1979 1982 1949 MIN. 0 0 0 0 0 0 0 0 0 0 0 0 1 YEAR 1989+ 1990+ 1989+ 1990+ 1984+ 1990+ 1988+ 1989+ 1990+ 1989+ 1989+ 1990+ 1954 YEARS OF RECORD 42. 42. 39. 42. 41. 42. 42. 42. 42. 41. 41. 41. 36. NO DAYS PRECIP GTR OR EO 1.0 IN AVE. 0.0 0.0 0.1 0.2 0.6 0.3 0.5 0.3 0.2 0.1 0.0 0.0 2.3 MAX. 0 0 1 1 3 3 2 2 2 1 1 0 6 YEAR 1948 1948 1983+ 1984+ 1957 1965 1985+ 1951 1963 1984+ 1972 1948 1969+ MIN. 0 0 0 0 0 0 0 0 0 0 0 0 0 YEAR 1990+ 1990+ 1990+ 1990+ 1990+ 1990+ 1990+ 1990+ 1990+ 1990+ 1990+ 1990+ 1990+ YEARS OF RECORD 42. 42. 39. 42. 42. 42. 43. 42. 42. 41. 42. 41. 37. NUMBER OF DAYS WITH HAIL AVE. 0.0 0.0 0.0 0.2 0.9 0.8 0.3 0.2 0.2 0.0 0.0 0.0 2.6 MAX. 0 0 1 2 3 4 2 2 1 0 0 0 9 YEAR 1956 1956 1966 1968 1967+ 1962 1967+ 1969 1966+ 1956 1956 1956 1964 MIN. 0 0 -0 0 0 0 0 0 0 0 0 0 0 YEAR 1981+ 1981+ 1981+ 1981+ 1981+ 1979+ 1981+ 1981+ 1981+ 1981+ 1981+ 1981+ 1976+ YEARS OF RECORD 26. 26. 25. 26. 26. 26. 26. 26. 26. 26. 26. 26. 25. *' NOTE : MANY WEATHER STATIONS DO NOT RECORD ALL HAIL OCCURRENCES. THEREFORE THESE DATA MAY NOT BE REPRESENTATIVE. NO. OF DAYS WITH SNOW ON GROUND AVE. 16.3 11.6 6.7 2.1 0.1 0.0 0.0 0.0 0.1 1.3 6.3 12.1 59.7 (GTR OR EQ 1 INCH ON GROUND) MAX. 31 29 24 8 2 0 0 0 2 11 30 31 109 YEAR 1988+ 1984+ 1984 1984 1979 1963 1963 1963 1985+ 1969 1972 1986+ 1984 MIN. 0 0 1 0 0 0 0 0 0 0 0 0 18 YEAR 1970 1970+ 1989+ 1990+ 1990+ 1990+ 1990+ 1990+ 1990+ 1988+ 1988+ 1980 1976 YEARS OF RECORD 27. 28. 27. 28. 27. 28. 28. 28. 28. 28. 27. 28. 24. PREPARED BY: COLORADO CLIMATE CENTER, DEPT. OF ATMOSPHERIC SCIENCE, COLORADO STATE UNIV. FT. COLLINS, CO 80523, (303)491-8545 • m — i • _ — =t• N • • - •• • h • •• • • U ! • • • •_•• - .am' • •• •> a• V 0 1V CO _� • • s°. a r1.. — g d' ._. - U•e • s P O a to oa a C C • 6 I, • I. • S a = u y V1 a. m cu a 9 O 0 U p < a ..1 -.-- c y A O m Q .= i c • < C\-L t, 0 • 156 •;.. • H • ' s a • .'. - ._ I' w a • - O O m t00 O N O I C •O I ( .4) asn3esadtuay 9.4 _0_39 Hello