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Home My WebLink About20060440.tiff Weld County Sheriff's Office M e mo To: Kim Ogle From: Ken Poncelow CC: Date: October 28,2005 Re: USR-1529 The Sheriffs Office approves this plan. Please notify the developer/owner that the Sheriffs Office would be willing to assist in the development of a security plan for the site free of charge. If this is of interest, please have them contact me. 2006-0440 lb_EXHIBIT 1 1 Dec 05 2005 12: 48PM HP LASERJET FAX 303-652-8788 p. 1 ASPHALT !'fir �. +r..,, ;+�•en v�.'.► vwr� — � ' ; �„R. SPECIALTIES Co . 10100 Dallas St. • Henderson, CO 80640 • (303)289-8555 • Fax: (303) 289-7707 FACSIMILE TRANSMITTAL SHEET To: Kim Ogle From: Rob Laird,Land Manager Company: Weld County Planning Date: December 5,2005 Fax Number. 1-970-304-6498 Phone Number: Total Number of Pages Including Cover. 2 Re: DMG Approval for Nelson Mining Resource, USR-1529 O URGENT ❑ FOR REVIEW O PLEASE COMMENT O PLEASE REPLY O PLEASE RECYCLE Kim: Please see following approval from DMG for Nelson Mining Resource, USR-1529. Please call if there are any questions re. this approval. I will be submitting warranties to DMG in the near future. We are working on approvals for the temp sub supply plan and from the oil companies. Thanks.Rob EXFII R Dec O5 2OO5 12: 48PM HP LASERJET FAX 3O3-652-8788 02-DEC-2005 12:21 FROMtolorSo Dryly Ion of Minerals & Geology ♦19039128100 7-250 P,001/004 F-441 STATE OF COLORADO DIVISION OF MINEIIALS AND GEOLOGY DiraratYaent of Neon(aaseum e 1313 Rieman St,Roan 215 Denver,Colorado 10203 ncoLoRAD1 Plum PM 1166.1537 FFAX 13031032100 SY. December 1,2005 {i10MSK 'lr_ Cana.Dan Hunt Ranellcy,ee Mr. Asphalt Specialties Co.,Inc. taw,*arum 10100 Dallas St Rears W.caw Henderson,CO 80640 Owlet aLeaor NruNnir eumUmm Rae lie Ne. M-2005.199, Nelson Mining Resource, 112e Decision Performance Warranty latter - Conditions, Financial and Request-Construction Material Operation Derr Mr. Hind: On November 29, 2005, the Division of Minerals and Geology approved your 112o mining permit application. The conditions to the approval are noted below: Stipulation No. Description 1 No mining within two feet of the normal static i groundwater. level until substitute water supply plan is issued by the State En&racers Office. The amount of financial watrannty set by the Division for this operation is $186,81351. You must submit a financial warranty in this amount and a performance warranty in order for us to issue a permit. In the event you hove requested a financial warranty fort, we have enclosed it in this letter. If you have not,please select a type of financial warranty from Rule 4.3. Then contact us so that we can provide you with the appropriate warranty form. We have enclosed a performance warranty form with this letter for your use. PLEASE NOTE THAT MINING OPERATIONS MAY NOT COMMENCE UNTIL A PERMIT HAS BEEN ISSUED BY THE DIVISIONAUEg RECEIPT OF YOUR FINANCIAL WARRANTY AND PERFORMANCE WARRANTY. A PERMIT WILL NOT BE ISSUED UNTIL WE VERIFY THE ADEQUACY 01?BOTH YOUR FINANCIAL WARRANTY AND PERFORMANCE WARRANTY. If you have any questions,please contact me. Sincerely, cbt 1 rY Senior Environmental Protection Specialist Enclosure ORka _ of Mined LandReclanudon Active and h,acdre Minot Colorado Geological Survey Weiland. Inc. Environmental& Engineering November 22, 2005 Environmental Support for; • Transportation • Land Development Mr. Harry Posey • Mining Senior Reclamation Specialist Colorado Div. of Minerals and Geology • • Industry 1313 Sherman Street, Room 215 Denver, Colorado 80203 RE: Responses to Adequacy Review Comments for Permit Application, Nelson Mininq Resource, DMG Application No. M-2005-059 Dear Mr. Posey: Per the adequacy review comments sent by Tony Waldron sent on November 4, • 2005, below are our responses to the adequacy comments. I will address only those comments made under the Exhibits where you determined that further clarification or additional information is required. I will present the responses in the order received by you in your comments. 6.4.3 Exhibit C-Pre-Mining and Mininq Plan Maps • Exhibit C-1 and Exhibit C-2 have been edited to show the approximate location of both topsoil and overburden ("OB") stockpiles. Topsoil will be segregated and stockpiled just to the north of the farmhouse for placement near the later stages of mining on the permit area. OB will be stockpiled only during the first phase of mining of Cell A. OB will be stockpiled in the northern area of Cell B for backfilling into the mined out portion of Cell A, before moving onto the remainder of Cell A. In all subsequent mining, backfilling will be concurrent with mining. Additionally, Exhibit C-1 and Exhibit C-2 have been edited to include an updated pit boundary to reflect the results of 6.5 Geotechnical Stability Exhibit. 6.4.5 Exhibit E-Reclamation Plan All backfilled slopes will be at 3H: 1V as shown on the reclamation plan map and hereby corrected for the text, under 6.4.5. 6.4.6 Exhibit F-Reclamation Plan Map 525 id Avenue. Suite 211. Longmont, CO 80507 -� ph 303-532-0951 fax 303-532-0953 ?Ai l?e1//cam r'c PC I AD The reclamation plan map (Exhibit F) has been edited in the cross-section view (A-A') to show that the 4 ft. thick clay liner will be keyed a minimum of 4 ft. into the underlying shale. The issue regarding mounding of alluvial groundwater has been reviewed and a groundwater modeling report has been provided (Addendum A) to address the potential effects of groundwater mounding to nearby structures. 6.4.7 Exhibit G-Water Information The substitute supply plan (SSP) and well permit application have been 'submitted to the State Engineers Office (SEO) and has been sent out for review by the SEO's consultant (Wright Water Engineers). We received a request for additional information on November 21, 2005 and will have responded to this request by the date of this letter. It is, however unlikely the SWSP will be approved by the decision date of December 1, 2005, therefore, we request that a condition be placed on the permit that would disallow mining any deeper that 2 ft. above the normal static groundwater level on the permit area. All dry mining discharge from this site will be pumped through the two existing 18 in. culverts on the owner's property and into the pond to the north, also owned by the.Nelsons. All wells, whether alluvial or bedrock, within and outside of 600 ft. of the -- proposed permit boundary, are shown on Exhibit C-1 "Pre-Mine Map". The applicant will adhere to the SEO 600 ft well spacing policy. 6.4.19 Exhibit S-Permanent Man-Made Structures Attempts have been made to secure agreements with owners of permanent man-made structures within 200 ft (owners) of the affected area. The applicant has been able to execute an agreement with the Last Chance Ditch Company. Per rule 6.4.19 (b) and given that such agreements could not be reached with all other owners in a reasonable period of time, the applicant is providing an engineering evaluation (6.5 Geotechnical Stability Exhibit). Pit setbacks from all structures are defined by the results of 6.5 Geotechnical Stability Exhibit. Weld County Roads 15 and 26, and the structures immediately southeast of the permit boundary (Nelson House and Associated Outbuildings) have been added to Exhibit C-2 Sheet-1 and Exhibit S. The Nelson House and Associated Outbuildings are owned by the same landowner from which ASCI is leasing the gravel and has no issue with the mining setback in this area. A signed letter documenting this has been enclosed. #ft Weiland, Inc. Environmental & Engineering Please review these responses to your adequacy concerns and get us any further concerns you may have in a timely manner so that we can have approval for this permit and can then start on site preparation in time for production in the Spring. Thanks for attention to this matter. • • • Sincerely, Peter Wayland President End. 2-copies Revised Exhibits C-1, C-2, E, F,G, S, 6.5 Geotechnical Stability Exhibit, Addendum A Groundwater Modeling Report Weiland Inc. Environmental E Engineering 6.4.5 Exhibit E — Reclamation Plan Description All areas adjacent to oil and gas wells will be backfilled to a radial distance of 150ft following excavation. Reclamation will occur concurrently with mining following completion of gravel extraction in the western 1/3 of Cell A. Reclamation will backfill slopes to 3H:1V in the pit and the pit will be reclaimed as a water-storage reservoir. All affected areas above the normal pool elevation of the reservoir will have topsoil replacement and be re-vegetated with native vegetation followed by a weed control program. Exhibit F- Reclamation Plan Map shows final grading and topsoil/ re-vegetation areas. Reclamation Earthwork Reclamation earthwork will occur concurrently with mining and will begin following extraction of sand and gravel from the northern 1/3 of Cell A. Stockpiled overburden located adjacent to the mined out cell (-60,000 yd3) will then be placed onto the slopes of the northern 1/3 of Cell A. Additional overburden stripped from the remaining mine area will be directly replaced onto mined out slopes as the operation proceeds. There is approximately 500,000 yd3 of overburden within the pit area. Approximately 500,000 yd3 of overburden will be used to backfill the slopes. Following slope backfilling, clay material will be ripped from the pit floor and used to construct a compacted clay liner. About 34,000 yd3 of clay material located on the pit floor will be ripped, moisture conditioned and placed in 1 ft thick lifts on the pit slopes. Compaction will then occur for each lift and scarification between lifts will be achieved. The compacted clay liner will be constructed to a thickness of 4 feet. The applicant chooses to place a 100% bond for the clay liner. Topsoil Replacement Topsoil will be placed to a depth of 1 ft on all affected areas above the normal pool elevation of the reservoir. The total area to undergo topsoil replacement is 10.7 acres and the total topsoil replacement volume is approximately 17,300 yd3 Nelson Mining Resource Regular 112 Permit Application 6.4.5 Exhibit E — Reclamation Plan Seeding and Fertilizing Currently, the entire pit area is used as a grass hay field The proposed seeding areas are shown on Exhibit F — Reclamation Plan Map. The recommended seeding method is by drill and seeding rates assume this method. The species composition of the seed mixture recommended for reclamation is shown in Table 4 below. Table 6.4.5-4. Recommended Seed Mixture Species (Variety) Rate-pure live Native/ W/C Cost seed(pis) Introduced Season pls/ac lbs/ac Thickspike wheatgrass 8.0 to 10.0 Native Cool $11.70 (Critana) Sideoats grama (Vaughn) 5.0 to 7.0 Native Warm $7.25 Switchgrass (Nebraska-28) 4.0 to 6.0 Native Warm $5.00 Alfalfa (Nomad) 3.0 to 5.0 Introduced NA $1.90 TOTAL 20.0 to 28.0 $28.85 Based on this seed mixture an application rate of approximately 20.0 to 28.0 pls/ac will be used. Topsoil will be disked prior to seeding. It is recommended that fertilizer be utilized for reclamation. A standard application of a fertilizer will be used and applied at a rate of 250 lbs/ac. The total area to be seeded is approximately 10.7 acres. The total area to be fertilized is approximately 10.7 acres. Seeding and fertilizing will be completed after the overburden and topsoil is replaced, smoothed to conform to the existing topography and disked. Optimal periods of seeding are in the fall (after November 1st) or in the spring from late March up to April 30th. Mulching will not be completed as the quality soils and availability of water should facilitate the rapid establishment of perennial grasses. Following revegetation, weed management strategies will be implemented to facilitate and achieve native grassland. Years 1 thru 5 following revegetation will include an aggressive mowing program to prevent the growth and establishment of weeds, specifically, the eight noxious weeds including: Canada thistle (Cirsium arvense), Dalmation toadflax (Linaria dalmatica), diffuse knapweed (Centaurea diffusa), leafy spurge (Euphorbia esula), musk thistle (Carduus nutans), Russian knapweed (Centaurea repens), spotted knapweed (Centaurea maculosa) and Yellow toadflax (Linaria vulgaris) as mandated by Colorado State Law (35-5.5CRS1990, 1996). If needed, herbicide application will be applied as needed to further control these weeds. Herbicides will also be used to control saltecedar (Tamarix spp.) if it becomes established in the reclaimed area. Table 6.4.5-5 presents recommended herbicides, application rate, and time of Nelson Mining Resource Regular 112 Permit Application 6.4.5 Exhibit E — Reclamation Plan application for each of the 9 species. It may be necessary to replant treated areas. 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K Q co co f6 a a f6 f6 c C LU cn LL LL LL U) co LL LL Q Q in a <C o +1- + co co O- CO @ co 0) (6 co O 6 O L L c0 co CO co co co M Q in cu Q N d N L 4 L N ,-- O 6 r 6 V- O r r r U o as L f0 co + to to rn o o p o- co co p C0m c`6 C 2 -O ' c >. t coca E co o t O O c6 O O t co C C) o 7 C 7 U O V H I— F— N > c6 C..) -O O_ o a a 'O N 0) co a 0) t o as rn N 0 (Tsa co -- a 0) 7 m co O co as o_ 7 N 7 d J U) 2 Q' Y coY 6.4.7 Exhibit G —Water Information Groundwater Groundwater occurs at an average depth of 10 ft below ground surface in the local area. There are no alluvial water supply wells within 600 ft of the pit excavation. Mining of the proposed excavation area of the permit will be by the "dry-mining" method. De-watering operations will begin prior to sand and gravel excavation. The Applicant has obtained one share of water from the Last Chance Ditch Company, which will provide 383 acre-feet of water for use in augmentation. A groundwater modeling report has been provided in Addendum A for the purpose of evaluating the effects of groundwater mounding due to the placement of a low permeability clay liner in the aquifer as specified in the reclamation plan. Surface Water The nearest major watercourse is St. Vrain Creek, which flows within one-half mile of the northwest corner of the property. Final discharge of excess water recovered and clarified from de-watering of excavation areas on the permit site may be made to the Nelson Pond immediately north of the permit area. Prior to any discharge activity to the Nelson Pond, the operator will obtain a Colorado Discharge Permit System (CPDS) Permit. Nelson Mining Resource Regular 112 Permit Application 6.4.19 -Exhibit S — Permanent Man-Made Structures Permanent man-made structures within 200 feet of the affected land for this application are shown on Exhibit C-2, Mine Plan Map. Per rule 6.4.19 (b) and given that such agreements could not be reached with all other owners in a reasonable period of time, the applicant has provided an engineering evaluation (6.5 Geotechnical Stability Exhibit). Pit setbacks from all structures are defined by the results of 6.5 Geotechnical Stability Exhibit. Table 6.4.19.1 — Permanent manmade structures within 200 ft Structure I.D.* Owner& Description A United Power Underground Electric B Kerr-McGee Oil & Gas Well - Harold Nelson Unit A True C Kerr-McGee Flow Line for Harold Nelson Unit A True D Duke Energy Corporation Gas Line • E Central Weld County Water District Water Main F United Power Overhead Electric G AT&T Monitor H Kerr-McGee Oil & Gas Storage Tank Kerr-McGee Oil & Gas Separator J Kerr-McGee Oil &Gas Well -9-31A Nelson Corp K Kerr-McGee Flow Line for 9-31A Nelson Corp L Last Chance Ditch and Box Culvert M Tri-state Generation and Transmission Association, Inc. Utility Pole N Tri-state Generation and Transmission Association, Inc. Utility Pole O Tri-state Generation and Transmission Association, Inc. Utility Pole P Qwest Communications Telephone Wire Q Kerr-McGee High Pressure Gas Line R Weld County Road 15 S Weld County Road 26 T Nelson House and Outbuildings U Nelson Fence *As shown on Sheet C-2 Nelson Mining Resource Regular 112 Permit Application 6.4.19 -Exhibit S — Permanent Man-Made Structures Permanent man-made structures within 200 feet of the affected land for this application are shown on Exhibit C-2, Mine Plan Map. Per rule 6.4.19 (b) and given that such agreements could not be reached with all other owners in a reasonable period of time, the applicant has provided an engineering evaluation (6.5 Geotechnical Stability Exhibit). Pit setbacks from all structures are defined by the results of 6.5 Geotechnical Stability Exhibit. Table 6.4.19.1 — Permanent manmade structures within 200 ft Structure I.D.' Owner& Description A United Power Underground Electric B Kerr-McGee Oil & Gas Well - Harold Nelson Unit A True C Kerr-McGee Flow Line for Harold Nelson Unit A True D Duke Energy Corporation Gas Line E Central Weld County Water District Water Main F United Power Overhead Electric G AT&T Monitor H Kerr-McGee Oil & Gas Storage Tank Kerr-McGee Oil &Gas Separator J Kerr-McGee Oil &Gas Well -9-31A Nelson Corp K Kerr-McGee Flow Line for 9-31A Nelson Corp L Last Chance Ditch and Box Culvert M Tri-state Generation and Transmission Association, Inc. Utility Pole N Tri-state Generation and Transmission Association, Inc. Utility Pole O Tri-state Generation and Transmission Association, Inc. Utility Pole P Qwest Communications Telephone Wire Q Kerr-McGee High Pressure Gas Line R Weld County Road 15 S Weld County Road 26 T Nelson House and Outbuildings U Nelson Fence *As shown on Sheet C-2 Nelson Mining Resource Regular 112 Permit Application AGREEMENT TO MINE WITHIN 200 FT OF A PERMANENT MAN-MADE STRUCTURE THIS AGREEMENT dated effectively October 5,2005 is made between Asphalt Specialties Company, Inc., 10100 Dallas St.,Henderson CO 80538,herein called"ASCI"and the Last Chance Ditch Company herein called"Last Chance"hereinafter referred to as the"Parties"to this agreement. WHEREAS, ASCI represents that they are the gravel permit Operator for the Nelson Mining Resource proposed to occur on described lands in un-incorporated Weld County,Colorado to wit: E1/2 of the SE1/4, Sec. 31,T3N, R67W,6th PM WHEREAS,Last Chance owns the irrigation ditch and water rights within the canal immediately to the southeast of the proposed gravel pit as shown on the attached and referenced Exhibit"A" to this agreement. WHEREAS,ASCI wishes to mine sand and gravel on said property utilizing dry mining techniques. NOW THEREFORE, 1. Last Chance agrees to allow ASCI to mine within approximately 75 ft of the canal as a temporary condition and ASCI will backfill a total of approximately 100 ft of the 75 ft. mined to approximate historic grade and from that point inward to the pit floor at a 3:1 slope within 1 year of mining. 2. ASCI agrees to monetarily compensate Last Chance for any damage to the canal that would be caused by ASCI's mining activities. IN WITNESS WHEREOF,the Parties have executed this agreement on the date set forth above: Robert Nelson Daniel W.Hunt President President Last Chance Ditch Company Asphalt Specialties Co., Inc. STATE OF COLORADO ) O��i1Y PO; t < ?.? /p i, ss. 4 RHONDAJ. COUNTY OF (26.1a/77..71 ) i k OLSON The foregoing instrument was acknowledged before me this day of• ile1? 1.772005 Iti OF Witness my hand and official seal My Commission Expires My Commission expires:`r'/&7Y Notary Publi i ' Z xr , w0 , , 1 , „ .,.., N N b Re - i 2 Egl § , bi g a I 15 ir ri - i ul ct a ' ®•.., I I I k1/4I1ilfliti!t z Z b - 2 zr It 3 silk Ia3 1 i o I & ' a 5Q i tt 5e g �@@ rig f! d Y I \ f/ a &11/2 l 11 15 ril 1 I Ili irli € zm . Hnokan ,.. qm® @ ®® © o®oo © o® ® @ 00 / W t I I es / I i ‘ / \.., ::-) --- u, W oW z w ....--' c `1( ,_ �. J W of �/ I — /Li w a �a I;I :..: Z 111 li e n i IL i _ i ► -7 I I I vo II :` milF ■ I: I C. 7A IA O / ri ,� -4 E_� a r I $ r W �` x � � a I I / 3 xit 1,------ S' :1--- .-- 1 / lit I 1 i IL ! E % I B / I Ill' Rl t- p i, r I \ i n ___ / in z b q o / 1 II Ina 0 / D a O o / November 17, 2005 Colorado Div. of Minerals and Geology 1313 Sherman Street,Room 215 Denver, Colorado 80203 RE: Approval of Mining Adjacent to Structures for Nelson Mining Resource.DMG Application/File No. M-2005-059 Dear Division of Minerals and Geology: The undersigned, Harold and LaVema June Nelson, do hereby consent to allowing Asphalt Specialties Co., Inc(ASCI) to mine adjacent to and within 200ft. of all structures owned by us. These structures include, but are not limited to, the farmhouse and outbuildings located to the southeast of the mining area (near the corner of WCR-26 and WCR-15), all stock fences and irrigation laterals located on or nearby the mining permit area, and any roads or buildings located on our property to the north and northwest of the mining permit area. We also have no concerns regarding the effects of"dry" mining and the subsequent clay-lined reservoir on the local groundwater table as it affects our structures described above. We are also the owners of the property and minerals that are to be mined by ASCI in the referenced permit area and have given our permission to ASCI to apply for the necessary permits to mine our property as shown in "Exhibit N-Legal Right to Enter" of the DMG application submitted in August 2005. Please contact us if you have any further concerns and thank you for your attention to these matters. Sincerely, � Gz ' �� ///b'—oC Harold Nelson La erna June N n 6.5- Geotechnical Stability Exhibit Methodology SB-Slope, v. 3.0 (Von Gunten Engineering Software, Inc.) is the slope stability application utilized for this application. The program uses the "Simplified Bishop Method of Slices" based on the limiting equilibrium circular failure surface method as developed by A.W. Bishop (1955). The program was used to predict the factor of safety for a given setback from the mine excavation where the factor of safety is defined as: Traveltable shear strength)/T1(required shear strength) = Factor of Safety(FS) For each setback analyzed, the critical failure surface was determined. Data Input Model input data is based on test hole boring data. Soil strength data is based on published values and data provided by the Colorado Division of Minerals and Geology. Table 6.5.1 — Soil Strength Parameter data Soil Density Cohesion Number Stratigraphic Layer (pfc) (psf) Phi (0) 1 Overburden (ML) 90 3.6 34 2 Unsaturated Gravel 130 0 35 (GW-UNSAT) 3 Saturated Gravel 137 0 35 (GW-SAT) 4 Weathered Shale 142 0 14 5 Shale 150 500 25 The mine slope was divided into three different sections: east, southwest and northwest mine slopes. For each section, the stratigraphic layer thickness was determined by averaging the nearest test holes. Soil thickness information is shown in Appendix I. The model input phreatic surface was determined by the following analytical solutions. The Theis method was used for approximating drawdown at distances greater than 100 ft. Dupuit-Forsheimer solution was used for approximating the drawdown geometry (phreatic surface) close to the seepage face. The mine slope was set to 0.5 to 1. Model Output The model output information is shown in Appendix I. The minimum setback and critical surface factor of safety are shown below. 6.5- Geotechnical Stability Exhibit Table 6.5.2 — Model Output Critical Surface Mine Slope Minimum Setback Factor of Safety East 55' 1.00 Southwest 50' 1.01 Northwest 45' 1.06 Discussion Maintaining a minimum setback as shown above from any road or oil and gas structure is considered safe for this project. REINFORCED CONCRETE SLAB GAS LINE CROSSING DESIGN Introduction In order to construct an access road for the Nelson Mining Resource in Weld County, Colorado, the access road will need to cross a future buried Kerr-McGee and Noble Energy Production Inc. Gas Line. Kerr-McGee's requirements for heavy vehicle crossings include eight feet of cover for load dissipation to protect the buried pipe from excessive localized deflection. The proximity of this crossing to an existing County road precludes changes in vertical alignment necessary to accommodate eight feet of cover. Instead, we propose 3.25 feet of cover (including six inches of aggregate compacted to 100%), plus a 9.5-inch reinforced concrete slab for load dissipation. The concrete slab would extend ten feet on each side of the pipeline (as per Kerr-McGee's requirements), for a total length of 20 feet, and it would cover the full 30-foot width of the roadway. Design Criteria We anticipate that traffic for the access road will include fully-loaded concrete mixers and 18-wheeled semi-trailers. To approximate those loading conditions, our design is based on an AASHTO HL-93 live load in each traffic lane (distributed load of 0.64kip/ft, and three concentrated loads of 8 kips, 32 kips, and 32 kips). Additionally, we have included a live load factor of 1.6. 6.5- Geotechnical Stability Exhibit Further, we specify concrete with a 28-day compressive strength of 3,000 psi, and grade 40 reinforcing steel. Assumptions The bearing capacity of the underlying soil is unknown. Consequently, we have made assumptions about the slab's support conditions. For positive reinforcement, the slab is treated as a simple span. However, for negative reinforcement, the outer 'A of the slab is treated as a cantilever. Methodology Maximum positive moments were found when a concentrated 32 kip load was applied at mid-span (10 feet longitudinally, 7.5 feet transversely). Maximum negative moments resulted from the application of 16 kip concentrated loads at the slab edge, and another 16 kip concentrated load six feet from the edge. Moments due to dead loads have not been included in the calculations because although the soil's bearing capacity is not known, it can be safely assumed adequate to support the weight of the concrete slab and asphalt overlay. Results and Conclusions The reinforced concrete slab will have greater rigidity than the additional four feet of fill material, and will therefore be able to protect the underlying pipe by distributing sub- grade shear and compressive stresses over a greater area. Table AI.1 -Soil Thickness Information OBT BOG DEPTH GT EAST SIDE MW-1A 3.5 42 38.5 TB-5 3.5 43 39.5 MW-3A 3.5 38.5 35 AVERAGE 3.5 41.2 37.7 SOUTH WEST MW-2A 6 37 31 NORTH WEST • TB-1 3 23 20 TB-3 2.5 27 24.5 AVERAGE 2.75 25 22.25 • In — o y HF ui II m y P E I- g W p. 1 a a IZ y 2 81 a N 1- I O�O. O W ?T Le N W U {WY Z W M f t0 M It en Q O w F W II O 0 N Z 0 O a W Z rt a O9 w a. 2 0 3 N ci' N • 2 m I tD Y ii In UM C O W UM a. 2 i b r. O O I w E N I— O Q w N 1- CC Z Q w cc, N H w . J _i 3 3 x cD ca W v fr Si ri a vi wu�y aB 3 fiti b Iii: M LC) M N N� -PnN •b ki— • 4 I i G Point Listing made Thu Oct 06 11:04:55 2005 Page 1 of 1 Drawing Name: slope stability - northwest Project Name: NELSON MINING RESOURCE '^' Project Path: F:\Cad Projects\NELSON MINING RESOURCE\ _ Username: WS2 �C\ Number Northing Easting Elevation Raw Desc Full Desc 18 29.10 0.00 0.00 1 1 95 10.97 88.00 . 10 10 94 8.89 93.00 . 11 11 82 8.00 96.00 . 12 12 83 4.00 0.00 . 13 13 84 4.00 98.00 . 14 14 85 0.00 0.00 . 15 15 86 0.00 100.00 . 16 16 71 29.10 85.45 . 2 2 72 26.30 0.00 . 3 3 73 26.30 86.85 . 4 4 100 15.40 0.00 5 5 99 14.97 23.00 . 6 6 98 14.29 48.00 . 7 • 97 97 13.37 68.00 . 8 8 96 12.56 78.00 . 9 9 • NELSON MINING RESOURCE -NORTHWEST Input Data for prediction of drawdown K , Equation used in prediction Hydraulic conductivity,K,ft/day .: @O Wu Aquifer Thickness,b,ft fi�;,aC 0.01 0.1 1 10 100 1000 s o �� U = f S StorageRat ,Coefficient,S �O"@Q09SO 4;rT 4Tt Pumping Rate,GPM �i;kx 5541 S Distance from well,ft •;is3` iti0o s is drawdown,W(u)is the well 0.000001 0.00001 0.0001 0.001 0.01 0.1 1 PREDICTED DRAWDOWN 6 1 ; ; LL 2 � D _ 0:00:01 0:00:09 0:01:26 0:14:24 2:24:00 24:00:00 TIME IN HOUR:MINUTE:SECOND T 1 2 � O 1 1 000:00 r 3:00:00 6:00:00 9:00:00 12:00'.00 15:00:00 16:00:00 21:00:00 24:00:00 TIME IN HOUR:MINUTE:SECOND GEOSYSTEM SLOPE STABILITY PROGRAM SB-SLOPE PROJECT DATA: Project : NELSON MINING RESOURCE Location: NORTHWEST Filename : NMR-NW Description: NELSON - NORTHWEST ANALYSIS DATA: Point Coordinates Line Left Right Soil Phreatic Soil Density Cohesion Phi No. X Y No. Point Point No. Line No. pcf psf Deg 1 0 . 0 29 . 1 1 1 2 1 N 1 90 . 0 4 34 . 0 2 85 . 5 29 . 1 2 3 4 2 N 2 130 . 0 0 35. 0 3 0 . 0 26 . 3 3 5 6 3 Y 3 137 . 0 0 35 . 0 4 86 . 9 26 . 3 4 6 7 3. Y 4 142 . 0 0 14 . 0 5 0 . 0 15 . 4 5 7 8 3 Y 5 150 . 0 500 25 . 0 6 23 . 0 15 . 0 6 8 9 3 Y 7 48 . 0 14 . 3 7 9 10 3 Y 8 68 . 0 13 . 4 8 10 11 3 Y 9 78 . 0 12 . 6 9 11 12 3 Y 10 88 . 0 11 . 0 10 13 14 4 N 11 93 . 0 8 . 9 11 15 16 5 N 12 96 . 0 8 . 0 12 14 16 4 N 13 0 . 0 4 . 0 13 12 14 3 N 14 98 . 0 4 . 0 14 4 12 2 N 15 0 . 0. 0 . 0 15 2 4 1 N 16 100 . 0 0 . 0 • ill -N i1 H 0 0 0 0 0 t a virilein M M N) 7 N _N _ • O U) Z —o N HH (0 0000 O O O - '- W ("10 O O O o 2 N O _ O a _o .. n N C v I "o L P am H 0 0 0 0 0 '^ L m .o 000C-, NO °i `y N 0 n -w o n co 7 _oo N O O C E Q + • —N 0 J N n 7 n n Z r O U) _o - • n — • W O n _L co n F V a _p H H O a> n m (2, H J 0. I N 7L----•-amm N O > V1 O in Z Q V/ a �y o —N H H J 0 _N 0 CO v I V O O _o .- H v ri 0 N 3 v _N n a W 2 N —n N ct D Z O O O (1 H } N -Ln N IX 0 O W O N o N H N Z H n O _N H V 0 3 X n CC Z 2 m -O O H W C/) Cr 0 • J O 3 0 W Z Z J N Z I N Z 2 W W H O Z H J U H W a W H •• J H o H X OO H 0 CL J W O I I I I I I I I I I I I I I O in O N O N 0In 0 N O in O N O �, .G in N Y Y nn N N I _ NOIIVA313 i y — "o N W I. i"• a O 1 — tA 7 s 3 a N t- sk a, = +°„ f W 1 S a 7 00 O CO CO E 3I a N a ° N t0 r(7� O,'• U ' ; crl • • a II S H 1.1 m 02 • ✓ 2 m N Z Q • O co O 11 Nix o o O i W J . Q N H O a L u (n (• H W I w ri in . _idO O O co re-) v • • 9 • i Point Listing made Thu Oct 06 10:58:58 2005 Page 1 of 1 Drawing Name: slope stability - southwest Project Name: NELSON MINING RESOURCE Project Path: F:\Cad Projects\NELSON MINING RESOURCE\ "-' Username: WS2 Number Northing Easting Elevation Raw Desc Full Desc 18 41.00 0.00 0.00 1 1 88 13.31 88.00 10 10 87 9.76 93.00 . 11 11 82 8.00 96.00 . 12 12 83 4.00 0.00 . 13 13 84 4.00 98.00 . 14 14 85 0.00 0.00 . 15 15 86 0.00 100.00 . 16 16 71 41.00 79.50 . 2 2 72 35.00 0.00 . 3 3 73 35.00 82.50 . 4 4 93 20.20 0.00 . 5 5' 92 19.55 23.00 . 6 6 91 18.51 48.00 . 7 7 90 17.09 68.00 . 8 8 89 15.83 78.00 . 9 9 NELSON MINING RESOURCE -SOUTHWEST '^ Input Data for prediction of drawdown k , Equation used in prediction Hydraulic conductive K.Nda x .000 Y Y. Y Aquifer Thickness,b,ft h, i.x 20 0.01 0.1 1 10 100 1000 s c Q�W�u�� U o ITt StorageR , P S 4;00051:0 S 47IT 4Tt Pumping Rate,GPM ;Y`fT450 Distance from well,ft +# *ia'400: s is drawdown,W(u)is the well 0.000001 0.00001 0.0001 0.001 0 01 0.1 1 PREDICTED DRAWDOWN 1a 1 . u 10 I O I a3 6 f I 0:00:01 0:00:09 0:01:26 0:14:24 2:24.00 24:00:00 TIME IN HOUR:MINUTE:SEC0ND 14 i 12 I w I I LL ? 8 o• e p 4 1 i 0:00:00 3:00:00 8:00:00 9:00:00 12:00.00 15:00:00 18:00:00 21'.00:00 24:00:00 TIME IN HOUR:MINUTE:SECOND GEOSYSTEM SLOPE STABILITY PROGRAM SB-SLOPE --� PROJECT DATA: Project : NELSON MINING RESOURCE Location: SOUTHWEST Filename : NMR-SW Description: NELSON - SOUTHWEST ANALYSIS DATA: Point Coordinates Line Left Right Soil Phreatic Soil Density Cohesion Phi No. X Y No. Point Point No. Line No. pcf psf Deg 1 0 . 0 41 . 0 1 1 2 1 N 1 90 . 0 4 34.0 2 79 . 5 41 . 0 2 3 4 2 N 2 130 . 0 0 35 . 0 3 0 . 0 35 . 0 3 5 6 3 Y 3 137 . 0 0 35 . 0 4 82 . 5 35 . 0 4 6 7 3 Y 4 142 . 0 0 14 . 0 5 0 . 0 20 . 2 5 7 8 3 Y 5 150 . 0 500 25 . 0 6 23 . 0 19 . 6 6 8 9 3 Y 7 48 . 0 18 . 5 7 9 10 3 Y 8 68 . 0 17 . 1 8 10 11 3 Y 9 78 . 0 15 . 8 9 11 12 3 Y 10 88 . 0 13 . 3 10 13 14 4 N 11 93 . 0 9 . 8 11 15 16 5 N 12 96 . 0 8 . 0 12 14 16 4 N 13 0 . 0 4 . 0 13 12 14 3 N 14 98 . 0 4 . 0 14 4 12 2 N 15 0 . 0 0. 0 15 2 4 1 N 16 100 . 0 0 . 0 v H 0 0 0 0 0 o a a C in in t V) H re) r0 n N 0 o V1 _n Z O O H CO O O 00 W M 0 0 0 0 2 0 _N O U O W L O a X } L H00000 0 0 0 O VI O O N N 0 Y Wm M rl d- to a _OO y 0 n N 0 0 m Ul • T 0 cv n _O E m m D C , / v Z Q H N n 7 in it a »+ 00 n - to _o W _ m U Z Q • O in H U W " • co V) Z o 0 H O a J O ¢ O N H Z Zg CO an 0 n to O (0 aIL . I N 0 x W (n O 2 • CO a n _0 N o m a 2 O H • O N Z < N EN 3 N -O 0. O E W I n U V1 I co ' a O O 0 o (11 H r'7 _ >- W H N LC U W O V1 Z H V) —O Z H N O 04 H VI 0 M 3 CC X Z = Cr) n O F d n -o —I 0 3 0 W V7 N J Z 1 V) 0 2 W W H H Z Z H J W F U J cc i- 0 U J M U 0' O H O a J Li_ U I I I I I I 1 I �� 0 0 0 0 0 0 0 0 0 I-. 0 to a n N N0ILVA313 6 W — o Ni-- J W 8 Z :1"C < }} J h L. F- W J 2 w ' Ea wG H F o toint W W &w 3 a O N ` 3 i co N a a MI m W O Ind� Kw Z a • • H W SS N Cr.I W K CO w en aM J o 2 a a • u 0oP _ IL o u to 3 m O 2 _ )" M II = a n W O a 2 • o . b to b to II cc . 00 Lo I In I- o IJ < ° 5 CO ¢ I J a� In if9 0 bo M 0 0 tail d 1 II II r N M V to ii fn to T T b a ki,_ _.....k _ tn V i e £ n, g i i Point Listing made Thu Oct 06 10:44:40 2005 Page 1 of 1 Drawing Name: slope stability - east Project Name: NELSON MINING RESOURCE ..-P-. Project Path: F:\Cad Projects\NELSON MINING RESOURCE\ Username: WS2 _ Number Northing Easting Elevation Raw Desc Full Desc 18 45.50 0.00 0.00 1 1 12 14.87 88.00 . 10 10 11 10.39 93.00 . 11 11 82 8.00 96.00 . 12 12 83 4.00 0.00 . 13 13 84 4.00 98.00 . 14 14 85 0.00 0.00 . 15 15 86 0.00 100.00 . 16 16 71 45.50 77.25 . 2 2 72 42.00 0.00 . 3 3 73 42.00 79.00 . 4 4 17 23.30 0.00 . 5 5 16 22.51 23.00 . 6 6 15 21.25 48.00 . 7 7 14 19.51 68.00 . 8 8 13 17.98 78.00 . 9 9 • NELSON MINING RESOURCE-EAST Input Data for prediction of drawdown K , Equation used in prediction Hydraulic conductivity,K,ft/day 4,600'. Aquifer Thickness,b,ft �-"4 `^`°, q 001 01 1 10 100 1000 S _ Q�W�u�� U _ r'5 Storage Coefficient,s .0'000642' s 47CT 4Tt Pumping Rate,GPM r ,2#60 Distance from well,tt ?Y.1"1.06F s is drawdown,W(u)is the well 0.000001 0 00001 0.0001 IIMMill0.001 0.01 0.1 1 16 PREDICTED DRAW DOWN r r � 14 W t2 ' Z 10 r 1 G � I 2 I 0 0:00:01 0:00:09 0:01:26 0:14:24 2:24.00 24:00:00 TIME IN HOUR:MINUTE:SECOND i6 14 l j • K � � O 4 f 2 i 0:00:00 3:00:00 fi:00:00 9.00:00 12:00:00 15:00:0o 0 16 0000 21.00.00 24:00:00 TIME IN HOUR:MINUTE:SECOND GEOSYSTEM SLOPE STABILITY PROGRAM SB-SLOPE PROJECT DATA: Project : NELSON MINING RESOURCE Location: EAST SIDE Filename : NMR-E Description: NELSON - EAST ANALYSIS DATA: Point Coordinates Line Left Right Soil Phreatic Soil Density Cohesion Phi No. X Y No . Point Point No. Line No. pcf psf Deg 1 0 . 0 45 . 5 1 1 2 1 N 1 90 . 0 4 34 . 0 2 77 . 3 45 . 5 2 3 4 2 N 2 130 . 0 0 35 . 0 3 0 . 0 42 . 0 3 5 6 3 Y 3 137 . 0 0 35 . 0 4 79 . 0 42 . 0 4 6 7 3 Y 4 142 . 0 0 14 . 0 5 0 . 0 23 . 3 5 7 8 3 Y 5 150 . 0 500 25 . 0 6 22 . 5 23 . 0 6 8 9 3 Y 7 48 . 0 21 . 3 7 9 10 3 Y 8 68 . 0 19 . 5 8 10 11 3 Y 9 78 . 0 18 . 0 9 11 12 3 Y 10 88 . 0 14 . 9 10 13 14 4 N 11 93 . 0 10 . 4 11 15 16 5 N 12 96 . 0 8 . 0 12 14 16 4 N 13 0 . 0 4 . 0 13 12 14 3 N 14 98 . 0 4 . 0 14 4 12 2 N 15 0 . 0 0 . 0 15 2 4 1 N 1,4, 100 .0 0 . 0 H00000 0 0 0 0 o - a v vi vi a T M M M ,- N H - -o O - N Z In HH O O O O O 0 W M 0 0 0 0 I O - I O 'n 0 o C n ill _C a T H 0 0 0 0 0 o _ L W 0 0 fN N O Y M M ain in -0 0 T 0 O E Q• * ' a -i - N M a i m y Z T HO + .- U 41 n m r m m U Z o H • n U La N _ - f/ • o H Z. o a n m O H 0 I- 0 — n ° I- L N .. o • o g N L H Hi K W N O I in n N 7 O ._ H • M a in ._ Z Q CO o _o 3 Ln E O I - 0 N ct n —o m Z O i <v < O O ›- n w H I--- M a CC U O W -o U, N M Z H UI Z W VI O H O O in U X • N Z m • O H w C11 0 a n W W U W J n o Z I In Z I- _I H O Z Z H J W H J U H M OU H 0 a J L. U I I I I I I i I I o m 0 n O 0 a n o o 0 0 �\ NOI1VA313 • OBT BOG DEPTH GT EAST SIDE MW-1A 3.5 42 38.5 TB-5 3.5 43 39.5 MW-3A 3.5 38.5 35 AVERAGE 3.5 41.2 37.7 SOUTH SIDE MW-2A 6 37 31 TB-6 7.5 36 28.5 AVERAGE 6.75 36.5 29.75 SOUTH WEST MW-2A 6 37 31 NORTH WEST TB-1 3 23 20 TB-3 2.5 27 24.5 AVERAGE 2.75 25 22.25 s-. • 5 L bCJ&LT I I.-.LAL_ LC u 0 E/l rt7-0 l-kl.._-G3 LOAT:,tt.1& M _ 160 FT- K 11bV. Tlb K. n.”/L' 3Z IC 3LIC 9G FT - 8 YL �/ �/ A RNA 13ZK %LC `c m z, -3Z.e i 64 IC 0 — 3'00 FT — K W 13Z N1 = - 160 rT-K_ z 5 --T r" �.L5 v F Psi'F r ,I.Y-�b C' E LLT 73 4A-5 HTO t4 L-9 3 1-0 t4D L tv.6 O. L br L y ww =Ma,_ Vat- (Z ) -ab (4 L) ` O 7w --- y✓L ( ) ` 21, (4 L) 'M WL` 4 z � !L gas - - 2b 4- ' 3 __—— _ 25 ... P_a. = 3 vtL `71 kb - (3 wt._ )(4., L ) - (4,,,, L X8 L ) ` - — WLL / q 1 3 r--/ z. / O L ? f Lpr»7 Jot T L4 K F6'< /y cT—K 1 .hkk: atZr 3 1-1-7Z 16 K 0 I CeT4>; izz.'l K 3 lot }}% t T Hr C F 1 � 1� L iiILK 1LGK z�s 3 .A.A... HT a H —at -cAD/Ka z to bs� b k. i L I I t-Z•I is 11-Z5" f 3'1-I 1< Is/ net W iii _ aA a 14 LONGITUDINAL POSITIVE REINFORCEMENT I As, inA2 b, in 180 #4 0.20 d, in 6 I#5 0.31 fc, psi 3000; #6 0.44 fy, psi 40,0001 #7 0.60 Mco„ce„trated, ft-k 160i #8 0.79 Mlane, ft-k 32 E M, ft-k 307.2 Muc, in # 3,686,400 , • e 0.9— As, inA2 19.971 As/lf, in^2 1.33 spacing, in-total depth #4 1.8 9.25• #5 2.8 9.31 #6 i 4.0 9.38 I — I #7 I 5.41 9.44 #8 I 7.1 9.5 • A.. TRANSVERSE POSITIVE REINFORCEMENT 1 As, inA2 b, in 240 #4 0.20 d, in 5.125 #5 0.31 fc, psi 3000 #6 0.44 fy, Psi 40,000 #7 Mmncentrated. ft-k 72L 0.60 #8 0.79 Mt,ne, ft-k 181 E M, ft-k 1441 J Muc, in-# T 1,728,000 0 0.9' As, inA2 10.01 As/If, inA2 0.50. I- - — spacing, in #4 4.8I I I #57 4 #7 14.41 #8 a 18.9. I - I_ LONGITUDINAL NEGATIVE REINFORCEMENT As, In^2 b, in 180 _ #4 0.20 d, in 7.5 #5 0.31 fc, psi 3000 #6 I 0.44 fy, psi 1 40,000 #7 i 0.60 Mconeenhaled, ft-k 1601 #8 I 0.79 Mime,ft-k 81 4 E M, ft-k 268.8: Muc, in-It 3,225,600I c 0.9 As, in^2 1 12.92 ___. As/if, inA2 I . 0.86 spacing, in i #4 2.81 #5 4.3 _ 1 1 #6 6.1 —1 I. #7 I 8.4 r 1 #8 1 11.0 i I ' I TRANSVERSE NEGATIVE REINFORCEMENT As, inA2 b, in 240 #4 0.20 d, in 6.625 #5 0.31 Pc, psi 3000 I #6 0.44 fy, psi 40,000 #7 ! 0.60 Mco„ce„ ed,ft-k 60! #8 0.79 Mme,ft-k 8 F M, ft-k 108.8 Muc, in-# 1,305,6001 0.9 • I As, inA2 5.63 As/If, inA2 0.28' spacing, in #4 8.5 #5 13.2 #6 18.7 #7 25.6 #8 33.7 LARGE MAPS AVAILABLE FOR VIEWING AT THE CLERK TO THE BOARD'S OFFICE, IN THE PUBLIC REVIEW FILE. ADDENDUM A NELSON MINING RESOURCE GROUNDWATER MODELING REPORT WELD COUNTY Prepared for Asphalt Specialties Co., Inc. 10100 Dallas Henderson, CO 80640 Prepared by: Weiland, Inc. 525 3RD Ave, Suite 211 Longmont, CO 80501 November 2005 r-- Weiland, Inc. Environmental & Engineering TABLE OF CONTENTS Page 1.0 INTRODUCTION 1 2.0 MODEL PURPOSE AND DESIGN 2 2.1. MODEL DISCRETIZATION AND METHODS 2 2.2. HYDRO-STRATIGRAPHIC UNITS 2 2.3. AQUIFER CHARACTERIZATION 3 2.4. INPUT PARAMETERS 3 2.4.1. Hydraulic Conductivities 3 2.4.2. St Vrain River 3 2.4.3. Nelson Pond 3 2.4.4. Pit Reclamation 4 2.5. MODEL BOUNDARY CONDITIONS 5 2.6. MODEL CALIBRATION AND STEADY STATE SIMULATION 5 3.0 MODEL OUTPUT 6 3.1. EXISTING WATER TABLE 6 3.2. RECLAMATION CONDITIONS 6 4.0 STUDY CONCLUSIONS 7 4.1. GROUNDWATER MOUNDING 7 4.2. EFFECTS ON SURFACE OR NEAR SURFACE PERMANENT MAN- MADE STRUCTURES. 7 LIST OF SHEETS SHEET 1 MODFLOW OUTPUT- EXISTING WATER TABLE SHEET 2 MODFLOW OUTPUT- RECLAMATION WATER TABLE SHEET 3 MODFLOW OUTPUT - RECLAMATION WATER TABLE DRAWDOWN SHEET 4 MODFLOW OUTPUT- CROSS SECTIONS 1.0 INTRODUCTION The Nelson Mining Resource will mine gravel below the natural water table. The reclamation plan will place a low permeability compacted clay liner around the interior perimeter for the purpose of preventing local groundwater from entering the reservoir. Placement of low permeability material in a groundwater flow path has been demonstrated to produce higher water table elevations up-gradient of the low permeability zone in other gravel pits. This phenomenon is commonly referred to as groundwater mounding. The questions this study attempts to answer are 1) Will groundwater mounding occur as the result of the placement of a compacted clay liner 2) To what extent will groundwater mounding occur and 3) Will groundwater mounding have any effect on surface or near surface permanent man-made structures. This study utilizes the digital program MODFLOW, which is a 3-dimensional finite difference numerical model of groundwater flow. MODFLOW is used as a predictive tool to approximate the potential influence the compacted clay liner on local water table elevations. Nelson Mining Resource Groundwater Modeling Report 1 of 7 2.0 MODEL PURPOSE AND DESIGN The objective of this model is to predict ground water levels and flow rates in the alluvium surrounding the Nelson Mining Resource resulting from the placement of a compacted clay liner in the aquifer. The model is used to simulate conditions before and after reclamation conditions. To accomplish this, a one layer unconfined model to simulating the gravel aquifer was used. The MODFLOW lake package was used to simulate the pond occurring just north of the project. It should be noted that the applicant, (Howard Nelson) owns this pond and is not concerned with the effects of the clay liner (shadowing) on pond water surface elevations. 2.1. MODEL DISCRETIZATION AND METHODS The finite difference grid measures 4200ft in the X direction and 6600ft in the Y direction. The grid is oriented North-South with no rotation. The Grid cell size is set to 75ft. The model consists of one hydro-stratigraphic unit consisting of a sand and gravel unit that is 25-30 feet thick. Top and bottom elevations are based on test hole data and resultant TINs developed in Autodesk Land Desktop Development 3. The TINs were sampled at node centers and exported to MODFLOW via the pre-processor Argus One utilizing the MODFLOW GUI developed by the USGS. 2.2. HYDRO-STRATIGRAPHIC UNITS The general physiographic setting can be described as a broad flat valley generally trending northeast southwest. The principal aquifer in the valley is composed of alluvial sand and gravel with an average thickness of 25-30ft. The water table varies seasonally with local irrigation both in the valley and to the north and south of the valley contributing to enhanced recharge and higher water tables during the irrigation season. The primary direction of groundwater flow is generally north east. Nelson Mining Resource Groundwater Modeling Report 2 of 7 2.3. AQUIFER CHARACTERIZATION In conformance with the Division of Minerals and Geology Rule 6.4.7(2(b), we must characterize the alluvial aquifer to be excavated via mining. The characterization should describe the direction of groundwater movement in this shallow alluvial aquifer in and around the area to be excavated, transmissivity, and storage coefficient of the aquifer in the area of excavation. The direction of flow of groundwater in the alluvial aquifer is shown in Sheet 1. Groundwater moves perpendicular to the contour lines, generally downstream and sub-parallel to the river in the existing and post reclamation stages. The hydraulic conductivity of alluvial sediments in the Denver Basin range from 100 to 2000 ft/day. The Office of the State Engineer recommends that we use 600 ft/day in this area. The transmissivity is the product of aquifer thickness and conductivity so where the gravel is 25 feet thick the transmissivity is 15,000 sq.ft/day. The specific yield is assumed to be 0.20. 2.4. INPUT PARAMETERS 2.4.1. Hydraulic Conductivities Hydraulic conductivity for the lower gravel layer was set to 600 ft/day (Sy=0.2). The value has been accepted by the Colorado Office of the State Engineer as a representative value for gravel deposits on the St Vrain River. The clay liner for the reclaimed pit in the model was set to a hydraulic conductivity of 0.00026 ft/day as is required by the State Engineer. 2.4.2. St Vrain River The St. Vrain River is simulated through application of a Constant Head boundary in MODFLOW. 2.4.3. Nelson Pond The pond due north of the pit is called Nelson pond for the purpose of this report, named after the owner Howard Nelson. This pond is simulated through application if the LAKES package in MODFLOW. The lakebed hydraulic conductivity was set at 3 ft/day and the lakebed thickness was set at 2 feet. The lake stage was set to 15 ft above lakebed bottom elevations. Nelson Mining Resource Groundwater Modeling Report 3 of 7 2.4.4. Pit Reclamation The pit excavation will be lined with a compacted clay liner to disconnect it from the natural ground water table and the river. The clay liner in the model has been set to a hydraulic conductivity of 0.00026 ft/day as is required by the State Engineer. Nelson Mining Resource Groundwater Modeling Report 4 of 7 • 2.5. MODEL BOUNDARY CONDITIONS The principle boundary conditions set to prescribed heads at perimeter cells of the model domain. Water table elevations were extrapolated from observation wells shown in Sheet 1. 2.6. MODEL CALIBRATION AND STEADY STATE SIMULATION The model was calibrated to simulate existing conditions. Calibration was performed by varying the values for constant head boundary cells. This process was repeated until the water levels from the model output matched the measured heads to within about 10 percent of observed heads in both observation wells and the surface water elevations of the lakes in the model. The constant head boundary was selected as the calibration "variable parameter" due to the fact that the hydraulic conductivity value is a required office of the state engineer. The model was calibrated to water table elevations measured onsite in 2001(see Sheet 1 — MW-01, MW-02, MW-03), before significant drawdown due to other gravel operations in the area occurred. Offsite water table elevations were determined by direct measurement of historic high water marks in two wells (See Sheet 1 SW-1, SW-2) on the pump piping. The model was therefore calibrated to historic high water table elevations for the purpose of producing worst case scenario water table mounding elevations. The model was run under steady state conditions which estimate heads and flows after infinite time. Steady state models simulate equilibrium conditions for both the baseline existing condition model and the post-development reclamation condition model. Similarly the steady state model runs simulate worst case water table mounding. The model was created to assess the relative and worst case effects a of low permeability clay liner on the nearby up-gradient structures. The model is not designed to simulate seasonal variations in river flow, evaporation and recharge. Evaluation of these parameters in seasonally varying transient simulations would add unnecessary complexity to the model and far exceed the intended use of the model. Nelson Mining Resource Groundwater Modeling Report 5 of 7 3.0 MODEL OUTPUT Model output was contoured and is shown in Sheets 1-2. Proposed reclamation modeled water table elevations were subtracted from existing water table model output to show relative drawdown due to placement of the low permeability clay liner under reclamation conditions (Sheet 3). Due to the large number of grid cells, MODFLOW model input and output files are too cumbersome to be printed out and included with this report. These input and output files and the Argus One MODFLOW GUI versions of the models are saved onto a data CD which is included with this report. 3.1. EXISTING WATER TABLE The first model run was developed to simulate existing water table elevations. The model output for the existing Water Table simulation following calibration is shown in Sheet-1. 3.2. RECLAMATION CONDITIONS The reclamation model output water table elevation contours are plotted on Sheet 2. These elevations were subtracted from the existing water table elevations to produce drawdown values which are contoured as shown on Sheet 3. Positive numbers indicate that the reclamation water table elevations are predicted to be higher than the existing water table elevations (mounding). Negative values indicate lower water table elevations (shadowing). Drawdown values are consistent with what might be expected to result from the reclamation ground configuration. Nelson Mining Resource Groundwater Modeling Report 6 of 7 4.0 STUDY CONCLUSIONS 4.1. GROUNDWATER MOUNDING The model results predict that mounding will occur. Sheet 3 shows predicted drawdown, where positive values indicate mounding and negative values indicate drawdown. The maximum water table mounding is approximately 4 ft and occurs along the western pit boundary. The maximum shadowing (drawdown) is 2 ft and occurs just east of the pit boundary. 4.2. EFFECTS ON SURFACE OR NEAR SURFACE PERMANENT MAN- MADE STRUCTURES. There are two structures with basements that occur in the groundwater mounding area. For the purpose of evaluating the existing and proposed condition water table elevations relative to the basement elevations, Sheet 4 has been prepared, which shows cross section views. The two basement structures are owned by Thelma Swarts and are called Swarts House land Swarts House 2 for the purpose of this report. The existing condition water table occurs at 13.51 ft below Swarts House 1 and 11.16 ft below Swarts House 2. The Reclamation water table is predicted to occur at 13.08 ft below Swarts House 1 and 10.18 ft below Swarts House 2. The increase in water table elevation at Swarts House 1 is 0.43 ft and 0.98 ft at Swarts House 2. Both of these structures have adequate head space above the water table under predicted reclamation water table conditions. There are no structures on the west side of the pit where mounding is predicted to occur. There are no alluvial wells where shadowing is predicted to occur. Based on the model results, no water table mitigation is recommended. Nelson Mining Resource Groundwater Modeling Report 7of7 LARGE MAPS AVAILABLE FOR VIEWING AT THE CLERK TO THE BOARD'S OFFICE, IN THE PUBLIC REVIEW FILE. K» KERR AMCGCORPORATION1999 BROADY,SUITE 3700•DENVER, ADO 80202 MOUNTAIN CORPORATION PHONE: 303-296-3600 FAX: 303-296-3601 December 5, 2005 VIA FACSIMILIE AND U.S. MAIL Weld County Planning Department GREELEY OFFICE DEC X 7 2005 Weld County Board of Commissioners RECEIVED 918 10`h Street Greeley, Colorado 80631 Re: Nelson Mining Resource—Hearing USR-1259 3N-6W, Section 31: E/2SE/4 Dear Weld County Board of Commissioners Members: Kerr-McGee Rocky Mountain Corporation ("KMRMC") is the owner of valid oil and gas leases underlying all or part of the Nelson Mining Resource Development, for which Asphalt Specialties Co. is seeking USR approval. KMRMC and Asphalt Specialties have been negotiating a Mining Agreement, the terms of which will govern the parties' simultaneous use of the subject property. KMRMC does not object to the USR application for which Asphalt Specialties is applying. However, the parties have not yet concluded an agreement, and KMRMC therefore requests that the Weld County Board of Commissioners withhold final approval of this USR application until the parties execute and record a surface use agreement. Sincerely, Kerr T-McGee Rocky Mountain Corporation b. Terry D. 'nn.'t Landman Specialist cc: James P. Wason—Kerr-McGee Rocky Mountain Corporation Peter Wayland—Weiland, Inc. for the Applicant, Asphalt Specialties IDCHIBIT Feb 022006 1 : 04PM HP LASERJET FRX 303-652-8788 p , 1 ASPHALT �tF SPECIALTIES CO . 10100 Dallas St. • Henderson, CO 80640 • (303) 289-8555 • Fax: (303) 289-7707 FACSIMILE TRANSMITTAL SHEET To: Kim Ogle/Esther Gesick (w.o. From: Rob Laird,Land Manager attachments) Company. Weld County Planning Date: February 2,2006 Fax Number 970 304-6498/970-352- Phone Number: 0242 Total Number of Pages Including Cover: 4 Re:Final Approval from State Engineer on Sub Supply Plan so can Schedule BCC Hearing for Nelson Mining Resource,USR-1529 0 URGENT 0 FOR REVIEW 0 PLEASE COMMENT ❑PLEASE REPLY ❑ PLEASE RECYCLE Kim and Esther: Please see following. This is the first two pages of the approval letter from the State Engineer approving the Nelson Mining Resource temporary substitute supply plan (I did not think you needed all 7. A complete clean copy will be mailed to you). Per the requirements of Weld County relating to a mining USR,two government approvals are required for the Planning Dept. to set a hearing date before the County Commissioners: A DMG permit and the sub supply plan. With this approval letter, both of those conditions have been satisfied. I am requesting that you, Kim, please confirm this statement and send the case file to Esther as soon as possible. She has informed that if she can get everything in order next week, she can publish the notice in the paper beginning Friday 2-10-06 (?) and therefore we can set the hearing date for March 1, 2006. We really, really need to try and get that hearing date. As you know Kim,this will go very smoothly as all conditions are agreed upon and there is no citizen opposition. The only other contingency is an agreement with the oil companies, although that is NOT a requirement in having a hearing. We are very close to an agreement with both oil companies and that will be done by March 1, and more likely by next week. I have a file an inch thick to show the time and money spent in getting an agreement. Please contact me if you have any concerns and lets try and get this thing on the March 1 agenda. Thanks! Rob EXHIBIT t\ Feb 02 2006 1 : 04PM HP LASERJET FAX 303-652-8788 p. 2 • FE9-02-2006 11:14AM FROM-WEILAND INC 3034360053 T-513 P.001 F-953 STATE OF COLORADO OFFICE OF THE STATE ENGINEER Division entof N ur l rcesResources Mti Department of NeturMt Newuren $'� • sue, 1313 Sherman Street Room 816 Denver,Colorado 80203 'are78 •' Phone(303)866-3581 FAX 13031866-3389 January 19, 2006 Sill Owrn www.waterliite.CO.OS Onvernof a Peter Wayland "n.9i mss. ftufAlr drec[or Welland, Inc. Ha p.Simpson,P.E 525 3fa Avenue, Suite 211 stag e,l,",er Longmont, CO 80501 Re: Nelson Mining Resource Gravel Pit, Substitute Water Supply Plan DMG File No. M-05-059 Section 31, T3N, R67W of the 6th P.M, Water Division 1, Water Disirint S Approval Period: January 1, 2006 through December 31, 2007 Dear Mr, ay an : This letter is in response to your application of October 20, 2005 requesting approval of a substitute water supply plan ("SWSP") for a sand and gravel pit owned and operated by Asphalt Specialties Company, Inc. The Applicant shall be responsible for compliance with this plan. The required fee of $1,343 for the substitute water supply plan has been submitted (receipt no. 545112). • Plan Operation This plan seeks to replace depletions resulting from mining at the Nelson Mining Resources Gravel Pit ("Nelson Pit"). The project proposes to dewater the pit and pump that water into to the unlined Varra Companies Pit No. 1 (M-74-052) located to the north of the Nelson Pit. Depletions from evaporation at the Varra Companies Pit No. 1 ("Varra Pit") are augmented pursuant to a pre-1989 augmentation agreement with the St. Vrairl & Left hand Water Conservancy District. According to the plan, the Varra Pit is located at the same approximate distance from St. Vrain Creek as the dewatering pump. Therefore, the water will recharge hack to the stream in the same approximate timing as the depletions from dewatering. The reclamation plan for the Nelson Pit is to place a compacted clay liner around the interior of the mine slopes for the purpose of preventing groundwater seepage from entering the pit. The applicant has bonded for lining of the pit through the Division of Minerals and Geology. Depletions This plan describes the proposed water uses at the previously un-mined Nelson Mining Resource Gravel Pit during the first two years of this operation. The proposed plan anticipates a maximum annual net depletion of 15.02 acre-feet for up to 1.19 acres of exposed groundwater surface (0.34 acres of dewatering trench and 0.85 acres of wash pond) during the approval period. Since this is a new mining operation, no groundwater was exposed at this site Feb O2 2OO6 1 : 04PM HP LASERJET FAX 3O3-652-8788 P . 3 FEB-Oa-2006 11:14AL1 FROM-WEILAND INC 3034300053 T-513 P.002/00T F-653 Peter Wayland January 19, 2008 Page 2 . prior to January 1, 1981. Depletions from the mining of this proposed operation will accrue to ,St. Vrain Creek. You have provided a monthly breakdown of the maximum year annual depletions totaling 2.89 acre-feet of evaporative loss from a maximum of 1.19 acres of groundwater exposed after January 1, 1981, 1.2 acre-feet of water used and consumed for dust control,and 10.92 acre-feet of water lost with 371,000 tons of mined product. The mining operation is located greater than 100 feet from St. Vrain Creek. As a result, a stream depletion analysis using Glover techniques has been performed as a means to assess the lagged depletions to St. Vraln Creek resulting from the proposed operation of the Nelson Mining Resource Gravel Pit. The schedule for replacement of depletions takes Into full account all annual depletions accounting for the lagged effect over 10 years and normalized according those monthly percentages. As a result, full replacement of depletions to St. Vraln Creek are made on a monthly basis, Replacements The proposed source of replacement for this pit is fully consumable wastewater treatment plant effluent or reservoir releases from a lease with the City of Longmont. The City of Longmont wastewater treatment plant is located approximately 10.5 miles upstream of this new mining operation. A 0.25 percent per mile transit loss (2.625 percent overall loss) has been accounted for in the replacements, The monthly depletions and replacement requirements are found on the attached table. 4422:::. • -• •y Section 8 of Senate Bill 89-120, this substitute water supply plan has been provided to an outside consultant f lew. The consultant t this le as ory requ remen s an t e recommendations of the consultant, I here y approve the proposed substitute water supply plan in accordance with Section 37-90-137(11), C.R.S., subject to the following conditions: 1. This SWSP shall be valid for the period of January 1, 2006 through December 31. 2007, unless otherwise revoked, modified, or superceded by decree. If this plan will not be made absolute by a water court action by the plan's expiration date, a renewal request must be submitted to this office with the statutory fee by November 1, 2007, 2. The losses associated with this mining operation must not exceed a total of 15.02 acre- feet annually for the duration of this plan approval. These tosses Include 2.89 acre-feet of evaporation from the proposed exposure of up to 1.19 acres of groundwater, 1.2 acre- feet of water used for dust suppression and 10.92 acre-feet of water lost In 371,000 tons Of mined aggregate. Should the losses associated with the mining operation exceed 15.02 acre-feet annually, prior to the expiration date of this plan, an amendment will need to be filed with this office. aliimslmigonr- 3. copy of the lease with the City of Longmont must be submitted to the State Engineer's A COffice prior to commencing mining at the site. Feb 02 2006 1 : 04PM HP LRSERJET FAX 303-652-8788 p. 4 OV LOAF G ry . �� . vi 7/ 1 emu. 4 F �' i► January 17, 2006 4A O Rob Laird L OR N� Asphalt Specialties Co. 10100 Dallas Street Henderson, CO 80640 RE: ase of Augmentation Water for the Nelson Mining Resource; Located in Section 31, Township 3N, Range 67 West, Weld County,CO Dear Mr. Laird: On January 13, 2006, this office received your request and a check for for lease of augmentation water for the referenced gravel mine. This letter is to confirm that Longmont will make available 15.41 acre-feet of reuse water for the Nelson Mining Resource. These releases will be based upon the following schedule: Month Acre-Feet April 2006 1.10 May 2006 1.20 June 2006 1.39 July 2006 1.63 August 2006 1.73 September 2006 1.64 October 2006 1.44 November 2006 133 December 2006 1.17 January 2007 0.97 February 2007 0.89 March 2007 0.94 Total 15.41 , The source of the water will be from Longmont's following decrees: 81CW355/87CW212, Longmont Supply Ditch; 81CW356/87CW213, Rough& Ready Ditch; 81CW357, Smead Ditch; 81CW360, Palmerton Ditch; 81CW361/87CW214 Oligarchy Ditch; 81CW362, Swede Ditch; 87CW215, Beckwith Ditch; 87CW216, Clover Basin Ditch; 87CW218, Niwot Ditch; 87CW219, Pella Ditch; 87CW220, South Flat Ditch; 87CW221,Zweck&Turner Ditch and 87CW233, Clover Basin Reservoir; 87C W222 Union Reservoir; and 87CW231 Pleasant Valley Reservoir. The lease will be from April 2006 through March 2007 only. Lease of the water does not initiate or give rise to any vested right for a continuation of the same rental and use of the water for more than the time period specified. The City does not assume any obligation for delivery of water beyond the release of the water at the outflow of the Wastewater Treatment Plant into St. Water/Wastewater Department 1100 South Sherman Street• Longmont,Colorado 80501 303-651-8376 •Fax: 303-651-8812 • www.ci.longmont.co.us v':tt/ ` ia'i tta'a'g "kt, m O; teM% yea kid 3 raikrAtr£:ffi.�'3 nsWe!a"". 'ifk; "a-s�. 1 "a?li'..t;;:+f_ iG"rti'; Hello