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Home My WebLink About20252604.tiffFinal Drainage Report Pintail Compressor Station Created for PHILLIPS 66 Weld Co Case Number: USR23-0041 Project Number: B22.DCP.0002 Report Number: FDR 01 REV 3 Issue Date Seotember 2024 ;.y IA" "."a• 41) 4e ,9f: n O qn Fa 1, 011A(:4. 1{ 4 j dect 111 4jt4 q ') C .)) S '+�3 w 4 ti e9 alb tin Alay vt�al "tee s\ . J> ,f •G1 r . $0411 commiCS, S0UIII0NS 8620 Wolff court Westminster, CO 80031 303-928-7128 Accepted by DEVELOPMENT REVIEW August 14, 2025 Pintail Compressor Station: Final Drainage Report Document: FDR 01 Rev 3 Page i September 2024 REFERENCE CONTRACT This work has been conducted by Ascent Geomatic Solutions (Ascent) for PHILLIPS 66 (P66) under contract number B22.DCP.0002 - CO1. This work has been performed under Ascent project number B22.DCP.0002. The P66 project manager for Pintail Compressor Station is Mr. Eloy Celis; Matt Parse is the project manager for Ascent. DOCUMENT REVISION HISTORY Rev Date Issued Prepared Reviewed Approved 0 01/25/2024 Issued for Permit AS MS MS 1 04/29/2024 Issued for Permit AMS MS MS 2 05/06/2024 Issued for Permit AMS MS MS 3 09/23/2024 Issued for Permit AS MS MS This report, and all associated materials, has been prepared by Ascent Geomatic Solutions for the exclusive use of PHILLIPS 66 for Pintail Compressor Station. No other party is an intended beneficiary of this report or any of the information, opinions, and conclusions contained herein. The use of this report shall be at the sole risk of the user regardless of any fault or negligence of PHILLIPS 66 or Ascent Geomatic Solutions. Ascent Geomatic Solutions accepts no responsibility for damages, if any, suffered by any third party as a result of decisions or actions based on this report. Note that this report is a controlled document and any reproductions are uncontrolled and may not be the most recent version. ASCENT GinWis SJIWiIntl`_, Pintail Compressor Station: Final Drainage Report Page ii Document: FDR 01 Rev 3 September 2024 EXECUTIVE SUMMARY A drainage analysis was performed for the project site in accordance with the Weld County requirements for a final drainage report. It was determined that a detention pond is required to maintain historic release rates off site. A grading and stormwater management system has been designed based on the hydrological analysis. The drainage system was designed to be phased. The design implements a detention pond during the construction phase. Once reclamation occurs the pond will service the site throughout its life. BMP practices will be utilized during the construction phase to ensure stormwater release from the site is in compliance with Weld County and State requirements. ASCENT GinWis SJIWiIntl`_, Pintail Compressor Station: Final Drainage Report Page iii Document: FDR 01 Rev 3 September 2024 TABLE OF CONTENTS REFERENCE CONTRACT DOCUMENT REVISION HISTORY EXECUTIVE SUMMARY TABLE OF CONTENTS WELD COUNTY FINAL DRAINAGE REPORT CHECKLIST CERTIFICATE OF COMPLIANCE 1. INTRODUCTION AND PURPOSE 2. PROJECT DESCRIPTION AND BACKGROUND 3. DESIGN CRITERIA 4. DESIGN CONDITIONS 4.1 Existing Conditions 4.2 Proposed Conditions 4.2.1 Stormwater System Design 5. MAINTENANCE PLAN 6. SUMMARY AND CONCLUSIONS Appendix A — REFERENCE DOCUMENTS, SOFTWARE AND WEBSITES Appendix B — ABBREVIATIONS AND ACRONYMS Appendix C — DRAINAGE REPORT CHECKLIST Appendix D — VICINITY MAP Appendix E — FEMA MAP Appendix F — NOAA ATLAS 14 PRECIPITATION FREQUENCY TABLE Appendix G — GROUND SURFACE IMPERVIOUS CALCULATIONS Appendix H — HYDROLOGIC CALCULATIONS Appendix I — DETENTION / WQCV CALCULATIONS Appendix J — HYDRAULIC CALCULATIONS ASCENT OEOMATICS 8 8 9 9 10 12 14 A.1 B.1 C.1 D.1 E.1 F.1 G.1 H.1 1.1 J.1 Pintail Compressor Station: Final Drainage Report Page iv Document: FDR 01 Rev 3 September 2024 Appendix K — DRAINAGE DRAWINGS Appendix L — GEOTECHNICAL REPORT ASCENT O1OMATICS K.1 LA Pintail Compressor Station: Final Drainage Report Document: FDR 01 Rev 3 Page 5 September 2024 WELD COUNTY FINAL DRAINAGE REPORT CHECKLIST Yes ❑ No v4 Is the project in the MS4? Report Content Section Cover Page yo Weld County Case Number Certificate of Compliance vo Certificate of Compliance Signed and Stamped by a Colorado Licensed PE 1 & 2 vii Description/Scope of Work 2 yo Location (County Roads, S -T -R) 2 � Nearby Water Features and Ownership 2 " Total Acres vs. Developed Acres 4 & Appendix L " Hydrological Soil Types/Maps 4 & Appendix E '1 FEMA Flood Zones 2 I, Urbanizing or Non -urbanizing 3 " Methodologies Used For Report & Analysis (Full Spectrum is not accepted) 4.2 vii Discussion of Offsite Drainage Routing 6 yo Conclusion Statement indicating that the design will adequately protect public health, safety, and general welfare and have no adverse impacts on public rights -of -way or offsite properties Hydrology and Hydraulic Analysis 4, Appendix F vo Design Storm / Rainfall Information (NOAA Atlas or Local Data) 4.2 & Appendix H & 40 Release Rate Calculations Appendix g yo Post Construction Site Imperviousness 4.1&4.2, Appendix G & H +o Hydrologic calculations (historic & developed basins) Appendix J y• Hydraulic Calculations for Proposed Drainage Improvements (Swales, Culverts, Riprap, Pond, Outlet, Spillway, WQCV Outlet, etc.) Appendix I &J Detention WQCV calculations Construction Drawings 40 Stamped by PE Appendix K Appendix K Engineering scale and north arrow Appendix K 4, Property lines, rights -of -way and easements Appendix K 40 1' contours & elevations (existing and proposed) Appendix K yo Pre- and post -development drainage basins Appendix K Nei Arrows depicting flow direction Appendix K Time of Concentration Critical Path Appendix K v. Drainage Design Points Appendix K yo Improvements Labeled Appendix K +o Permanent Control Measure and Associated Drainage Features Labeled 'No Build/No Storage', Include Design Volume Appendix K 4, Cross Sections for Open Channel, Profiles for Pipes Appendix K 6, Elevations for Inverts, Flow Lines, Top of Grates, Orifice(s), etc. Appendix K vo Pipe Specs (Size, Material, Length, Slope) Appendix K v• Outlet and Spillway Details Maintenance Plan 'o Frequency of Onsite Inspections 5 5 40 Repairs, If Needed 5 40 Cleaning of Sediment and Debris 5 yo Vegetation Maintenance 5 yo Manufacturer Maintenance Specifications, If Applicable Other Required Documents (If applicable) ❑ Variance Request and Documentation - Explain hardship, applicable code section, and proposed Certificate of Compliance mitigation. A copy of the Weld County issued drainage report checklist can be found in Appendix C. ASCENT GEOMAJIGS 501111IONS Pintail Compressor Station: Final Drainage Report Page 6 Document: FDR 01 Rev 3 September 2024 CERTIFICATE OF COMPLIANCE Weld County Drainage COde Certificate of Compliance • Weid County Case Number SF rt O$ paccsi r 105725000016 tc_egal D esaipUom Secti ani own i pI Date: '.' ` ' 23, 2024 t Mark St t ! ,....._ ...._.. FConsultarit Erg. #7194 W4 25466 (4R 614, STI 25,T _ R66W later fl4fi .t:PS 66 understand ..ackftcmilede NI the appitant seeking land use away have desigmd or revie,:wed the stn for the 'oposed set for in t allies; that T cn , a?af %TO variance 2y�� }({-� tidy anti: i' �' � - ttat M 1� 4 A:: v suettwo t'iptlY IP S S It 4f • Descsibe List the design c tot 4'4 (Applicant) the e and to deS7 1, * ye_ ap is l .. t hereby certify, _ haff of the &ainage sownd the Wet County Code with the exception of the certification is not a guarantee or warranty either' expressed d oitt implied, Bariance Request Of A0 #cabled alliance is S requested. lie County Codeof which variance i being requested a fir tin ear :f Recora' : estuary f Desalt* the proposed *lomat" " with nearing rationale which supports the intent of the Weld County Code. Demonstrate that grantingf the variance iii still dequ tely protect public health_: safety: and general welfare and that there t o adverse impacts from t runoff f to tie public Le %Sway agar offsite ro i math of the pros. .._ --na% !PTO?MICtset•tn'J v,PSV. t LIrClcz a1 _. RWSniRt i'+Or'��TaRY4�SG'aVs15-X.1 1-4.:araVaianV>aLyf<NiiWKD•vaPiearetIaft"':aa�l.—x9•t"-n;.C ,y- e%f .a% F�.�NACIR -- .u. ...cn....-. +W- zr.-v•�-a __ .nclrr`t: r- f. MD .I I U a.r $ eoabP0.0ar-U4ff..CCOasnI Snni N[V+Vtrattige- a...Iw.n(..4....r.f eo.am_a'�rfwN:n+glitraiatUw vatW4b Pa Sits Diveciternsinte Name ature cable - Signature Mal S. tJ . . .-Ea.+f.rv.a`arJretr+rtAtAcsiv ette7ierr-, 'It?!it•e-Ati'an :ni5reSArpa iit "�:* .,....:rr:n�"S'It'?�c_+a.Intti•f,^3`�b 7.11S .941VYr/!Stottttf.<.. �x.9**71e!CYtiY.ceAtraA�'+Y*..m•n�a^_�- a-fl>,ra► ter _:: :.r.. :--J!4'. �1C'p+a+WR�!':�n� ••,., kiS bVO� ..L�t_'+J.V?3-+ S}- X'-?w"t'>ilY:v--�}'q Nv.-t:•.'yn'!+C.tK w w..•e..-ti a.,un.....a..n us+v. �.r.... ... net .,w.- -wnK•5+..Maa 1. DepartYper4 of Pubic Mots `Develtyprneftl Review 1111 Street re e# C0W631 Ph 970-304406jwise weilcjrfl c EdeP t&.} b4t mss' v -n(eyam i32.2019 AS NT Pintail Compressor Station: Final Drainage Report Page 7 Document: FDR 01 Rev 3 September 2024 1. INTRODUCTION AND PURPOSE PHILLIPS 66 (P66) is constructing a new compressor site in Weld County, Colorado. The project is referred to as the Pintail Compressor Station. As part of the project, a compressor pad, substation pad, offload equipment area and temporary laydown area will need to be constructed. Ascent Geomatic Solutions (Ascent) has been contracted to perform the grading, drainage analysis and drainage report for the Pintail Compressor Station. This report presents the findings and recommendations for the grading and stormwater management for the project. 2. PROJECT DESCRIPTION AND BACKGROUND The Pintail Compressor Station is located in the Northeast quarter of the Southwest quarter of Section 25, Township 4 North, Range 66 West of the 6th Principal Meridian in Weld County, Colorado'. Figure 1 shows an aerial photo of the project site location. A vicinity map showing the project location relative to the surrounding area can be found in Appendix D. Figure 1: Aerial of Project Location 1 The project site is located at latitude: 40.280558° N, longitude: 104.728686° W. ;:.;:. ASCENT f:iLILilMS silluirMS Pintail Compressor Station: Final Drainage Report Page 8 Document: FDR 01 Rev 3 September 2024 The proposed oil and gas facility is located on a 21-acre2 site which is a portion of a 162 -acre parcel owned by Korwell Land Holdings LLC and resides at a mean elevation 4,788 ft. amsl. The site is located 0.3 miles East of County Road 35 and 0.3 miles North of County Road 40. The site is in a non -urbanizing area and is bounded on all sides by agricultural land. There are no major water features on the site. A geotechnical investigation was performed at this location. 3. DESIGN CRITERIA The proposed drainage plan follows Weld County Code requirements and Weld County Engineering and Construction Criteria (WC-ECC)3. Weld County Charter and County Code (WC- CCC)3 incorporates many of the Mile High Flood District (MHFD) requirements by reference into its code. As such UDFCD requirements have been included in the design and analysis for the Pintail Compressor Station project. Hydraflow Express Extension for Autodesk AutoCAD Civil 3D (Hydraflow)5 was used to perform many of the hydrologic and hydraulic calculations for this project. The Rational Method was used for most of the hydrologic calculations. The Modified -FAA Method was used for detention pond sizing. The runoff coefficients used in the Rational calculations are taken from USDCM-1-20083 in accordance with Weld County Public Works (WC-PW) requirements. The overall design directives include mitigation of stormwater so as not to negatively impact adjacent properties. 4. DESIGN CONDITIONS The existing conditions ground cover of the project site and the ground cover of the rangeland adjacent to the pad has been stripped of topsoil and can be described as nearly bare ground. The basin delineation map is presented in Appendix K. The hydrologic soil classifications for the project were obtained from the Geotechnical Engineering Study (GES3). The hydrologic soil group is 100% Type B for all basins. 2 Acreage per Surface Use Agreement (SUA). 3 Reference Appendix A, Table 2: Reference Documents for more information. 4 Particular attention to Weld County Code Chapter 8 (Public Works), Article XI (Storm Drainage Criteria) has been given for this project designs. 5 Reference Appendix A, Table 3: Reference Software and Websites for more information. 6 The "nearly bare ground" condition has a corresponding Conveyance Factor (K) of 10 within the Rational Method. ASCENT f:iilt ilMS +UlUiirMS Pintail Compressor Station: Final Drainage Report Page 9 Document: FDR 01 Rev 3 September 2024 Selection of imperviousness values for the project site are based on whether the conditions are existing or proposed; the specific imperviousness values selected for the hydrologic analysis are discussed in Sections 4.1 and 4.2. The design storm data used to analyze both existing and proposed conditions were taken from NOAA Atlas 14 (NOAA-14)'. The NOAA-14 precipitation frequency data used for the hydrologic analysis is provided in Appendix F. The proposed site is not located within the FEMA 100-yr floodplain. The mean groundwater depth at this location is > 6.5 ft (200 cm) below grade$. 4.1 Existing Conditions The existing conditions design values are provided in Table 1. Nearly bare ground is the current condition over the project area as the topsoil has been stripped of the site. Stormwater from the project site travels down gradient to Weld County Road 35 flowing North along roadside ditches, then along Colorado Highway 85 roadside ditches where it ultimately discharges into the South Platte River approximately 6.5 miles north of the site. Table 1: Existing Conditions Design Values Parameter Value Average Slope 1-6% Existing Condition Flow Direction South to North Coverage Type Nearly bare ground Conveyance Factor 10 4.2 Proposed Conditions The proposed drainage drawings located in Appendix K show the proposed project site with construction disturbance area and grading. The stormwater management systems for the construction phase were designed based on the construction phase conditions with equipment, which provides a hydrologic "worst case" design. The proposed compressor pad will be capped with 5" minimum Martin Marietta #57/67 washed crushed rock. The Substation Pad will be capped with minimum 4" of 1-1/2" crushed rock over 8" minimum CDOT Class 5 or Class 6 Aggregate Road base. The compressor station and substation 7 Reference Appendix A, Table 3: Reference Software and Websites for more information. 8 Groundwater elevation taken from GES (see GES in Table 2: Reference Documents). r_1 itireaTh ASCENT f:iilt.iilMS silluirMS Pintail Compressor Station: Final Drainage Report Page 10 Document: FDR 01 Rev 3 September 2024 pads are assigned an assumed imperviousness of 40%. Piers, concrete pads and/or footers are expected and were assigned an assumed imperviousness of 100%. The detention pond was assigned an assumed imperviousness of 2%. Reference Appendix G for composite value for total imperviousness calculations. See Drainage Drawings in Appendix K for basin delineations. 4.2.1 Stormwater System Design The stormwater system for the Pintail Compressor Station Pad is designed to be phased. The construction phase includes three onsite channels, two offsite channels, five culverts, and a detention pond with a concrete outlet box. Sheet K.2 in Appendix K identifies the stormwater design elements. Once construction phase is complete, approximately 5.1 acres of the site will be reclaimed as close to existing conditions as possible, and the permanent compressor and substation pads will remain as constructed. Sheet K.5 in Appendix K depicts the reclaimed design. 4.2.1.1 Site Drainage Features Compressor Pad During the construction phase rainfall that lands on the pad will either flow southwest to northeast to either the east onsite channel or to the north onsite channel or will flow directly to the detention pond; from there water will flow through the concrete outlet structure and out onto existing ground where it will resume historic flow patterns. Offsite runoff is diverted around the site via a channel on the south side. Culvert C is designed to take care of the runoff from the spillway of 18.8 cfs if needed. Substation Pad During the construction phase rainfall that lands on the pad will flow south to north to an onsite channel, from there water will flow through two culverts and into another onsite channel: from there water will flow to the detention pond and thorough the concrete outlet structure and out onto existing ground where it will resume historic flow patterns. Laydown Yard During the construction phase rainfall that lands on the temporary laydown pad will flow south to north onto existing ground where it will resume historic flow patterns. 9 Imperviousness calculations were performed by referencing USDCM-1 Table 6-3 "Recommended Percentage Imperviousness Values" (see Appendix A for more information on USDCM-1) rant ASCENT irLI ilMS +UluirMS Pintail Compressor Station: Final Drainage Report Page 11 Document: FDR 01 Rev 3 September 2024 4.2.1.2 Detention Ponds Stonnwater for Basin 1 — Design Point 1 will flow across the substation pad surface towards the south to an onsite channel, from there water will flow through two culverts and into another onsite channel: from there water will flow into the detention pond on the north edge of the pad. The modified -FAA method was used to size the detention pond (Design Point 1). The required detention pond volume is 0.98 ac -ft (42,831 cu-ft)1°. The total detention pond volume is 1.09 ac -ft (47,591 cu -ft). The depth of the proposed pond at the outlet structure is 4.0' deep plus 1.1' (minimum) of freeboard above the 1 -hr, 100-yr water surface elevation. slopes. The pond is graded at 4:1 interior side The detention pond utilizes a concrete outlet structure with a maximum design (4.03 cfs) less than the 10 -year historical release rate of 4.08 includes a 17' wide emergency spillway. cfsio release rate The detention pond design also 4.2.1.3Best Management Practices The production pad will be serviced by a stormwater pond in accordance with Weld County criteria. Stonnwater runoff will be treated through Best Management Practices (BMP) to reduce sediment transport from the pad. The following BMPs are intended for the production pad: • Fiber roll, wattles • Revegetation/Mulching • Surface Roughening 10 Reference Appendix I- DETENTION / WQCV CALCULATIONS fl ASCENT Pintail Compressor Station: Final Drainage Report Page 12 Document: FDR 01 Rev 3 September 2024 5. MAINTENANCE PLAN Drainage Basin Detention ponds have low to moderate maintenance requirements on a routine basis but may require significant maintenance once every 15 to 25 years. Maintenance frequency depends on the amount of construction activity within the tributary watershed, the erosion control measures implemented, the size of the watershed, and the design of the facility. Inspection of the surface system will include functional and aesthetic needs. Functional maintenance is important for performance and safety reasons and aesthetic is important primarily for public acceptance of stormwater facilities. The removal of debris, sediment, overgrown or weedy vegetation will be prioritized based upon the inspection results. Inspection Inspect the drainage structures at least once annually, generally in the Spring, observing the amount of sediment where channels discharge into the pond and checking for debris at the outlet structure. Maintenance Debris and Litter Removal - Remove debris and litter from the detention area as required to minimize clogging of the outlet. Mowing and Plant Care- When starting from seed, mow native/drought tolerant grasses only when required to deter weeds during the first three years. Following this period, mowing of native/drought tolerant grass may stop or be reduced to maintain a height of no less than 6 inches (higher mowing heights are associated with deeper roots and greater drought tolerance). In general, mowing should be done as needed to maintain appropriate height and control weeds. Mowing of manicured grasses may vary from as frequently as weekly during the summer, to no mowing during the winter. Sediment Removal from the Basin Bottom- Remove sediment from the bottom of the basin when accumulated sediment occupies about 20% of the water quality design volume or when sediment accumulation results in poor drainage within the basin. The required frequency may be every 15 to 25 years or more frequently in basins where construction activities are occurring. Erosion and Structural Repairs- Repair basin inlets, outlets, trickle channels, and all other structural components required for the basin to operate as intended. Repair and vegetate eroded areas as needed following inspection. airet ASCENT f:iLILilMS silluirMS Pintail Compressor Station: Final Drainage Report Document: FDR 01 Rev 3 Page 13 September 2024 The following is a more detailed guideline for detention pond maintenance considerations: Action Maintenance Objective Frequency of Action Lawn mowing and lawn care Occasional mowing Maintain irrigated non -irrigated to limit turf natives grasses unwanted vegetation. grass as 2 to 4 inches at 4 to 6 inches. tall and Routine - Depending on aesthetic requirements. Debris and litter removal Remove debris minimize outlet and litter from the clogging and improve entire pond aesthetics. to Routine - Including and May) and annual, following significant pre -storm season rainfall (April events. Erosion and sediment control Repair and revegetate and channels. eroded areas in the basins Non -routine - Periodic and repair as necessary based on inspection. Structural Repair channel pond inlets, outlets, forebays, low flow liners, and energy dissipaters as needed. Non -routine - Repair as needed based on regular inspections. Inspections Inspect basins to insure function as initially for clogging, erosion, sedimentation levels, and spillway integrity, element. intended. slumping, that overgrowth, and the damage basin continues Examine the excessive embankment to any to outlet structural Routine structural during plugging - Annual inspection of facilities. Also check for routine maintenance visits, of outlets. hydraulic obvious especially and problems for Nuisance control Address associated bottom odor, zone. insects, and with stagnant or overgrowth standing issues water in the Non -routine complaints. - Handle as necessary per inspection or Sediment Removal Remove and the accumulated bottom of the sediment from the basin. forebay Non -routine accumulation may necessary more pond. vary frequent - Performed occupies considerably, per inspection. cleanout 20 but than when sediment percent of the expect to do The forebay other areas WQCV. This this as will require of the ASCENT GEOMAJIGS 501111IONS Pintail Compressor Station: Final Drainage Report Page 14 Document: FDR 01 Rev 3 September 2024 6. SUMMARY AND CONCLUSIONS The proposed drainage plan follows Weld County's Charter and County Code (WC-CCC) and the Weld County Engineering and Construction Criteria (WC-ECC). Rational Method and modified - FAA method were used to perform many of the calculations for drainage analysis. The drainage system was designed to be phased. The design implements a detention pond that will service the compressor and substation pad and will remain and serve the site during its life. Best Management Practices will be utilized during production phase to reduce sediment transport from the pad. This report and the calculations have been produced after proper due diligence for the site and surrounding adjacent offsite areas. The drainage design is adequate to protect public health, safety, and general welfare and has no adverse impacts on public rights -of -way or offsite properties. The stormwater management designs provided in this report have been performed in accordance with Weld County requirements. Andreas Savland Project Engineer September 23, 2024 airet ASCENT Mark Skelskey, P.E. Engineer of Record LILilMS silluirMS Pintail Compressor Station: Final Drainage Report Document: FDR 01 Rev 3 Page A.1 September 2024 APPENDIX A - REFERENCE DOCUMENTS, SOFTWARE AND WEBSITES Table 2: Reference Documents Document Abbreviation "Urban Storm Hydrology, and Revised August Drainage Criteria Manual: Hydraulics ", by Urban 2018; Originally Published Drainage Volume September 1 & —Management, Control District; USDCM-1 Flood 1969 "Urban Storm Drainage Criteria Manual: Volume 1", by Flood Control District; Revised April 2008; Originally Published Urban Drainage & June 2001 USDCM-1-2008 "Urban and September Recreation Storm Drainage ", by Urban 2017; Originally Criteria Drainage Manual: Volume 2 & Flood Control September 1969 — Structures, Storage, Updated USDCM-2 District; Published "Urban Practices 2019; Storm Drainage ", by Urban Drainage Originally Published Criteria Manual: & Flood September 1992 Volume 3 Control District; — Best Management Updated October USDCM-3 "Weld County Engineering and Construction Originally Published March 2021. Criteria", by Weld County, CO; WC-ECC "Geotechnical Published Engineering Study," by Kumar & Associates, 2023. Inc., Originally GES-1 June 15, Table 3: Reference Software and Websites Document Abbreviation "Hydra f low Express Extension for A utodesk AutoCAD Civil 3D v2023.3 ", by Hydraflow Autodesk, Inc.; released 2023. "AutoCAD Civil 3D - 2023", by Autodesk; released 2023. CAD -CAD "NOAA Updated https://hdsc.nws.noaa.gov/hdsc/pfds/pfdsmapcont.html Atlas 14", by April 21, 2017 the National Oceanic and Atmospheric Administration, NOAA-14 WC-CCC "Weld County Charter and County Code - Supplement 63", by Weld County, CO; Codified through Ordinance No. 2019-14, adopted September 23, 2019; Updated December 19, 2019. "USDA/NRCS Society. https://websoilsurvey. Web Soil Survey ", sc.egov.usda.gov/App/WebSoilSurvey.aspx by National Resource Conservation NRCS airet ASCENT f:iilt ilMS +UlUiirMS Pintail Compressor Station: Final Drainage Report Page B.1 Document: FDR 01 Rev 2 September 2024 APPENDIX B - ABBREVIATIONS AND ACRONYMS ABC ac AMSL Avg. BMP C CDOT cfs ECMC cm CM ECD EURV FAA FEMA FIRM ft. fps HEC-HMS hr. K LACT MHFD MLVT min. RG RI T0C UD UDFCD Aggregate Base Course acres Above Mean Sea Level Average Best Management Practice Runoff Coefficient Colorado Department of Transportation Cubic feet per second Energy and Carbon Management Commission Centimeters Criteria Manual Emissions Control Device Excess Urban Runoff Volume Federal Aviation Administration Federal Emergency Management Agency Flood Insurance Rate Map feet Feet Per Second Hydrologic Engineering Center - Hydrologic Modeling System hour Conveyance Factor (UD-Rational)" Lease Automatic Custody Transfer Mile High Flood District Modular Large Volume Tanks minutes Rough Grade Recurrence interval (rainstorm) Top of Concrete Urban Drainage Urban Drainage and Flood Control District 11 Reference Table 3: Reference Software and Websites for additional information on this engineering reference document. I?,, f.r rik ASCENT f:iLIL1 l([IS UlUiirMS Pintail Compressor Station: Final Drainage Report Document: FDR 01 Rev 2 Page B.2 September 2024 USDCM-1 USDCM-1-2008 USDCM-2 USDCM-3 WC WC-ECC WC -ED WC-SDC WC-SDC WOGLA WQCV Urban Storm Drainage Criteria Manual — Volume 1 12 Urban Storm Drainage Criteria Manual — Volume 1(2008) 12 Urban Storm Drainage Criteria Manual — Volume 2 12 Urban Storm Drainage Criteria Manual — Volume 3 12 Weld County Weld County Engineering and Construction Criteria 12 Weld County Energy Department Weld County Storm Drainage Criteria Weld County Storm Drainage Criteria Addendum 12 Weld County Oil & Gas Location Assessment (permit) Water Quality Capture Volume 12 Reference Table 2: Reference Documents for additional information on this engineering reference document. rs Abio fl ASCENT f:iilt.ib1([IS U1UiiDh; Pintail Compressor Station: Final Drainage Report Page C.1 Document: FDR 01 Rev 2 September 2024 APPENDIX C - DRAINAGE REPORT CHECKLIST Drainage Report Checklist Project Name: The purpose of this checklist is to assist the applicant's Engineer with developing a drainage report that supports the intent of the Weld County Code using commonly accepted engineering practices and methodologies. Is the project in the MS4? DYes D No If yes, the following requirements in blue apply„ See Chapter 8, Article IX of the Weld County Code. Report Content Weld County Case Number Certificate of Compliance signed and stamped by a Colorado Licensed PE ❑ Description/Scope of Work El Location (County Roads, S -T -R) ❑ Nearby water features and ownership CI Total acres vs. developed acres ❑ Hydrological soil types/maps • FEMA Flood Zones Urbanizing or non -urbanizing ❑ Methodologies used for report & analysis (full spectrum is not accepted) ❑ Base Design Standard used for permanent control measure design in the MS4 ❑ Discussion of offsite drainage routing Conclusion statement indicating that the design will adequately protect public health, safety, and general welfare and have no adverse impacts on public rights -of -way or offsite properties Hydrology and Hydraulic Analysis ❑ Design Storm / Rainfall Information (NOM Atlas or Local Data) ❑ Release Rate calculations • Post construction site imperviousness ❑ Hydrologic calculations (historic & developed basins) ❑ Hydraulic calculations for proposed drainage improvements (swales, culverts, riprap, pond, outlet, spillway, WQCV outlet, etc.) ❑ DetentionNVOCV calculations Construction Drawings ❑ Stamped ped by PE ❑ Engineering scale & north arrow El Property lines, rights -of -way, and easements ❑ 1' Contours & elevations (existing & proposed) ❑ Pre- and post -development drainage basins ❑ Arrows depicting flow direction 1 Time of concentration critical path Drainage design points ❑ Improvements labeled El Permanent control measure and associated drainage features labeled "No Build/No Storage', include design volume ❑ Cross sections for open channels, profiles for pipes ❑ Elevations for inverts, flow lines, top of grates, orifice(s), etc. IE] Pipe specs (size, material, length, slope) • Outlet and spillway details Maintenance Plan ❑ Frequency of onsite inspections Li Repairs, if needed Cleaning of sediment and debris • Vegetation maintenance ❑ Manufacturer maintenance specifications, if applicable l9 Other Required Documents (If Applicable) l _ a Variance Request and documentation— explain hardship, applicable code section, and proposed mitigation. Variances will not be granted for the Base Design Standard requirement in the MS4. Highlighted Items _ Minimum Requirements for Preliminary Drainage Report *Note: Additional information may be necessary on a case by case basis* Department of Public Works I Development Review 1111 H Street, Greeley, CO 80631 I Ph: 970-304-6496 I wwwv.weldgov.comidepartmentsipublic_worksidevelopment_rerriew ASCENT f:iilt ilMS ;UIUiiDh; Pintail Compressor Station: Final Drainage Report Page D.1 Document: FDR 01 Rev 3 September 2024 APPENDIX D - VICINITY MAP :LAMER t HIS PLO I DOES N C REPRESENT P. MONUMEN I EL LAND SURVEY C1 SHOULD NOT Ub H ,L ILL] UPON 0 Lit IMMUNE 6C& JNOARY LINES. PROPERTY OWNERSHIP OR OTHER PROPERTY INTERESTS. PARCEL ,LU _ IF DEPICTED. HAVE M)T BEEN FIELD VERIFIED AND MAY BE .BASED UPON PUBLICLY AVAILABLE DATA THAT ALSO HAS BEEN INDEPENDENTLY VERIFIED. ASCENT DATA SOURCE: AERIAL NARY: NAIP 2021 PUBLICLY AVAILABLE DATA SOURCES HAVE NOT BEEN manFpFNDFlens vERIFIED BY ASCENT GEOMATICS SOLUTIONS Pintail Compressor Station: Final Drainage Report Page E.1 Document: FDR 01 Rev 3 September 2024 APPENDIX E - FEMA MAP National Flood Hazard Layer FIRMette 104°447'W 40°L74'N 104°4329'W 40°16'36"N Cr 250 500 .000 1,500 Feet 2,000 1:6,000 FEMA Basemap Imagery Source: USGS Natiiona! Map 2023 ASCENT Legend SEE RS REPORT FOR DETAILED LEGEND AND INDEX! MAP FOR RRM PANEL LAYOUT SPECIAL FLOOD HAZARD AREAS Without Base Flood Elevation (BFE) L i.,nit A. Y. MI With BFE at Depth ._,rr,g.AO, AM, YE. AR Regulatory Floodway OTHER AREAS OF nom) HAZARD OTHER AREAS GENERAL STRUCTURES OTHER FEATURES MAP PANELS 9 gal Frd r', 02% Annual Chance Flood Hazard, Areas of 1% annual chance flood with average depth loss than one foot or with drainage areas of less than one square mile tcina x Future Conditions 1% Annual Chance Flood Hazard Area with Reduced Flood Risk due to Levee. See Notes. t,,;,• Area with Flood Risk due to L evee zvn• xr NO SCREEN: Area of Minimal Flood Hazard Zara .Y Effective LOMRs Area of Undetermined Flood Hazard rape iJ a — - Channel. Culvert, or Storm Sewer milli Levee, Dike, or FroadwaN 24.2 0 _i1 Cross Sections with 1% Annual Chance Water Surface Elevation Coastal Transect Base Flood Elevation Line (BFE) Limit of Study Jurisdiction Boundary Coastal Transact Baseline Profile Baseline Hydrographic Feature Bigotat Data Available No Digital Data Available Unmapped ry The pin displayed on the map is an approximate point selected by the user and does not represent an authoritative property location, This map compiles with FEMA's standards for the use of digital flood maps if it is not void as described below. The basemap shown complies with FEMA's basemap accuracy standards The flood hazard information is derived directly from the authoritative POHL web services provided by FEMA. This map was exported on 6,'26/2023 at 8:37 AM and does not reflect changes or amendments subsequent to this date and time. The NFHL and eflective Information may change or become superseded by new data over time. This map image is void if the one or (pore of the following map elements do not appear: basentap Imagery, flood zone labels, legend, scale bar, map creation date, community Identifiers, FIRM panel number. and ARM effective date. Map images for unmapped and unmodernized areas cannot be used for regulatory purposes. GEOMATICS SOLUTIONS Pintail Compressor Station: Final Drainage Report Page F.1 Document: FDR 01 Rev 3 September 2024 4-they APPENDIX F - NOAA ATLAS 14 PRECIPITATION FREQUENCY TABLE Prechpileden Frequency Data Server NOAA Atlas 114, Volume Si Version 2 Location name; La Salsa, Colorado USA` Latitude; 4..280'4 Longitude; -1 1114.7287° Elevation; 47S3 if" scion tee- E.SRI I',iao 't seine J3GS POINT PRECIPITATION FREQUENCY ESTIMATES Sa ig Pis i , DlrL-affill Man, Swillh nifiti4c& Mari !Ray", Mkhaital 31 Lassatril, Carl Trimakic, Data Unruh. PA ttktu 'ft t•'. Ge :r4r+ry Fc-nn n 'CAA. N KONA Waite Stria -Ai S+hetr Grn5. Kltrylontl PF IarthuIcsv I r r,.i ":c.. I ws R PF tabular P'DS Kiser point precipitation frequency estimates with 90% confidence Intervals (irl Inshes)1 Duredlo Average recurrence interval (years) 1 estiiiin 5-rnIn 3a -min 34w 0 210 ee��6.352 ' ..i' 66--(1 433 0429 0.349 0.53.; 0.575 .462-0 TITN 0,712 dl,SH-0282 2 I 0,25101 QQ21Y S 10 25 0:368 n -467 iO. i1h•Ci 40::1 II) .F S.C E4:61 I {1.634 li i 41.CJ-fl.9&3) 100 6.757 1.tl4) 0.915 ..tifi! -1 2.6A I]1.5*8. 0_706 VI 1.11 ii i"( tl .�a -3.1:: r-11 0_11.91.x. y IO.56i O!811 0.9NN I I; 721..1.1 .251 1:1.2 &1'-1.52) 8.611 1_13 1.,JP` 1 469; 1 cei i r ;.E21 Chi 118)h 1 4, ap11.9 71-1 89, 1..63 0_'524 i0.7L9-1.1 t 1.155 �I Wit-+• 1.4.11 51 1-84 1.'I'-'l.1.14i 1.Is.L491 1.12 10.905-1 MI 1,39 11 12-4 741 1:.85 (1.46-2.SC•i .1 $ 1.59-311'; 2.26 (11.72-3.48) 2.72 (1'.58-3 soy 0.8:491 a;11 5915-1 04) 0.920 0.766 1 1.05 tu.H9?-1.31 1.27 41,06-15 l' 0.968 p c.i 914_1 :c 1.043 I` aIJM 1 h1 126 -(1.34-1 52.1m 1.50 (1.25-1801 1.31 1.64 2.1B i r7)7.1 f tn.2.4)34 1.41 1.75 2.94 11.15 ?. ?Cc] 41.4 2.16i i I.4 J. -E 1.63 f1.3e-1.r E. 2.111 I I t' '•..41 ca - I:5.9.521 1.14 11.61-233i 2.36 (1 25-2.li6) &43 19,Q37 a 24 -hr 1.51 2i-1'1 2 1.7'3 OA? 7 AI 2.C'±i i eat 1. �5 4 i,.ta •'., 2.02 i1,73-23elo 1.m l".19-2.11) 2.22 '1 .E1t1 I" 2.35 (1,'41- '.5) liallY11. 2.30 90-2.67 2.61 2.111 ill del 2.tf+ 2 20h.2.93N 247 (2.56343 3.74 Y 3. 9-4 2.95 2Ili 3.24 i°2'.0!!-3.1'" 9.37 3;42.1 (" tt Ql le.e.-4.32 4P4ay .048 9.44 0{1 2 604aey 9 4 vS t'=',' 5.14 i 512: 5.71 11 h'.) I 1 9ry-2 70) 2.7'2 r2 27-3.27 3.14 :434 ;:!.7a 3A3 i2 781.36'1 9 _+..17 4.86'1 2.80 l".3 9. -k 2J J 3.32 4..16 Imo' • '3.2.Ic''•i _1•!..14-9.11E1 2. (2.514.45) 3 46 .-4.:i 4,_23 p.47-5,21) 3.33 12 414!'7,4•:,2 6ei 3.B) 13 : �24S5i 4.61) I.:3 list+5.74 J 3.67 0.1.64.251 4.16 6.10 (.65 4.9:`,I '4.2O-6. `4) 4.56 p 1,3.imi-1231 II 5.22 (d.fi I l•.1_a I E..14 IS Crii-7.291 -5,2 I (42421 6,027111 1521-5•.a I, .1:5-$4412.6) 2..0 e• "162) 2-48• g� :' 1•Ia�111 124 35-i 504 0- 1.> k 2.59-4.84 124 191 '` ;—'.3?yi 2!.92.1: i 9.62 2%64—a.74 jl I 478 a_2' —5.74 4.4. 43. 1f: -5.l9 4.10 ..1. :3 96 ≥ IN tvii I 41 3.5x7 5.?L1 i 5.16 x•1.42 tan Ia?t -a.91'i 5.36. /4.' LIZ e12; i 466 43.574,"47) 0 5.52 It 24-7.081 I 5I:33 1 •q ~S=. 5O l 539 4.634980 641 ,4.96-8.05. • 1..1'8, x.52 ;004 3• 6.54A.24. 7,52: '5,011-9.I2 ,- 4E.-.29 7't7'6 84510 x;67-10. 6:51 7.05 i.543.7Co; I IN, 1•i -'?1.1;31 B.1 B if, m-9 7.110 x'".96 152.1`_. !.ill fI=' 'x•9.101 Sf 1'74.1 II.71 $.02 7.38-10.7) 9.69. 7,76-12..1 10.2 11.E i6..:13-1 2.0.4 0.' 4.1 1,06 (0.71..,T45 -1.551i 1.58 A!9-2271 1.0, inia3 2771 2.59 i[ 1.719.3 73 324 (2244 srj 31:8#1 J1 S 551 t2 4.20 i2.e'rl3 5 ` i 4.6dl 5,00 (15$.6 sit 5,42 X90.7 37 500 10110 1,32 p.859.1 %j 2.3$ I1 55 3.,4! I 3.1E .09-4.111 t 52 22 1.41-9:31 2_71 1 7.--" 4.041 346 2.12-5.4M 464 I2 -944,W •1 4.63 � I � :22-7 10( �f1 82 _I..604F1.27) M ISIS 13.53 7.6ei 6.14 la t:. 0.91! i 5.76 633 r 6.06 9 j4 14-I'.:5 :21 6.'44 14 S-5.w`'I 6.46 7.30 (.1 •4.1-'-:9 1.41 I (•1 E-10 a) ...5 2 41 - I l - 762 ., li 11).e 6.67 i-t.L_1'id. I -b1 6.23 (41 23) 6.51 4934721 .. (5.25 1.181 322 9.23 P:Fi i3-111 7) 7.05 7.84 7 22 5 01 I5.cki-5(5u-11 . U :I 7.53 t:5 3-1. mm X71 5.3$ p (5 7•i,-11 i,' a 1 \ 6.81 l.5r.'I.ice II 8•_71 iP _11.iI.0 sh 01,13 re iti-1; 0 I 4' 111 Ii,1?-i-13. ' 1 10,2 2 ie."Li 10,9 ,.• 54-14.7'. 12,4 18 744.3 13.7 75-10.1; ' Precipitation iraquancy 1139 tali maw; In this, tatPl4 ara bawl on lnaepancy analysts p r1r€ai iiaa'atloa r :rIec. (PD5) NLtrtC,rs Ir F,arnnthess are PF est. �I s a Iowa and uppor bounds nt that u c rdcncc inlet#al. The peababllty4 That prP dell Bier- frequency animates cs (tar a goon Jura en and average recurrence au be greater than he upper t}_'.nni ice !leas than the Irt a b3und) is 5%. EsIrnales al upper bounds are rot chatb M agent pp:Amble rnalurrim prac pita1k n (PPAI) as imates and may be higher tai'arrertiy valid P\1P YaluaS. tv -.IM 53+1555 r5INIC:4/+,ul)H! 1-t9 ;1.C'P7_I'n+,larl fIa11 np rN Baal par—rrs'ir, flack Ice T:.zrt PF graphical ASCENT GEOMATICS SOLUTIONS Pintail Compressor Station: Final Drainage Report Page F.2 Document: FDR 01 Rev 3 September 2024 Large scale aerial Maps & aerial's Smmll S ile e:rairn Print:1 0nm Fr squency PIMA $er r Lirgr bogie :tale 1113p 1OUkr Zr� S tpr sties, LoO el w so.dsser t. i I jai r � er 1 Jkn ASCENT oY r • U GEOMATICS SOLUTIONS Pintail Compressor Station: Final Drainage Report Document: FDR 01 Rev 3 Page G.1 September 2024 Appendix G - GROUND SURFACE IMPERVIOUS CALCULATIONS COMPOSITE BASIN -WEIGHTED "%IMPERVIOUS" CALCULATIONS -REFERENCE : UDFCD USDCM V1 Table 6-3 Recommended Percentase Imperviousness Values Undeveloped areas Street Historic flow analysis Greenbelts, Agricultural Off -site flow analysis (when land use not defined) Paved Gravel Recycled as phalts Drives and walks Roofs Imperv. 2.00% 2.00% 45.00% 100.00% 40.00% 75.00% 90.00% 90.00% Area Area Area Area Area Area Area Area Total Area Percent Imperv. 8.0 8.0 40% BASIN 1 DESIGN POINT 1 0.7 0.7 100% 1.7 1.7 2% 0.0 1.7 0.0 0.7 8.0 0.0 0.0 0.0 ir 10.4 P 38% 5.6 5.6 40% BASIN 1 DESIGN POINT 2 0.5 0.5 100% 1.1 1.1 2% 0.0 1.1 0.0 0.5 5.6 0.0 0.0 0.0 P 7.2 p 38% 2.0 2.0 40% BA SIN 1 DESIGN POINT 3 0.1 0.1 100% 0.5 0.5 2% 0.0 0.5 0.0 0.1 2.0 0.0 0.0 0.0 P 2.5 p 35% CONSTRUCTION (DRILLING) PHA SE 0.6 0.6 409/0 BASIN 1 DESIGN POINT 4 0.0 0.0 100% 0.1 0.1 2% 0.0 0.1 0.0 0.0 0.6 0.0 0.0 0.0 r 0.6 p 39% 1.2 1.2 40% BASIN 1 DESIGN POINT 5 0.1 0.1 100% 0.3 0.3 2% 0.3 0.0 0.1 1.2 0.0 0.0 0.0 1.5 Pr0.0 36% 0.0 0.0 0% BASIN 2 DESIGN POINT 6 0.0 0.0 0% 12.2 12.2 2% 0.0 12.2 0.0 0.0 0.0 0.0 0.0 0.0 P 12.2 P 2% 0.0 0.0 0% BASIN 3 DESIGN POINT 7 0.0 0.0 0% 3.3 3.3 2% 0.0 3.3 0.0 0.0 0.0 0.0 0.0 0.0 3.3 2% ASCENT UEOMATICS SULUiIONS Pintail Compressor Station: Final Drainage Report Document: FDR 01 Rev 3 Page H.1 September 2024 Project: Pintail Location: Weld County Owner: PHILLIPS 66 Designer: AS Date: 9/18/2024 APPENDIX H - HYDROLOGIC CALCULATIONS 5-yr 10-yr 100-yr 1 -hr rainfall depth Pi 1.12 in 1.39 in 2.72 in Basin ID Design Point Area (ac) Imperviousness o (%) MRCS Hydrologic Soil Group o (%) Overland Flow length (ft) Overland Slope (ft/ft) Channelized Flow length (ft) Channelized Slope (ft/ft) Type of Land Surface MRCS Conveyance Factor i A B C/D L; So LC Sc Existing Conditions Basin 1 1 10.4 2% 0% 100% 0% 100 0.009 493 0.016 Nearly bare ground Basin 2 6 12.2 2% 0% 100% 0% 100 0.008 826 0.009 Nearly bare ground Basin 3 7 3.3 2% 0% 100% 0% 100 0.017 643 0.010 Nearly bare ground Proposed Condtions Basin 1 1 10.4 38% 0% 100% 0% 100 0.008 1139 0.007 Nearly bare ground Basin 1 2 7.2 38% 0% 100% 0% 100 0.008 956 0.007 Nearly bare ground Basin 1 3 2.5 35% 0% 100% 0% 100 0.008 506 0.006 Nearly bare ground Basin 1 4 0.6 39% 0% 100% 0% 100 0.008 253 0.013 Nearly bare ground Basin 1 5 1.5 36% 0% 100% 0% 100 0.008 319 0.007 Nearly bare ground Basin 2 6 12.2 2% 0% 100% 0% 100 0.008 1633 0.007 Nearly bare ground Basin 3 7 3.3 2% 0% 100% 0% 100 0.002 793 0.009 Nearly bare ground 4-11 ASCENT LEOhIAUUGS SLIWFIONS Pintail Compressor Station: Final Drainage Report Document: FDR 01 Rev 3 Page H.2 September 2024 Project: Pintail Location: Weld County Owner: PHILLIPS 66 Designer: AS Date: 9/18/2024 Basin ID Design Point Area (ac) Runoff Coefficient Time of Concentration (min) Rainfall (in/hr) Intensity Peak Flow (cfs) C5 C10 C100 Initial ti Channelized tt Total tc 15 110 1100 O5 qua, O100 1.53 IC& 17.49 Existing Conditions Basin 1 1 10.4 0.08 0.17 0.36 19.45 6.50 25.94 1.91 2.37 4.64 Basin 2 6 12.2 0.08 0.17 0.36 19.54 14.28 33.82 1.64 2.03 3.97 1.53 4.10 17.56 Basin 3 7 3.3 0.08 0.17 0.36 15.63 10.72 26.34 1.89 2.35 4.60 0.48 1.28 5.50 Proposed Condtions Basin 1 1 10.4 0.29 0.35 0.49 16.14 22.07 38.20 1.52 1.88 3.69 4.53 6.87 18.78 Basin 1 2 7.2 0.29 0.35 0.49 16.14 19.70 35.84 1.58 1.96 3.83 3.27 4.95 13.52 Basin 1 3 2.5 0.27 0.34 0.48 16.42 11.07 27.50 1.85 2.29 4.49 1.26 1.94 5.41 Basin 1 4 0.6 0.29 0.35 0.49 16.04 3.70 19.74 2.22 2.75 5.39 0.39 0.59 1.59 Basin 1 5 1.5 0.28 0.34 0.48 15.98 6.35 22.34 2.08 2.58 5.04 0.86 1.32 3.67 Basin 2 6 12.2 0.08 0.17 0.36 19.88 32.53 52.41 1.24 1.54 3.01 1.16 3.10 13.30 Basin 3 7 3.3 0.08 0.17 0.36 33.15 13.93 47.08 1.33 1.65 3.23 0.34 0.90 3.86 sat ASCENT 6E0MATICS SOLUTIONS Pintail Compressor Station: Final Drainage Report Page H.3 Document: FDR 01 Rev 3 September 2024 4-11 ASCENT 6EOM4FIGS SIRLIFIONS Pintail Compressor Station: Final Drainage Report Page 1.1 Document: FDR 01 Rev 3 September 2024 APPENDIX I - DETENTION / WQCV CALCULATIONS Project: Pintail Location: Weld County Owner: PHILLIPS 66 Designer: AS Date: 8/23/2024 Return Interval: 100-yr Time of concentration Tc 38.20 min Runoff Coefficient C100 0.49 Tributary Area A 10.4 ac Time Step t 3 min .r_et Release Rat Cci 4.08 cfs Imperviosness I 38 Storage Facility Type Extended Detention Storm Duration (minutes) Rainfall Intensity (in/hr) Inflow Volume (ft3' Outflow adjustment factor Outflow Volume (ft3 Storage Volume ft3) T I V; m Vo VS 0 0.00 0 0.00 0 0 3 10.32 9,470 1.00 734 8,736 6 8.77 16,088 1.00 1,469 14,619 9 7.66 21,083 1.00 2,203 18,880 12 6.83 25,051 1.00 2,938 22,114 15 6.17 28,321 1.00 3,672 24,649 18 5.65 31,089 1.00 4,406 26,682 21 5.21 33,481 1.00 5,141 28,341 24 4.85 35,585 1.00 5,875 29,709 27 4.54 37,459 1.00 6,610 30,849 30 4.27 39,147 1.00 7,344 31,803 33 4.03 40,682 1.00 8,078 32,604 36 3.82 42,089 1.00 8,813 33,276 39 3.64 43,388 0.99 9,449 33,938 42 3.47 44,593 0.95 9,816 34,776 45 3.32 45,717 0.92 10,184 35,534 48 3.19 46,771 0.90 10,551 36,221 51 3.06 47, 763 0.87 10,918 36,845 54 2.95 48,700 0.85 11,285 37,415 57 2.85 19,588 0.84 11,652 37,935 60 2.75 50,431 0.82 12,020 38,411 63 2.66 51,235 0.80 12,387 38,848 66 2.58 52,002 0.79 12,754 39,248 69 2.50 32,736 0.78 13,121 39,615 72 2.43 53,440 0.77 13,488 39,952 75 2.36 34,117 0.75 13,856 40,261 78 2.30 54,768 0.74 14,223 40,545 81 2.24 55,395 0.74 14,590 40,805 84 2.18 56,001 0.73 14,957 41,044 87 2.13 36,586 0.72 15,324 41,262 90 2.08 57,153 0.71 15,692 41,461 93 2.03 37,702 0.71 16,059 41,643 96 1.98 38,234 0.70 16,426 41,808 99 1.94 58,751 0.69 16,793 41,957 102 1.90 39,253 0.69 17,160 /2,092 105 1.86 59,741 0.68 17,528 12,214 108 1.82 60,217 0.68 17,895 42,322 111 1.79 60,680 (167 18,262 42,418 114 1.75 61,132 0.67 18,629 42,503 117 1.72 61,573 0.66 18,996 42,577 120 1.69 62,003 0.66 19,364 42,640 123 1.66 62,424 0.66 19,731 42,693 126 1.63 62,835 0.65 20,098 42,737 129 1.60 63,237 0.65 20,465 12,772 132 1.58 63,631 0.64 20,832 42,799 135 1.55 64,017 0.64 21,200 42,817 138 1.53 64,394 0.64 21,567 42,827 141 1.50 64,765 0.64 21,934 42,831 144 1.48 65,128 0.63 22,301 42,826 147 1.46 65,484 0.63 22,668 42,815 150 1.44 65,834 0.63 23,036 42,798 153 1.41 66,177 0.62 23,403 12,774 156 1.39 66,514 0.62 23,770 42,744 159 1.37 66,846 0.62 24,137 42,708 162 1.36 67,171 0.62 24,504 42,667 165 1.34 67,492 0.62 24,872 42,620 168 1.32 67,807 0.61 25,239 42,568 171 1.30 68,117 0.61 25,606 42,511 174 1.29 68,422 0.61 25,973 42,449 177 1.27 68,723 0.61 26,340 42,382 180 1.25 69,019 0.61 26,708 42,311 ASCENT Required Storage Volume V 5 42,831 ft3 0.98 ac -ft WQCV Design Storage Volume II 7,905 ft3 0.18 ac -ft :f S Pintail Compressor Station: Final Drainage Report Page 1.2 Document: FDR 01 Rev 3 September 2024 80,000 70,000 60,000 M 50,000 4- 40,000 30,000 20,000 10,000 0 20 40 60 80 100 120 0 Volume Hydrograph 140 160 180 200 Duration (minutes) Major Storm Inflow Volume Major Storm Outflow Volume Major Storm Storage Volume Minor Storm Inflow Volume Minor Storm Outflow Volume Minor Storm Storage Volume ASCENT GEOMAIICS SOLUTIONS Pintail Compressor Station: Final Drainage Report Page 1.3 Document: FDR 01 Rev 3 September 2024 Project: Pintail Location: Weld County Owner: PHILLIPS 66 Designer: AS Date: 9/18/2024 Legend: Input Output Warning Stage Storage Increment Pond (ft) Depth Pond Volume (ft3) 1 0.0 0.0 2 0.1 15.7 3 0.2 66.3 4 0.3 167.2 5 0.4 334.5 6 0.5 584.6 7 0.6 933.9 8 0.7 1398.2 9 0.8 1974.5 10 0.9 2649.3 11 1.0 3418.4 12 1.1 4280.6 13 1.2 5235.5 14 1.3 6283.1 15 1.4 7424.1 16 1.5 8654.0 17 1.6 9948.7 18 1.7 11277.7 19 1.8 12628.0 20 1.9 13998.3 21 2.0 15388.5 22 2.1 16799.0 23 2.2 18229.6 24 2.3 19680.7 25 2.4 21152.3 26 2.5 22644.5 27 2.6 24157.5 28 2.7 25691.3 29 2.8 27246.2 30 2.9 28822.2 31 3.0 30419.5 32 3.1 32038.2 33 3.2 33678.4 34 3.3 35340.3 35 3.4 37024.0 36 3.5 38729.6 37 3.6 40457.2 38 3.7 42207.0 39 3.8 43979.1 40 3.9 45773.7 41 4.0 47590.8 ASCENT GEOMATICS SOLUTIONS Pintail Compressor Station: Final Drainage Report Page 1.4 Document: FDR 01 Rev 3 September 2024 Volume Outflow Hydrograph 40,000 35,000 30,000 25,000 m ec E 20,000 d 15,000 10,000 5,000 0 10 20 30 40 Time (hours) 50 60 WQCV S-YR 10-YR 100-YR 70 80 i1/40) ASCENT Pintail Compressor Station: Final Drainage Report Document: FDR 01 Rev 3 Page 1.5 September 2024 Project: Pintail Location: Weld County Owner: PHILLIPS 66 Designer: AS Date: 9/18/2024 Legend: Input Output Warning Pond Design Storm Event Volume Water Surface Elev. Drain Time % Drained Peak Flow WQCV VWQ 7,905 ft^3 ZWQ 1./I/ ft 38.33 hr 100% QWQ 0.07 cfs 5-yr V5 2,992 ft^3 75 0.94 ft 18.00 hr 100% O5 0.06 cfs 10-yr V10 6,743 ft^3 Z10 1.34 ft 34.50 hr 100% O10 0.07 cfs 100-yr V100 42,831 f t ^3 Z1oo 3.74 ft 87.00 hr 100% 0100 4.03 cf s WQ Orifices # of Orifice Rows 1 # of Orifices per row 3 Orifice Spacing 4.0 in Discharge Coefficient Co 0.60 Orifice Diameter D0 0.875 in Orifice Diameter Do 7/8 in Orifice Area A0 0.0042 ft^2 Minor Storm Orifice Rectangular Orifice Width Wo Rectangular Orifice Height Ho Orifice Diameter Do Orifice Diameter Do Orifice Elevation Zo Discharge Coefficient Co Orifice Area A0 Box Weir Box Width WB 3.00 ft Box Length LB 3.00 ft Top of Box Elevation ZB 2.50 ft Weir Coefficient CW 3.33 Trash Rack Area Reduction 50% Spillway Weir Discharge Q 18.8 cfs Weir Coefficient CBcW 3.0 Depth of flow through weir H 6.0 in Side slope of weir (H:V) Z 4.0 Minimum Length of Weir L 16.1 ft Design Length of Weir Lc 17 ft ASCENT GEOMATICS SOLUTIONS Pintail Compressor Station: Final Drainage Report Document: FDR 01 Rev 3 Page 1.6 September 2024 Project: Pintail Location: Weld County Owner: PHILLIPS 66 Designer: AS Date: 8/23/2024 Legend: Input Output Warning Restrictor Plate Sizing 100-yr Water Surface Depth h 3.74 ft Q (4.08cfss aiis Maximum Allowable Flow Pipe Inner Diameter D 15.00 in Pipe Inner Radius r 7.50 in Distance from Pipe Invert to Bottom of Restrictor Plate d 5.75 in Distance from Pipe Invert to Bottom of Restrictor Plate d Cp 3/4 in Central Angle 43, 2.671 Discharge Coefficient Co 0.60 Required Orifice Flow Area A0 63.14 in^2 Design Orifice Flow Area A 62.35 in^2 0 d 0 c les 00 dr ssk 0 0 ) Pintail Compressor Station: Final Drainage Report Page 1.7 Document: FDR 01 Rev 3 September 2024 Project: Pintail Location: Weld County Owner: PHILLIPS 66 Designer: AS Date: 8/23/2024 Legend: Input Output Warning Outlet Pipe Maximum Capacity Manning Roughness Coefficient n 0.013 Diameter D 15 i n Slope S 0.005 Area A 1.227 f t"2 Hydraulic Radius (full flow) R 0.313 ft Maximum Flow Rate Q 4.58 cfs Culvert Outlet Protection Design Discharge Q (8ft1'3,s 3.0 yl ft/s Allowable Velocity V Number of Barrels 1 Pipe Inside Diameter (in) D 15 in Pipe Inside Diameter (ft) D 1.3 ft Froude Parameter Q/D2.s 2.34 QI/Dts 2.92 Tailwater Depth (If known) Yt ii Calculated Tailwater Depth (If unknown) Yt 0.50 ft Tailwater Depth / Depth of Water Yt/D 0.4 Expansion Factor 1/(2tan 0) 5.5 Area of flow At 1.4 ft"2 Riprap Design Type 1 I D50 9 in Depth of Protection Hp 18 in Length of Protection Lp 8 ft Width of Protection T 3 ft OK OK OK Pintail Compressor Station: Final Drainage Report Page J.1 Document: FDR 01 Rev 3 September 2024 APPENDIX J - HYDRAULIC CALCULATIONS Channel Report Hydraflorwv Express Extension for Autodesk€' Civil 3DEI by Autodesk, Inc_ Channel 'I (Design Port 2) Trapezoidal Bottom Width (ft) Side Slopes (z:1) Total Depth (ft) Invert Elev (ft) Slope (%) NNalue Calculations Compute by: Known n O (cfs) Elev (ft) 4793.00 4792,50 4792.00 4791.50 4791.00 4790.50 4790,00 4789.50 a 2.00 = 4.00, 4.00 =2.02 4790.40 = 0.40 0.030 Known Q = 13,52 Section Highlighted Depth (ft) O (cfs) Area (sqft) Velocity (Ws) WettedPerim (ft) Grit Depth, Yo (ft) Top Width (ft) EGL (ft) Thursday. Aug 22 2024 =1.02 = 13.52 = 6.20 = 2,18 = 10.41 = 0.73 =10.16 = 1,09 Depth (ft) 0 2 4 6 8 10 12 14 16 18 Reach (ft) ASCENT 20 22 24 2.60 2:10 1.60 1.10 0.60 010 -0,40 -0.90 GEOMATICS SOLUTIONS Pintail Compressor Station: Final Drainage Report Page J.2 Document: FDR 01 Rev 3 September 2024 Channel 1 Outlet Protection Design Discharge Q 13.5 ft"3/s Allowable Velocity V 3.0 ft/s 1 Width of Channel (at H/2) W 5.8 ft Design Water Depth H 1.0 ft Froude Parameter Q/WH1.s 2 Q/WHo.s 2.36 Tailwater Depth (If known) Yt Calculated Tailwater Depth (If unknown) Yt 0.38 ft Tailwater Depth / Depth of Water Yt/H 0.4 Expansion Factor 1/(2tan 0) i 6 Area of flow At 4.5 ft^2 Riprap Design Type ig L D50 9 in Depth of Protection Hp 18 in Length of Protection Lp 35 ft width of Protection T Use Lp =10H Pintail Compressor Station: Final Drainage Report Page J.3 Document: FDR 01 Rev 3 September 2024 Channel. Report Hydra lc+w Express Extension for Autodeske AubaCADE. Civil 3D® by Autodeek, Channel 2 (Design Point 3) Trapezoidal Bottom Width (ft) Side Slopes (z:1) Total Depth (ft) Invert Elev (ft) Slope (%) N -Value Calculations Compute by: Known (cfs) Elev (ft) 4795.00 4794.50 4794.00 4793,50 4793,00 4792,50 4792.00 = 2.#0 = 4.00, 4.00 1.67 = 4792.80 = 0.40 0.030 Known O Section !dig lighted Depth (ft) (cfs) Area (sqft) Velocity (Ws) Wetted Perim (ft) Crit Depth, Yo eft) Top Width (ft) EGL (ft) Wednesday, Apr 24 2024 - 0.67 _ 5.410 = 3.14 = 1.'73 7.5 2 0.46 _, 7.3 0.72 (Depth (:ft) 0 2 4 6 8 10 12 14 16 Reach (ft) ASCENT 18 20 220 1.10 1.20 030 0.20 -0.30 -0.80 GEOMATICS SOLUTIONS Pintail Compressor Station: Final Drainage Report Page J.4 Document: FDR 01 Rev 3 September 2024 Channel Report Hydra9loww Express Extension M Auttadesk®. !mil 3Ce by /utoc sk, Inc. Channel 3 (Design Point 4) Trapezoidal Bottom Width (ft) Side Slopes (z:1) Total Depth (ft) Invert Elev (ft) Slope (%) NNalue Calculations Compute by: Known (cfs) Elev (ft) 4792.00 491.0 4791,00 91.00 4790.50 4790.00 4789.50 4789.00 _2.00 = 4.00, 4.00 = 1.40 = 4789.60 = 0.40 0.030 Known O =1.59 Section Highlighted Depth (ft) (cfs) Area (sqft) Velocity (Ws) Wetted Perim (It) Crit Depth, Ye (ft) Top Width (ft) EGL (ft) Thursday, Aug 22 2024 = 0.37 = 1,590 = 1,29 = 1,23 _ 5,05. = 0,23 = 4,'g 0.39 2 4 6 8 10 12 14 Reach (ft) ASCENT 1s1 18 Depth (ft) 2.40 1.90 1.40 0.90 0.40 4..10 -0,60 GEOMATICS SOLUTIONS Pintail Compressor Station: Final Drainage Report Page J.5 Document: FDR 01 Rev 3 September 2024 Channel 3 Outlet Protection Design Discharge Q 1.6 ft''3/s Allowable Velocity V 3.0 ft/s 1 Width of Channel (at H/2) W 3.6 ft Design Water Depth H 0.4ft Froude Parameter Q /WH1.5 1./ Q/WHo.s 0.70 Tailwater Depth (If known) Yt Calculated Tailwater Depth (If unknown) Yt 0.16ft Tailwater Depth / Depth of Water Yt/H 0.4 Expansion Factor 1/(2tan 0) 1 6.5 Area of flow At 0.5ft^2 Riprap Design Type qu L Dso 9 in Depth of Protection Hp 18 in Length of Protection La -2ft Width of Protection T 4ft Use Lp = 6H 2ft Pintail Compressor Station: Final Drainage Report Page J.6 Document: FDR 01 Rev 3 September 2024 Channel Report Hydreflc+w Express Extension lug Autodes`tkii Civil 3 Channel 4 (design Point 6) Trapezoidal Bottom Width (ft) Side Slopes (z:1) Total Depth (ft) Invert Elev (It) Slope (%) N - Value Calculations Compute by: Known Q (cis) Elev (ft) 4798,00 4797.50 4797.00 4796.50 4796,00 4795,50 4795.00 4794.50 by Autodesk, Inc. 3.00 4.00, 4.00 2,00 mt 4795.03 0.30 = 0.030 Known O _ 13.30 Section Highlighted Depth (ft) Q (cis) Area (sgft) Velocity (ft's) Wetted Perim (ft) Grit Depth, Yc (ft) Top Width eft) EGL Thursday, Aiig 22 2028 0.9 1�� 3��. 4.3 0 Y f Yl' 1.93 = 1116 0.64 = 10.92 = 1,05 4 6 8 10 12 14 16 18 20 24 0 2 Reach (t) ASCENT Depth (ft) 27 2.47 1,97 1.47 0,97 OAT c0.03 -0.53' GEOMATICS SOLUTIONS Pintail Compressor Station: Final Drainage Report Page J.7 Document: FDR 01 Rev 3 September 2024 Channel 4 Outlet Protection Design Discharge 0 13.3 ft^3/s Allowable Velocity V 3.0ft/s I Width of Channel (at H/2) W 7.0 ft Design Water Depth H 1.0 ft Froude Parameter QJWH1.s QJWHo.s Tailwater Depth (If known) Yt i Calculated Tailwater Depth (If unknown) Yt Tailwater Depth / Depth of Water Yt/H 0.4 Expansion Factor 1/(2tan 0) 6 Area of flow At 4.4 ft^2 Riprap Design Type L Dso 9 in Depth of Protection Hp 18 in Length of Protection LP 25 ft Width of Protection T 9 ft Use Lp=1OH Pintail Compressor Station: Final Drainage Report Page J.8 Document: FDR 01 Rev 3 September 2024 Channel Report Hydraflow Express Extension for AutcdeskiE Civil 3DF3 by Autodesk, Inc. Channel 5 (Design Point 7) Trapezoidal Bottom Width (It) Side Slopes (r1) Total Depth (ft) Invert Elev (ft) Slope (%) N -Value Calculations Compute by: Known 0 (cis) Elev (ft) 4797,00 4796.50 4796,00 4795.50 4795.00 4794,50 3.00 = 4000, 4,00 1.65 4795.03 = 0.30 a 0.030 Known 5.15 Section Highlighted Depth (ft) Q (cfs) Area (sgft Velocity (fs) Wetted Perim (ft) Cr-it Depth, Ye (ft) Top Width (ft) E L(ft) Thursday, Aug 22 2024 0.62 5.150 = 3.40 1.52 = 8.11 a 0.38 '7.96 0.66 Depth (ft) 0 2 .4 6 8 10 12 14 16 Reach (ft) ASCENT 18 20 22 1 :97 1.47 �I 97 I 47 -0.03 0.53 GEOMATICS SOLUTIONS Pintail Compressor Station: Final Drainage Report Page J.9 Document: FDR 01 Rev 3 September 2024 Channel 5 Outlet Protection Design Discharge Q 5.2 ft^3/s Allowable Velocity V 3.0 ft/s i Width of Channel (at H/2) W 5.5 ft Design Water Depth H 0.6 ft Froude Parameter q/N/H1.s 1.93 q/WH(1s 1.19 Tailwater Depth (If known) Yt Calculated Tailwater Depth (If unknown) Yt 0.25 ft Tailwater Depth / Depth of Water Yt/H 0.4 Expansion Factor 1/(2tan 8) 6 Area of flow At 1.7 ft^2 Riprap Design Type L Dso 9 in Depth of Protection HP 18 in Length of Protection LP 9 ft Width of Protection T 7 ft OK Use Lp =10H 6ft Pintail Compressor Station: Final Drainage Report Page 110 Document: FDR 01 Rev 3 September 2024 Culvert Report I-#wirsrikbr• Exprrs. ELi n im far Aubadaskai Gail 3[a by Auln n ,k:, Inc. Culvert A (Design Point 3) Invert Elev Dn (ft) Pipe Length (t) Slope (%) Invert Elev Up (ft) Rise (i Shape Span (in) No. Barrels n -Value Culvert Type Culvert Entrance Coeff. KINA,c,Yik Embankment Top Elevation (ft) Top Width (ft) Crest Width (ft) Elev (ft) 4194.00 4793.00 479019 58.00 1,59 = 479111 15.0 = Circular _ 15.0 0.013 Circular Culvert Smooth tapered inlet throat _ 0534.,0555,0.0196,0.910.' 4793,52 30.00 100,00 Profile Calculations Orrin (cis) Orn (cfs) Tailwater Elev (ft) Highlighted total (els) Opipe (cfs) Dove rtop (cis) Veloc Dn Os) Veloc Lip (fits) HGL Dn (ft) HGL Up t Hw Elev {ft) HMO (ft) Flow Regime Thursday II .1 2024 = 5.41 _ 5.41 (dc+DY2 = 5.41 _ 5.41 0.00! 4_x'4 _ 5.45 = 4791.29 4792.05 = 4792,61 =1.20 Inlet Control w Depth (ft) 47..00 -, _ 4791.0D 11790.00 471;39.00 EGL ai 15( @ 1,59 % 0.0 5,0 10,0 15.0 20:0 25.0 30,0 _O 40:0 45..0 SO 55,0 60_0 65.0 70:0 75.0 80.0 Reach (f) ASCENT 2.89 1.89 0.89 -0.11 -2.11 GEOMATICS somms Pintail Compressor Station: Final Drainage Report Page J.11 Document: FDR 01 Rev 3 September 2024 Culvert A Outlet Protection Design Discharge Q 5.4 ft^3/s Allowable Velocity V 3.0 ft/s Number of Barrels 1 Pipe Inside Diameter (in) D 15 in Pipe Inside Diameter (ft) D 1.3 ft Froude Parameter (VD2.5 3.11 QI /Ds.s 3.89 Tailwater Depth (If known) Yt Calculated Tailwater Depth (If unknown) Yt 0.50 ft Tailwater Depth / Depth of Water YID 0.4 Expansion Factor 1/(2tan e) 1 4.2 Area of flow At 1.8 ft^2 Riprap Design Type L D50 9 in Depth of Protection Hp 18 in Length of Protection L, 10 ft Width of Protection T 4 ft OK OK Pintail Compressor Station: Final Drainage Report Document: FDR 01 Rev 3 Page J.12 September 2024 Culvert Report Hvdraflaww Express Extension los Auludask® Civil 3De by Autadesk, Inc. Culvert B (Design Point ) Invert Elev Dn (if) Pipe Length (ft) Slope (%) Invert Elev Up (ft) Rise (in) Shape Span (in) No, 'Barrels n -Value Culvert Type Culvert Entrance Coeff. K, ycYrk Embankment Top Elevation (ft) Top Width (ft) Crest Width (ft) Elev (ft) 479:00 4793.50 479.00 `1 Jf 2. 1 `JAI 4792.00 4791.50 4791.00 4791.71 40.00 025 = 4791.85 12.0 = Circular 12;D =1 0.013 Circular Culvert Smooth tapered inlet throat 0,53410.555,0.0196p 0. ,0.2 4793.82 30.00 100.00 Profile Calculations Qmin (cfs) Qrna (cis) Tailwater Elev (ft) Highlighted Qtotal (cis) Qpipe (cfs) Qovertop (cis) Veloc On Otis) Veloc Up (ft/s) HGL Dn (ft) HGL Up (ft) Hw Elev (ft) II 1 TYI D (ft) Row Regime Thursday, Jul 11 2024 3.67 3.67 = (dc+D)/2 _ 3.67 _ 3.67 0.00 4.9O 4.67 4792.62 4793.05 = 4793.18 _ 1.33 = Inlet Control Hw Depth (ft) Embarkm • Ham, , --- HGL: @ 0:35 % 40_0U LI of 121.In) 0.0 5,0 10.0 1 5.1; 201) 25.0 30..E 35.9 4O,x+ 45.0 Reach (ft) ASCENT 50.0 55.0 2.15 1.65 1.15 0.65 0.15 -0.85 60.0 GEOMATICS SOLUTIONS Pintail Compressor Station: Final Drainage Report Page J.13 Document: FDR 01 Rev 3 September 2024 Culvert B Outlet Protection Design Discharge Q 3.7 ft^3/s Allowable Velocity V 3.0 ft/s Number of Barrels 1 Pipe Inside Diameter (in) D 12 in Pipe Inside Diameter (ft) D 1.0 ft Froude Parameter Qi/D2.5 3.67 QI/D1.5 3.67 Tailwater Depth (If known) Yt Calculated Tailwater Depth (If unknown) Yt 0.40 ft Tailwater Depth/ Depth of Water YID 0.4 Expansion Factor 1/(2tan 0) 1 4 Area of flow At 1.2 ft^2 Riprap Design Type 1 L Dso gin Depth of Protection Hp 18 in Length of Protection Lp 8 ft Width of Protection T 4 ft p cam. -w .--' r_ OK OK Pintail Compressor Station: Final Drainage Report Page 114 Document: FDR 01 Rev 3 September 2024 Culvert Report Hp:Waflo w' Express Extension for AuftodeskilD CM 3D8i by Autaoesk. Inc. Culvert C (Design Point 1) Invert. Elev On (ft) Pipe Length (ft) Slope ('°k.) Invert Elev Up (ft) Rise (in) Shape Span (in) No.. Barrels n -Value Culvert Type C u lve rt Entrance `jn t rya'c ne Coshlr . ,Mjc1. Y ,.k Embankment Top Elevation (ft) Top Width (ft) Crest Width (ft) Elev (ft) 4788.00 4787.50 4787.00 4786.50 4786.00 4+7 .50 4765.00 4784.50 4785.04 44.00 = 0,48 = 4785.25 1,x_0 Circular I$_0 = 2 = 0,013 Circular Culvert Smooth tapered inlet throat 00.534, 0.555, 0.0196, 0.9, 0.2 = 4787.64 30.010 = 150.00 Profile Calculations 0min (cfs) Uma (cis) Tailwater Elev (ft) Highlighted ()total (cfs) Qpipe (cfs) Qovertop (cfs) Veloc On (Ws) Veloc Up (Ws) HGL On (ft) HGL Up (ft) Hw Elev (ft) HwID (ft) Flow Regime Friday. Aug 23 2024 18.78 18.78 = (do+C)/.2 = 18..78 = 18.78 = 0.01 5.53 = 5,3`1 4786,38 4730.77 = 4787,15 _ 1.27 = Inlet Control Hw Depth (ft) � i I Y st cl1.. M�.., ET i EGL' • 1 FIG L_ '- I I Y 1 tl 1 � Y tl I i 0.0 5.0 1O.0 15.0 20,0 25.0 3O.0 35.0 40.O Reach (ft) ASCENT 45.0 50.0 55,0 60.0 2.75 2.25 1.75 1.25 0,.75 0.25 -025 -0.75 65.0 GEOMATICS SOLUTIONS Pintail Compressor Station: Final Drainage Report Page J.15 Document: FDR 01 Rev 3 September 2024 Culvert C Outlet Protection Design Discharge Q 18.8 ft^3/s Allowable Velocity V 3.0 ft/s Number of Barrels 2 Pipe Inside Diameter (in) D 18 in Pipe Inside Diameter (ft) D 1.5 ft Froude Parameter Q/D2.5 3.41 Q/D1i5 5.12 Tailwater Depth (If known) Yt 1 Calculated Depth Of unknown) Yt 0.60 ft Tailwater Tailwater Depth / Depth of Water Yt/D 0.4 Expansion Factor 1/(2tan 0) II 4 Area of flow At 3.1 ft^2 Riprap Design Type 44 L D50 9 in Depth of Protection Hp 18 in Length g of Protection . L P 15 ft Width of Protection T 11 ft OK OK Pintail Compressor Station: Final Drainage Report Page K.1 Document: FDR 01 Rev 3 September 2024 APPENDIX K - DRAINAGE DRAWINGS ASCENT GEOMATICS SOLUTIONS Pintail Compressor Station: Final Drainage Report Page L.1 Document: FDR 01 Rev 3 September 2024 APPENDIX L - GEOTECHNICAL REPORT ASCENT GEOMATICS SOLUTIONS c+n Kumar & Associates, Inc. Geotechnical and Materials Engineers and Environmental Scientists An Employee Owned Company 2390 South Lipan Street Denver, CO 80223 phone: (303) 742-9700 fax: (303) 742-9666 email: kadenver@kumarusa.com www.kumarusa.com Office Locations: Denver (HQ), Parker, Colorado Springs, Fort Collins, Glenwood Springs, and Summit County, Colorado Prepared By: Justin Cupich, P.E. GEOTECHNICAL ENGINEERING STUDY PINTAIL COMPRESSOR STATION NORTHEAST OF THE INTERSECTION OF WELD COUNTY ROADS 40 & 35 LA SALLE / WELD COUNTY, COLORADO Reviewed By: Joshua L. Barker, P.E. Prepared For: Phillips 66 6900 East Layton Avenue. Suite 900 Denver, Colorado 80237 Attention: Bryan White Project No. 23-1-330 June 15, 2023 TABLE OF CONTENTS SUMMARY 1 PURPOSE AND SCOPE OF WORK 2 PROPOSED CONSTRUCTION 2 SITE CONDITIONS 3 GEOLOGIC SETTING 3 SUBSURFACE CONDITIONS 4 LABORATORY TESTING 6 GEOTECHNICAL CONSIDERATIONS 7 SITE GRADING AND EARTHWORK 8 FOUNDATION RECOMMENDATIONS 12 FOUNDATION DYNAMIC ANALYSIS 19 SEISMIC DESIGN CRITERIA 20 SLABS ON GRADE 20 SURFACE DRAINAGE 20 WATER-SOLUBLE SULFATES 21 THERMAL RESISTIVITY TESTING 22 ELECTRICAL RESISTIVITY AND BURIED METAL CORROSION 22 PERMEABILITY OF ON -SITE SOILS 24 AGGREGATE -SURFACED ROADWAYS AND YARD AREAS 24 DESIGN AND CONSTRUCTION SUPPORT SERVICES 25 LIMITATIONS 26 FIG. 1 - LOCATION OF EXPLORATORY BORINGS FIGS. 2 and 3 — LOGS OF EXPLORATORY BORINGS FIG. 4 - LEGEND AND EXPLANATORY NOTES FIGS. 5 through 7 - SWELL -CONSOLIDATION TEST RESULTS FIGS. 8 and 9 — GRADATION TEST RESULTS FIG. 10 - LABORATORY RESISTIVITY RESULTS FIG. 11 - MOISTURE -DENSITY RELATIONSHIPS FIG. 12 - THERMAL DRYOUT CURVE TABLE I - SUMMARY OF LABORATORY TEST RESULTS Kumar & Associates, Inc.® SUMMARY 1 The borings generally encountered a relatively thin layer of top soil underlain by naturally deposited (native) overburden soils primarily consisting of granular soils with lenses and zones of native clay soils. The native soils extended to the maximum explored depths of about 30 feet in Borings 1 through 6 and to sandstone bedrock at a depth of about 34 feet in Borings 7 and 8. The sandstone bedrock continued to the maximum explored depth of about 50 feet in Borings 7 and 8. Groundwater was encountered in all of the borings during or shortly after the completion of drilling at depths ranging from about 8 feet to 19 feet below the ground surface. Four of the borings (Borings 1, 2, 3, and 8) were left open to allow for follow-up stabilized groundwater level measurements with the remaining borings backfilled. A follow-up groundwater level measurement was made on May 17, 2023 (14 to 15 days subsequent to drilling) and encountered groundwater in the open borings at depths ranging from about 6.5 feet to 8 feet. Shallow foundations, including gravel pads, spread footings, mat/thickened slabs, and soil -supported slabs should be feasible. Shallow foundations should be supported on structural fill extending to native undisturbed soils as described here in. Allowable bearing/contact pressures and an associated increase for transient loads for shallow foundations are presented herein. 3 Short drilled piers/footings and drilled piers extending into the bedrock and installed as recommended herein should also feasible. Recommendations for drilled piers and short drilled footings are provided herein. A thickness of 10 inches should be considered for aggregate surfacing for unpaved roadways and other areas accessed by vehicles. Greater thicknesses should be used in turn -around areas and areas that may be used routinely by heavier vehicles. A thickness greater than 12 inches may be preferred for any heavily -used access driveways. 5. The onsite soils should be suitable for use as general site grading fill and as structural fill beneath foundations and floor slabs. The majority of existing native soils are relatively dry, and a significant amount of water may be necessary to properly moisture condition the soils. Kumar & Associates, Inc.® PURPOSE AND SCOPE OF WORK This report presents the results of a geotechnical engineering study performed for the proposed Pintail Compressor Station to be constructed approximately 0.5 -miles northeast of the intersection of Weld County Roads 40 & 35 in La Salle/Weld County, Colorado. The project site is shown on Fig. 1. The study was conducted in general accordance with the scope of work presented in our Proposal No. P-23-393 to Ascent Geomatic Solutions (Ascent), dated April 20, 2023. A field exploration program consisting of exploratory borings was conducted to obtain information on subsurface conditions. Samples of the soils and bedrock, where encountered, obtained during the field exploration program were tested in the laboratory to determine their classification and engineering characteristics. The results of the field exploration and laboratory testing programs were analyzed to develop geotechnical engineering recommendations for design and construction of the proposed facility improvements. This report has been prepared to summarize the data obtained during this study and to present our conclusions and recommendations based on the proposed construction and the subsurface conditions encountered. Design parameters and a discussion of geotechnical engineering considerations related to construction of the proposed compressor station are included in the report. PROPOSED CONSTRUCTION Based on the information provided to us, site development will consist of the construction of a new compressor station. We assume the compressor station will be similar to the other compressor stations we have worked on for DCP in the project vicinity and may include gas turbine compressors, gas air coolers, horizontal and vertical vessels, skid mounted process equipment, pipe racks, pumps, flares, and various smaller ancillary equipment. We assume aggregate -surfaced drive lanes will be constructed throughout the compressor station. Based on the existing topography of the site, we anticipate minimal site grading and no need for engineered retaining walls or grade separation solutions. We assume various equipment and building foundation types will be used for the project including spread footing, mats, gravel pads, drilled footings/short drilled piers, and drilled piers. Kumar & Associates, Inc.® 3 If the proposed construction varies significantly from that described above or depicted in this report, we should be notified to reevaluate the recommendations provided in this report. SITE CONDITIONS The project site is a roughly 39 -acre, generally undeveloped property primarily utilized for agricultural purposes. A small oil/gas facility is located at the northeast corner of the property. The site is bounded on the north by the existing compacted soil roadway, on the east, south, and west by similar agricultural property. Weld County roads 35 and 40 are located further to the west and south, respectively. The GPS coordinates for the project site are: 40.281319N and -104.727529W. Based on available topographical information and site visual observations, the site is gently sloping down from south to north with about 8 feet or less of relief across the proposed development area. GEOLOGIC SETTING The public geologic map "Geologic Map of the La Salle Quadrangle, Weld County, Colorado" (Palkovic, M.J., Lindsey, K.O., and Morgan, M.L., 2019) depict the project site area as underlain by Eolian Sand ((Wind-blown sand) (Middle Holocene to Upper Pleistocene)). A portion of that geologic map is reproduced below with the approximate project site marked by the blue indicator near the center of the map. Kumar & Associates, Inc.® 4 SUBSURFACE CONDITIONS The field exploration program for the project was performed on May 2 and 3, 2023. Eight (8) exploratory borings were drilled at the locations staked in the field by Ascent. The approximate locations of the borings are shown on Fig. 1. The borings were drilled to depths ranging from about 15 to 50 feet below existing grades to explore subsurface conditions and to obtain samples for laboratory testing. Logs of the exploratory borings are presented on Figs. 2 and 3 with a legend and explanatory notes for the logs presented on Fig. 4. The borings were advanced into the overburden soils and bedrock, where encountered, with 4 - inch -diameter, continuous -flight, solid -stem augers, and were logged by a representative of Kumar & Associates, Inc (K+A). Samples of the soils and bedrock were obtained with either a 1- 3/8 -inch I.D. split -spoon sampler of a 2 -inch I.D. California -liner sampler driven into the various strata with blows from a 140 -pound hammer falling 30 inches. Sampling with the split -spoon sampler is the standard penetration test described by ASTM Method D1586. Sampling with the California -liner sampler is generally similar to the standard penetration test. Penetration resistance values (blow counts), when properly evaluated, indicate the relative density or Kumar & Associates, Inc.® consistency of the soils. Depths at which the samples were obtained and the penetration resistance values are shown adjacent to the boring logs on Figs. 2 and 3. Subsurface Soil Conditions: The borings generally encountered a relatively thin layer of top soil ranging from about 4 inches to 6 inches. Thicker layers of topsoil may be encountered in areas outside the limits of our boring locations. The topsoil layer was underlain by primarily naturally deposited (native) overburden soils consisting of granular soils with lenses and zones of native clay soils. The native soils extended to the maximum explored depths of about 30 feet in Borings 1 through 6 and to sandstone bedrock at a depth of about 34 feet in Borings 7 and 8. The sandstone bedrock continued to the maximum explored depth of about 50 feet in Borings 7 and 8. The native granular soils varied between silty sand, clayey sand, and poorly -graded sand with silt at depth. The native granular soils were generally fine- to coarse -grained with isolated gravels, slightly moist to moist to wet (below groundwater), and tan to brown to dark brown. The native clay soils consisted of lean clay with variable fine- to medium -grained sand content, and were moist to very moist (below groundwater), occasionally highly plastic, silty and calcareous in places, and tan to brown. Based on sampler penetration resistance values (blow counts), the native granular soils ranged from loose to medium dense. The native clay soils ranged from medium stiff to very stiff in consistency. The sandstone bedrock was fine- to medium -grained, weakly cemented, moist, and brown to gray with iron oxidation staining. Based on blow counts, the bedrock was hard to very hard with a medium hard zone near the bedrock surface. Groundwater Conditions: Groundwater was encountered all of the borings during or shortly after the completion of drilling at depths ranging from about 8 feet to 19 feet. Four of the borings (Borings 1, 2, 3, and 8) were left open to allow for follow-up stabilized groundwater level measurements with the remaining borings backfilled. A follow-up groundwater level measurement was made on May 17, 2023 (14 to 15 days subsequent to drilling) and encountered groundwater in the open borings at depths ranging from about 6.5 feet to 8 feet. The open bore holes were backfilled upon completion of the groundwater level measurements. Kumar & Associates, Inc.® 6 LABORATORY TESTING Samples obtained from the exploratory borings were visually classified in the laboratory by the project engineer. Laboratory testing was performed on representative samples to evaluate in - situ moisture content and dry unit weight, grain size distribution, percent organics, liquid and plastic limits, and swell -consolidation behavior. The moisture -density relationship (standard Proctor) was also evaluated for a composite bulk sample of the overburden soils. Corrosion testing consisting of minimum electrical soils resistivity, thermal resistivity, pH, and chloride content was also performed on selected samples. The above testing was performed in accordance with the applicable ASTM standard test procedures. The percentage of water- soluble sulfates was evaluated in general accordance with the Colorado Department of Transportation (CDOT) CP-L 2103 test procedure. The results of the laboratory tests are shown to the right of the logs on Figs. 2 and 3, plotted graphically on Figs. 5 through 12, and summarized in Table I. Swell -Consolidation: Swell -consolidation (Method B) tests were conducted on representative samples of the native clay and sandstone bedrock to evaluate their swell and/or compressibility under loading and when submerged in water. Each sample the prepared and placed in a confining ring between porous discs, subjected to a surcharge pressure of 1,000 psf, and allowed to consolidate before being submerged. The samples were then loaded incrementally to a maximum surcharge pressure of 3,000 psf. The sample heights were monitored until deformation practically ceased under each load increment. Results of the swell -consolidation tests are presented on Figs. 5 through 7 as plots of the curve of the final strain at each increment of pressure against the log of the pressure. Based on the results of the swell -consolidation tests, the samples of native clay soils and sandstone bedrock exhibited slight additional compression when wetted. We believe the majority of the additional compression exhibited by the samples is primarily due to sample disturbance and is not indicative of collapse potential. Index Properties: Samples were classified into categories of similar engineering properties in general accordance with the Unified Soil Classification System. This system is based on index properties, including liquid limit, plasticity index and grain size distribution. Values for in -situ moisture content and dry density, liquid limit and plasticity index, and the percent of soil retained on the U.S. No 4 sieve and percent soil passing the U.S. No. 200 sieve are presented in Table Kumar & Associates, Inc.® and adjacent to the corresponding sample on the boring logs. Results of laboratory gradation and hydrometer testing are presented on Figs. 8 and 9. USDA Classifications: Soils are typically classified for engineering purposes using the Unified Soil Classification System (USCS) and the American Association of Highway and Transportation Officials (AASHTO) soil classification systems. The United States Department of Agriculture (USDA) also has a soil classification that is based on gradation characteristics and Atterberg limits, similar to the USCS and AASHTO systems. Based on the USDA soil classification methodology, the site native granular soils will primarily classify as Loamy Sand to occasionally Sandy Loam and the native clay soils will primarily classify as Sandy Clay Loam and occasionally Clay Loam. The USCS and AASHTO classifications determined for samples tested in the laboratory are summarized on Table I. Moisture -Density Relationship: Standard Proctor testing (ASTM D698) was performed on a composited bulk sample of the native granular overburden soils obtained from Borings 1 through 3 in order to determine the maximum dry density and optimum moisture content of the soil. The results of the standard Proctor test are presented on Fig. 11 and indicated the composited sample of overburden soils had a maximum dry density of 119.6 pcf and an optimum moisture content of 10.2%. GEOTECHNICAL CONSIDERATIONS Based on the data obtained from the field exploration and laboratory testing programs, we believe shallow foundations, including spread footings and mat/thickened slabs will be feasible for the majority of the structures with proper subgrade preparation. Shallow drilled piers/footings are also feasible. We understand deeper drilled piers terminating in the bedrock may be used for some to the heavier equipment. Aggregate pads for lighter equipment should also be feasible with proper subgrade preparation. The native overburden soils should generally be suitable for reuse as site grading and structural fill. The natural moisture content of the granular soils above groundwater appear to be several percent below the optimum moisture content. The in -situ dry densities of the granular soils also generally appear a few to several pounds per cubic foot (pcf) below the standard Proctor maximum dry density. These items combined indicate there will be a high likelihood the materials will 1) require significant quantities of water to achieve proper moisture conditioning, Kumar & Associates, Inc.® 8 and 2) the materials may have a significant shrink factor for compacted soils. We estimate that the shrink factor for properly compacted on -site granular soils will be about 10%; however, this value could be much higher (15% to 25%) depending on the in -place thickness of the granular soils at specific locations on the site. SITE GRADING AND EARTHWORK Based upon the existing topography, we anticipate finished grades across most of the site are anticipated to be relatively close to existing site grades, with cuts and fills expected to be less than about 5 feet. Permanent Cut and Fill Slopes: The native overburden soils, particularly the granular soils, are anticipated to be moderately erodible. While cut and properly compacted fill slopes above groundwater as steep as 2H:1V should have adequate factors of safety against global instability, surficial instability in the form of sloughing and shallow slumps is likely to result from precipitation, runoff flows, and cycles of freeze/thaw and wetting/drying. Consequently, we recommend permanent cut and fill slopes be designed and constructed more with the intent of limiting significant slope face erosion than deep-seated slope instability. Erosion potential can be reduced by constructing flatter slopes, introducing native vegetation, or covering the slopes with a more erosion -resistant gravel or long-term erosion control blankets. Erosion potential can also be reduced by the use of diversion berms, ditches, and other grading measures to mitigate concentrated surface runoff down cut and fill slopes. Flatter slopes may be necessary for cuts in relatively loose granular materials. The risk of slope instability will be significantly increased if seepage from perched groundwater is encountered in cuts. Although not anticipated, if groundwater seepage is anticipated or encountered during construction, a stability analysis should be conducted to determine if the seepage will adversely affect the stability of the cut slope. The ground surface underlying all fills should be carefully prepared by removing all organic matter, scarifying and moisture -conditioning the fill subgrade soils to a depth of 12 inches, and compacting the scarified soils to at least 95% of the standard Proctor (ASTM D698) maximum dry density at moisture contents within 2 percentage points of optimum for predominantly granular soils and within the range of optimum to 3 percentage points above optimum for Kumar & Associates, Inc.® 9 predominately clay soils, if encountered. New fills should be benched into existing slopes that exceeding 4 horizontal to 1 vertical. Since cut and fill slopes, if constructed, are expected to be relatively low in height, no formal stability analyses were performed to evaluate the slopes recommended above. Published literature and our experience with similar cuts and fills indicate the recommended slope ratios should have adequate factors of safety. If a detailed stability analysis is required based on the above discussion, we should be notified. Temporary Excavations: We assume temporary site excavations will be constructed by generally over -excavating the side slopes to a stable configuration where enough space is available. All excavations greater than 4 feet in depth should be constructed in accordance with OSHA requirements, as well as state, local and other applicable requirements. OSHA requires excavations or trenching over 20 feet deep, or those extending below the groundwater table, be designed by a registered professional engineer. The native overburden granular soils will classify as OSHA Type C soils and the native clay soils will classify as OSHA Type B soils. Although not anticipated, if unstable soil conditions or groundwater are encountered, the geotechnical engineer should be notified so additional recommendations can be provided, if necessary. Excavated slopes may soften or loosen due to construction traffic and erode from surface runoff. Measures to keep surface runoff from excavation slopes, including diversion berms, should be considered. Based on standard penetration blow counts obtained during the field exploration program, standard heavy duty hydraulic equipment should be able to excavate the overburn soils. Excavation Dewatering: Excavations extending to depths greater than about 6 feet may encounter groundwater. Excavations extending below groundwater should be properly dewatered prior to and during the excavation process to help maintain the stability of the excavation side slopes and stable subgrade conditions for foundation and slab construction and structural fill placement. Kumar & Associates, Inc.® 10 We believe it may be feasible to dewater an excavation extending a foot or so below groundwater using perimeter (and lateral) trenches combined with sumps. The trenches should be sloped to sumps where water can be pumped from the excavation. Dewatering means and methods should be designed and selected by the contractor. Dewatering should maintain the groundwater level at a point at least 2 feet below the bottom of the excavation and maintain that level until backfill extends to or above the stabilized groundwater level. If necessary, wells and well -points can be used to dewater in the native granular soils. Material Specifications: Unless specifically modified in other sections of this report, the following recommended material and compaction requirements are presented for site grading and structural fills on the project site. A geotechnical engineer should evaluate the suitability of all proposed fill materials to be used on the site prior to placement. 1 Structural Fill: Structural fill placed beneath and adjacent to foundation elements and beneath soil -supported slabs and site flatwork should consist of on -site native overburden granular soils or imported materials with similar properties as the on -site native granular soils. Clayey imported fill source materials may be acceptable if the swell potential for samples remolded to 95% of the standard Proctor (ASTM D698) maximum dry density at optimum moisture content does not exceed 1% when wetted under a 200 psf surcharge pressure. Evaluation of potential imported fill sources will require determination of laboratory moisture -density relationships and swell characteristics. Utility Trench Backfill: Material excavated from the utility and pipe trenches may be used for utility trench backfill provided it does not contain unsuitable material or particles larger than 4 inches. 3 Material Suitability: All fill material should be free of vegetation, brush, and other deleterious substances and should not contain rocks, debris or lumps having a diameter of more than 4 inches. Rocks, debris or lumps should be dispersed throughout the fill and "nesting" of these materials should be avoided. The geotechnical engineer should evaluate the suitability of proposed imported fill materials prior to placement, if required. Kumar & Associates, Inc.® 11 Based on the results of laboratory testing, the on -site overburden soils should generally be suitable for use as compacted fill beneath foundations and soil -supported slabs. The majority of on -site soils have relatively low natural moisture contents and will likely require the addition of water to meet the fill compaction criteria recommended herein. Placement and Compaction Specifications: We recommend the following compaction criteria be used on the project: 1 Moisture Content: All fill materials should be compacted as outlined below with moisture contents within -2 to +2 percentage points of the optimum moisture content for granular soils and between optimum and +3 percentage points of optimum for clay soils, if used. The contractor should be aware clay or clayey soils placed near the upper end of the moisture content range may become unstable. Additionally, achieving the above moisture criteria for on -site soils will require the addition of water to help facilitate compaction and meet the placement criteria recommended herein. Placement and Degree of Compaction: Fill should be placed in maximum 8 -inch loose lifts as necessary, provided proper compaction can be achieved. The following compaction criteria should be followed during construction: Percentage of Maximum Standard Proctor Density Fill Location (ASTM D698) Beneath Spread Footing and Mat Foundations 100% Adjacent to Spread Footing and Mat Foundations 98% Beneath Soil -Supported Slabs 95% Beneath Aggregate Surfacing 95% Utility Trenches 95% 2 General Subgrade Preparation: Areas receiving new fill should be prepared as recommended in specific sections of this report to provide a uniform base for fill placement. All other areas receiving new fill should be scarified to a depth of at least 8 inches and recompacted to at least 95% of the standard Proctor (ASTM D698) maximum dry density at moisture contents recommended above. Kumar & Associates, Inc.® 12 Construction Monitoring: We recommend K+A should observe and test fill placement. Structural fills beneath foundations, slabs on grade, tanks, and other structures, as well as compacted fill placed beneath other site facilities, should be observed and tested on a full-time basis. FOUNDATION RECOMMENDATIONS Spread Footings: The design and construction criteria presented below should be observed for a spread footing foundation system. The construction details should be considered when preparing project documents. 1 Spread footings should be placed on a minimum of 1 foot of structural fill extending to undisturbed native overburden soils. Areas of loose or soft material encountered within the foundation excavation should be removed and replaced with structural fill. Structural fill should meet the material and placement requirements outlined in the "Site Grading and Earthwork" section of this report. Structural fill should extend down and out from the edges of the footings at a I horizontal to 1 vertical projection. 2 Footings supported as recommended herein may be designed for a net allowable bearing pressure of 2,500 psf. The allowable soil bearing pressure may be increased by one-third for transient loads, including wind and seismic loads. Spread footings should have a minimum footing width of 18 inches for continuous footings and 24 inches for isolated pads. 4 Based on experience and empirical correlations between soil relative density, compressibility and settlement potential, we estimate total settlement for spread footings designed and constructed as discussed in this section will be approximately 1 inch or less. Differential settlements are estimated to be approximately % to % of the total settlement. 5. Exterior footings and footings beneath unheated areas should be provided with adequate soil cover above their bearing elevation for frost protection. Placement of foundations at least 30 inches below lowest adjacent exterior grade is typically used in this area. Kumar & Associates, Inc.® 13 6 The lateral resistance of a spread footing will be a combination of the sliding resistance of the footing on the foundation materials and passive earth pressure against the side of the footing. Resistance to sliding at the bottoms of the footings can be calculated based on a coefficient of friction of 0.35. Passive pressure against the sides of the footings can be calculated using an equivalent fluid density of 200 pcf. The above values are working values with a factor of safety of 2. 7 Compacted fill placed against the sides of the footings to resist lateral loads should meet the material and placement requirements for structural fill in the "Site Grading and Earthwork" section of this report. 8 Granular foundation soils should be densified with a smooth vibratory compactor prior to placement of concrete. 9 A representative of a qualified geotechnical engineering firm should observe all footing excavations prior to concrete placement. Mat/Thickened Slab Foundation: The design and construction criteria presented below should be observed for a mat foundation system. Construction details should be considered when preparing project documents. Mat/thickened slab foundations should be placed on a minimum of 2 feet of structural fill extending to undisturbed native soils. Areas of loose or soft material encountered within the foundation excavation should be removed and replaced with structural fill. 2 Structural fill should meet the material and placement requirements outlined in the "Site Grading and Earthwork" section of this report. Structural fill should extend down and out from the edges of the foundations at a 1 horizontal to 1 vertical projection. A mat/thickened slab foundation supported as recommended above may be designed for an allowable base contact pressure of 2,500 psf. This contact pressure may be increased by one-third for transient loadings other than machine dynamic loads. Higher net allowable base contact pressures may be feasible but should be evaluated based on actual loading conditions. Kumar & Associates, Inc.® 14 4 For average sustained loads approaching the allowable base contact pressure, and assuming a rigid mat/thickened slab with symmetrically distributed loads, we estimate total settlements will be on the order of 1 inch or less, depending on the size of the foundation. Post -construction differential settlements between the middle and the edges/corners of a rigid foundation should be negligible for relatively small mats/thickened slabs, but may range up to about one-half of the total settlement for foundations of significant width and length. Non -uniformity of the subsurface conditions and deviation from the rigid foundation assumption will contribute to total and differential settlements. If the foundation cannot be considered rigid, the soil pressure distribution should be computed using a method that models the soil -structure interaction, such as the beam on an elastic foundation procedure. A modulus of vertical subgrade reaction of 175 pci is recommended for the foundation subgrade conditions recommended herein. When the soil pressure distribution has been determined, we should be contacted to evaluate the settlement pattern of the foundation. The process of evaluating the soil pressure distribution beneath the foundation may require several iterations for a foundation that classifies between rigid and flexible. 5 The bottom of the mat/thickened slab should be below exterior grade or have turned - down edges extending to depths similar to that described for spread footings. 6 The lateral resistance of a mat/thickened slab foundation placed on structural fill should be calculated using the lateral resistance parameters presented in the "Spread Footings" section of this report. 7 Compacted fill placed against the sides of the foundation to resist lateral loads should meet the material and placement requirements outlined in the "Site Grading and Earthwork" section of this report. 8 Granular foundation soils should be densified with a smooth vibratory compactor prior to placement of concrete. Kumar & Associates, Inc.® 15 9 A representative of a qualified geotechnical engineering firm should observe all mat/thickened slab excavations prior to concrete placement in order to evaluate the supporting capacity of foundation materials. Gravel Pads: We understand gravel pads will be constructed for the support of various lighter equipment. The gravel pads should consist of a minimum of 18 inches of aggregate base course meeting the specifications for CDOT Class 5 of 6 aggregate base course. The gravel pad should be underlain by a minimum of 1 foot of structural fill extending to undisturbed native soils placed as recommended in the "Site -Grading and Earthwork Section" of this report. The gravel pad should be elevated above the surrounding grades as high as feasible to promote positive surface drainage away from the gravel pad foundation. The gravel should be placed in maximum 8 -inch -loose lifts and compacted to at least 95 percent of the modified Proctor (ASTM D1557) maximum dry density at the moisture contents presented in the "Site -Grading and Earthwork Section" of this report. Short Drilled Pier/Footing Foundations: The design and construction criteria presented below should be observed for straight -shaft drilled pier/footing foundations. The construction details should be considered when preparing project documents. 1 Short drilled piers/footings should extend at least 5 feet below finished grades. For compressive resistance, short drilled piers installed as recommended should be designed for an allowable end bearing pressure of 3,500 psf. A linearly increasing allowable unit side friction of 15 psf times the depth at which the unit side friction is applied for piers with less than 10 feet embedment and a linearly increasing allowable unit side friction of 25 psf times the depth for piers with 10 feet or more embedment. The upper 3 feet of embedment should be ignored in calculating frictional resistance. These values may be increased by one-third for transient loads, including wind and seismic loads. 3 The base of the pier/footing excavation should be clean and undisturbed prior to placement of concrete. 4 Based on the results of our field exploration and laboratory testing programs, and our experience with similar, properly constructed short drilled pier/footing foundations, we Kumar & Associates, Inc.® 16 estimate foundation settlement under the anticipated compressive loads will be less than 1 inch. For ASD calculation of lateral resistance, a modulus of horizontal subgrade reaction of 50 tcf should be used. This method is more suitable for piers with an L/D of less than 10. For piers with an L/D greater than 10, the lateral capacity of the piers may be analyzed using the LPILE computer program and the parameters provided in deep drilled pier section. The criteria provided in the table are for use with that software application only and may not be appropriate for other uses. 6 Site grading should be performed as recommended in the "Surface Drainage" section of this report to reduce the potential for post -construction wetting of the soils supporting the piers. 7 A representative of the geotechnical engineer should observe pier drilling operations on a full-time basis to monitor pier construction procedures, including confirmation that the base of the excavation is clean and undisturbed. Deep Drilled Pier: 1. Piers should have a minimum bedrock penetration of 6 feet or 3 pier diameters, whichever is greater. The minimum bedrock penetration will result in pier lengths of about 40 feet. 2 We recommend piers be designed for an allowable side shear of 3,000 psf for the portion of the piers in upper 4 feet of bedrock and 4,000 psf for the portion of the piers embedded greater than 4 feet into the bedrock. Piers with the recommended minimum bedrock penetration may be designed for an allowable end bearing pressure of 40,000 psf. Uplift due to structural loadings on the piers can be resisted by using 75% of the allowable skin friction value plus an allowance for pier weight. 3 The lateral capacity of the piers may be analyzed using the LPILE computer program and the parameters provided in the following table. The strength criteria provided in the table are for use with that software application only and may not be appropriate for other Kumar & Associates, Inc.® 17 usages. The strength criteria provided in the table are for use with this software application only and may not be appropriate for other usages: Material c(psf) 0 yt ks kc €50 Soil Type Granular soils above groundwater 0 32 115 25 25 --- 1 Granular soils below groundwater 0 32 63 60 60 - 1 Clay soils 1,500 0 125 500 200 0.007 2 Bedrock 7,000 0 120 2,000 800 0.004 2 c Cohesion intercept (pounds per square foot) 0 Angle of internal friction (degrees) yt Total unit weight (pounds per cubic foot) k5 Initial static modulus of horizontal subgrade reaction (pounds per cubic inch) kc Initial cyclic modulus of horizontal subgrade reaction (pounds per cubic inch) 650 Strain at 50 percent of peak shear strength Soil Types: 1. Sand (Reese) 2. Stiff Clay (Reese) 4 Closely -spaced piers may require appropriate reductions of the lateral and axial capacities. Reduction in lateral load capacity may be avoided by spacing the piers at least five pier diameters center -to -center in the direction parallel to pier loading. For axial loading, the piers should be spaced a minimum of 3 pier diameters center -to -center. More closely spaced piers should be evaluated on an individual basis to estimate appropriate reductions in axial and lateral load design parameters. If the recommended minimum center -to -center pier spacings for lateral loading cannot be achieved, we recommend the load -displacement curve (p -y curve) for an isolated pier be modified for closely -spaced piers using p -multipliers to reduce all the p values on the curve. With this approach, the computed load carrying capacity of the pier in a group is reduced relative to the isolated pier capacity. The modified p -y curve should then be reentered into the LPILE software to calculate the pier deflection. The reduction in capacity for the leading pier, the pier leading the direction of movement of the group, is less than that for the trailing piers. For loading in the direction parallel to the row of piers, we recommend p -multipliers of 0.8 and 1.0 for pier spacings of 3 and 5 diameters, respectively, for the leading row of piers, 0.4 and 0.85 for pier spacings of 3 and 5 diameters, respectively, for the second row of piers, and 0.3 and 0.7 for pier spacings of 3 and 5 diameters, respectively, for the Kumar & Associates, Inc.® 18 third row and higher. For loading in the direction perpendicular to the row of piers, the p - multipliers are 1.0 for a pier spacing of 5 diameters, 0.8 for a pier spacing of 3 diameters, and 0.5 for a pier spacing of 1 diameter. P -multiplier values for other pier spacing values should be determined by interpolation. These values are consistent with Section 10.7.2.4 of the 2021 AASHTO LRFD Bridge Design Specifications (9th Edition). It will be necessary to determine the load distribution between the piers that attain deflection compatibility because the leading pier carries a higher proportion of the group load and the pier cap prevents differential movement between the piers. 5. Based on the results of our field exploration, laboratory testing, and our experience with similar, properly constructed drilled pier foundations, we estimate pier settlement will be low. Generally, we estimate the settlement of drilled piers will be less than 0.5 -inches when designed according to the criteria presented herein. The settlement of closely spaced piers will be larger and should be studied on an individual basis. A minimum pier diameter of 18 inches is recommended to facilitate proper cleaning and observation of the pier hole. The pier length -to -diameter ratio should not exceed 30. 7 The drilled shaft contractor should mobilize equipment of sufficient size and operating condition to achieve the required penetration in the hard to very hard bedrock. A small diameter pilot hole may be required to advance auger drilling if very hard bedrock is encountered. 8. The presence of water and saturated granular soils in the borings suggest the use of dewatering and casing equipment in the pier holes may be necessary to control water infiltration. The requirements for dewatering equipment can sometimes be reduced by placing concrete immediately upon cleaning and observing the pier hole. In no case should concrete be placed in more than 3 inches of water unless placed using an approved tremie method. 9 Care should be taken that the pier shafts are not oversized at the top. Mushroomed pier tops can reduce the effective dead load pressure on the piers. Sono -Tubes or similar forming should be used at the top of the piers, as necessary, to prevent mushrooming of the top of the piers. Kumar & Associates, Inc.® 19 10. Pier holes should be properly cleaned prior to the placement of concrete. 11. Concrete used in the piers should be a fluid mix with sufficient slump so it will fill the void between reinforcing steel and the pier hole. We recommend a concrete slump in the range of 5 to 8 inches be used. 12. Concrete should be placed in piers the same day they are drilled. If water is present, concrete should be placed immediately after the pier hole is completed. Failure to place concrete the day of drilling will normally result in a requirement for additional bedrock penetration. 13. A representative of the geotechnical engineer should observe pier drilling operations on a full-time basis to monitor pier construction procedures, including confirmation that the base of the excavation is clean and undisturbed. FOUNDATION DYNAMIC ANALYSIS We anticipate machinery generating dynamic loads will generally be underlain primarily by granular structural fill and native granular soils underlain by sandstone bedrock a depth of about 35 feet. Stabilized groundwater is anticipated to be encountered at depths ranging from about 3.5 to 9 feet below the foundations. For dynamic analysis of the foundations, we recommend considering the following soil dynamic properties: Low -Strain Dynamic Shear Poisson's Damping Ratio Soil Unit Modulus (ksf) Ratio r/o) Native Soils 1,500 0.35 3 Structural Fill 2,000 0.35 3 The values for the low -strain dynamic shear modulus are estimated based on our experience with sites underlain by similar soils, including shear wave velocity data, and on published correlations for Poisson's ratio and the damping ratio. Kumar & Associates, Inc.® 20 S EISMIC DESIGN CRITERIA The soil profile at the site is anticipated to consist of about 35 feet of generally loose to medium dense native granular soils with zones of medium stiff to very stiff native clay soils. The overburden soils are anticipated to be underlain by primarily hard to very hard bedrock. The overburden soils classify as International Building Code (IBC) Site Class D and the bedrock will classify as Site Class C based on procedures presented in the code. Based on our general experience on sites with similar types and depths of overburden soils, the design soil profile for the site is considered to be IBC Site Class D. Based on the subsurface profile, site seismicity, and the anticipated depth of groundwater, liquefaction is not a design consideration. S LABS ON GRADE Soil -supported slabs should be underlain by a minimum of 2 feet of structural fill meeting the material type and placement recommendations presented in the "Site Grading and Earthwork" section of this report. The native on -site soils, exclusive of any topsoil, are suitable to support lightly to moderately loaded slab -on -grade construction. To reduce the effects of some differential movement, floor slabs, if constructed, should be separated from all bearing walls and columns with expansion joints which allow unrestrained vertical movement. Floor slab control joints should be used to reduce damage due to shrinkage cracking. Joint spacing is dependent on slab thickness, concrete aggregate size, and slump, and should be consistent with recognized guidelines such as those of the Portland Cement Association (PCA) and American Concrete Institute (ACI). The joint spacing and any requirements for slab reinforcement should be established by the designer based on experience and the intended slab use. All fill materials for support of soil -supported slabs should be placed and compacted according to the criteria presented in the "Site Grading and Earthwork" section of this report. The suitability of the on -site soils for use as underslab fill is also discussed in "Site Grading and Earthwork" section. S URFACE DRAINAGE Proper surface drainage is very important for acceptable performance of site structures and other facilities during construction and after the construction has been completed. Drainage recommendations provided by local, state and national entities should be followed based on the Kumar & Associates, Inc.® 21 intended use of each structure. The following recommendations should be used as guidelines and changes should be made only after consultation with the geotechnical engineer. 1 Excessive wetting or drying of the foundation and slab subgrades should be avoided during construction. The ground surface surrounding the exterior of site structures and facilities should be sloped to drain away from the foundations in all directions. We recommend a minimum slope of 6 inches in the first 10 feet. Site drainage beyond the 10 -foot zone should be designed to promote runoff and reduce infiltration. The slopes may be changed as required for handicap access points in accordance with the Americans with Disabilities Act. Exterior backfill should meet the material and placement requirements outlined in the "Site Grading and Earthwork" section of this report. The upper 2 feet of backfill adjacent to site structures and facilities should be relatively impervious compacted material to promote runoff and limit infiltration of surface water. 4 Ponding of water should not be allowed in backfill material or in a zone within 10 feet of site structures and facilities, whichever is greater. WATER-SOLUBLE SULFATES Concentrations of water-soluble sulfates measured in samples of the native overburden soils ranged from 0.00% to 0.17%. These concentrations represent a Class SO to S1 severity exposure to sulfate attack on concrete exposed to these materials. The concentration of water- soluble sulfates measured in a representative sample of the bedrock obtained from the borings was 0.02%. This concentration represents a Class SO severity exposure to sulfate attack on concrete exposed to the bedrock materials. The degree of attack is based on a range of Class SO (not applicable), Class S1 (moderate), Class S2 (severe), and Class S3 (very severe) severity of exposure as presented in ACI 201.2R-16. Based on the laboratory data and our experience, we recommend all concrete exposed to the on -site materials meet the requirements for resistance to a Class S1 severity exposure as presented in ACI 201.2R. Alternatively, the concrete could meet the Colorado Department of Kumar & Associates, Inc.® 22 Transportation's (CDOT) cement requirements for Class 1 exposure as presented in Section 601.04 of the CDOT Standard Specifications for Road and Bridge Construction (2021). THERMAL RESISTIVITY TESTING Laboratory thermal resistivity testing was performed on a composite bulk sample consisting of native granular soils obtained from Borings 1 through 3 at depths ranging from about 1 to 5 feet. A thermal dryout curve along with measure gravimetric water content and measured resistivity (Rho) used to generate the curve are presented on Fig. 12. ELECTRICAL RESISTIVITY AND BURIED METAL CORROSION The potential for corrosion of buried metals or metal pipes placed beneath the ground surface at the site was evaluated based on the results of laboratory tests on representative samples of the native granular overburden soils. These materials were tested to evaluate electrical resistivity, pH, and chloride concentration. Field electrical resistivity testing was also performed at the site. The results of the pH testing indicated the tested materials had pH values of 7.21 and 8.31 corresponding to slightly basic and should not accelerate corrosion. The results of the chloride testing indicated chloride concentration in the tested materials of 0.011% and 0.009% (110 ppm and 90 ppm, respectively) corresponding to a low degree of corrosivity potential. Corrosion protection against chlorides in soils for buried metal pipes should be considered. The results of the two laboratory electrical resistivity tests indicated minimum laboratory electrical resistivity values of 2,610 ohm -cm and 3,605 ohm -cm. Corresponding resistivity values of about 4,200 and greater than 7,000 ohm -cm were measured at the optimum moisture content of about 10% and at the in -situ moisture content of about 5%, respectively. Based on the resistivity test results, the native granular soils would generally be classified as moderately corrosive at moistures generally greater than about 10% and generally mildly corrosive at lower moisture contests as presented by the U.S. Bureau of Reclamation and the National Association of Corrosion Engineers. The results of the electrical resistivity testing are presented on Fig. 10. Field electrical resistivity testing was also performed at the approximate locations indicated on Fig. 1. The electrical resistivity of the near -surface soils at each site was measured in the field using the Wenner Four -Electrode method on June 14, 2023. The testing was completed at spacing intervals of about 1-, 2.5-, 5-, 10-, and 25 -feet, along two lines in opposite directions. Kumar & Associates, Inc.® 23 One line was generally oriented in the north -south direction and the other line was generally oriented in the east -west direction. The calculated results of the field electrical resistivity testing are summarized in the following table. Field Resistivity Testing Results Test Location Spacing Probe (ft.) Calculated Electrical Resistivity (ohm -cm) Line 1 (North North - -South) South Line 2 (East-West) Boring Location 7 1 2,451 1,973 2.5 2,442 3,198 5 2643 2,882 10 2,298 2,470 25 1,915 1,963 Boring Location 8 1 2,222 2,260 2.5 3,418 3,825 5 4,261 4,500 10 3, 869 3, 830 25 2,442 2, 394 The results of the field resistivity testing for the project indicate the on -site overburden soils would generally be classified as moderately corrosive in accordance with a classification system published by the U.S. Bureau of Reclamation and the National Association of Corrosion Engineers. The results of the field electrical resistivity testing are very similar to the laboratory electrical resistivity testing results presented above. Based on laboratory test results, the in -situ moisture contents of the native granular soils located above groundwater generally ranged between about 4% and 7%. The moisture contented measured in the native clay samples ranged from about 17% to 21%. The moisture content measured in two samples of the sandstone bedrock were 18.0% and 21.4%. The native granular soils are expected to exhibit good to fair drainage characteristics and the native clay soils and bedrock will likely exhibit poor drainage characteristics. Corrosion of buried metal is a complex process and requires an understanding of the combined effects of ion content, pH, electrical resistivity, soil moisture, which were evaluated as part of this study and various other conditions not evaluated as part of this study. We recommend a qualified corrosion engineer review the information presented herein to determine the need for an appropriate level of corrosion protection for buried metals at the site. Kumar & Associates, Inc.® 24 PERMEABILITY OF ON -SITE SOILS We have evaluated the permeability, or hydraulic conductivity, of the overburden soils based on our experience, the results of gradation tests on those materials, and published correlations between hydraulic conductivity, coefficient of uniformity, and estimated in situ relative density. The native granular overburden soils consisting of silty sands and poorly -graded sands with variable silt content are anticipated to have permeability values ranging from about 1 x 10-5 to 1 x 10-4 centimeters per second. Accordingly, these soils would generally be classified as USDA hydrologic soil group B. The native clay soils consisting of lean clay soils are permeability values ranging from about 1 x 10-8 to 1 x 10-11 centimeters per second. Accordingly, these soils would generally be classified as USDA hydrologic soil group D. AGGREGATE -SURFACED ROADWAYS AND YARD AREAS Subgrade Materials: Based on the results of the field exploration and laboratory testing programs, the subgrade materials underlying aggregate -surfaced areas are anticipated to consist primarily of the native granular soils with areas native clay soils, and to primarily classify as A -1-a and A -1-b soils with group index values of 0 in accordance with the American Association of State Highway and Transportation Officials (AASHTO) soil classification system. One sample classified as an A-4 soil with a group index value of 0. Soils classifying as A -1-a and A -1-b would generally be considered to provide excellent subgrade support. Soils classifying as A-4 would generally be considered to provide fair subgrade support. Design Traffic: In general, traffic over most of the site roadways and yard areas is expected to consist of a relatively low volume of light- to medium- weight trucks, and occasional heavy- weight trucks. Aggregate -Surface Thicknesses: Based on our experience, a thickness of 10 inches should be considered for aggregate surfacing for unpaved roadways and other areas accessed by vehicles. Greater thicknesses should be used in turn -around areas and areas that may be used routinely by heavier vehicles. A thickness greater than 12 inches may be preferred for any heavily used access driveways. We recommend aggregate surfacing consist of a CDOT Class 5 or 6 Aggregate Base Course (ABC) material. For ease of maintenance, particularly for high traffic site roadways, the upper 6 inches of the aggregate surfacing should consist of a CDOT Class 6 ABC material preferably Kumar & Associates, Inc.® 25 containing some clay fines. For high -traffic site roadways subject to a significant number of heavier vehicles, the aggregate surfacing should be underlain by at least 12 inches of granular sub -base material consisting of compacted granular fill consistent with a material classifying as A-6 or better. The owner may have other preferences for construction of unpaved on -site roadways and other vehicle areas based on their experience. Subgrade Preparation: Prior to placing the aggregate surfacing, the entire subgrade area should be scarified to a depth of 12 inches, adjusted to a moisture content near optimum and compacted to at least 95% of the standard Proctor (ASTM D698) maximum dry density. Structural fill placed beneath the aggregate -surfacing should be placed and compacted as recommended in the "Site Grading and Earthwork" section of this report. Prepared subgrades for aggregate surfacing should be proofrolled with a heavily loaded pneumatic -tired vehicle. Areas that deform excessively under heavy wheel loads are not considered stable and should be removed and replaced to achieve a stable subgrade prior to placement of the aggregate surfacing, including the sub -base layer where recommended. The collection and diversion of surface drainage away from roadway and yard areas is extremely important to the satisfactory performance of the aggregate surfacing. DESIGN AND CONSTRUCTION SUPPORT SERVICES K+A should be retained to review the project plans and specifications for conformance with the recommendations provided in our report. We are also available to assist the design team in preparing specifications for geotechnical aspects of the project, and performing additional studies, if necessary, to accommodate possible changes in the proposed construction. We recommend K+A. be retained to provide construction observation and testing services to document the intent of this report and the requirements of the plans and specifications are being followed during construction. This will allow us to identify possible variations in subsurface conditions from those encountered during this study and to allow us to re-evaluate our recommendations, if needed. We will not be responsible for implementation of the Kumar & Associates, Inc.® 26 recommendations presented in this report by others, if we are not retained to provide construction observation and testing services LIMITATIONS This study has been conducted in accordance with generally accepted geotechnical engineering practices in this area for exclusive use by the client for design purposes. The conclusions and recommendations submitted in this report are based upon the data obtained from the exploratory borings at the locations indicated on Fig. 1, and the proposed type of construction. This report may not reflect subsurface variations that occur between or beyond the exploratory borings, and the nature and extent of variations across the site may not become evident until site grading and excavations are performed. If during construction, fill, soil, rock or water conditions appear to be different from those described herein, K+A should be advised at once so a re-evaluation of the recommendations presented in this report can be made. K+A is not responsible for liability associated with interpretation of subsurface data by others. J DC/ad Rev: JLB cc: File Kumar & Associates, Inc.® O3 a 0 O M M N CO N W N s N 3 d U a E m r O U O J a as rnn fa , a O M o° N E in ;4_ rm m � Pawl I. C -W 1/16 COR. SEC. 25 FOUND 3 1/4" ALUM. CAP (ILLEGIBLE) N 88'09'41" E 1365.67' (AM) -- r\ f- O z WATER LINE-' (SEE NOTE 10) BARTELS 25.11E WELL-\ (TO BE PLUGGED) N 88°09'41" E 1337.47' N he - 4 N 4 � BOR 1 l - 4790- • BORING 2 • BORING 3 • BORING 5 • BORING 4 BORING 6 • BORING -4 i hp • fy N 4` 4 IIBOtING 8 7 S 87'38'09"1/1i 1342.04' C 1/4 COR. SEC. 25 FOUND 3 1/4" ALUM. CAP "LS 34995" NJ) S 01°09'02" E 1255/1' N j4 N hit N V N ` - 8'± a ,h m CV N \W 0 O IC) O a CO 23-1-330 I Kumar & Associates PINTAIL COMPRESSOR STATION, NORTHEAST OF WELD COUNTY ROADS 40 & 35, LA SALLE/WELD COUNTY, COLORADO 100 0 100 200 SCALE -FEET LEGEND: • BORING LOCATIONS. LOCATIONS OF FIELD ELECTRICAL RESISTIVITY TESTING. GREELEY HWY 34 LOVELAND GARDEN CITY Campion BERTHOUD Mead INTERSTATE 25 VICINITY MAP NOT TO SCALE SITE VA LOCATION OF EXPLORATORY BORINGS I Fig. 1 Compressor Station\Drofting\231330-02 to 04.dwg O M M El ar M I M M N M O N rn N N +- U m O >> DEPTH -FEET 0 5 10 15 20 25 30 BORING 1 EL. 4788' (6) 14 0 10/12 WC=5.6 DD=102.9 02.9 -200=8 _1 NV NP A-1 -a (0) 8/12 8/12 10/12 5/12 WC=20.7 DD=1 07.8 +4=0 -200=72 LL=26 P1=13 WSS=0.17 BORING 2 EL. 4790.5' (4) 14 0 :/ 11/12 WC=5.5 DD=112.6 -200=12 NV NP A-1 -a (0) 9/12 8/12 9/12 9/12 13/12 WC=16.3 DD=115.9 -200=46 LL=19 P1=8 27/12 1 3/1 2 r \Ai BORING 3 EL. 4794' (4) 14 0 1 2/1 2 9/12 A� / 13/12 25/12 1 2/1 2 18/12 OMC=10.2 MDD=1 19.6 +4=0 -200=19 NV NP WSS=0.00 RES=2,610 CL=0.009 0rg=1.0 pH=8.31 A-4 (0) 8/12 WC=5.8 DD=109.8 -200=17 NV NP A-1 -b (0) BORING 4 EL. 4793.5' (6) / 0 / 10/12 9/12 11/12 WC=4.4 DD=111.1 -200=17 NV NP A-1 -b (0) 11/12 WC=1 7.2 DD -1O9.7 -200=57 LL=24 P1=9 1 6/1 2 24/12 5/12 17/12 BORING 5 EL. 4791.5' (6) 10/12 7/12 6/12 13/12 1 2/1 2 17/12 24/12 WC=1 9.2 +4=0 -200=23 NV NP 24/12 11/12 WC=7.1 DD=112.7 2.7 -200=20 NV NP A-1- (0) BORING 6 EL. 4794.5' 11/12 10/12 8/12 0 / / / / 17/12 15/12 9/12 1 0/1 2 10/12 WC=17.9 DD -112.5 +4=0 -200=59 LL=26 P1=15 14/12 WC=1 9.3 DD=111.6 +4=1 -200=69 LL=31 P1=18 0 5 10 15 20 25 30 DEPTH -FEET 23-1-330 i Kumar & Associates PINTAIL COMPRESSOR STATION, NORTHEAST OF WELD COUNTY ROADS 40 & 35, LA SALLE/WELD COUNTY, COLORADO LOGS OF EXPLORATORY BORINGS Fig. 2 1333—Hld3a Compressor Station\Drofting\231330-02 to 04.dwg W .i ^ rV Z OJ mw N.h O O, Z O . m J w o Ln O r r N cd rr g I N \ DI DI O r \ tr- -- CDN>w l :5 CD I Z a ri r O CO O r N) to O o r N O II O K) O Ni rO II II c; N. I II II O V) r °N° II II rO I fix° a < r o Ln r r N O .00 " r 1 N N r II N N \ \ II II O N I— N r r O U) \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ O O Ii LU r r 0 r t (N DI r ® r H N �U N j DI r 10_ N N O N Ln N N LU N O N to r N N \ \ \ \ \ \ \ \ \ Ln r� t NI N .N NrCD DI,t r O) O N O Ln O Ln Ln O Ln O LU N N N ® r DI O O prrN DI DI DI DI O DI Ui 0 "Kt. 2Jl J CI_ Qn + I _iz ••::: i�:: ::Y :•:::.:;:;f:::;:;� f ...:. �:.:.:.k. f IA' sk N DI DI O Nn N�O(DI o i _JCL O V) LU O CO O LU O in O 1333—H1d3a 23-1-330 I Kumar & Associates PINTAIL COMPRESSOR STATION, NORTHEAST OF WELD COUNTY ROADS 40 & 35, LA SALLE/WELD COUNTY, COLORADO LOGS OF EXPLORATORY BORINGS I Fig. 3 Compressor Station\Drafting\231330-02 to 04.dwg C O M El ar MI OM "N M I O r N M ' N.- 0 r h O LEGEND (6) TOPSOIL/ROOTED MATTER, APPROXIMATE THICKNESS IN INCHES SHOWN IN PARENTHESES TO LEFT OF THE LOG. SILTY SAND (SM) WITH POORLY -GRADED SAND WITH SILT (SP-SM) ZONES, FINE- TO MEDIUM -GRAINED, LOOSE TO MEDIUM DENSE WITH ISOLATED VERY LOOSE ZONES, SLIGHTLY MOIST TO MOIST TO WET (BELOW GROUNDWATER), TAN TO BROWN TO OCCASIONALLY DARK BROWN. LEAN CLAY (CL) WITH VARIABLE FINE- TO MEDIUM -GRAINED SAND CONTENT, MEDIUM STIFF TO VERY STIFF, MOIST TO VERY MOIST (BELOW GROUNDWATER), OCCASIONALLY HIGHLY PLASTIC, SILTY AND CALCAREOUS IN PLACES, TAN TO BROWN. CLAYEY SAND (SC), FINE-GRAINED, LOOSE, MOIST TO WET (BELOW GROUNDWATER), BROWN TO DARK BROWN. POORLY -GRADED SAND WITH SILT (SP-SM), FINE- TO COARSE -GRAINED, MEDIUM DENSE, WET (BELOW GROUNDWATER), BROWN. SANDSTONE BEDROCK, FINE- TO MEDIUM -GRAINED, HARD TO VERY HARD WITH A MEDIUM HARD ZONE NEAR THE BEDROCK SURFACE, WEAKLY CEMENTED, MOIST, BROWN TO GRAY WITH IRON OXIDATION STAINING. DRIVE SAMPLE, 2 -INCH I.D. CALIFORNIA LINER SAMPLE. DRIVE SAMPLE, 1 -3/8 -INCH I.D. SPLIT SPOON STANDARD PENETRATION TEST. DISTURBED BULK SAMPLE. 10/12 DRIVE SAMPLE BLOW COUNT. INDICATES THAT 10 BLOWS OF A 140 -POUND HAMMER FALLING 30 INCHES WERE REQUIRED TO DRIVE THE SAMPLER 12 INCHES. 14 DEPTH TO WATER LEVEL AND NUMBER OF DAYS AFTER DRILLING MEASUREMENT WAS MADE. NOTES 1. THE EXPLORATORY BORINGS WERE DRILLED ON MAY 2 AND 3, 2023 WITH A 7.25 -INCH -DIAMETER HOLLOW -STEM AUGER. 2. THE EXPLORATORY BORINGS WERE LOCATED AND STAKED BY THE CLIENT. 3. THE ELEVATIONS OF THE EXPLORATORY BORINGS WERE OBTAINED BY INTERPOLATION BETWEEN CONTOURS ON THE SITE PLAN PROVIDED. 4. THE EXPLORATORY BORING LOCATIONS AND ELEVATIONS SHOULD BE CONSIDERED ACCURATE O NLY TO THE DEGREE IMPLIED BY THE METHOD USED. 5. THE LINES BETWEEN MATERIALS SHOWN ON THE EXPLORATORY BORING LOGS REPRESENT THE APPROXIMATE BOUNDARIES BETWEEN MATERIAL TYPES AND THE TRANSITIONS MAY BE GRADUAL. 6. GROUNDWATER LEVELS SHOWN ON THE LOGS WERE MEASURED AT THE TIME AND UNDER CONDITIONS INDICATED. FLUCTUATIONS IN THE WATER LEVEL MAY OCCUR WITH TIME. 7. LABORATORY TEST RESULTS: WATER CONTENT (%) (ASTM D2216); DRY DENSITY (pcf) (ASTM D2216); PERCENTAGE RETAINED ON NO. 4 SIEVE (ASTM D6913); PERCENTAGE PASSING NO. 200 SIEVE (ASTM D1140); LIQUID LIMIT (ASTM D4318); PLASTICITY INDEX (ASTM D4318); NO LIQUID LIMIT VALUE (ASTM D4318); NON -PLASTIC (ASTM D4318); WATER SOLUBLE SULFATES (%) (CP-L 2103); O rg = ORGANIC CONTENT (%) (AASHTO T267); pH = HYDROGEN ION CONCENTRATION (ASTM E 70); RES = MINIMUM LABORATORY RESISTIVITY (ohm —cm.) (ASTM G 57); O MC = OPTIMUM MOISTURE CONTENT (ASTM D698); MDD = MAXIMUM DRY DENSITY (pcf) (ASTM D698); CL = CHLORIDE CONTENT (%) (AASHTO T291): A -1-a (0) = AASHTO CLASSIFICATION (GROUP INDEX) (AASHTO WC = DD = +4 = -200= LL PI NV NP WSS M 145). 23-1 —330 1 Kumar & Associates PINTAIL COMPRESSOR STATION, NORTHEAST OF WELD COUNTY ROADS 40 & 35, LA SALLE/WELD COUNTY, COLORADO LEGEND AND EXPLANATORY NOTES Fig. 4 0 0 to 0 I 0 cn M N O C O 0 C O C Q L 0 0, N C t a E 0 U 0 C 0 EM d M cn h O M N IM M N O N O N N • a ma c 1 n - L -3 -4 _5 -6 .1 SAMPLE FROM: WC —200 = OF: Boring 20.7 = 72 Lean 1 %, %, DD LL Clay © 7.5' = 107.8 = 26, with PI Sand pcf = 13 (CL) - - - I - I UNDER - ADDITIONAL DUE CONSTANT - TO COMPRESSION WETTING PRESSURE - SWELL (%) z 0 I- Q o - o 0 z 0 O These test results apply only to the samples tested. The testing report shall not be reproduced, except in full, without the written approval of Kumar and Associates, Inc. Swell Consolidation testing performed in accordance with ASTM D-4546. 1.0 APPLIED PRESSURE - KSF 10 100 23-1-330 Kumar & Associates SWELL -CONSOLIDATION TEST RESULTS Fig. 5 Compressor Station\Drafting\231330-05 to 07.dwg SAMPLE FROM: OF: Sandy Boring 4 © Lean Clay 10' (CL) 1 WC = 17.2 —200 = %, 57 %, DD LL = 109.7 = 24, PI pcf = 9 \ 0 0 ' ADDITIONAL COMPRESSION UNDER CONSTANT PRESSURE DUE TO WETTING CO 1.0 APPLIED PRESSURE - KSF 10 100 SAMPLE FROM: Boring OF: Lean 7 Clay © 10' with Sand (CL) WC —200 = 18.0 = 78 %, %, DD LL = 111.3 = 27, PI pcf = 14 ADDITIONAL COMPRESSION UNDER CONSTANT PRESSURE DUE TO WETTING - S These test results apply only to the samples tested. The testing report shall not be reproduced, except in full, without the written approval of Kumar and Associates, Inc. Swell Consolidation testing performed in accordance with ASTM D-4546. .1 1.0 APPLIED PRESSURE - KSF 10 100 23-1-330 Kumar & Associates SWELL -CONSOLIDATION TEST RESULTS Fig. 6 Compressor Station\Drafting\231330-05 to 07.dwg SAMPLE FROM: OF: Sandstone Boring 7 @ Bedrock 34' 1 WC = 21.4 —200 = %, 22 %, DD LL = 99.3 = 24, PI pcf = 3 \ 0 0 ADDITIONAL COMPRESSION UNDER CONSTANT PRESSURE U 1 DUE TO WETTING 1 N N NOIIVaf1OS Z `i 0 -4 .1 1.0 APPLIED PRESSURE - KSF 10 100 SAMPLE FROM: Boring OF: Sandstone 8 @ Bedrock 49' WC —200 = 18.0 = %, 42 %, DD LL = 100.2 = 20, NP pcf em 0 1 ADDITIONAL COMPRESSION J UNDER CONSTANT PRESSURE L' n DUE TO WETTING N I LVaI1OSNOO These test results apply only to the samples tested. The testing report shall not be reproduced, except in full, without the written approval of Kumar and Associates, Inc. Swell Consolidation testing performed in accordance with ASTM D-4546. .1 1.0 APPLIED PRESSURE - KSF 10 100 23-1-330 Kumar & Associates SWELL -CONSOLIDATION TEST RESULTS Fig. 7 01 v of 0 0 0 I 0 M M 17) O C 0 O 0 0 a 4- N 0 /n O a 0 U 0 O E"> m O N M N Pr) O 0 N N 0 4- U n 0 d c > HYDROMETER ANALYSIS SIEVE ANALYSIS 100 TIME READINGS 24 HRS 7 HRS 45 MIN 15 MIN 60MIN 19MIN 4MIN 1MIN #200 U.S. STANDARD SERIES #100 #50 #40F30 #16 #10 $ CLEAR SQUARE OPENINGS 4 3/8" 3/4" 1 1L2" 3" 5"6" 8"0 - I I I H 90 10 I I 80 20 70 30 PERCENT PASSING 0 O 0 O 0 0 0 I I- O O 0 0 0)0 o al a 0 PERCENT RETAINED I I_ I I I I 1 I I I- I III 1 1 1-1-1 1-i III I T I r CL I I I I I T I I I- 1-i-1 1-1 Fl 1 .001 .002 .005 .009 .019 .037 .075 DIAMETER .150 .300 .425 OF PARTICLES .600 1.18 IN MILLIMETERS 2.0 2.36 4.75 9.5 19 38.1 76.2 127 152 200 CLAY TO SILT SAND GRAVEL COBBLES FINE MEDIUM COARSE FINE COARSE GRAVEL SAMPLE 0 LIQUID LIMIT OF: Silty % Sand NV (SM) SAND 77 % PLASTICITY INDEX NP SILT FROM: AND CLAY Boring 5 ® 23 24' HYDROMETER ANALYSIS SIEVE ANALYSIS 100 TIME READINGS 24 HRS 7 HRS 45 MIN 15 MIN 60MIN 19MIN 4MIN _ 1MIN #200 U.S. STANDARD 100 50 ; SERIES 40 #30 ; 16 #1-0 , 8 #4 CLEAR 3/8" 3/4" SQUARE OPENINGS 1 1/2" 3" 5"6" 8"„ o o 0 O o 0 o O O O 0 PERCENT RETAINED I I I 90 I I I I I -- 80 70 60 I Z I 50 La II LJ re W 40 I I 30 I I I f � I 20 I � I 10 0 1 I I (AI _IL I I I 1 I III 1 1 .1 1.11 I 1 .1 1 1 1 1 1 1 I .001 .002 .005 .009 .019 .037 DIAMETER .075 .150 OF .300 .425 PARTICLES .600 IN 1.18 MILLIMETERS 2.0 2.36 4.75 9.5 19 38.1 76.2 127 152 200 CLAY TO SILT SAND GRAVEL COBBLES FINE MEDIUM COARSE FINE COARSE GRAVEL 0 LIQUID LIMIT SAMPLE OF: Sandy % SAND 41 % 26 PLASTICITY Lean Clay (CL) FROM: SILT AND CLAY 59 INDEX 15 These test results apply only to the samples which were tested. The Boring 6 © 7.5' testing report shall not be reproduced, except in full, without the written approval of Kumar & Associates, Inc. Sieve analysis testing is performed in accordance with ASTM D6913, ASTM D7928, ASTM C136 and/or ASTM D1140. 23-1-330 Kumar & Associates GRADATION TEST RESULTS Fig. 8 O 0 4- 0 I 0 M M M N C O O O 0 0 a O N 0 A 0 a E 0 U 0 0 O E"> Li)rn O N I M N Pr) O 0 N N 0 4- U n O d c -n > HYDROMETER ANALYSIS SIEVE ANALYSIS 100 TIME READINGS 24 HRS 7 HRS 45 MIN 15 MIN 60MIN 19MIN 4MIN 1MIN #200 U.S. STANDARD SERIES #100 #_50 #40 #30 #16 1 • , 8 CLEAR SQUARE OPENINGS 4 3/8" 3/4" 1 1L2" 3" 5"6" 8"0 i - I I 90 10 80 20 70 30 I I PERCENT PASSING 0 o O in is o 0 I I O 0 0 0 o O O 0 PERCENT RETAINED I )_ I I I I 1 I I I I I- t I -I -I II III_ I I 1- I-1 1-i III I Ili r u I I I I I I ITI I I- I I F I Ft .001 .002 .005 .009 .019 .037 .075 DIAMETER .150 .300 .600 1.18 .425 OF PARTICLES IN MILLIMETERS 2.0 2.36 4.75 9.5 19 38.1 76.2 127 152 200 CLAY TO SILT SAND GRAVEL COBBLES FINE MEDIUM COARSE FINE COARSE GRAVEL SAMPLE 0 LIQUID LIMIT OF: Silty % Sand NV (SM) SAND 81 % PLASTICITY INDEX NP SILT FROM: AND CLAY Borings 1-3 19 These samples testing except approval Sieve accordance ASTM © 0'-5' test results apply only to the which were tested. The report shall not be reproduced, in full, without the written of Kumar & Associates, Inc. analysis testing is performed in with ASTM D6913, ASTM D7928, C136 and/or ASTM D1140. 23-1-330 Kumar & Associates GRADATION TEST RESULTS Fig. 9 Compressor Station\Drafting\231330-10.dwg 0 10 9000 20 30 40 50 60 7500 L I I L � 1 6000 7 7 A ' >.-- \ > e E in 0 4500 e w E ,� o O `�'•. ..Q ,....1.r...l,. •••• 3000 1500 0 0 10 20 MOISTURE 30 40 (%) 50 60 CURVE SYMBOL IDENTIFICATION SAMPLE SOIL OR BEDROCK TYPE RESISTIVITY (ohm MINIMUM —cm) RESISTIVITY AT IN SITU MOISTURE CONTENT (ohm —cm) • BORINGS 1-3 © 1 TO 5 FT. SILTY SAND (SM) 2,610 :4,200* O BORING 7 © 2.5 FT. SILTY SAND (SM) 3,605 >7,000 * AT OPTIMUM MOISTURE CONTENT (ASTM D 698) 23-1-330 Kumar & Associates LABORATORY RESISTIVITY RESULTS Fig. 10 COMPACTION TEST REPORT Curve No. 2704 121 10.2%, 119.6 pcf ZAV SpG 2.60 Preparation Method Rammer: Wt. 5.5 lb. Drop 12 in. Type Manual Layers: No. 3 Blows per 25 Mold Size 0.03333 cu. ft. Test Performed on Material Passing #4 Sieve tensity, %>#4 0 %<No.200 19 Atterberg (D 4318): LL NV PI NP NM (D 2216) Sp.G. (D 854) 2.6 uscs (D 2487) SM AASHTO (M 145) A-2-4(0) Date: Sampled 5/5/23 Received 5/5/23 Tested 5/8/23 5 7 9 11 13 15 17 Tested By DN Water COMPACTION ASTM D content, 698-12 TESTING Method DATA A Standard SIEVE TEST RESULTS 1 2 3 4 5 6 Opening Size % Passing Specs. WM + WS 6289.0 6366.0 6383.0 6334.0 #4 100 100 WM 4376.0 4376.0 4376.0 4376.0 #10 #16 98 WW + T #1 595.6 600.3 564.4 648.8 #30 #50 82 58 WD + T #1 566.0 560.2 521.2 587.4 #100 34 TARE #1 153.4 152.9 153.3 145.3 #200 0.0361 mm. 19 12 WW + T #2 0.0230 mm. 11 WD + T #2 0.0133 0.0094 mm. mm. 11 9.7 TARE #2 0.0067 mm. 9.6 MOIST. 7.2 9.8 11.7 13.9 0.0033 mm. 0.0014 mm. 8.5 7.1 DRY DENS. 117.8 119.6 118.6 113.5 TEST RESULTS Material Description Maximum Optimum dry moisture density = 10.2 = 119.6 pcf silty sand Remarks: These test tested. in full, Associates, accordance performed performed results apply only to the samples which were the testing report shall not be reproduced, except without the written approval of Kumar and Inc. Moisture/density relationships performed in with ASTM D698, D1557. Atterberg limits in accordance with ASTM D4318 sieve analysis in accordance with ASTM D422, D1140. Project No. 23—1-330 Project: Pintail Compressor Station O Location: Boring B1 —B3 Depth: 1'-5' Sample Number: 2704 Checked by: JJM Title: Lab Manager 23-1-330 Kumar & Associates MOISTURE —DENSITY RELATIONSHIPS Fig. 11 THERMAL DRYOUT CURVE 300 —C)— Interpolated Rho (C cm/W) u, .a CN a tn M CV 41 c V d 0 0 O 0 E n M O N No 0 L O 4 C 3 250 200 100 50 0 • Measured Rho (C cm/W) 0% 5% 10% 15% Gravi metric Water Content (percent) 20% 25% Sample of: silty sand From: Boring B1 -B3 @ 1'-5' Gravel: Sand: Silt/Clay: LL: PI: OMC DD 0 % 41 % 59 % 26 15 10.2 % 119.6 pcf GWC (percent) 0.0 13.9 10.8 Average Density as Tested Measured Rho (C cm/W) 138.5 46.2 43.8 113.8 pcf 95.2 % compaction 23-1-330 Kumar & Associates i THERMAL DRYOUT CURVE 1 Fig.12 TABLE I SUMMARY OF LABORATORY TEST RESULTS PROJECT NO.: PROJECT NAME: DATE SAMPLED: DATE RECEIVED: 23-1-330 Pintail Compressor Station 5/2/2023-5/3/2023 5/5/2023 SAMPLE LOCATION DATE TESTED MOISTURE NATURAL CONTENT (%) NATURAL DRY DENSITY (pcf) GRADATION PERCENT PASSING NO. 200 SIEVE LIMITS WATER SOLUBLE SULFATES (%) MINIMUM ELECTRICAL RESISTIVITY (ohm -cm) CHLORIDE (Cl) CONTENT IN SOIL ORGANIC pH AASHTO CLASSIFICATION (group index) SOIL OR BEDROCK TYPE ATTERBERG BORING DEPTH (feet) GRAVEL (%) SAND (%) LIQUID LIMIT (%) PLASTICITY INDEX (%) MATTER IN SOILS (%) 1 2.5 5/5/23 5.6 102.9 8 NV NP A -1-a (0) Poorly -Graded Sand with Silt (SP-SM) 1 7.5 5/5/23 20.7 107.8 0 28 72 26 13 0.17 Lean Clay with Sand (CL) 2 1 5/5/23 5.5 112.6 12 NV NP A -1-a (0) Poorly -Graded Sand with Silt (SP-SM) 2 14 5/5/23 16.3 115.9 46 19 8 Clayey Sand (SC) 3 5 5/5/23 5.8 109.8 17 NV NP A -1-b (0) Silty Sand (SM) 4 2.5 5/5/23 4.4 111.1 17 NV NP A -1-b (0) Silty Sand (SM) 4 10 5/5/23 17.2 109.7 57 24 9 Sandy Lean Clay (CL) 5 5 5/5/23 7.1 112.7 20 NV NP A -1-b (0) Silty Sand (SM) 5 24 5/5/23 19.2 0 77 23 NV NP Silty Sand (SM) 6 7.5 5/5/23 17.9 112.5 0 41 59 26 15 Sandy Lean Clay (CL) 6 29 5/5/23 19.3 111.6 1 30 69 31 18 Sandy Lean Clay (CL) 7 2.5 5/5/23 5.2 109.9 14 0.17 3,605 0.011 7.21 A -1-a (0) Silty Sand (SM) 7 10 5/5/23 18.0 111.3 78 27 14 Lean Clay with Sand (CL) 7 34 5/5/23 21.4 99.3 22 24 3 Sandstone Bedrock 8 1 5/5/23 6.3 110.0 11 NV NP A -1-a (0) Poorly -Graded Sand with Silt (SP-SM) 8 19 5/5/23 17.1 44 21 10 Clayey Sand (SC) 8 49 5/5/23 18.0 100.2 11 47 42 20 NP 0.02 Sandstone Bedrock B1 -B3 1-5 5/8/23 10.2* 119.6* 0 81 19 NV NP 0.00 2,610 0.009 1.0 8.31 A-4 (0) Silty Sand (SM) *Optimum Moisture Content (OMC) and Maximum Dry Density (MDD) based on the standard Proctor (ASTM D698) TRIP GENERATION MEMORANDU M M 4* -1341 Date: July 13, 2023 To: Jay Knutson From: Chris Rolling, PE RE: Pintail Compressor Station — Weld County, CO Project #: 022-03158 Cc: File (ic2s0P,i( Introduction and Objective This traffic memorandum summarizes the existing and projected traffic conditions of the proposed Pintail compressor Station in Gilcrest, Colorado. The site will be located on the east side of Weld County Road 35 (WCR 35) approximately two miles east of US Highway 85. Access to the site will be by an existing dirt road adjacent to the west end of the site. Upon completion, access to the site is proposed to be from an existing unpaved road approximately one -quarter of a mile north of WCR 40 which is currently being used for access to other operators. The objective of this memorandum is to review the existing adjacent roadway network and to determine both the trip generation and distribution of traffic during all phases of the project. Upon completion in early 2024, the site is not expected to generate daily traffic volumes. This memorandum is performed in accordance with Weld County and Institute of Transportation Engineers (ITE) criteria. Figure 1 shows the vicinity map of the project. 1880 Fall River Drive / Suite 200 / Loveland, CO 80538 O 970.461.7733 / olsson.com Pintail Compressor Station — Weld County, CO Olsson Project No. 022-03158 LEGEND Scale: NTS Project Site Figure 1: Site Vicinity Map Trip Generation Memorandum July 2023 Page 2 of 10 Pintail Compressor Station — Weld County, CO Trip Generation Memorandum Olsson Project No. 022-03158 July 2023 Existing Roadways There are three public roads near the site that will be used by site traffic. These include US Highway 85, WCR 42, and WCR 35. US Highway 85 is a 4 -lane regional divided freeway/expressway which has left and right deceleration -lanes onto WCR 42. The CDOT State Highway Access Code (SHAG) defines the access category for state routes and the Online Transportation Information System (OTIS) provides an online catalogue of data for CDOT facilities. The latter shows this as an Expressway (E -X) as defined by CDOT. The intersection of US Highway 85 and WCR 42 is a full movement, signalized intersection and is expected to serve most of the site traffic. Existing average annual daily traffic (AADT) is 19,000 vehicles per day (vpd). There is an at -grade rail crossing directly east of this intersection which leaves space for approximately one passenger car to stop at the signal and not reach the gates. Trucks waiting at the signal would need to wait east of the crossing gates to avoid blocking the tracks. WCR 42 is a collector which is currently a paved rural two-lane roadway with eleven -foot lanes and no shoulder. This will be one of the roads used by site traffic to gain access to the site. There is no posted speed, so the speed limit is assumed to be the statutory speed limit of 55 mph. WCR 35, is a collector and is an unimproved roadway with approximately sixteen feet of travel width. It intersects with WCR 42 and will be used by most trips to reach the site. There is no posted speed, so the speed limit is assumed to be the statutory speed limit of 55 mph. The existing roadway characteristics are listed in Table 1 and the roadway geometry is shown in Figure 2. Table 1: Existing Roadway Characteristics Roadway Access Section Me C Type Category Posted Speed Functional Classification US Highway 85 4 -Lane Divided Highway E -X 50 mph Principal Arterial � WCR 42 2 -Lane Paved 55 mph Collector2 WCR 35 2 -Lane Unpaved 55 mph Collector2 1. Per CDOT SHAG and OTIS 2. Per Weld County Classification Map Page 3 of 10 Pintail Compressor Station — Weld County, CO Trip Generation Memorandum Olsson Project No. 022-03158 July 2023 Scale: NTS LEGEND O O LU o N N f • • 40' O O (Y) LO Co CTS D N U) 0 Ct H- D C6 0 oc WCR 42 • • xxx' Stop Controlled Intersection Stop Sign Existing Turn -Lanes Signalized Instersection Turn Bay Storage Length Figure 2: Roadway Geometrics co U Page 4 of 10 Pintail Compressor Station — Weld County, CO Trip Generation Memorandum Olsson Project No. 022-03158 July 2023 Site Access The site will be developed northeast of WCR 40 and WCR 35. The site is to be accessed by an existing dirt access road running along the half section line one -quarter mile north of the site. This road connects to WCR 35 at an existing access for an existing natural gas facility. From the unpaved road, a new gravel road will be constructed through private property to the site. Itn FyiRTinin PM'. 1ACILRY J / 1_ N 2 t ,::::.�' ; N. . -...lb N. �`�� " .� N. INCH :. .. N . . N. .. t. N. N.N.:‘.. \' J�� .11••.,...> .<44‘ ' ' ' \� ' \ _ = .J(ISTINC MITT 4- �- NWU-IN\\ X — — EXISTING CJLVERT (EX I ENO AS NECESSSAi' V) tI`�i`. 30' PIPELINE R.C.W. D..___ F0' WILD COUNTY F RGPD y R f7 W LC) sap =FNRI-map V. ELEY: 41I* L4' N: 1346416 73 E: 3214346.18 I 3iT PIPELINE EASEMENT T • —I. -i-- -- T ,- PROPOSED UNDERGROUND AS _ ^ - "1 �I II I EXISTING CULVERT (xTEND As NEcessARY•• ~\ _�.. •. — c — - I 4 40 E7418TIN0 UNDERGROUND OAC -1 Image credits: Ascent Geomatics Solutions N:13.1466028=0�,--- E '214'158:86'= 0 rxls-lrx7 nrr^.N I DUSTING UNDERGROUND GAS14 — L PROPERTY LINE �` I —.._--- r 'II II �If II I I� I� FXIR-ING DIRT II,r ROAD -- �•r l Imo. 1 cuaaHEIE comer eox I II DETENTION D� —11 (I — 26 .2 — l F - . ROep CENTER LINE 1 N N. EXISI INS I IN-FRGROLINI1 Y,ATR 1FIlIMFNT I h:N' 476 5 WIDE Mtl4NRMEti OUTLET �.' HYF / EMERGENCY SPILLWAY NI rfororo) G V3 CHANNEL 2 OUSTING A. UNDERGROUND GAS < 456 /h LAYt7JP/N AMEA / (1r11 nal sn \ � f — _ a FMRANNIENT I EXISTING WELL L RARTFI R 7ri-11F (iv oh YL<:lilitin 47o 600• lr� PROPOSED J CHANNEL 1 Ill Plc u _ n F---1--I C3 h. � —. .. .... flL=TI ' 1 I 1 11 u Figure 3: Proposed Site Plan morocco J UHANNEL3 INS \ r‘ ."s 4 In, HAMMFRHFAf1 TURN / 725' 1 /y/i/ r 47t, — SIP f., — ,106 :.i•_ — - <Z-4. Aere ,.. f / / emir 0 L'A L UI CONTOUR INTERVAL = t 00 Page 5 of 10 Pintail Compressor Station — Weld County, CO Trip Generation Memorandum Olsson Project No. 022-03158 July 2023 Trip Generation Trip generation is typically determined using rates found in the ITE Trip Generation Manual, it" Edition. However, the land use proposed for this site is not included in the manual, so trip generation the traffic volumes are estimated information provided from the owner based on comparable sites previously constructed. Note that the peak trip generation of this site is expected to be during construction of the site, after which traffic will reduce to infrequent maintenance staff. The existing site is undeveloped and does not generate traffic beyond very low demand to serve the agricultural use. The construction schedule for the site is expected to take place for 6 months between September 2023, and March 2024. The construction of the site is expected to first consist of grading crews with heavy machinery being mobilized and demobilized during this period, then general construction which will have the highest expected craft workers and delivery trucks, and lastly demobilization. Construction activities are expected to be vary throughout the year, with the peak trip generation occurring during general construction. The expected construction timeline and trips generated is outlined in Table 2. Table 2: Trip Generation Phase General Construction Demobilization Timeline 9/1/23 Through 10/1/23 10/1/23 Through 2/1/24 2/1/24 Through 3/1/24 Site Trip Generation During Construction Daily Volumes PM Peak Hour (Site) Daily Volumes Trucks Passenger Trips Trip Distribution Primary Trips Vehicles Generated Enter Exit Enter 6 24 50% 50% 12 12 6 8 90% 10% 7 1 12 40 1 104 50% 50% 40 44 5% 95% 10 90% 10% The trip generation of the site is expected to be the highest during the general construction phase in which 12 trucks and 40 passenger vehicles are expected to both enter and exit the site each day. Trucks are assumed to be spaced out throughout the day and all craft workers and construction staff are assumed to enter and exit the site during a single AM and PM peak hour, respectively. A specific contactor and construction schedule have not been determined. Typically, the construction AM peak hour is expected to coincide with the adjacent street traffic peak hour at 7 AM, and the construction PM peak hour is expected to occur before the adjacent street traffic peak hour at 3PM. Page 6 of 10 Pintail Compressor Station — Weld County, CO Trip Generation Memorandum Olsson Project No. 022-03158 July 2023 Trip Assignment Trips are expected to reach the site using the US Highway 85 and WCR 42 intersection roughly two miles west of the site. This is the most direct access to the site which accommodates vehicle and truck turning. The staff is expected to arrive from surrounding communities and be distributed according to a gravity model in which the origin -destination of trips are weighed according to the distance and population of local communities in the Northern Front Range. The assigned trips and external trip distribution for the general construction phase are shown in Figure 4. Trucks are to access the haul route via US Highway 85 at WCR 42. Attached to the end of the memo is a reference to the haul route which includes more in-depth information about the route. The existing roadway infrastructure accommodates trucks turning into the site. Vehicles exiting the site may experience slight delays trying to exit the site during peak hours. The intersection is signalized so all trucks can use the same route. As noted above, there is an at grade rail crossing to the east of the US 85 and WCR 42 intersection. Spacing between the highway and tracks does not allow for a tractor -trailer to wait at the westbound stop bar, so trucks leaving the site will need to wait for the signal behind the tracks. Page 7 of 10 Pintail Compressor Station — Weld County, CO Trip Generation Memorandum Olsson Project No. 022-03158 July 2023 sca,e,NTs LEGEND 50% 0 O LO L • • XX% XX% 50% 50% P 0 0 Le 00 CO 2 D 50% WCR 42 Stop Controlled Intersection Stop Sign Existing Turn -Lanes Signalized lnstersection Turn Bay Storage Length Exiting Volumes Entering Volumes Lo co cc O O O O r L„ 100% Figure 4: General Construction Phase Site Traffic Volumes Page 8 of 10 Pintail Compressor Station — Weld County, CO Trip Generation Memorandum Olsson Project No. 022-03158 July 2023 Summary and Conclusions The purpose of this memorandum is to summarize the existing site conditions and the expected trips generated by the proposed Pintail Compressor Station to be constructed east of WCR 35 approximately two miles east of US Highway 85. The site is on an undeveloped agricultural parcel which is accessible via an unpaved drive along WCR 35. During the initial stages of construction, the site proposes to use the existing access roughly 1,300 feet south of WCR 42. Site construction will include a drive that connects to WCR 35 as shown in Figure 3. The site construction is expected to last for approximately 6 months from September 2023 through 2024. Construction consists of grading, general construction, and demobilization periods. The most intensive period of construction is expected to be the general construction phase, lasting roughly 3 months during the middle of the construction timeline. During the general construction period, the site is expected to have 12 daily truck deliveries/hauls, and 40 staff which generate roughly 104 daily trips, and 44 trips during each of the site peak hours as shown in Table 2. Most of these trips are expected to reach the site using the intersection of US Highway 85 and WCR 42 as the most direct route to the site. Upon completion of construction, the site is not expected to generate significant daily trips. Page 9 of 10 PINTAIL COMPRESSOR STATION HAUL ROUTE MAP TOWN OF GILCREST HAUL ROUTE PASSES NO LOCAL TOWNS, SCHOOL FACILITIES, FUTURE SCHOOL FACILITIES AND/OR CHILD CARE CENTERS WELD COUNTY ROAD 44 WELD COUNTY ROAD 42 .1 WELD COUNTY ROAD 40 LEGEND: / / = OIL & GAS LOCATION = PROPOSED ACCESS ROAD = TOWN OF GILCREST = SECTION LINE = PUBLIC ROAD - GRAVEL = PUBLIC ROAD - PAVED = HAUL ROUTE 8620 Wolff Court Westminster, CO 80031 (303)928-7128 ASC E NT www•ascentgeomatics,com 6EUM.ATICS SOLUTION:, FIELD DATE: N/A DRAWING DATE: 06-26-23 B Y HJL CHECKED: CSG DISCLAIMER: THIS PLOT DOES NOT REPRESENT A MONUMENTED LAND SURVEY AND SHOULD NOT BE RELIED UPON TO DETERMINE BOUNDARY LINES, PROPERTY OWNERSHIP OR OTHER PROPERTY INTERESTS. PARCEL LINES, IF DEPICTED HAVE NOT BEEN FIELD VERIFIED AND MAY BE BASED UPON PUBLICLY AVAILABLE DATA THAT ALSO HAS NOT BEEN INDEPENDENTLY VERIFIED. SITE NAME: PINTAIL COMPRESSOR STATION SURFACE LOCATION: NE 1/4 SW 1/4 SEC. 25, T4N, R66W, 6TH P.M. WELD COUNTY, COLORADO DATA SOURCE: AERIAL IMAGERY: NAIP 2021 PLSS: BLM PUBLICLY AVAILABLE DATA SOURCES HAVE NOT BEEN INDEPENDENTLY VERIFIED BY ASCENT. Hello