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Home My WebLink About20142291.tiff Final Drainage Report ,444 For AKA Energy Group, LLC Weideman Compressor Station r Weld County, Colorado Prepared For: AKA Energy Group, LLC r 13472 Weld County Road 40 Platteville, CO 80651 r 737-2601 (970) r r April 14, 2014 FSI# 14- 100501 • r Prepared By: *if- ' Flatirons, Inc. Surveying, Engineering & Geomatics 655 Fourth Avenue Longmont, Colorado 80501 303-443-7001 I \ ...,.;!, . .,; .---,. • \,e-i, A ., WEIDEMAN COMPESSOR STATION . •,„: ,,..„.. ' ; ;� ::.,. DRAINAGE CONSTRUCTION PLANS I ' ^ }_ A PORTION OF LAND LOCATED IN THE NORTH HALF OF SECTION 29, 1 1 1 1 1 1 1 1 1 TOWNSHIP 4 NORTH, RANGE 66 WEST OF THE 6TH P. M. , t i ( `•''' \ fir%' \ COUNTY OF WELD, STATE OF COLORADO • ` I I v 4750 00 \ I- i I mo '. \ �\ • • '• `� yid• ' : 1•'� r 76203 • / ' N .....;.. -- i -- 7--, A Iti 1 ' ` a/ � :. SITE aii ^ iIiiiIiI _ .. 07 LF.-IEVEL SPREADER / ti •t j is ' 1�• (SEE ORATING CO r _ •, �- ` ^`•_ ` h -. fy j / Z •/ SECTION A-A \ \• .:� r+ . t r N ` I j�'q! O < 't } LE141 SPEEDER a > . _. I N. / /I��'�� p Vt WA1EN DUALITY POND \ �"''•% \ - I ! O L• = < r• I•� Ii L f, • •• �.��1 ' ^SEE DRA1MNd C0C1� •`•, ' II •:' . , V i 1 1 , „ 1M V O r- . suatal • 'r .�':1.:1 '. 1 aa.,Li �,,;�_ m O o m I i.1..l 267 \ • i . , I • ,' 7 13 W O 7 [ 1 '� •t �� Jt 55 f ig 2 / sc..... �— SUMP TANK 4764 0 t k' us • • , L 4757.3 ` -..f.;.',,'•••••\ IN \ -' {{CC// - •tir f. I //'/*' . . ` 47532 y ~''\ •' .• RbY.1JE' G E7EO/7LY/ _ � 1 . „1 J1 r I' 80.75 ((SP 4r 9{, ♦ , •` ......:4,41,(1 . s. 'v t imaAL . C WI ,1 • / ."{:lit` 00 CRlAIpIE1 1 ., qq t I/ 4. S•� 'c� ♦ � VICINITY MAP O < w / �j j' . slop TANK • SCALE: 16=15001 C °' x 0 n I. 6 i 1�a''' CULVERT I ` TK-1004 763.74 ';"+. . .:'.. \ m ^ M YATACH [c: /• • % � ♦ c7�" • 476217 a ' -~•,• .. BENCHMARK INFC�IYMTION ^ 0 �rg'a t 2 a 4781.08 .. 4701.\ r � / A GPS DERIVED ELEVATION WAS ESTABLISHED AT AN ONSITE / \ • ??. BENCHMARK AT THE EASTERLY CORNER OF SAID LOT D BEING A fi i 7b� .1�,� \ MAC NAIL IN THE DITCH ACCESS ROAD, WITH AN ELEVATION OF •.. ,-0 / MA476 E0: . ,to tI 4703• • PERSETER:. ? •. 4781.07 •: 1 ` Boy � .- ATP::, 4767.55 FEET. A CHECK SHOT, 0.1'±, WAS TAKEN ON NOS POINT ts w Ia} 'may1::: ` \ 1; SIAM EVILLE AZ MK 3, +�T, / I ` BEING A NGS DISK IN CONCRETE, r d STAMPED 'PLATTEVILLE, 1935, 1978-, LOCATED 6.2 MILES FROM "r ~ UOVD �. \ SITE, WITH A PUBLISHED ELEVATION OF 4819.97 FEET (NAVDBB). AK>�7D ' ,� 476x64- v. \\ t ` t / NO DIFFERENTIAL LEVEUNG WAS PERFORMED TO ESTABUSH THIS ACCESS - 47x4 \. ELEVATION. PAW 1 / / ! 0 - -C '* -.•:'--: . \ `] / TER _ . . i _ //- CONTACTOR • �.. (,; • / 750.72 /`( V-2101 ..'�.'' :•. � v VAPOR \ \, •siATW Ea Legend / COMPRESSOR 01901. COMBUSTOR � ` ,\• •4 SZ .. 762.a COALESONO Mu \O \, EXISTING an QFSCRIPTION PROPOSFp / F-2200 • - -• • ••� �y / MATCH 4761 23 TEG �„ PL PROPERTY UNE Li / •`�- • ♦ O C01WEriSW SK1DDthY PROPOSED / ` �- .� ;,:•• '•.• "• ADJACENT PROP. EkK O / 4751•. d BEAM - -'-•• ` / O 150 476A . •. »...••n EMT EASEMENT UNE0 j/ �,rsni� CONTACTOR OUILET TANKMAKE-UF 4762. \ %+;•�•� SOL DESIGNATION 0/ COALESCING FILTER AO • . ..• �. th C . Z� /// 1 /-2202 ! / y,� 1 �•:r� 1 - - - CONE CONCRETE �1, 'A s " . Y. J` \ / - - - -�i- - - - 5-FT CONTOUR uNE 5D2�— d Z Q. z /•_� OIL TANK ',, ...):its: -W- - - 1-FT CONTOUR UNE 3021-- O Z TX-1003 / /! 1' SW STALE O [L ♦ ♦ // CONDENSATE �� !y:Wt sT STORM SENOR UNE /0 CC () /pp°10S27 / TANK/ - 4752 j/ ,'•.`4` — c'^1. — — Ow — OW OVERHEAD UDU1Y UNE v Q j /4PpRrovlY[wdr ` • 4764.3 C// / / ..;•./..:: FNC w� I. = Q i •♦ • / NR RECEIVTR l / . i / i. ••w a. IA s / / BERM op. V—� 1 1 70' .. •,• 1 Q V/ U / t 2 z NR COMPRESSOR ' 6 / ♦ TWATER K-10D1ANK / / ELECTRICAL .,,/ in CI / / r 4764,00••./104101 '•i� V / EiULDWc ti �,, Grading Notes W 47-•.703.x8 / .t.::::;;;.1.0' i t 10 / .A'/ / •/'• . 1. EROSION CONTROL MEASURES MUST BE IN PLACE PRIOR TO ANY LAND DISTURBING 4♦ / let STALE NP. - /1 / r ..14>?. •• ACTIVITY COMMENCING. LOT D / 476310 / / �1 2. CLEARING AND GRUBBING UMITS SHALL INCLUDE ALL AREAS DISTURBED BY GRADING AMENDED RECORDED PERIMETER ` CHANNEL 2 // 476,8 • // // / 4. .l• / OPERATIONS. x k EXEMPTION NO. BEM / ; / ,-) IOS7-29-2 ,. / / 3. ANY GRADING OF DISTURBED AREAS SHALL RECEIVE SUFFICIENT EROSION PROTECTION TO yy AMRE-4022 ♦ / PROPOSED / �+ ; INHIBIT WIND AND WATER EROSION, a 3C REC NO 3463093 0 SECTION B-B / SWALE - / / / • a r �if 03/20/2007 / (sEE DRAWING Ci) / / 4. SUBGRADE SHALL BE COMPACTED AND SHAPED PER SPECIFICATIONS PRIOR TO gg 0 r 5 f 6 / • 1 APPLICATION OF SITE OR ROAD SURFACE. $ 1- PROPOSED / / _ / 5. GRADES SHOWN ARE FINISHED GRADES. I 4 0 / / / ////1 6. CAUTION - NOTICE TO CONTRACTOR " ``'� � / 'THE CONTRACTOR IS SPECIFICALLY CAUTIONED THAT THE LOCATION AND/OR ELEVATION ♦ / / / OF EXISTING UTIUTIES AS SHOWN ON THESE PLANS IS BASED ON RECORDS OF THE r 4$• / / / / / ' .� VARIOUS UTILITY COMPANIES AND, WHERE POSSIBLE, MEASUREMENTS TAKEN IN THE / / / �` ,/ / / FIELD. THE INFORMATION IS NOT TO BE RELIED ON AS BEING EXACT OR COMPLETE. // / / •• • ' ... r. / // // //^:eo� / THE CONTRACTOR MUST CALL THE APPROPRIATE UTILITY COMPANY AT LEAST 48 HOURS :oQ'*Oo.REC<' ., - / '4 61' , / / BEFORE ANY EXCAVATION TO REQUEST EXACT FIELD LOCATION OF UTIUTIES. IT SHALL I /, / / ,`• / BE THE RESPONSIBIUTY OF THE CONTRACTOR TO RELOCATE ALL EXISTING UTIUTIES if ✓ �' ° 4% // ` / / / / t / 4* WHICH CONFLICT WITH THE PROPOSED IMPROVEMENTS SHOWN ON THE PLANS. •I : 25620 > I if. / ` ,. ., d / i ie / .- ♦ �` 7. IT IS THE CONTRACTORS RESPONSIBILITY TO PROVIDE SITE GRADING IN A MANNER .,J� r.-4 // , ,1 / CONSISTENT WITH DEVELOPMENT PLANS REGARDING SITE DRAINAGE. n • • / OA/ /GRAPHIC SCALE �� - , ; / i., 476* / ;� / �' / DRAWING - 4702.47 / • / ( M 710r7 ) 4761 ;. r /G-1 t 1 innh - 90 R MATCH EQ / / / /` ` / 4764,10 // / // ;... SHEET , / / oil ' / 1 OF 2 y - WEIDEMAN COMPESSOR STATION DRAINAGE CONSTRUCTION PLANS A PORTION OF LAND LOCATED IN THE NORTH HALF OF SECTION 29, , , , , , , , II TOWNSHIP 4 NORTH, RANGE 66 WEST OF THE 6TH P. M. , COUNTY OF WELD, STATE OF COLORADO s N E a Culvert1 - Plan View ,�•} �,�� '- - - - - - - - - - - - r •�S/(Aq'j�7 ,7. • ', • : . , I �, - 1 1 1 1 1 1 1 1 1t •'�,2C �.. ti � e• ar eanewRTACei4 a+s� '? f��'� c ‘ LEVEL SPREADER 1t waiter � ,�° Jai :Ftit;`s . jj-4., y, 186 LF. EVE o a a .� isr' '�•.�„✓�"•�� r' r, ^l."t;• '/. a{.L •� • r�rr}•ti'.f.�lrlr/•'. t h ,..s.- (A .. 'r I / 'Y t �:�:��.'.•'1��' : ten\ f.i.•r<l! tin r:(11--4 ••r •�•� �1,i .ff• ��' •'� V w 70200 O N D a rl •. ^• � ,�.C `. fiat ♦��'la ;R?l 73 hr••r •.��.. 1• �..a��l. �_\r!•4 " ,�• M 0 :• �'L .;1•r '%ti e >�'J r1'tial. r 1'. �. // • y-`. �' 1l' ♦ �' , aay� r?�:'� 4 �.`� \,� • f , •tea' ! •• ' • 1...��,(, x47 \r :.�. J V D y lr1 .2 ,.tea, .a� af. •• .� t _t r �,�11�1!��.:��•,� \Y �• � .1. 1. i' ,•. 6 rR '` 40 isi •••,, •n1 ;1 . ty, r- . ,.• •.�` - "' ?• : f�f'10Y��'�rei� (� 'ate \ � }1N♦ rCr. 7 O i5i 1. ••�'! •(1'• �L.•fi 4. 3: 4702 •- •. }.. `•. .>�?. .. .r.71.• a.• : 1 !�•.rT = .� 4761.00 02 a_ ':7; r:. . •" Y:ItJ ' r. ,l r.•nf�!at•ati:�a -:f.•.••rf_ra;..�^.3r,r'i>t..••_r�t G ♦i�)h��r • / m 47 :cC f I.•, :cal en "y�r 6 4701 476L• 4761----.....„..„;___ .)} }!f-�•:� / / , m CO m O Jm , Ir, •4,i,t�: yy � � ��4762 , :;:•.�•',:;,„, . '� . 6 fi� GRAPHIC SCALE ` our.aea7r47a, * // i 1�. D 5 nY o x— .70, r "^• — V IXJT 47si 79 • •• m 0 t : i ;i; ; •• • 311 �- RE0 Q • etiCulvert 1 Level Spreader Section (Section A—A) �, _o O ~t t 3is- 00 "'0 PROFILE VIEW PROFILE VIEW t t in z vX HORIZONTAL SCALE 1 INCH = 20 FEET HORIZONTAL SCALE 1 INCH = 20 FEET C o a < VERTICAL SCALE 1 INCH = 5 FEET VERTICAL SCALE 1 INCH = 5 FEET •..... y 1.4 4 770 ♦ 770 �{ .z 4• DU. WRAP -. L 4 DOS 0 come ED GRADE 705 47 - ,. . TO FU ' TION AS 76S EXISTING MAX _ 8.0. , FINISHED GRADE /// -- k1 '. V. . • — - way Cr is GIP • LOS SLOPE. 01 LF. 4 i.. Teo u. • ' a �•-' ....4.A. , � 700 • c 0 SURFACE to su o+00.00 II`=11= i 0 INV. ELEV:4760 • STA.r+80.89 .. INV. E 4759.79 COMPACTED CO SU9GRADE 1' . AMMER /WPAM) ye - �.� AttL rKi Po. . 0' MIX 4 755 4 755 Q SPREADER >I V;4761.50' i Ai -f a 1~,1 CI IC 0aw ° 6 4 4 750 a c c o nO U Q N 4 o .o r U ap /; [j a r If. C , g Rr.W G W W Y/ Z Z 0+00 0+50 D+00 0+50 W O 0 D V v Typical Perimeter Cross Section (Section B-B) PROFILE VIEW HORIZONTAL SCALE 1 INCH = 20 FEET VERTICAL SCALE 1 INCH = 5 FEET 4770 677D 21 a � 033 ��( J ti oo � W • o U T_ r T Zo CO Et. e.4 4705 RN11HE0 GRADE .76' 54 d _ DOMING GRADE _d•.• •��• . . 6° .II=��rll= u>=n' RECTUM �,e. 4700 RIPRAP 6. MK '� 4700 r 00 RE �'` ,P w COMPACTED {�J�q,. d s11E1GRAOE I�' �,.►u; ' a• Gri r r 4755- o, 4755 /rrr 25620 r s t Ft 6 g 8 ,,c AI'flrf . * e , 0+00 0+50 DRAWING 4 fl C-1 6. SHEET 20F2 t4 FINAL DRAINAGE REPORT FOR AKA ENERGY GROUP, LLC Weideman Compressor Station WELD COUNTY, COLORADO Prepared for: AKA Energy Group, LLC 13472 Weld County Road 40 Platteville, CO 80651 (970) 737-2601 April 14, 2014 Prepared by: Flatirons, Inc. Surveying & Engineering 655 Fourth Avenue Longmont, CO 80501 FSI# 14-100501 Flatirons, Inc. — Surveying & Engineering TABLE OF CONTENTS Certification 1 Vicinity Map 2 1 .0 Location and Description 3 Background 3 Project Location 3 Property Description 3 Project Description 4 2.0 Drainage Basins and Sub-Basins 4 Major Basin Description 4 Sub-Basin Description 5 3.0 Drainage Design Criteria 5 Regulations 5 Development Criteria Reference and Restraints 5 Hydrological Criteria 6 Hydraulic Criteria 6 4.0 Drainage Facility Design 7 General Concept 7 Specific Details 9 5.0 Conclusions 11 References 12 Appendix A A Hydrology Computations A Appendix B B Hydraulic Computations B Appendix C C Floodplain Information C Appendix D D Geotechnical Report D Appendix E E Inspection Report E Weideman Compressor Station April 14, 2014 Flatirons, Inc. — Surveying & Engineering CERTIFICATION "I hereby certify that this report for the final drainage design of the Weideman Compressor Station was prepared by me (or under my direct supervision) in accordance with the provisions of the Weld County storm drainage criteria for the owners thereof." o_ •REGIS .�1 G p" =<c" t :o II I j 02 S : O : w a : / Kenneth W. Curfman PE, PLS 25620 z: For and on Behalf of Flatirons, Inc. �� State of Colorado No. 25620 k,uv `ND ? Weideman Compressor Station 1 April 14, 2014 Flatirons, Inc. -- Surveying & Engineering VICINITY MAP 1 -. t . ►► , Ll - 8 .1.7- 1 v County Road 42 t . _ �• ;d ; . t k_ --.4 y .0 4 . V 0 rf cam 1 i • . $ , /, 85 t - - - Ili . �• t :5 81TE *11,114.411.ti.. si . /77..i s..I l �• f�• k-- _ F A , g :, a: litli / /aft k k --- ► , .)1IP�� 60 #4, _, .! ' I A • It. r . 1. • , 7 h is. , i ^_' / e 9 , , .1 • / s de riirri ti- 4 i e r. _ Gcwnty.Rra38,5 85 L,i © GOOGLE 2014 _ (Not to Scale) A NI Weideman Compressor Station 2 April 14, 2014 Flatirons, Inc. — Surveying & Engineering 1 . O LOCATION AND DESCRIPTION Background This Final Drainage Report is prepared for a Use by Special Review (USR) Permit application from AKA Energy Group, LLC of Platteville, CO for the Weideman Compressor Station. The Final Drainage Report follows the criteria set forth by Urban Storm Drainage Criteria Manuals (USDCM), Volumes 1, 2 and 3, and the Weld County Storm Drainage Criteria Addendum to the Urban Storm Drainage Criteria Manuals, Volumes 1, 2 and 3 dated October 2006. Project Location The Weideman Compressor Station is located in a portion Lot D, Amended Recorded Exemption No. 1057-29-2 AMRE 4022 described under Reception Number 3463093 in the records of Weld County, and situated in the Northwest Quarter of Section 29, Township 4 North, Range 66 West of the 6th P.M., County of Weld, State of Colorado. The property is surrounded by land designated as Agricultural Zoning. The project site and all of the surrounding land are under Weld County jurisdiction. There are no major lakes, streams, or water resource facilities within the property. A small concrete lined irrigation ditch parallels the eastern and northern project boundaries. The Farmer's Independent Ditch flows northeasterly and parallels the eastern property boundary approximately 25 feet east the property. The top of Farmer's Independent Ditch is elevated approximately 3 feet above the subject property, and water from the ditch feeds the concrete lined irrigation ditch on the north and east sides of the property. Land owned by the Boney Trust bounds the property on the north, and the Strear Farms Company owns the land that forms the eastern property boundary. The adjacent property to the south and west are portions of Lot D, Exemption No. 1057-32-2 RE 4508. Property Description The site is approximately 3.3 acres in size, and has historically been agricultural land. The land was cultivated during the 2013 growing season. The rectangular shaped property extends 500 feet in a northwest/southeast direction and 250 feet in a northeast/southwest direction. The site is relatively flat and has 3-feet of fall from the higher eastern side to the lower western side. The eastern side of the property is at an elevation of 4764, and the elevation of the western part is 4761 . The average slope across the property is 0.6%. Runoff from the site flows northwesterly to center pivot irrigated crop land adjacent to the project. The property is located one-half mile south of Weld County Road (WCR) 42 at the intersection of an undesignated 2-tract dirt road and the Farmer's Independent Ditch service road. The service road for the Farmer's Independent Ditch intersects WCR 42 to Weideman Compressor Station 3 April 14, 2014 Flatirons, Inc. — Surveying & Engineering the northeast of the property and WCR 40 to the southwest. Access to the property will be from WCR 42 along the undesignated, 2-track dirt road, or from the service road that parallels the Farmer's Independent Ditch. A concrete lined irrigation ditch parallels the eastern and northern property lines. The irrigation ditch has a trapezoidal shape and is 1 .5-feet deep, 4-feet across the top, and has a 1 -foot wide flat bottom. Flows in the ditch move northerly and westerly, and the ditch is fed by an outlet structure located near the southeast corner of the property connected to the Farmer's Independent Ditch. The top of the west and south sides of the concrete lined ditch are elevated 9 to 12-inches above the natural ground surface. Runoff from the property does not enter the ditch, and water in the ditch is conveyed away from the property to the north. The soil covering the site is Julesburg Sandy Loam. The soil is divided between Map Unit 29 and Map Unit 30. Both units are comprised of the Julesburg Sandy Loam, with Unit 29 associated with slopes of 0% to 1 %, and Unit 30 associated with slopes of 1 % to 3%. Unit 30 soils cover a 100-foot strip of land along the eastern property line, and the remainder of the site is covered with Unit 29 soils. Both Julesburg Sandy Loam soils are well drained and assigned to Hydrologic Group 'B' by the United States Department of Agriculture (USDA) National Resources Conservation Service (NRCS). Project Description The Weideman Compressor Station is a natural gas facility. Buried pipelines connected to local infrastructure are used to feed the compressor station, and the compressed natural gas from the station will be delivered through other buried pipes. The proposed development will add five compressors and associated infrastructure to the property. The portions of the site that are not be used for appurtenances or buildings will be covered with a crushed recycled concrete surface. The proposed drainage concept is to replicate historic drainage patterns while utilizing a water quality pond situated at the northwestern edge of the property. The layout of the proposed improvements will not adversely impact the drainage concept, and increased runoff from the site will be allowed to infiltrate in the surrounding farm fields. 2 . O DRAINAGE BASINS AND SUB- BASINS Major Basin Description The property is located in the South Platte River Basin approximately 2 miles southeast of river. The South Platte River flows to the northeast, and the land between the river and the site is irrigated agricultural land. The excess runoff from the site will infiltrate in downstream agricultural fields to the west of the site. Runoff from the site will not flow directly to the river. The Farmers Independent Ditch, which is located uphill from the site meanders in a northeasterly direction above the South Platte River delivering irrigation water to farms. Weideman Compressor Station 4 April 14, 2014 Flatirons, Inc. — Surveying & Engineering According to the FEMA Food Insurance Rate Map; Community Panel No. 080266-0750 C, Dated September 28, 1982, the Weideman Compressor Station property is located in Zone C, Areas of minimal flooding. Sub-Basin Description Historically one sub-basin, X1 , defines the existing, onsite drainage basin. Runoff from Basin X1 sheet flows across the property in a northeasterly direction and drains to cultivated farm fields located west of the site. Offsite surface runoff flowing towards the property from the east is intercepted by the concrete lined irrigation ditch and conveyed around the property. Refer to drainage exhibit DR- 1 in the back of this drainage report for the delineation of existing drainage basin. 3 . O DRAINAGE DESIGN CRITERIA Regulations This final drainage report is prepared with criteria set forth in the Weld County Storm Drainage Criteria (WCSDC) Addendum to the Urban Storm Drainage Criteria Manual (USDCM), and Volumes 1 , 2, and 3 of the Urban Storm Drainage Criteria Manual. Spreadsheets supplied by Urban Storm Drainage website and developed by Flatirons, Inc. were used to calculate runoff, water quality capture volume, open channels, and culverts. No deviations from the either the WCSDC or the USDCM are required for the installation of the drainage improvements, except detention, which is not proposed for the site. The site is surrounded by farm fields that create a buffer that extends nearly one-half mile in all directions around the site. Runoff from the site will flow northwesterly onto an irrigated farm field where it will infiltrate. The area of the field to the northwest of the compressor station is approximately 160 acres, and the proposed development site contains less than 4 acres. Assuming the compressor station is part of the 160 acres of farm field, and the proposed development is 42% impervious. The imperviousness of the farm field will increase by less than 1 .5% due to the development of the site. A water quality pond will be constructed at the northwest corner of the compressor site in lieu of a detention pond. The water quality pond will treat the runoff from the developed site before releasing it over a level spreader and to the farm field to the northwest of the property. Development Criteria Reference and Restraints There is neither a project master plan, nor a regional drainage master plan for the site. The site is located on a relatively flat, undeveloped piece of land with no existing structures. Overhead utility lines and power poles are situated along the eastern side of the property. There are no existing buried utilities on the site; however, buried pipelines will be installed as part of the proposed improvements for the property. Weideman Compressor Station 5 April 14, 2014 Flatirons, Inc. -- Surveying & Engineering Hydrological Criteria This drainage report was prepared using the 10-year event for the minor storm in accordance with Section 7. 1 of the Weld County Storm Drainage Criteria Addendum to the Urban Storm Drainage Criteria Manuals, Volumes 1 , 2 and 3 ; and the 100-year event for the major storm. The design rainfall was obtained from NOAA's Precipitation Frequency Data Server website. The values are based on National Oceanic and Atmospheric Administration (NOAA) Atlas 14, Volume 8, Version. The latitude and longitude of the site, 40.2833° North and 104.8011° West, was used to obtain the point frequency rainfall for the project. The minor storm (10-year) precipitation depths are 1 .39 inches for the 1 -hour event, 2.01 inches for the 6-hour event, and 2.75 inches for the 24-hour event. The major storm (100- year) precipitation depths are 2.73 inches for the 1 -hour event, 3 .94 inches for the 6-hour event, and 4.75 inches for the 24-hour event. The Rational Method as outlined in the USDCM, Volumes 1 and 2 was used for calculating peak runoffs for the drainage report. Proprietary spreadsheets developed by Flatirons, Inc. based on the formulas developed in the USDCM were used for runoff calculations and to calculate the Water Quality Capture Volume (WQCV). Copies of the spreadsheets can be found in Appendix A and Appendix B. The Detention Basin Volume Estimating Workbook spreadsheet, version 2.32, distributed by the Urban Drainage and Flood Control District (UDFCD) was used to calculate stage- storage volume for the water quality pond. Hydrological calculations for this report are based on UDFCD spreadsheets that are available to the public. Proprietary spreadsheets from Flatirons Inc. based on formulas developed for the Rational Method by UDFCD were also used. Hydraulic Criteria The drainage facilities that will be used to convey and treat storm water runoff on the site are based on parameters developed in the USDCM and WCSDC literature. There are no inlets or storm sewers on the site. Runoff is conveyed on the surface of the proposed site, except where a culvert is required under the project entry. No check or drop structures are included as part of the drainage facilities for the site. Open channels are designed to carry the 100-year flows with at least a 0.5-foot freeboard. The side slopes of the channels are 4 to 1 , and the channels are considered to be riprap lined excavated channels that are straight, uniform and clean. The Manning's "n" value for such a channel is 0.025 for capacity checks and 0.018 for stability checks. The Hydraflow Express Extension for AutoCAD Civil 3D 2013 was used for open channel calculations. Minimum culvert capacity is based on the developed 100-year storm, and the maximum headwater to diameter ratio (HW/D) is 1 .0 for the 10-year storm and 1 .5 for the 100-year Weideman Compressor Station 6 April 14, 2014 Flatirons, Inc. — Surveying & Engineering storm. Both reinforced concrete and corrugated metal pipe were considered, but CMP was ultimately chosen. The Manning's "n" value for CMP is 0.025 . No flared end sections are proposed for the culvert. The Hydraflow Express Extension for AutoCAD Civil 3D 2013 was used for culvert calculations. The applicant is proposing to construct a linear shaped water quality pond located at the northwest corner of the property in lieu of a detention pond. Storage in the water quality pond will be comprised of the volume of the open channels that surround the property. Runoff from the site will be conveyed to the water quality pond and released to the same cultivated field to which it has historically flowed. The subject site is surrounded by agricultural fields and runoff generated from the site will be directed to the farm fields. The area of the farm fields to the northwest of the compressor station is approximately 160 acres, and the proposed development site contains less than 4 acres. Assuming the compressor station is part of the 160 acres of farm field, and the development is 45% impervious. The imperviousness of the farm field will increase by less than 1 .5% due to the development of the site. The water quality pond will provide the required Water Quality Capture Volume (WQCV). All water in the water quality pond including the WQCV below the elevation of 4761 .50 will be allowed to infiltrate. The pond will empty based on location specific infiltration rates given in the Geotechnical Engineering Study prepared by HP Geotech, dated April 11 , 2014. An additional one-foot of freeboard is included in the pond above the elevation of the level spreader. All hydraulic calculations for this report are based on spreadsheets, and methods that are available to the public. The calculations and results can be found in the appendix. 4 . O DRAINAGE FACILITY DESIGN General Concept The drainage patterns of the existing onsite basin will not be significantly altered by the site improvements. Historically, the property of the Weideman Compressor Station has been irrigated agricultural land that was cultivated as recently as the 2013 growing season. The proposed drainage concept for the Weideman Compressor Station is to replicate historic drainage patterns. Onsite flows will be directed to the water quality pond at the northwest corner of the project which is the natural low spot of the site. From the water quality pond, runoff will be allowed to sheet flow over a level spreader and into the surrounding farm fields. The existing drainage basin is designated Basin Xl , and it contains the total developed site. The area of Basin X1 is 3 .57 acres, and the 10-year and 100-year peak flows are 1 .0 cfs and 4.4 cfs respectively. Drawing DR- 1 , found in the back of this report, shows the drainage patterns and tabulates the drainage calculations for historic conditions. • The developed site is divided into two drainage basins, designated Basin A and Basin B. Each basin is approximately 1 .5 acres in size, and both basins drain to the 2-feet deep swale Weideman Compressor Station 7 April 14, 2014 Flatirons, Inc. — Surveying & Engineering that surrounds the onsite pad. The peak 10-year flows for Basins A and B are 2.0 cfs and 1 .8 cfs, respectively. The peak 100-year flows are 5.2 cfs for Basin A and 4.9 cfs for Basin B. Surface runoff will be allowed to sheet flow from the middle of the property toward the open channels that surround the property. The open channels are 2-feet deep with 4 to 1 side slopes. The high point of the open channels is near the midpoint of the eastern side of the property. The open channels are designated Channel 1 and Channel 2. Channel 1 runs along the north property line, and Channel 2 runs along the south project boundary. From the high point, the open channels flow to the north and south along the eastern edge of the property. The open channels then continue to the west along the north and south property boundaries of the site. Upon reaching the western edge of site, the north channel (Channel 1 ) enters the northern side of the water quality pond located at the northwest corner of the property. The southerly channel (Channel 2) flows to the north and directs flows to an 18- inch CMP culvert under the entry road. The culvert is designated Culver 1 and it conveys the water in the swale into the south end of the water quality pond. The water quality pond will only treat onsite generated flows. Three small developed basins, designated C 1 , C2, and C3, are situated around the periphery of Basins A and B. Basins Cl , C2, and C3 are located on the outside slope of the 2-foot berm that surrounds the site, and contain 0.32 acres, 0. 10 acres, and 0. 16 acres, respectively. The peak 10-year flows for Basins Cl , C2, and C3 are 0.2 cfs, 0. 1 cfs, and 0. 1 cfs. The peak 100-year flows for the basins are 0.8 cfs, 0.4 cfs, and 0.4 cfs. Runoff from the basins will be allowed to sheet flow off the berms and flow toward the northwest following natural drainage patterns. Basin Al is a sub-basin of Basin A and was defined to estimate the peak flows that are conveyed by the northerly swale that surrounds the onsite pad. The area of Basin Al is 1 . 14 acres and the peak 10-year and 100-year flows are 1 .5 cfs and 3.9 cfs, respectively. Drawing DR-2, located in the back of this report, shows the drainage patterns, site improvements, and tabulates the drainage calculations for developed conditions. Basin Summary Basin Area (ac.) Impervious % Tc (min.) Qio (cfs) Qioo (cfs) X1 3.57 2 45 .5 1 .0 4.4 A 1 .52 44 12.7 2.0 5 .2 Al 1 . 14 44 12.7 1 .5 3 .9 B 1 .47 40 12.7 1 .8 4.9 CI 0.32 2 13 .2 0.2 0.8 C2 0. 10 29 5.2 0. 1 0.4 C3 0. 16 2 12.7 0. 1 0.4 Table 1 Weideman Compressor Station 8 April 14, 2014 Flatirons, Inc. — Surveying & Engineering No offsite runoff is conveyed across the site. The runoff that approaches the site is prevented from entering the site by a 2-foot high berm that will be built on the periphery of the developed site. The berm is set a minimum of 8 feet outside of the open channels that surrounds the onsite pad. The top of berm is elevated at least 2-feet above the flowline of the swale around the onsite pad and has side slopes set at 4 to 1 . The berm does not exist at the entry road, but the high point of the entry road is set at an elevation that is equal to the surrounding berm. The proposed hydraulic structures for the developed site includes open channels (Channels 1 and 2) that surround the property, an 18" CMP culvert (Culvert 1) to convey flows under the entry road, and a level spreader that will release the flows from the developed site. Open Channel Summary Description Ditch Design Max. Water Max. Depth Peak Q100 Depth** Velocity*** Freeboard (ft) (cfs) (ft) (fps) (ft) Channel 1 2.0 3.9 0.67 2.8 1 .3 Channel 2 2.0 4.9 0.79 2.5 1 .2 Table 2 ** Based on design channel with a manning's n of 0.025 and the minimum channel slope. ***Based on design channel with a manning's n of 0.018 and maximum channel slope Culvert Summary Description Culvert Design Max. Water Max. Diameter Peak Q100 Depth Velocity Slope (in) (cfs) (in) (fps) (%) Culvert 1 18 4.9 12.9 3.61 1 .00 Table 3 Specific Details All drainage improvements for the expansion property are in compliance with the Weld County Storm Drainage Criteria Addendum and the Urban Storm Drainage Criteria Manuals, Volumes 1, 2, and 3. No drainage problems were encountered during the design of the expansion property improvements. Weideman Compressor Station 9 April 14, 2014 Flatirons, Inc. — Surveying & Engineering Five natural gas compressors and associated infrastructure will be constructed on the site. The compressors and associated infrastructure are assigned an imperviousness of 90. The site will be leveled and surfaced with a crushed recycled concrete product which is assigned an imperviousness of 40. Undeveloped portions of the site will be assigned an imperviousness of 2. The weighted average of the imperviousness was used to assign runoff coefficients for each delineated basin that contained more than one type of imperviousness. The calculations for the weighted averages can be found in Appendix B. Detention is not proposed for the site. The site is surrounded by agricultural fields that are irrigated with center pivots. The farm fields create a buffer that extends nearly one-half mile in all directions around the site. Runoff from the site will flow northwesterly into an irrigated farm field where it will infiltrate. A water quality pond will be constructed at the northwest corner of the site in lieu of a detention pond. The water quality pond will treat the runoff from the developed site before releasing it over a level spreader and into the farm fields to the west of the property. Water in the pond below the elevation of 4761 .50 will be allowed to infiltrate. Calculations indicate the required detention volume for the 10-year storm is 5067 cubic feet, which is less than the volume of the water quality pond. The maximum depth of water in the water quality pond is 2.21 feet, and based on the geotechnical report, the water quality pond will be constructed in loose silty sand. The water quality pond contains 5809 cubic feet, and the required WQCV is 2642 cubic feet. The infiltration rate of the soil at the southwest corner of the property, which is near the pond, is 60 minutes per inch or 1 -inch per hour based on the geotechnical report. Based on the recommended infiltration rate, it will 26.5 hours for the full pond to infiltrate. Calculations indicate the required detention volume for the 10-year event is 5067 cubic feet, and the required detention volume for 100-year event is 9085 cubic feet. Water Quality Pond Stage Storage Table Elevation Area at Elevation Volume Below Stage Comments (sf) (cf) 4759.79 0 0 Bottom of Pond 4760.00 229 24 4760.50 927 313 4761 .00 2166 1086 4761 .50 4266 2694 WQCV Elev = 4761 .50 4762.00 8192 5 809 Level Spreader = 4762.00 9762.50 14,621 11 ,512 Table 4 Access to the drainage facilities will be easily accessible from the onsite pad. There are no anticipated issues accessing the drainage facilities for maintenance purposes. The water quality pond, open channels, berms and culvert are adjacent to the onsite pad. Maintenance Weideman Compressor Station 10 April 14, 2014 Flatirons, Inc. — Surveying & Engineering will include keeping culverts, swales, and pond free of accumulated sediment, obstructions, and debris, keeping berms and embankments erosion free, and inspecting the yard for uncontrolled spills. All onsite drainage facilities will be private, and the plant operator will be responsible for the maintenance of onsite drainage facilities. The plant operator will inspect offsite drainage patterns and flows to make sure unforeseen offsite drainage issues don't have an adverse impact on plant operations. Inspections will take place at least every six months or following major precipitation events. Copies of the inspections shall be kept on file at the site and made available upon request to those authorized to review the inspections reports. An inspection log can be found in Appendix E. 5 . O CONCLUSIONS The Final Drainage Report has been prepared in compliance with the criteria set forth by Urban Storm Drainage Criteria Manuals (USDCM), Volumes 1 , 2 and 3, and the Weld County Storm Drainage Criteria Addendum to the Urban Storm Drainage Criteria Manuals, Volumes 1 , 2 and 3 dated October 2006. It is intended to be submitted as part of, and in support of a Weld County Use by Special Review Permit application for AKA Energy Group, LLC of Platteville, CO for the Weideman Compressor Station. This proposed development is located in the middle of farm fields and will not have any negative impacts on the upstream or downstream properties, or adversely affect adjoining property owners. The site is surrounded by agricultural land, and there are no structures that could be damaged by surface runoff immediately downstream from the property. Weideman Compressor Station 11 April 14, 2014 Flatirons, Inc. — Surveying & Engineering REFERENCES - Weld County Strom Drainage Criteria Addendum to the Urban Storm Drainage Criteria Manuals Volumes 1 , 2, and 3 October 2006 Weld County Public Works Department. - Urban Storm Drainage Criteria Manual Volumes 1 and 2 June 2001 ; Revised April 2008 Urban Drainage and Flood Control District - Urban Storm Drainage Criteria Manual Volume 3 - Best Management Practices November 2010 Urban Drainage and Flood Control District - FEMA Flood Insurance Rate Map September 28, 1982 Community Panel No. 080266-0750 C - USDA Natural Resources Conservation Service National Cooperative Soil Survey http://websoilsurvey.nrcs.usda.gov/app/ - NOAA National Weather Service Precipitation Frequency Data Server Hsdc.nws.noaa.gov/hdsc/pfds - Hepworth-Pawlak Geotechnical, Inc. Geotechnical Engineering Study Proposed Addition to the Weideman Compressor Station Located Approximately on 'A Mile South and '/2 Mile East of intersection of County Road 27 and County Road 42, Weld County, Colorado, April 11 , 2014. Weideman Compressor Station 12 April 14, 2014 Flatirons, Inc. — Surveying & Engineering APPENDIX A Hydrology Computations ➢ Land Use Assumptions o NOAA Rainfall intensity maps o NRCS soils maps and descriptions ➢ Historic Runoff o Runoff Coefficient vs. Watershed Impervious Tables o Runoff coefficients determination o Time of Concentration calculations (Tc) o Peak Q calculations ➢ Developed Runoff o Runoff Coefficient vs. Watershed Impervious Tables o Runoff coefficients determination o Time of Concentration calculations (Tc) o Peak Q calculations o Design point calculations Weideman Compressor Station A April 14, 2014 Precipitation Frequency Data Server http://hdsc.nws.noaa.gov/hdsc/pfds/pfds jrintpage.html?Iat=40.2833&lo... NOAA Atlas 14, Volume 8, Version 2 `\ Location name: Platteville, Colorado, US* t ro.4 Latitude: 40.2833°, Longitude: -104.8011° A di Elevation: 4762 ft* sk*4Thrn Is * source: Google Maps %.,9 POINT PRECIPITATION FREQUENCY ESTIMATES Sanja Perica, Deborah Martin, Sandra Paviovic, Ishani Roy, Michael St Laurent, Carl Trypaluk, Dale Unruh, Michael Yekta, Geoffery Bonnin NOAA National Weather Service, Silver Spring, Maryland PF tabular I pF graphical I Maps & aerials PF tabular PDS-based point precipitation frequency estimates with 90% confidence intervals (in inches)1 _ Average recurrence interval (years) Duration' 1 2 I 5 I 10 25 50 100 200 500 It 1000 0.238 0.288 ' 0.386 I 0.481 0.635 0.772 0.924 1.09 1.34 1.55 5-min (0.190-0.301) (0.229-0.364) (0.306-0.489), (0.379-0.613) (0.492-0.871) (0.578-1.07) (0.664-1.31)i (0.750-1.59) (0.861-2.01). (0.980-2.33) 0.349 0.422 0.564 0.705 0.930 1.13 1.35 1.60 1.97 2.27 10-min I (0.278-0.441) (0.336-0.533) (0.448-0.716) (0.555-0.898) (0.721-1.27) , (0.846-1.56) (0.973-1.92) (1.10-2.33) (1.29-2.95) (1.44-3.41) 0.426 0.515 I 0.688 0.859 1.14 1.38 1.65 1.95 2.40 2.77 15-min (0.339-0.538) (0.410-0.650), (0.546-0.873), (0.677-1.09) (0.879-1.55) (1.03-1.90) (1.19-2.34) (1.34-2.85) (1.57-160) (1.75-4.16) 30-min 0.571 0.688 ' 0.918 I 1.15 1.51 1.84 2.21 2.62 3.22 3.72 (0.455-0.721) (0.547-0.869), (0.728-1.16) , (0.903-1.46) (1.17-2.08) (1.38-2.54) (1.59-3.13) (1.80-3.82) (2.11-4.83) (2.35-5.60) 0.706 0.839 ' 1.11 1.39 1.85 2.26 2,73 3.26 4.04 4.70 60-min (0.563-0.892) (0.668-1.06) I (0.881-1.41) 1 (1.09-1.77) (1.44-2.55) (1.70-3.14) (1.97-3.89) (2.24-4.77) (2.66-6.08) , (2.97-7.08) 2-hr 0.842 0.991 I 1.30 i 1.63 2.18 2.69 3.26 3.90 4.87 5.68 (0.676-1.05) (0.795-1.24) (1.04-1.64) (1.30-2.06) (1.72-2.99) (2.04-3.69) (2.37=4.59) (2.71-5.66) (3.24-7.24) (3.63-8.45) 3-hr 0.921 1.07 1.40 1.75 2.35 2.90 3.52 4.24 5.30 6.20 (0.744-1.15) (0.866-1,34) : (1.13-1.75) (1.40-2.20) (1.86-3.20) (2.21-3.96) (2.58-4.94) (2.96-6.10) (3.55-7.84) (3.99-9.15) 6-hr 1,08 1.25 1.62 2.01 2.66 3.26 3.94 4.71 5.86 6.83 (0.879-1.33) (1.02-1.54) (1.32-2.00) (1.62-2.50) (2.13-3.58) (2.51-4.40) (2.92-5.45) (3.33-6.70) (3.96-8.55) (4.44-9.96) 12-hr 1.27 ' 1.50 ' 1.94 4 2.37 3.06 3.66 4.33 5.07 6.15 I 7.04 (1.04-1.54) (1.23-1.83) I (1.59-2.37) (1.93-2.91) (2.44-4.01) (2.83-4.84) (3.22-5.86) (3.60-7.06) (4.19-8.81) I (4.63-10.1) 1.51 1.78 2.28 2.75 3.46 4.08 4.75 5.49 6.55 7.42 24-hr (1.25-1.82) (1.48-2.15) (1.88-2.76) I (2.25-3.34) (2.78-4.46) (3.18-5.30) (3.56-6.34) (3.93-7.53) (4.50-9.23) (4.93-10.5) 2-day 1.74 2.07 2.65 1 3.17 3.93 4.56 5.23 5.94 6.94 7.74 (1.45-2.07) (1.73-2.47) (2.20-3.17) (2.62-3.81) (3.16-4.95) (3.57-5.82) (3.94-6.84) (4.29-8.00) (4.81-9.62) (5.20-10.8) 3-day 1.90 2.23 2.82 3.35 4.12 4.75 5.43 6.15 7.16 7.97 (1.59-2.25) (1.88-2.65) (2,36-3.36) (2.78-4.00) (3.33-5.15) (3.74-6.02) (4.12-7.05) (4.47-8.22) (4.99-9.84) (5.39-11.1) 4-day 2.02 2.36 I 2.96 3.49 4.27 4.91 5.59 6.31 7.33 8.14 (1.71-2.39) (1.99-2.79) ( (2.48-3.50) (2.91-4.15) (3.46-5.31) (3.88-6.18) (4.26-7.22) (4.60-8.39) (5.13-10.0) (5.53-11.2) 2.31 I 2.69 3.35 3.92 4.73 5.39 6.06 6.78 7.75 8.52 7-day (1.96-2.70) (2.29-3.16) (2.83-3.94) (3.29-4.62) (3.85-5.80) (4.28-6.70) (4.65-7.73) (4.97-8.88) (5.47-10.5) (5.84-11.6) 10-day 1----I 2.55 2.98 3.69 4.29 5.14 5.80 6.48 7.18 8.13 8.86 j (2.18-2.97) (2.54-3.47) (3.14-4.31) (3.63-5.04) (4.20-6.24) (4.63-7.15) (4.99-8.19) (5.29-9.33) (5.76-10.9) (6.11-12.0) 3.25 3.76 4.58 5.25 6.18 6.89 7.59 8.31 9.24 9.95 20-day (2.80-3.75) (3.23-4.33) 1 (3.92-5.29) (4.48-6.10) (5.08-7.38) (5.54-8.35) (5.89-9.44) (6.18-10.6) (6.61-12.2) (6.94-13.3) n30-day 3.81 4.38 5.29 6.04 7.05 7.82 8.57 9.32 10.3 11.0 (3.30-4.36) (3.79-5.02) (4.57-6.08) (5.18-6.97) (5.83-8.35) (6.31-9.40) (6.69-10.6) (6.97-11.8) (7.40-13.4) (7.73-14.6) 45-day 4.48 5.15 6.21 7.07 8.22 9.07 9.90 10.7 11.8 12.5 (3.90-5.10) (4.48-5.86) (5.39-7.09) (6.10-8.10) (6.82-9.65) (7.37-10.8) (7.77-12.1) (8.06-13.4) (8.51-15.2) (8.84-16.5) 60-day 5.02 5.79 7.01 I 7.98 9.27 10.2 11.1 12.0 13.1 13.9 (4.39-5.68) (5.06-6.56) (6.10-7.96) (6.91-9.11) (7.71-10.8) (8.32-12.1) (8.75-13.5) (9.06-15.0) (9.52-16.8) , (9.86-18.2) 1 Precipitation frequency (PF) estimates in this table are based on frequency analysis of partial duration series (PDS). Numbers in parenthesis are PF estimates at lower and upper bounds of the 90% confidence interval. The probability that precipitation frequency estimates (for a given duration and average recurrence interval) will be greater than the upper bound (or less than the lower bound) is 5%. Estimates at upper bounds are not checked against probable maximum precipitation (PMP) estimates and may be higher than currently valid PMP values. Please refer to NOAA Atlas 14 document for more information. Back to Top PF graphical 1 of4 3/31/2014 12:02 PM Precipitation Frequency Data Server http://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=40.2833&l0... PDS-based depth-duration-frequency (DDF) curves Latitude: 40.2833°, Longitude: -104.8011° 14 r 1 ► 1 r r--11 r r r r r t 1 1 - • : • 12 • Average recurrence interval (years) / •. la - y :• — 1 i 2 CL 8 - t t • iI.- ' 5 ` _• 10 ,- - • • o ./ a - • _ — 6 25 a • — 50 U /'` --- 100 a, 4 • : . ---1200 • 500 • 1000 •%E E E E E r . L ti ro ro ro (IN ti r°o y 4 p p p p LA C 111 A N tb - Al No N M LAID Duration 14 r 1 1 t 1 I T 1 12 • r^ , E 10 - Duration a a 8 • . • 5-min _ 2-day — __ c 10-min 3-day 15-min 4-day 4.0 11,1 6 - . . ,. �- -- - 30-min 7-day V' • _ — 60-min — 10-day 4 , r — 2-hr — 20-day y_ - - 3-hr — 30-day 2 .c ,-1._-r:. . _ --- • • ` — 64u — 45-day -- . - -- _ -T- — — 12-hr — 60-day __ t —_ i i t i r 24-hr 01 2 5 10 25 50 100 200 500 1000 Average recurrence interval (years) NOAA Atlas 14, Volume 8, Version 2 Created (GMT): Mon Mar 31 18:00:57 2014 Back to Top Maps & aerials Small scale terrain `., a- ua.vuu,ouu . Rawlins ° Tom_ y * • tl `> :' �*-::ors,, , •• ,'N1atamie „� i c/e . t St L .: % '.:: ......c.;;;-- Sidney -`_"Ch eye n _ e_ _ �' :- Cit'� "'} ' ' #1,-,:14;.: t• :Ni sled --� a. 1x. 1 v. Greeley;,,;• e !4. 'r Icier ' , � 1(� ►i t. 1 <<Ii .cw '. ,P I` '' 50km 8 eagle � ' Pas l� a of 4 3/31/2014 12:02 PM Precipitation Frequency Data Server http://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=40.2833&lo... Large scale terrain T3 r` E I cif i E Q 256 85 1,I -,:ringlie i : a 35 , SOUW un�rr 0 85 T3 CI a 75 31l El II , ( rd L 2 k1n Pas 4440420h4a$eagle Large scale map Cl `R6 TI T3 *ti c It lii] ? O 3 85 O'° N !w• \ ` Iii`'S. l� de 0 N 1 SiJ S �w.w v ' nlicra :! 77 ,r L) es El 27 T> A S i' 25 n 3) ( C , * til'• " G • i • El 2'krit PQsfri iQ143PQogie Large scale aerial z . - - DIVE- PP I ; ' iii I 0 lalb • L . tip itOPY, .1 I . Mi �1 t .N. E. 0 mr P 4 1 • . qt t • • t C ,Ot1S1 on ti -�.sail .t! 2 _-- all Imagery O ;ibrTar strips 3 of 4 3/31/2014 12:02 PM USDA United States A product of the National Custom Soil Resource a Department of Cooperative Soil Survey, Agriculture a joint effort of the United Report for 4 States Department ofNRCS Agriculture and other Weld County, Federal agencies, State Natural agencies including the Colorado, Resources Agricultural Experiment Conservation Stations, and local Service participants Southern Part / ' _ .'- 7 . / / / -,/ ,,,.. , A �, . /714 /1, : /kg .. '-' 27:4• --W • , o -,; • Air% ‹ ' - - . dt .. • ,.- . I ' * iter r :-.16,11:-.1.:qp, t-i. • a �. _ _ _ r, i-PAH ; 1 21 0 walIMIIIII 8.000 (1] I March 26, 2014 Preface Soil surveys contain information that affects land use planning in survey areas. They highlight soil limitations that affect various land uses and provide Information about the properties of the soils in the survey areas. Soil surveys are designed for many different users, including farmers, ranchers, foresters, agronomists, urban planners, community officials, engineers, developers, builders, and home buyers. Also, conservationists, teachers, students, and specialists in recreation, waste disposal, and pollution control can use the surveys to help them understand, protect, or enhance the environment. Various land use regulations of Federal, State, and local governments may impose special restrictions on land use or land treatment. Soil surveys identify soil properties that are used in making various land use or land treatment decisions. The information is intended to help the land users identify and reduce the effects of soil limitations on various land uses. The landowner or user is responsible for identifying and complying with existing laws and regulations. Although soil survey information can be used for general farm, local, and wider area planning, onsite Investigation is needed to supplement this information in some cases. Examples include soil quality assessments (http://www.nres.usda.gov/wps/portal/ nrcs/main/soils/health/) and certain conservation and engineering applications. For more detailed information, contact your local USDA Service Center (http:// offices.sc.egov.usda.gov/locator/app?agency=nres) or your NRCS State Soil Scientist (http://www.nres.usda.gov/wps/portal/nres/detail/soils/contactus/? cid=nrcs142p2_053951). Great differences In soil properties can occur within short distances. Some soils are seasonally wet or subject to flooding. Some are too unstable to be used as a foundation for buildings or roads. Clayey or wet soils are poorly suited to use as septic tank absorption fields. A high water table makes a soil poorly suited to basements or underground installations. The National Cooperative Soil Survey is a joint effort of the United States Department of Agriculture and other Federal agencies, State agencies including the Agricultural Experiment Stations, and local agencies. The Natural Resources Conservation Service (NRCS) has leadership for the Federal part of the National Cooperative Soil Survey. Information about soils is updated periodically. Updated information is available through the NRCS Web Soil Survey, the site for official soil survey information. The U.S. Department of Agriculture (USDA)prohibits discrimination in all its programs and activities on the basis of race, color, national origin, age, disability, and where applicable, sex, marital status, familial status, parental status, religion, sexual orientation, genetic information, political beliefs, reprisal, or because all or a part of an individual's income is derived from any public assistance program. (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means 2 for communication of program information (Braille, large print, audiotape, etc.) should contact USDA's TARGET Center at (202) 720-2600 (voice and TDD). To file a complaint of discrimination, write to USDA, Director, Office of Civil Rights, 1400 Independence Avenue, S.W., Washington, D.C. 20250-9410 or call (800) 795-3272 (voice) or (202) 720-6382 (TDD). USDA is an equal opportunity provider and employer. 3 Contents Preface 2 Soil Map 5 Soil Map 6 Legend 7 Map Unit Legend 8 Map Unit Descriptions 8 Weld County, Colorado, Southern Part 10 11—MLRA 67B - Bresser sandy loam, 0 to 3 percent slopes 10 29—Julesburg sandy loam, 0 to 1 percent slopes 11 30--lulesburg sandy loam, 1 to 3 percent slopes 12 References 14 4 Soil Map The soil map section includes the soil map for the defined area of interest, a list of soil map units on the map and extent of each map unit, and cartographic symbols displayed on the map. Also presented are various metadata about data used to produce the map, and a description of each soil map unit. 5 Custom Soil Resource Report o Soil Map - S 3 b $16,60 5113300N0 311100 511400 310600 514707 11► 115900 517060 517100 311500 517300 317410 517100 117640 117100 }I114 o 40017'13'N $ m 400 IT}rN i v j Ji1. l a. \ I i i i f r Ill • r 1 I :1 3 i--- 8• 1 • • .t 8 II • ,fit trtik M . ,. .4 . 4.9r 0 o ` FF I .ft �f + . ^ z. •y , '• f w - ' l� 1'7' + •Y- - �, �,, " _ o (4 ' . ..r . . .. • .,r. 1 I 1 CA vr CO 7 0 F I / !r 40016 art: - - 40016VTN 310:00 516300 516400 516500 516600 516700 516S0O 516900 317000 517100 517200 517300 517400 117!00 317400 511100 117000 a t. b lviap Scale: 1:7,660 if printed on Alandscupc(11"x 8 5,sheet • _ 0 3.kten g N 0 100 200 4OO 600 3 Aeet 0 350 700 1400 211x1 t.hp prr eelnn: VfehAkmatnr CoCorneroantdv secs: WOS84 i'Egc tin:U1MZ6nc I3NWCS84 6 Custom Soil Resource Report MAP LEGEND MAP INFORMATION Area of Interest(Aot) Ili Spoil Area The soil surveys that comprise your AOI were mapped at 1:24,000. J Area of Interest(A01) 6 Stony Spot Soils Warning:Soil Map may not be valid at this scale. as Very Stony Spot Q Soil Map Unit Polygons 0 Wet Spot Enlargement of maps beyond the scale of mapping can cause w Soil Map Unit Lines misunderstanding of the detail of mapping and accuracy of soil line a Other placement.The maps do not show the small areas of contrasting Soil Map Unit Points P .. Special Line Features soils that could have been shown at a more detailed scale. Special Point Features Blowout Water Features w ,ti. Streams and Canals Please rely on the bar scale on each map sheet for map Iia Borrow Pit measurements. Transportation is Gay Spot N4 Rails Source of Map: Natural Resources Conservation Service 0 Closed Depression rt Interstate Highways Web Soil Survey URL: http://websoilsurvey.nrcs.usda.gov X Gravel Pit Coordinate System: Web Mercator(EPSG:3857) „ s US Routes ,,, Gravelly Spot Major Roads Maps from the Web Soil Survey are based on the Web Mercator O Landfill Local Roads projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the A Lava Flow Background Albers equal-area conic projection,should be used If more accurate o Marsh or swamp . Aerial Photography calculations of distance or area are required. IRi Mine or Quarry This product is generated from the USDA-NRCS certified data as of O Miscellaneous Water the version date(s) listed below. O Perennial Water Soil Survey Area: Weld County, Colorado, Southern Part v Rock Outcrop Survey Area Data: Version 12, Jan 3, 2014 .4. Saline Spot Soil map units are labeled(as space allows)for map scales 1:50,000 •.• Sandy Spot or larger. a Severely Eroded Spot Date(s)aerial images were photographed: Apr 22,2011—Apr 13, to Sinkhole 2012 Slide or Slip The orthophoto or other base map on which the soil lines were st Sodic Spot compiled and digitized probably differs from the background imagery displayed on these maps.As a result, some minor shifting of map unit boundaries may be-evident. 7 Custom Soil Resource Report Map Unit Legend Weld County, Colorado, Southern Part(CO618) Map Unit Symbol Map Unit Name Acres In AOI Percent of A01 11 MLRA 67B -Bresser sandy 8.3 2.8% loam, 0 to 3 percent slopes 29 Julesburg sandy loam,0 to 1 215.8 72.4% percent slopes 30 Julesburg sandy loam, 1 to 3 74.2 24.9% percent slopes Totals for Area of Interest 298.2 100.0% Map Unit Descriptions The map units delineated on the detailed soil maps in a soil survey represent the soils or miscellaneous areas in the survey area. The map unit descriptions, along with the maps, can be used to determine the composition and properties of a unit. A map unit delineation on a soil map represents an area dominated by one or more major kinds of soil or miscellaneous areas. A map unit is identified and named according to the taxonomic classification of the dominant soils. Within a taxonomic class there are precisely defined limits for the properties of the soils. On the landscape, however, the soils are natural phenomena, and they have the characteristic variability of all natural phenomena. Thus, the range of some observed properties may extend beyond the limits defined for a taxonomic class. Areas of soils of a single taxonomic class rarely, if ever, can be mapped without including areas of other taxonomic classes. Consequently, every map unit is made up of the soils or miscellaneous areas for which it is named and some minor components that belong to taxonomic classes other than those of the major soils. Most minor soils have properties similar to those of the dominant soil or soils in the map unit, and thus they do not affect use and management. These are called noncontrasting, or similar, components. They may or may not be mentioned in a particular map unit description. Other minor components, however, have properties and behavioral characteristics divergent enough to affect use or to require different management.These are called contrasting, or dissimilar, components. They generally are in small areas and could not be mapped separately because of the scale used. Some small areas of strongly contrasting soils or miscellaneous areas are identified by a special symbol on the maps. If included in the database for a given area, the contrasting minor components are identified in the map unit descriptions along with some characteristics of each. A few areas of minor components may not have been observed, and consequently they are not mentioned in the descriptions, especially where the pattern was so complex that it was Impractical to make enough observations to Identify all the soils and miscellaneous areas on the landscape. The presence of minor components in a map unit in no way diminishes the usefulness or accuracy of the data. The objective of mapping is not to delineate pure taxonomic classes but rather to separate the landscape into landforms or landform segments that have similar use and management requirements. The delineation of such segments 8 Custom Soil Resource Report on the map provides sufficient information for the development of resource plans. If intensive use of small areas is planned, however, onsite investigation is needed to define and locate the soils and miscellaneous areas. An identifying symbol precedes the map unit name in the map unit descriptions. Each description includes general facts about the unit and gives important soil properties and qualities. Soils that have profiles that are almost alike make up a soil series. Except for differences in texture of the surface layer, all the soils of a series have major horizons that are similar in composition, thickness, and arrangement. Soils of one series can differ in texture of the surface layer, slope, stoniness, salinity, degree of erosion, and other characteristics that affect their use. On the basis of such differences, a soil series is divided into soil phases. Most of the areas shown on the detailed soil maps are phases of soil series. The name of a soil phase commonly indicates a feature that affects use or management. For example, Alpha silt loam, 0 to 2 percent slopes, is a phase of the Alpha series. Some map units are made up of two or more major soils or miscellaneous areas. These map units are complexes, associations, or undifferentiated groups. A complex consists of two or more soils or miscellaneous areas In such an intricate pattern or in such small areas that they cannot be shown separately on the maps. The pattern and proportion of the soils or miscellaneous areas are somewhat similar In all areas. Alpha-Beta complex, 0 to 6 percent slopes, is an example. An association is made up of two or more geographically associated soils or miscellaneous areas that are shown as one unit on the maps. Because of present or anticipated uses of the map units in the survey area, it was not considered practical or necessary to map the soils or miscellaneous areas separately. The pattern and relative proportion of the soils or miscellaneous areas are somewhat similar. Alpha- Beta association, 0 to 2 percent slopes, is an example. An undifferentiated group is made up of two or more soils or miscellaneous areas that could be mapped individually but are mapped as one unit because similar Interpretations can be made for use and management. The pattern and proportion of the soils or miscellaneous areas in a mapped area are not uniform. An area can be made up of only one of the major soils or miscellaneous areas, or it can be made up of all of them. Alpha and Beta soils, 0 to 2 percent slopes, is an example. Some surveys include miscellaneous areas. Such areas have little or no soil material and support little or no vegetation. Rock outcrop is an example. 9 Custom Soil Resource Report Weld County, Colorado, Southern Part 11—MLRA 678 - Bresser sandy loam, 0 to 3 percent slopes Map Unit Setting Elevation: 4,050 to 6,800 feet Mean annual precipitation: 12 to 18 inches Mean annual air temperature: 45 to 55 degrees F Frost-free period: 135 to 190 days Map Unit Composition Bresser and similar soils: 90 percent Minor components: 10 percent Description of Bresser Setting Landform: Terraces Landform position (three-dimensional): Tread Down-slope shape: Linear Across-slope shape: Linear Parent material: Coarse sandy alluvium derived from igneous, metamorphic and sedimentary rock Properties and qualities Slope: 0 to 3 percent Depth to restrictive feature: More than 80 inches Drainage class: Well drained Capacity of the most limiting layer to transmit water (Ksat): Moderately high to high (0.60 to 2.00 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency ofponding: None Calcium carbonate, maximum content: 10 percent Maximum salinity: Nonsaline (0.0 to 0.1 mmhos/cm) Available water capacity: Low (about 5.8 inches) Interpretive groups Farmland classification: Prime farmland if irrigated and the product of I (soil erodiblllty) x C (climate factor) does not exceed 60 Land capability classification (irrigated): 4e Land capability (nonirrigated): 4c Hydrologic Soil Group: B Ecological site: Sandy Plains (R067BY024CO) Typical profile 0 to 9 inches: Sandy loam 9 to 25 inches: Sandy clay loam 25 to 30 inches: Sandy loam 30 to 79 inches: Loamy sand Minor Components Truckton Percent of map unit: 5 percent Landform: Terraces 10 Custom Soil Resource Report Landform position (three-dimensional): Tread Down-slope shape: Linear Across-slope shape: Linear Ecological site: Sandy Plains (R067BY024CO) Vona Percent ofmap unit: 5 percent Landform: Stream terraces Landform position (three-dimensional): Tread Down-slope shape: Linear Across-slope shape: Linear Ecological site: Sandy Plains (R067BY024CO) 29—Julesburg sandy loam, 0 to 1 percent slopes Map Unit Setting Elevation: 4,700 to 4,800 feet Mean annual precipitation: 15 to 19 inches Mean annual air temperature: 48 to 52 degrees F Frost-free period: 145 to 155 days Map Unit Composition Julesburg and similar soils: 85 percent Minor components: 15 percent Description of Julesburg Setting Landform: Terraces Down-slope shape: Linear Across-slope shape: Linear Parent material: South platte river alluvium Properties and qualities Slope: 0 to 1 percent Depth to restrictive feature: More than 80 inches Drainage class: Well drained Capacity of the most limiting layer to transmit water (Ksat): High (2.00 to 6.00 inlhr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency ofponding: None Available water capacity: Moderate (about 6.5 inches) Interpretive groups Farmland classification: Prime farmland if irrigated and the product of I (soil erodibility) x C (climate factor) does not exceed 60 Land capability classification (irrigated): 2s Land capability (nonirrigated): 3e Hydrologic Soil Group: B Ecological site: Sandy Plains (R067BY024CO) 11 Custom Soil Resource Report Typical profile 0 to 12 inches: Sandy loam 12 to 27 inches: Sandy loam 27 to 60 inches: Sand Minor Components Edgar Percent ofmap unit: 4 percent Remmlt Percent ofmap unit: 4 percent Valent Percent ofmap unit: 4 percent Vona Percent ofmap unit: 3 percent 30—Julesburg sandy loam, 9 to 3 percent slopes Map Unit Setting Elevation: 4,700 to 4,800 feet Mean annual precipitation: 15 to 19 inches Mean annual air temperature: 48 to 52 degrees F Frost-free period: 145 to 155 days Map Unit Composition Julesburg and similar soils: 90 percent Minor components: 10 percent Description of Julesburg Setting Landform: Terraces Down-slope shape: Linear Across-slope shape: Linear Parent material: South platte river alluvium Properties and qualities Slope: 1 to 3 percent Depth to restrictive feature: More than 80 inches Drainage class: Well drained Capacity of the most limiting layer to transmit water (Ksat): High (2.00 to 6.00 in/hr) Depth to water table: More than 80 Inches Frequency of flooding: None Frequency ofponding`. None Available water capacity: Moderate (about 6.5 inches) Interpretive groups Farmland classification: Prime farmland if irrigated and the product of I (soil erodibility) x C (climate factor) does not exceed 60 12 Custom Soil Resource Report Land capability classification (irrigated): 2e Land capability (nonirrigated): 3e Hydrologic S oa Group: B Ecological site: Sandy Plains (R067BY024CO) Typical profile 0 to 12 inches: Sandy loam 12 to 27 inches: Sandy loam 27 to 60 inches: Sand Minor Components Remmit Percent ofmap unit: 5 percent Valent Percent ofmap unit: 5 percent • 13 References American Association of State Highway and Transportation Officials(AASHTO). 2004. Standard specifications for transportation materials and methods of sampling and testing. 24th edition. American Society for Testing and Materials (ASTM). 2005. Standard classification of soils for engineering purposes. ASTM Standard D2487-00. Cowardin, L.M., V. Carter, F.C. Golet, and E.T. LaRoe. 1979. Classification of wetlands and deep-water habitats of the United States. U.S. Fish and Wildlife Service FWS/OBS-79/31. Federal Register. July 13, 1994. Changes in hydric soils of the United States. Federal Register. September 18, 2002. Hydric soils of the United States. Hurt, G.W., and L.M.Vasilas, editors.Version 6.0, 2006. Field indicators of hydric soils in the United States. National Research Council. 1995. Wetlands: Characteristics and boundaries. Soil Survey Division Staff. 1993. Soil survey manual. Soil Conservation Service. U.S. Department of Agriculture Handbook 18. http://www.nres.usda.gov/wps/portal/nres/ detaiUnational/soils/?cid=nres142p2_054262 Soil Survey Staff. 1999. Soil taxonomy:A basic system of soil classification for making and Interpreting soil surveys. 2nd edition. Natural Resources Conservation Service, U.S. Department of Agriculture Handbook 436. http://www.nres.usda.gov/wps/portal/ nres/detail/national/soils/?cid=nres142p2 053577 Soil Survey Staff. 2010. Keys to soil taxonomy. 11th edition. U.S. Department of Agriculture, Natural Resources Conservation Service. http://www.nres.usda.gov/wps/ portal/nresldetail/nationallsoils/?cid=nres142p2 053580 Tiner, R.W., Jr. 1985. Wetlands of Delaware. U.S. Fish and Wildlife Service and Delaware Department of Natural Resources and Environmental Control, Wetlands Section. United States Army Corps of Engineers, Environmental Laboratory. 1987. Corps of Engineers wetlands delineation manual. Waterways Experiment Station Technical Report Y-87-1. United States Department of Agriculture, Natural Resources Conservation Service. National forestry manual. http://www.nrcs.usda.gov/wps/portal/nrcs/main/national/ Ianduse/forestry/pub/ United States Department of Agriculture, Natural Resources Conservation Service. National range and pasture handbook. http://www.nrcs.usda.gov/wps/portal/nrcs/ detail/national/landuse/rangepasture/?cid=stelprdb 1043084 14 Custom Soil Resource Report United States Department of Agriculture, Natural Resources Conservation Service. National soil survey handbook, title 430-VI. http://www.nres.usda.gov/wps/portal/ nres/detall/solls/scientists/?cld=nresI42p2 054242 United States Department of Agriculture, Natural Resources Conservation Service. 2006. Land resource regions and major land resource areas of the United States, the Caribbean, and the Pacific Basin. U.S. Department of Agriculture Handbook 296. http://www.nrcs.usda.gov/wps/portal/nrcskletail/nationalkollsfl cid=nres 142p2_053624 United States Department of Agriculture, Soil Conservation Service. 1961. Land capability classification. U.S. Department of Agriculture Handbook 210. http:// www.nrcs.usda.gov/Intemet/FSE_DOCUMENTS/nrcs142p2_052290.pdf 15 DRAINAGE CRITERIA MANUAL (V. 1 ) RUNOFF Table RO-5— Runoff Coefficients, C Percentage Imperviousness Type C and D NRCS Hydrologic Soil Groups 2-yr 5-yr 10-yr 25-yr 50-yr 100-yr 0% 0.04 0.15 0.25 0.37 0.44 0.50 5% 0.08 0.18 0.28 0.39 0.46 0.52 10% 0. 11 0.21 0.30 0.41 0.47 0.53 15% 0. 14 0.24 0.32 0.43 0.49 0.54 20% 0. 17 0.26 0.34 0.44 0.50 0,55 25% 0.20 0.28 0.36 0.46 0.51 0.56 30% 0.22 0.30 0.38 0.47 0.52 0.57 35% 0.25 0.33 0.40 0.48 0.53 0.57 40% 0.28 0.35 0.42 0.50 0.54 0.58 45% 0.31 0.37 0.44 0.51 0.55 0.59 50% 0.34 0.40 0.46 0.53 0.57 0.60 55% 0.37 0.43 0.48 0.55 0.58 0.62 60% 0.41 0.46 0.51 0.57 0.60 0.63 65% 0.45 0.49 0.54 0.59 0.62 0.65 70% 0.49 0.53 0.57 0.62 0.65 0.68 75% 0.54 0.58 0.62 0.66 0.68 0.71 80% 0.60 0.63 0.66 0.70 0.72 0.74 85% 0.66 0.68 0.71 0.75 0.77 0.79 90% 0.73 0.75 0.77 0.80 0.82 0.83 95% 0.80 0.82 0.84 0.87 0.88 0.89 100% 0.89 0.90 0.92 0.94 0.95 0.96 TYPE B NRCS HYDROLOGIC SOILS GROUP 0% 0.02 0.08 0.15 0.25 0.30 0.35 5% 0.04 0.10 0.19 0.28 0.33 0.38 10% 0,06 0.14 0.22 0.31 0.36 0.40 15% 0.08 0.17 0.25 0.33 0.38 0.42 20% 0.12 0.20 0.27 0.35 0.40 0.44 25% 0. 15 0.22 0.30 0.37 0.41 0.46 30% 0. 18 0.25 0.32 0.39 0.43 0.47 35% 0.20 0.27 0.34 0.41 0.44 0.48 40% 0.23 0.30 0.36 0.42 0,46 0.50 45% 0.26 0.32 0.38 0.44 0.48 0.51 50% 0.29 0.35 0,40 0.46 0.49 0.52 55% 0.33 0.38 0.43 0.48 0.51 0.54 60% 0.37 0.41 0.46 0.51 0.54 0.56 65% 0.41 0.45 0.49 0.54 0.57 0.59 70% 0.45 0.49 0.53 0.58 0.60 0.62 75% 0.51 0.54 0.58 0.62 0.64 0.66 80% 0.57 0.59 0.63 0.66 0.68 0.70 85% 0.63 0.66 0.69 0.72 0.73 0.75 90% 0.71 0.73 0.75 0.78 0.80 0.81 95% 0.79 0.81 0.83 0.85 0.87 0.88 100% 0.89 0.90 0.92 0.94 0.95 0.96 2007-01 RO-11 Urban Drainage and Flood Control District u7 cup 0 U N Lt) '- •- t- N , ~ Ew c Co ° 0 r, E c s• •N cea .. a C c Y Y � N a C <� G N I- c W co N '- c (.O c0 "_ 2 ci +± c ttT O U Ln TCS U C C U c p p rY O I-, E. E Ec ro o_ ~ 0 ri Q) `c c cc U Q 1 J ca 03 FN 'C__ O Q b` o % — U "- > w oo o ,F •v v) 0 CD aNi C; a 3 o a E ~ S M > a) U 'as- com > r a co '. o r O ) 3 W ~ O _ coM V D a CO L F- c t z (0 O C r p `' m 0 = W J (r) Y .D a tY 0 (n o C >" U 6 0 607 N N v vs V •) z C) 2 LL RI .0 12 (a O 'aZ OS W N C' O o n o C Ii- II° > a 'C Z to 0 CO a f- E o Cl u. .- 2 to a 4 CD L 6�i CO> nQ a p + _ cn z c9 a w c f` c tL U o a) a O II z c'J > U) o (o o r r� 0 C J o0 V •++ Cu N O o O 6) - C t- O .p c N J >- t"- Q � D a E �. 0 - (Ti3 K ,co U Cr) Q z. ° 0 s C) Q — U a " 6) W �` w (n a C o aco N O rs U ro F- U E N 2 N Z d ~ V) 0 O 6 N o) Y (TiQ N N > a" (`� -0 _ •c CC❑ O = to O i' E, rn C'! et NN o tmC o fr v '— c≥ O n7 U c (6 C N (.n •-1 10to O in o a c p p c OI— " In 7.3 m F- �E i o 0- Coa - c > Q' o 2 a D o 0 H i - Q) W ( - r. •Y to W Q L- C) I II 3 m " Wig(o C o cn cn U U c 7 u� .- U o c >. = iso 0 V C c �� 67 d C p O T1 = a O o 0 (n O cu > N O G — f> 0) '-O U IA C C L�. ter-ft Y ' V) a zaE '(a OD c o c m o - ^ 6) o 0O0 Y .— iZ t v .o a) L .c �i rn c c o tt) ti COO N v! CO CO O r N > M G 0in > �p tG O d (NU to U N U U Q .8 CO Cr) CO V, d' V' 't V d' to to to O N O y d to U d N w L C C C o a0000000000o aNO3 tv a o oo` o o 0 as � � TU o 0 to N CA N tf) N O N cct� (O co O - to C H r CO W NA N t- ..-- CO f0 �' `� co U N w v- r r r- r N N N CO CO M M co V, p N 0 a o v, ('�+ V O' O -", !" O O 6C7 C:) J p 6 0 O O O O O d O 0 0 0 0 0 d u1 N = O u a .v" ,C E ` J u) (t$ > U 3 EE ti o ~ F- c I II II II II II II I I y N co O) O V N O N to N O N to >, Q) UL O 6) N U O O r r r- N N N N CO CO M o M w __ t in S' 3 W .--. It .". { to J W U L .G 0 0 6 0 0 C7 O O 6 O O O r r O N cp C r O w V w as a) ` , I L 2 trt O O N N M r1' go O CO N to CO O CO O 0) .., r E _ C coM N C,' M 0 Cl 0 0 O O O C� O r r r N N N N >. <- F, Q,_ :P () O U O O O O O O O 0 0 6 O O LC) r 6i E CO `a O C C > isi > Q E II O tt) O to O P) O >n O ` F- u' p tv p 1i O C o O N In N N M M V. t} u1 ( o O O o U o U ,C _C O _ _ is. '"' a E E 13 0 o HE idto O ° .C c N C .� so L a2 o c `0ai (p N F- U co o O __7 V cc a) L. I: to ro tT z Q W E 2 Q Q N — O O II C o ...7 c ° N N ° N N N (3 O C (a a a ... 110 J IL' E I E U �' L aQ. 0. -0 a U -0 'O a a a 'O c Q p O O N O 6) 6) N CD N 6) 6) 0 • LL W II II II .5 aaaaaaaaa a 0- Co O U Cc > > O 0 0 0 0 0 0 0 O 0 ... m C O II d N 6) 6) N 6) Q) (U 0 6) 0 0 0 O= C C to N ° ❑ O1 C c 6) N 0 6) N 6) 6) 6) O (3) •.C MI <- (o r• O (0 c/) Cl) D OOOOOOOOOO r co _X m < H LL O DRAINAGE CRITERIA MANUAL (V. 1 ) RUNOFF Table RO-5— Runoff Coefficients, C Percentage Imperviousness Type C and D NRCS Hydrologic Soil Groups 2-yr 5-yr 10-yr 25-yr 50-yr 100-yr 0% 0.04 0.15 0.25 0.37 0.44 0.50 5% 0.08 0.18 0.28 0.39 0.46 0.52 10% 0. 11 0.21 0.30 0.41 0.47 0.53 15% 0. 14 0.24 0.32 0.43 0.49 0.54 20% 0. 17 0.26 0.34 0.44 0.50 0.55 25% 0.20 0.28 0.36 0.46 0.51 0.56 30% 0.22 0.30 0.38 0.47 0.52 0.57 35% 0.25 0.33 0.40 0.48 0.53 0.57 40% 0.28 0.35 0.42 0.50 0.54 0.58 45% 0.31 0.37 0.44 0.51 0.55 0.59 50% 0.34 0.40 0.46 0.53 0.57 0.60 55% 0.37 0.43 0.48 0.55 0.58 0.62 60% 0.41 0.46 0.51 0.57 0.60 0.63 65% 0.45 0.49 0.54 0.59 0.62 0.65 70% 0.49 0.53 0.57 0.62 0.65 0.68 75% 0.54 0.58 0.62 0.66 0.68 0.71 80% 0.60 0.63 0.66 0.70 0.72 0.74 85% 0.66 0.68 0.71 0.75 0.77 0.79 90% 0.73 0.75 0.77 0.80 0.82 0.83 95% 0.80 0.82 0.84 0.87 0.88 0.89 100% 0.89 0.90 0.92 0.94 0.95 0.96 TYPE B NRCS HYDROLOGIC SOILS GROUP 0% 0.02 0.08 0.15 0.25 0.30 0.35 5% 0.04 0.10 0. 19 0.28 0.33 0.38 10% 0.06 0.14 0.22 0.31 0.36 0.40 15% 0.08 0.17 0.25 0.33 0.38 0.42 20% 0. 12 0.20 0.27 0.35 0.40 0.44 25% 0. 15 0.22 0.30 0.37 0.41 0.46 30% 0. 18 0.25 0.32 0.39 0.43 0.47 35% 0.20 0.27 0.34 0.41 0.44 0.48 40% 0.23 0.30 0.36 0.42 0.46 0.50 45% 0.26 0.32 0.38 0.44 0.48 0.51 50% 0.29 0.35 0.40 0.46 0.49 0.52 55% 0.33 0.38 0.43 0.48 0.51 0.54 60% 0.37 0.41 0.46 0.51 0.54 0.56 65% 0.41 0.45 0.49 0.54 0.57 0.59 70% 0.45 0.49 0.53 0.58 0.60 0.62 75% 0.51 0.54 0.58 0.62 0.64 0.66 80% 0.57 0.59 0.63 0.66 0.68 0.70 85% 0.63 0.66 0.69 0.72 0.73 0.75 90% 0.71 0.73 0.75 0.78 0.80 0.81 95% 0.79 0.81 0.83 0.85 0.87 0.88 100% 0.89 0.90 0.92 0.94 0.95 0.96 2007-01 RO-11 Urban Drainage and Flood Control District Area-Weighting for Impervious Calculation Project Title: Weideman Drainage (Developed, Catchment ID: Basin A Illustration 1-14 st5 � LEGEND: Flow Direction ea 4 S Cat aim ent Subarea 3Boundary Instructions: For each catchment subarea, enter values for A and C. Subarea Area Impervious Product ID acres A I CI input input input output Gravel 1 .39 40.00 55.60 Roof 0. 13 90.00 11 .70 sum: 1 .52 Sum: 67.30 Area-Weighted Runoff Coefficient (sum CA/sum A) = 44.28 Area-Weighting for Impervious Calculation Project Title: Weideman Drainage (Developed) Catchment ID: Basin Al Illustration <,.:O1%)35e te_At1 __--- LEGEND: flow Direction lEstale 4 Cat OEM MI uha:ueea 3Boundary Instructions: For each catchment subarea, enter values for A and C. Subarea Area Impervious Product ID acres A I CI input input input output Gravel 1 .04 40.00 41 .60 Roof 0.10 90.00 9.00 sum: 1 .14 sum: 50.60 Area-Weighted Runoff Coefficient (sum CA/sum A) = 44.39 Area-Weighting for Impervious Calculation Project Title: Weideman Drainage (Developed) Catchment ID: Basin B Illustration 6s)) LEGEND: now Direction ter: �` 4 Cat elm era Suba a 3 Boundary Instructions: For each catchment subarea, enter values for A and C. Subarea Area Impervious Product ID acres A I CI input input input output Gravel 1 .46 40.00 58.40 Roof 0.01 90.00 0.90 sum: 1 .47 Sum: 59.30 Area-Weighted Runoff Coefficient (sum CA/sum A) = 40.34 Area-Weighting for Impervious Calculation Project Title: Weideman Drainage (Developed) Catchment ID: Basin C3 Illustration . � 5 c oyae L.E GEND: Flow Direction IL ~�� Catch ent Suhsma Boundary Instructions: For each catchment subarea, enter values for A and C. Subarea Area Impervious Product ID acres A I CI input input input output Undeveloped 0. 16 2.00 0.32 Sum: 0.16 sum: 0.32 Area-Weighted Runoff Coefficient (sum CA/sum A) = 2.00 C C n n 0- N to r" S (0 N T C) W 'd d C > 000 Cl C t l � •M �7 O O O C•) LL O U N N -. a-' `7- --- c r- r-, r`• N N r- ` 8 ` h- n n CO O n C C t/'1 �, -C-- U �a ' �@d U f u •- . N M O ^ d - C 4' N O .�' Y c 4 to 4 (t) O 4 .. 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E E (/) } O v) d Q Z C N U CO C) O C• O N tt) n O N tt) t Q C M M n to 0 0 N ss�� a� yy t V w U r1 L-• L-• O O r r N N N N C7 M M M v r N N V OD to W 4. -C 00 00 N 00 00 O) co d b O O r 0 0 0 O a O 0 0 o O O c is E tJ ^ rD pi tt) to O O o 0 0 O •C j tt 0) CO M _ 00 'Y > N N O C) ti) O W rd M M W M ~ > ? N M In�{{ O N tt 1 W O M tD 0 r Q - O O O O r r r N N N N T C..) M M M O N O Cjt EE N N N O r 0 00000000000 ° r a O O O 0 d O a O O O a E E E P “ r r r W nt N C h n r- N N n CC •E •E E O N to O to tf) O U) O to O 5 30 `-t.' 000000 N ^J N r r N M M V [t it) N O O {-- 0 0 0 0 0 0 r 0) 0) LL C. LL LL, H I-- o wai T. I f- r) O tQ N �: r - t i t^ fr p T o C J Z� t•� M V r tom) w w it Lf) .- ti M r ig ,- o e r) o c 2 _ C d 0) V) h 2 .i .a O =O II w = N _ O CO a) Q 0 0 0 0 po�pp cocd� o o o " C' 1- 00 C 0 ca io a V V V N N N V �t V N N N t`S a x o m m m C O lU E vv — — < c > O m a. n a) a) ) w a a) m p OW r o o c t� a. ti E 2 ¢ Q C N g0) nnnnnu. a n [. a. c c m 7,52 J u u n u > > 0 o o a o o o o o .E `- N M •C cu Oco it U *a mn > > > > > > > > > o in m QQmUUU m Q Q � UOUiv •o d Ol N 3 D 0 0 0 0 0 4.) 0 0 0 .c r m m H 0 D Design Point Summary Design Associated Total Basin Impervious Q5 (CFS) O10 (CFS) Q100 (CFS) Point Basin Area (ac) Ratio 1 B 1 .47 40% 1 .2 1 .8 4.9 2 Al 1 . 14 44% 1 .0 1 .5 3.9 3 A & B 2.99 42% 2.5 3.8 10.1 Flatirons, Inc. — Surveying & Engineering APPENDIX B Hydraulic Computations > Culverts o Culvert sizing calculations > Open Channels o Open channel sizing calculations > Water Quality Capture Volume o WQCV calculations > Water Quality Pond o Stage storage volume calculations o Infiltration calculations Weideman Compressor Station B April 14, 2014 Culvert Report Hydraflow Express Extension for AutoCAD® Civil 3D® 2013 by Autodesk, Inc. Thursday, Apr 10 2014 Culvert 1 Invert Elev Dn (ft) = 4759.79 Calculations Pipe Length (ft) = 61 .00 Qmin (cfs) = 4 .90 Slope r/o) = 1 .00 Qmax (cfs) = 4. 90 Invert Elev Up (ft) = 4760.40 Tailwater Elev (ft) = Normal Rise (in) = 18.0 Shape = Circular Highlighted Span (in) = 18 .0 Qtotal (cfs) = 4.90 No. Barrels = 1 Qpipe (cfs) = 4.90 n-Value = 0.024 Qovertop (cfs) = 0.00 Culvert Type = Circular Corrugate Metal Pipe Veloc Dn (ft/s) = 3.61 Culvert Entrance = Projecting Veloc Up (ft/s) = 3.62 Coeff. K, M ,c,Y, k = 0.034 , 1 . 5, 0.0553 , 0 .54, 0.9 HGL Dn (ft) = 4760.87 HGL Up (ft) = 4761 .47 Embankment Hw Elev (ft) = 4761 .77 Top Elevation (ft) = 4763.00 Hw/D (ft) = 0.91 Top Width (ft) = 23.00 Flow Regime = Inlet Control Crest Width (ft) = 1 .00 Elev it Culvert 1 Mw Depth (n) 4764.00 - { - - 3.60 4763.00 -- _ -, 2.60 J" --1 l � 4762 00 // '- 1.60 -----------C-:: Wet tor tf01 476100 t - --- --� — -- 0.60 -- -- - 4780 00 0.40 4769 00 - - ` .1.40 4768 00 r I -2.40 0 6 10 16 20 26 30 36 40 AS != Fz 60 U 70 76 60 IS C1rwlerCulvert HGL Embank With(R1 Channel Report Hydraflow Express Extension for AutoCAD® Civil 3D® 2013 by Autodesk, inc. Thursday, Apr 10 2014 Channel 1 -capacity Triangular Highlighted Side Slopes (z: 1 ) = 4 .00 , 4.00 Depth (ft) = 0 .67 Total Depth (ft) = 2 .00 Q (cfs) = 3.900 Area (sqft) = 1 .80 Invert Elev (ft) = 4600.00 Velocity (ft/s) = 2 . 17 Slope (%) = 0 .64 Wetted Perim (ft) = 5 .52 N-Value = 0.025 Crit Depth, Yc (ft) = 0.57 Top Width (ft) = 5 .36 Calculations EGL (ft) = 0.74 Compute by: Known Q Known Q (cfs) = 3.90 Elev (ft) Depth (ft) Section 4603.00 . - 3.00 I 4602.50 2.50 4602.00 - \ --T - 2.00 4601 .50 , 1 .50 4601 .00 -- 1 .00 Vr 4600.50 0.50\.4600.00 - 0.00 4599.50 -0.50 0 2 4 6 8 10 12 14 16 18 20 Reach (ft) Channel Report Hydraflow Express Extension for AutoCAD® Civil 3D® 2013 by Autodesk, Inc Thursday, Apr 10 2014 Channel 1 -stability Triangular Highlighted Side Slopes (z: 1 ) = 4.00 , 4.00 Depth (ft) = 0.59 Total Depth (ft) = 2 .00 Q (cfs) = 3.900 Area (sqft) = 1 .39 Invert Elev (ft) = 4600.00 Velocity (ft/s) = 2.80 Slope (%) = 0 .64 Wetted Perim (ft) = 4.87 N-Value = 0.018 Crit Depth , Yc (ft) = 0.57 Top Width (ft) = 4.72 Calculations EGL (ft) = 0.71 Compute by: Known Q Known Q (cfs) = 3.90 Elev (ft) Section Depth (ft) 4603.00 3.00 4602. 50 2.50 4602.00 ` - 2.00 4601 .50 1 .50 4601 .00 // - 1 .00 / /4600.50 - 0.50 4600.00 - 0.00 4599.50 -0.50 0 2 4 6 8 10 12 14 16 18 20 Reach (ft) Channel Report Hydraflow Express Extension for AutoCAD® Civil 3D® 2013 by Autodesk, Inc. Thursday, Apr 10 2014 Channel 2 -capacity Triangular Highlighted Side Slopes (z: 1 ) = 4 .00, 4.00 Depth (ft) = 0 .79 Total Depth (ft) = 2 .00 Q (cfs) = 4.900 Area (sqft) = 2 .50 Invert Elev (ft) = 4600.00 Velocity (ft/s) = 1 .96 Slope (%) = 0.40 Wetted Perim (ft) = 6 .51 N-Value = 0.025 Crit Depth , Yc (ft) = 0 .63 Top Width (ft) = 6 .32 Calculations EGL (ft) = 0.85 Compute by: Known Q Known Q (cfs) = 4.90 Elev (ft) Section Depth (ft) 4603.00 3.00 4602. 50 , 2.50 4602.00 - f- 2.00 / 4601 .50 - 1 .50 4601 .00 1 .00 V 4600.50 - - 0.50 4600.00 0.00 4599.50 -0.50 0 2 4 6 8 10 12 14 16 18 20 Reach (ft) Channel Report Hydraflow Express Extension for AutoCAD® Civil 3D® 2013 by Autodesk, Inc. Thursday, Apr 10 2014 Channel 2-stability Triangular Highlighted Side Slopes (z: 1 ) = 4 . 00, 4 .00 Depth (ft) = 0 .70 Total Depth (ft) = 2 . 00 Q (cfs) = 4.900 Area (sqft) = 1 .96 Invert Elev (ft) = 4600.00 Velocity (ft/s) = 2 .50 Slope (%) = 0.40 Wetted Perim (ft) = 5 .77 N-Value = 0.018 Crit Depth , Yc (ft) = 0.63 Top Width (ft) = 5.60 Calculations EGL (ft) = 0.80 Compute by: Known Q Known 0 (cfs) = 4 .90 Elev (ft) Depth (ft) Section 4603.00 3.00 4602. 50 - 2.50 4602.00 2.00 4601 .50 - 1 .50 4601 .00 1 .00 \ N7 4600.50 - - 0.50 4600.00 • 0.00 4599.50 - -0.50 0 2 4 6 8 10 12 14 16 18 20 Reach (ft) Area-Weighting for Impervious Calculation Project Title: Weideman Drainage (Developed) Catchment ID: Basin A, B, C1 , C2, and C3 Illustration eat LEGEND: Flow Direction �= Z Catchment Subaxen 3 Boundary Instructions: For each catchment subarea, enter values for A and C. Subarea Area Impervious Product ID acres A I CI input input input output A 1 .52 44.00 66.88 B 1 .47 40.00 58.80 Cl 0.32 2.00 0.64 C2 0. 10 29.00 2.90 C3 0. 16 2.00 0.32 sum: 3.57 Sum: 129.54 Area-Weighted Runoff Coefficient (sum CA/sum A) = 36.29 el rn > > o � Q' is- • a) Tr o) U) (t o 8 V N co s CO • U N U a H > > � a 0 0 '� O (5 , o ce o r O cc > U 4 ti ca C t CO L C7 r- a) _ N 0 N— Tii (t d + $ o C Cr 0 ca w " o > • CD 75 en r, N = a- a � W0 '� to N .�-. c.O V c S w.. O a) CO 0 . ., o a) - CN o v as o cl)C a� G > co '—' O G ? 0 — a p RS U C > O _ C o �, O U E co 0 u O 2 as N Ce C Z5 ..., oc^ Co C O E 5 s 0 o 4t1 2 tC 0 al as C 0 V L o $ O a U (15 > o U 2 E O o Yo O D N a > '0 > To D C C c O QM 0 2 E > in o C (t) ca L Q) }0d 0 r E O U) CO a) o ��C)/ O p CD w O Q LL Q) c0 tt > r D o (d Q Q) O O o r c o c- ^ Ql 0 O O 2 I� CO o U a M N .(1) *O Y O � c a I Q K o o N M `o N O v- O 0 0 0 o a r-+ a o M U rn CV !'C E � co LA p ' ..c o (0 M U} c oo _ U N O H N 'n U 0 cH o T U) a a) 0 6 o Q o 0 0 0 0 d p M (n a) i Y o o s s.. f"' QII a CD D v Y Y w O = it a) o 0 (") tt 0 c M N CO D D a) 3 -5 M CO C O a o a) c -c d Cl. tu I U Ell o d a (� (n N * CL r r STAGE-STORAGE SIZING FOR DETENTION BASINS Project: Weideman Compressor Station Basin ID: Water Qualtiy Pond Da Sib 4t Duo {1bSlwI rc•s4.. , at M _1 Pm W Sale Th.Z < L < L i Sib Op L ate" Design Information (Input): Check Btkein Shape Width of Basin Bottom, W = ft Right Triangle OR... Length of Basin Bottom, L = ft Isosceles Triangle OR... Dam Side-slope (H:V), Zd = ftlft Rectangle OR... Circle / Ellipse OR... Irregular (Use Overide values in cells G32:G52) MINOR MAJOR Storage Requirement from Sheet 'Modified FAA': acre-ft Stage-Storage Relationship: Storage Requirement from Sheet 'Hydrograph': acre-ft. Storage Requirement from Sheet 'Full-Spectrum': _ acre-ft. Labels Water Side Basin Basin Surface Surface Volume Surface Volume Target Volumes for WQCV, Minor, Surface Slope Width at Length at Area at Area at Below Area at Below for WQCV, Minor. & Major Storage Elevation (H:V) Stage Stage Stage Stage Stage Stage Stage & Major Storage Stages ft Mt ft ft ft2 ft2 User ft2 acres acre-ft Volumes input) (input) Below El ;outpud) i (outL.ut) (output) Overide (outuul) (output) (output) (for noal scEH, 4759.79 [Inputi 0 0.000 0.000 Bottom 4760.00 0.00 0 00 229 24 0.005 0.001 4760.50 0.00 0.00 927 313 0.021 0.007 4761.00 0 00 0.00 2,166 1,086 0.050 0.025 WQCV=4761.50 4761.50 0.00 0 00 4,266 2.694 0.098 0.062 WOCV=2642 cf Level Spreader 4762 00 0.00 0.00 8,192 5,809 0.188 0.133 10 yr=5067 cf 4762.50 0.00 0.00 14,621 11,512 0.336 0.264 #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #WA #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A *NIA #N/A #N/A #N/A #N/A #WA #N/A #N1A _ #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A - 100501-UD-Detention_v2.33.ids, Basin 4/10/2014, 3:19 PM STAGE-STORAGE SIZING FOR DETENTION BASINS Project: Basin ID: STAGE-STORAGE CURVE FOR THE POND 4762.79 -- 4762.29 - 4761 .79 G7 C) 4761 .29 G? CI (LS a.+ t1, 4760.79 - 4760.29 • 4759.79 0.00 0.05 0. 10 0.15 0.20 0.25 0 30 Storage (acre-feet) 100501-UD-Detenion_v2.33.As, Basin 4/10/2014, 3:19 PM Weideman Compressor Station — Water Quality Ponds Draw Down Calculations Infiltration rates based on the Geotechnical Engineering Study; Proposed Addition to the Weideman Compressor Station; April 11 , 2014; HP Geotech Inc. WATER QUALITY POND Infiltration Rate = 60 min/in Depth of Pond at 100-year water surface elevation Top of Pond = 4762.00 Bottom of Pond = 4759.79 Depth of Water = 4762.00 — 4759.79 = 2.21 ft. = 26.5 in. Pond Draw Down = Depth of Water * Infiltration Rate = (26.5 in.)*(60 min/in) = 1590 min. = 26.5 hr Flatirons, Inc. — Surveying & Engineering APPENDIX C Floodplain Information Attached is copy of the FEMA Floodplain Flood Insurance Rate Map of the Area Weideman Compressor Station C April 14, 2014 v -1 �i a. ° OC V acv \ ro '° m t W W � of t..) o a o � �►Ct H a' r p ,p vs etV I. E W a. 7R Z/ill < ° = CC ii. 4IS 2 0 La 4.13 ch.. ac W- mi 0 ri4 g Lt W g lifc 2 � 0. 0 = A o is. W q Q s a a a v r. z tn. gg ro - a is 3 CI � O 'a 1 L c � _ $ a' . �.. a. o $ f § bN U,-------- TiLL igilg &LL. .c V 8P108. rl 7 4 ` E j _ - =s�=====JL:_— Q— 1_ _____13% .\ :.-----F tiii! al' s' III _ to8 ) "( II II W J : 43i , , , I6Tet. c a C....„....__ _.. o W � w 20 o � � O z TO ` - M \1 O O \------. ' N 4 Z CV w 0 a a N---.--\ \ 4 \ D N o ------ N 1 \•. N Ji • M Kb. W O,'L \ 7 it Jr It _____ II \ i C' I _ L^r, 1) —ii 1 - yam, Il Flatirons, Inc. — Surveying & Engineering APPENDIX D Geotechnical Report Attached is a copy of the Geotechnical Engineering Study prepared by HP Geotech, dated April 11, 2014. Weideman Compressor Station D April 14, 2014 ItP 1 h '11tvorth-1',i«•l,tk l<et,technical. In . i 301 South ProgressGeetech Parker, Col,mi.ltl SO i-} !'him ; 101-S4I -il1t) Fax. k' LS41 -i i 56 cniail: %w_ek$: histcocci11.Ct'ui GEOTECHNICAL ENGINEERING STUDY PROPOSED ADDITION TO THE WEIDEMAN COMPRESSION STATION LOCATED APPROXIMATELY ON 1 /4 MILE SOUTH AND 1/2 MILE EAST OF INTERSECTION OF COUNTY ROAD 27 AND COUNTY ROAD 42, WELD COUNTY, COLORADO JOB NO. 214152A APRIL 11 , 2014 PREPARED FOR: FLATIRONS, INC. ATTN: KEN CURFMAN, P.E., P.L.S. 955 FOURTH AVENUE LONGMONT, COLORADO 80501 TABLE OF CONTENTS PURPOSE AND SCOPE 1 PROPOSED CONSTRUCTION 1 SITE CONDITIONS 2 FIELD EXPLORATION 2 SUBSURFACE CONDITIONS 2 SEISMIC DESIGN 3 DESIGN RECOMMENDATIONS 3 SPREAD FOOTING FOUNDATION 3 MAT FOUNDATIONS 5 DEEP FOUNDATIONS 5 FOUNDATION AND RETAINING WALLS 6 FLOOR SLABS 7 PERIMETER DRAIN SYSTEM 8 INFILTRATION TESTING 8 SITE GRADING 8 SURFACE DRAINAGE AND MAINTENANCE 9 CONTINUING SERVICES 10 LIMITATIONS 10 FIGURE 1 SITE LOCATION • FIGURE 2 BORING LOCATIONS FIGURES 3 - 4 BORING LOGS FIGURE 5 LEGEND AND NOTES FIGURES 6 SWELL/COMPRESSION TEST RESULTS FIGURES 7 - 10 GRADATION ANALYSES RESULTS TABLE 1 SUMMARY OF LABORATORY TEST RESULTS TABLE 2 INFILTRATION TEST RESULTS PURPOSE AND SCOPE This report presents the results of a subsoil study for proposed expansion to Aka Energy Group's Weideman Gas Compression Station located about 1 /4 mile south and 1 /2 mile east of the intersection of County Road 27 and County Road 42 in Weld County, Colorado. The project site location is shown on Figure 1 . The purpose of the study was to evaluate the subsurface conditions, provide foundation type and construction recommendations for a compressor station and determine infiltration rates for a storm water detention/retention pond. A field exploration program consisting of 8 borings was conducted to obtain information on the subsurface conditions. Samples of the subsoils obtained during the field exploration were tested in the laboratory to determine their classification and other engineering characteristics. Infiltration rates were determined for detention/retention pond design. The results of the field exploration and laboratory testing were analyzed to develop recommendations for foundation types, depths and allowable pressures for the proposed addition foundations. This report summarizes the data obtained during the study and presents our conclusions, design recommendations and other geotechnical engineering considerations based on the proposed construction and the subsoil conditions encountered. PROPOSED CONSTRUCTION The proposed Weideman compressor station is shown on Figure 2. The new construction will include the installation of 6 Exterran C-Series compressors near the north end of the site, the construction of a storm water detention/retention pond located to the south of the site, and a storage tank bay near the southeast corner. Several other appurtenant structures will be located within the site. Specific loads were not provided, but we assume structure gravity loads range from light to moderate, typical of this type of construction. Job No. 214152A 1 Geiertech April 11 , 2014 SITE CONDITIONS The site is approximately 1 /4 mile south and 1 /2 mile east of the intersection of County Road 27 and County Road 42, Weld County, Colorado. Adjacent parcels have been cropped and irrigated. The ground surface is relatively flat. Access to the site was gained by way of an unpaved road leading to the area. A small ditch exists on the north side of the proposed construction. Vegetation in the area of the proposed construction consisted of harvested corn. FIELD EXPLORATION The field exploration for the project was conducted on March 24, 2014, A total of 8 borings were drilled at the locations shown on Figure 2 to evaluate the subsurface conditions in the area of the proposed construction. The borings were drilled with a truck mounted CME-55 drill rig equipped with an automatic hammer, and were logged by a representative of Hepworth-Pawlak Geotechnical, Inc. Samples of the soils were taken with a nominal 2-inch ID California spoon sampler. The sampler was driven into the subsoils at various depths with blows from a 140-pound hammer falling 30 inches. This test is similar to the standard penetration test described by ASTM Method D- 1586. The penetration resistance values are an indication of the relative density or consistency of the subsoils. Depths at which the samples were taken and the penetration resistance values are shown on the Boring Logs, Figures 3 and 4. The samples were returned to our laboratory for review by the project engineer and testing. SUBSURFACE CONDITIONS Below about 1 foot of top soil, the soils consisted of silty sands to the maximum depth drilled of 25 feet. Based on blow counts, the sands were loose to dense. In Borings B-1 , B-2, and B-4, groundwater was encountered near the bottom of the borings at the time of drilling and was found at depths ranging from 19 to 20 feet when measured the following day. Borings B-3, B-5, B-6, P-1 , and P-2 were dry both at the time of drilling, and when measured the following day. Groundwater levels are expected Job No. 214152A 2 c tech April 11 , 2014 to fluctuate due to seasonal, climatic, or other factors including irrigation of the adjacent land. Laboratory testing included natural moisture content, unit weight, swell/compression, gradation analysis, and water soluble sulfate concentration. The sample of silty sand from Boring B-3 at 4 feet exhibited a vertical compression is 3 .5 percent when wetted under a 1 ksf surcharge, indicating the soil is not expansive. Gradation analysis results of sand samples are shown on Figures 7 to 10. The concentration of water-soluble sulfates was found to range between nil and 0.005 percent in the samples tested. Sulfate concentrations below 0. 1 percent represent a negligible degree of sulfate attack on concrete, and therefore no special recommendations regarding cement type are required. Type I/II is recommended for this project due to its ready availability and common use in this area. SEISMIC DESIGN The following parameters are based on the 2009 International Building Code. 0.2 second spectral response acceleration Ss = 0.206 g [Fig. 1613 .5(1 )] 1 .0 second spectral response acceleration S1 = 0.054 g [Fig. 1613 .5(2)] Site Class = D Site coefficient Fe = 1 .6 Table 1613 .5 .3(1 ) Site coefficient F,, = 2.4, Table 1613 .5 .3(2) DESIGN RECOMMENDATIONS Based on the soils encountered in our investigation, it is our opinion that shallow foundations bearing on compacted fill are adequate for the proposed structures at this site, but understand that deep foundation may be desired, particularly for use with the compressors. Recommendations for both foundation types have been provided. SPREAD FOOTING AND RETAINING WALL FOUNDATIONS Relatively loose sands were encountered at the anticipated depth of the foundations, and therefore excavation, moisture conditioning, and re-compaction of the onsite soils to a depth of 2 feet below the foundations is recommended. Soils should be compacted to at Job No. 214152A 3 Gfregtech April 11 , 2014 least 98 percent of the maximum standard proctor density (ASTM D698A). Additionally, the following recommendations should be followed for the construction of footing foundations. 1 ) Footings placed on the undisturbed native silty sand or compacted fill should be designed for an allowable bearing pressure of 1 ,500 psi Based on experience, we expect settlement of footings designed and constructed as discussed in this section will be less than 1 inch total and about 3/ inch differential. 2) Loose or disturbed soil below the proposed footing area should be removed and replaced compacted to at least 98 percent of the standard Proctor (ASTM D698) density, and within 2 percent of the optimum moisture as described in the SITE GRADING section. 3) Footings should have a minimum width of 16 inches for continuous walls and 24 inches for isolated pads. 4) The lateral resistance of foundation or retaining wall footings 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 bottom of the footings can be calculated based on a coefficient of friction of 0.35. Passive pressure of compacted backfill against the sides of the footings can be calculated using an equivalent fluid unit weight of 350 pcf. The coefficient of friction and passive pressure values recommended above assume ultimate soil strength. Suitable factors of safety should be included in the design to limit the strain which will occur at the ultimate strength, particularly in the case of passive resistance, Fill placed against the sides of the footings to resist lateral loads should be compacted and moisture conditioned in accordance with the specifications listed in the SITE GRADING section. 5) All exterior footings and footings beneath unheated areas should be provided with adequate soil cover above the bearing elevation for frost protection. Placement of foundations at least 36 inches below exterior grade is typically used in this area. 6) Continuous foundation walls should be reinforced top and bottom to span local anomalies, such as by assuming an unsupported length of at least 12 feet. 7) Foundation excavations should not be wetted or dried excessively. The foundation soils should be tamped to compact loose soil prior to placing forms for footings. Job No. 214152A 4 Getet'h April 11 , 2014 8) A representative of the geotechnical engineer should observe the footing excavations prior to forming to evaluate bearing conditions. MAT FOUNDATIONS Reinforced concrete mats may be used to support some equipment. A modulus of vertical subgrade reaction of 100 pci can be used for the design of mat foundations bearing on at least 2 feet of moisture conditioned onsite silty sand re-compacted to at least 98 percent of the standard proctor density (ASTM D698). A maximum allowable bearing pressure of 1 ,500 psf may be used. If these recommendations are followed, settlement of large mats is expected to be less than about 1 inch. The Base of the mats should be constructed below frost level. Alternatively, edge thickened mats extending below the frost level may be used. Any loose or disturbed soil below the proposed footing area should be removed and replaced compacted to at least 98 percent of the standard Proctor (ASTM D698) density, and within 2 percent of the optimum moisture as described in the SITE GRADING section. A representative of the geotechnical engineer should observe the footing excavations prior to forming to evaluate bearing conditions. DEEP FOUNDATIONS 1 ) Drilled piers used to support structures may be designed for an allowable end bearing pressure of 8,000 psf at depths of 15 feet or greater. Side shear may be calculated based on 500 psf for the portion of the shaft below 5 feet. 2) A minimum pier length of 15 feet is recommended. To avoid caving, casings may be required during construction. Due to the soils type and the groundwater level at the time of drilling, construction of piers extending deeper than about 20 feet below existing grade may be difficult. A minimum diameter of 18 inches is recommended. 3) Piers should be designed to resist lateral loads assuming a modulus of horizontal subgrade reaction of 20 pci for loose sand and 60 pci for medium dense sand. The modulus value given is for a long, 1 foot wide pier and must be corrected for pier size. Job No. 214152A 5 asztech April 11 , 2014 The following LPILE values have been provided for the soil types encountered. LPILE PARAMETERS Soil Type Total Unit k Friction Cohesion, c Yp Weight (pci) Angle, p (psi) Eso (pci) (degrees ) Loose Silty Sand 0.064 20 30 N/A N/A Medium dense - - - to dense 0.070 60 32 N.A N/A Silty Sand _ 4) Concrete utilized in the piers should be a fluid mix with sufficient slump so that concrete will fill the void between the reinforcing steel and the pier shaft. 5) Pier shafts should be properly cleaned prior to the placement of concrete. 6) Free water was encountered in the borings drilled at the site, and seepage in the pier shaft will likely be encountered during drilling. Dewatering equipment may be required to reduce water infiltration into the pier shaft. If water cannot be removed prior to placement of concrete, the tremie method should be used after the hole has been cleaned of spoil. In no case should concrete be placed in more than 3 inches of water unless the tremie method is used. 7) A representative of the geotechnical engineer should observe pier drilling operations FOUNDATION AND RETAINING WALLS Foundation walls and retaining structures which are laterally supported and can be expected to undergo only a slight amount of deflection should be designed for a lateral earth pressure computed on the basis of an equivalent fluid unit weight of at least 55 pounds per cubic foot (pcf) for backfill consisting of the on-site sand soils. Cantilevered retaining structures which are separate from the structure and can be expected to deflect sufficiently to mobilize the full active earth pressure condition should be designed for a lateral earth pressure computed on the basis of an equivalent fluid unit weight of at least 35 pcf for backfill consisting of the on-site sand soils. Light compaction equipment should be used within 3 feet from the wall surface to avoid wall movement. Job No. 214152A - 6 atistech April 11 , 2014 All foundation and retaining structures should be designed for appropriate hydrostatic and surcharge pressures such as adjacent footings, traffic, construction materials and equipment. The pressures recommended above assume drained conditions behind the walls and a horizontal backfill surface. The buildup of water behind a wall or an upward sloping backfill surface will increase the lateral pressure imposed on a foundation wall or retaining structure. A drain system, weep holes or geosynthetic composite drain board should be provided to prevent hydrostatic pressure buildup behind walls. FLOOR SLABS The natural on-site silty sand is suitable to support lightly to moderately loaded slab-on- grade construction. The following details should be followed for slab on grade floors. Some movement, up to about one inch, could occur. If no movement is tolerable then a structurally supported floor should be considered. Where possible, floor slabs should be separated from all bearing walls and columns with expansion joints which allow unrestrained vertical movement. 1 ) Floor slab control joints should be used to reduce damage due to shrinkage cracking. Control joint spacing is a function of slab thickness, aggregate size, slump and curing conditions. The requirements for concrete slab thickness, joint spacing and reinforcement should be established by the designer based on experience, recognized design guidelines and the intended slab use. Placement and curing conditions will have an impact on the final concrete slab integrity. 2) If plumbing lines are below or penetrate the slab, they should be tested before operation. Where plumbing lines enter through the floor, a positive bond break should be provided. Flexible connections should be provided for slab-bearing mechanical equipment. Flexible connections should allow for at least 1 inch of vertical movement 3) Depending on the floor covering, a vapor retarder may be needed below the slab. However the vapor retarder may affect the concrete curing. Considerations and recommendations for the installation of vapor retarders below concrete slabs are outlined in section 3 .2,3 of the 2006 report of the American Concrete Institute (ACI) Committee 302, "Guide for Concrete Floor and Slab Construction (ACI 302, 1R-04)". Job No. 214152A Gggtecti April 11 , 2014 PERIMETER DRAIN SYSTEM It is our understanding that below grade levels are proposed for the construction of this site, and therefore, a perimeter drain system is not necessary. If below grade levels are considered, we should be contacted to provide additional recommendations. PERMEABILITY TESTING Two shallow holes P1 and P2 were drilled to depths of 3 to 31/2 feet to conduct in-place permeability tests in the area of the proposed detention/retention ponds. The shallow holes were filled with water the day they were drilled and the permeability was measured the following day. Detailed test results are presented on Table 2. Based on the measured rates, we recommend using a coefficient of permeability of 7 X 104 cm/s (60 min/inch) for design purposes. SITE GRADING General The following recommendations should be followed for grading, site preparation, and fill compaction. 1) All import and onsite backfill should be approved by the geotechnical engineer. 2) Where fill is to be placed, loose or otherwise unsuitable material, including topsoil and vegetation should be removed prior to placement of new fill. 3) Soils should be compacted with appropriate equipment for the lift thickness placed. 4) The following compaction requirements should be used: TYPE OF FILL MOISTURE CONTENT SOIL TYPE - Compaction Percent PLACEMENT (ASTM D698 - Standard Proctor) Under Foundations -2% to +2% of Optimum On site sands or structural import 98% Foundation Wall Racial -2% to +2% of Optimum Suitable Onsite or Import Fill min — 95% Below Concrete Flatwork, -2% to +2% of Optimum Slab-on-Grade and Pavement Suitable Onsite or Import Fill min --- 95% Landscape Areas -2% to +2% of Optimum Onsite or Import Fill -- 90% f Utility Trenches As they apply to the finished area — — — — Excavation The soils can be excavated with conventional equipment to the proposed grades. Job No. 214152A 8 April 11 , 2014 Suitability of On-site Soil The on-site sand soils can be used as fill on all areas of the site, provided that the above listed moisture and compaction specifications are followed. All fill should be processed so that it does not contain fragments larger than 3 inches in diameter. Imported Structural Fill If imported structural fill is required, a granular material, such as a CDOT Class 5 or 6 aggregate should be used. Imported structural fill should consist of minus 4-inch material having less than 35 percent passing the No. 200 sieve, a liquid limit less than 30, and a plasticity index less than 15 . Structural fill placed below footings should be compacted to at least 98 percent of the maximum standard Proctor density (ASTM D698) at moisture content within 2 percent of optimum. Drainage Good surface drainage should be provided around all cuts and fills to direct surface runoff away from these areas. Slopes and other stripped areas should be protected against erosion by paving, re-vegetation or other means. SURFACE DRAINAGE AND MAINTENANCE The success of foundations, slab-on-grade, and concrete flatwork is contingent upon keeping the bearing soils at approximately constant moisture content, and by not allowing surface water a path to the subsurface. Positive surface drainage away from the structure must be maintained at all times. Landscaped areas should be designed and built such that irrigation and other surface water will be collected and carried away from foundation elements. The ground surface surrounding the exterior of the structure and any overlying pavements should have a positive slope away from foundation walls on all sides. We recommend a minimum slope of 6 inches in the first 10 feet in unpaved areas and a minimum slope of 3 inches in the first 10 feet in paved areas. A swale should be provided at the base of cut slopes that are adjacent to the building. For entrance areas, ADA criteria may apply, and should take precedence over the above recommendations. Job No. 214152A --- - 9 Gtech April 11 , 2014 Proper compaction of exterior backfill is necessary in maintaining a long-term positive slope away from the structures. Areas of settlement of the exterior backfill after construction should be backfilled immediately to maintain positive slopes away from the structure. All roof downspouts and drains should discharge well beyond the limits of all backfill. CONTINUING SERVICES Two additional elements of geotechnical engineering service are important to the successful completion of this project. 1 ) Consultation with design professionals during the design phases. This is important to ensure that the intentions of our recommendations are properly incorporated in the design, and that any changes in the design concept properly consider geotechnical aspects. 2) Observation and monitoring during construction. A representative of the Geotechnical engineer from our firm should observe the exposed foundation excavation prior to placement of structural fill. We should observe and test placement of structural fill under foundations to judge whether the proper placement conditions have been achieved. We recommend observation and inspection of the underdrain system, damp proofing, installed vapor retarders under floor slabs and crawlspaces, LIMITATIONS This study has been conducted in accordance with generally accepted geotechnical engineering principles and practices in this area at this time. We make no warranty either express or implied. The conclusions and recommendations submitted in this report are based upon the data obtained from the exploratory borings drilled at the locations indicated on Figure 2, the proposed type of construction and our experience in the area. Our services do not include determining the presence, prevention or possibility of mold or other biological contaminants (MOBC) developing in the future. If the client is concerned about MOBC, then a professional in this special field of practice should be consulted. Our findings include interpolation and extrapolation of the subsurface conditions identified in the borings and variations in the subsurface conditions may not Job No. 214152A 10 Gettech April ] 1 , 2014 become evident until excavation is performed. If conditions encountered during construction appear different from those described in this report, we should be notified so that re-evaluation of the recommendations may be made. This report has been prepared for the exclusive use by our client for design purposes. We are not responsible for technical interpretations by others of our information . As the project evolves, we should provide continued consultation and field services during construction to review and monitor the implementation of our recommendations, and to verify that the recommendations have been appropriately interpreted. Significant design changes may require addition& analysis or modifications to the recommendations presented herein. We recommend on-site observation of excavations and foundation bearing strata and testing of structural fill by a representative of the geotechnical engineer. Respectfully Submitted, HEPWORTH - PAWLAK GEOTECHNICAL, INC. Cuong Vu, Ph.D., P.E. Reviewed by f,a-x,4_,4. • Arben Kalaveshi P.E. O `"° T �` `l -la ; 45969 FssI°NAI- %)\() Job No. 214152A 11 Gvasch April 11 , 2014 •fir-- -nw�r — _ - �`. t=:'�.-�;� oJ4 o.) ! l/ . � er ("V - • ► •• - - -- - • 4 .0742• • ♦i ! s • a .: 0 1{ r� / / 4_ J • � ' , JJ 1 werl / 4746 I ill • t. ° 0 • • Weil r• 2snit 1 I 1 c II - No % 0 O6 / Y J • li i � T a ti I II I 1 It ../ le I. ,. q01°C e° m of • 5l • 4 5 • • . v • BM a gN Li . APPROXIMATE SITE LOCATION• { '° • ' e 1 •— I • ... OETQH — -'T •. 4.155 ,4i• 1 -I Y A o�� .� 0 as.. ///...III l` • a 1 _ • i •ILe. ,f•- • -- I °• 4 �� ^. � � a, ,. • 2 • ?: > 3 476 \ I' 9 ' le 1 r : �, h. 0 de--; 7 .r• / . _ __ detest J sr 1..07 8M, „d. l • 418 i ea Is 7 • _V-.41. /- - I/ - --"\\ L 4750 itit s•07�3t P / — 1 Ir daft 11.7 2 .eu M —al ( ; . ail°( . \ .4 • • A 1176.8 Ast• / J 1 - Sli II 6 • \ _ __.s,,P•1, . . /C • t / 0 woo' 200a 41. _ /r • l I I ' a •t �i- ` � SCALE: 1" = 2000' .. I _{1111 . -± •a (-�Z I ., ` 2 HEPWORTH-PAWLAK WEIDEMAN COMPRESSOR STATION 214152A GEOTECHNICALI Inc. SITE LOCATION FIG. 1 S . .- - - - 1 - I•• . . a It . - • •...�;•:::::•••+.—.-.tea—A - • • • • _ • _ . . — . • ar •� • • •• I •_�.•••N.•r.Y•..••.N•......•• .r .may. •••,,, ; t ( ..\ l _� •� r ' ' p Bar ! - ^ I IAse.�r •' . J y t•',a t • ' C I • \ I 1 • SC it cli: ir 1 um, •r 1 - - - t • \:\• 1 r • •i• i Ifir-V \ Li of sit • • i in \ 1, .,• 1 it • •• 11 • li \ 1nu. N.,,,,,,, v1/4\sis.T.,,n.\\‘‘a. ! f ! 1 . . . - -- . . .. �1 . I 1 v. ,\t..:.\..:k., L . . \ . _. 1. \.... , ...\ c\ ,a• N .. 1 dITD• . , ii , .,, ,....a.a,,.. N ... 'A.."..‘"• *1 %.‘ flMall ' 1 I I • I444110.1 Infid.• • .• r -. .1 Y Y r V • r . II 0 20 40 I SCALE: 1" = 40' HEPWORTH-PAWLAK WEIDEMAN COMPRESSOR STATION 214152A GEOTECHNICAL, Inc. BORING LOCATIONS FIG. 2 B-1 6-2 B-3 BA __ o o __ 9/12 5/12 6/12 • 7/12 - MC = 9.2 Y 'MC=6.7 MC=10.2 DD = 121.6 • r- DD = 108.7 / - DD = 119,3 r- 8J12 :. 5/12 8/12 >( 6112 - 5 MC = 4.1 / � • MC = 3.9 MC - 3.9 MC = 4.3 5 _. DD = 93.6 1r DD = 149.6 DD = 111.4 DD = 111.4- Z SP 4 VvSS = 0.0 ✓ — - W = o.SS = 0.095 - 21/2 28/12 10/12 11/12 10 MC = 3.1 MC = 1.6 / MC = 6.2 10 .---,Dp = 116.8 DD = 117.1 • DD = 121.6 -2d0 = 3 7 / / — - 7 41112 /'� 23/12 21 J12 35/12 - Lt 15 MC =3.0 ;1. . 15 __ I /r DD = 117.2 - 0 -209 =7 - 0 12/12 22112 21/12 /'- 14/12 -' 20 - 0 !• • .F 1 MC = 2.8 1 /• • 20 OD = 119.5-200 = 11 • • - 0 7- 26/12 31/12 - 25 �• 25 30 30 HEPWORTH-PAWLAK WEIDEMAN COMPRESSOR STATION 214152A GEOTECHNICAL, Inc. BORING LOGS FIG. 3 B-5 B-6 P-1 P-2 0 0 7/12 10/12 , /. .je— :).<:e _ MC = 8.8 •� �_ / DD = 149.5 i 7/122. 7/12 8/12 6112 7 . MC = 5.4 - MC = 3.5 /`- DD = 110.9 DD = 113,5 5 4 ' _ MC = 4.1 MC = 4.3 +4 = 0 +4 = 0 5 DD = 112.4 / DD = 112.0 -200 = 14 -200 = 12 7:._./ _ - �/-• 11/12 � 13/12 - 10 10 LL n) a 22/12 27/12 - S 15 � / 15 '� /•� 28/12 -' 26/12 20 ;7- = . f!• _ MC = 5.4 20 DD = 124.8 +4 = 5 -200 = 24 25 25 HEPWORTH-PAWLAK WEIDEMAN COMPRESSOR STATION 214152A GEOTECHNICAL, Inc. BORING LOGS FIG. 4 LEGEND N Top soil, sand, sift, some clay, corn and grass, moist, brown. p- .j SAND (SM, SP-SM), silty, loose to dense, fine to medium, moist, light brown, dark brown to brown. 17112 Indicates 711.D. California sampler. 17/12 indicates 17 blows of a 140 lb hammer falling 30" were required to drive the sampler 12 inches. Indicates depth of free waterlevel at the day of drilling Indicates depth of free water level and 1 day after drilling NOTES: 1 . Borings were drilled on March 24, 2014 with a truck mounted CME-55 rig powering 4-inch diameter continuous flight augers. 2. Locations of borings shown on Figure 2 are approximate. 3. Borings were plotted by depth. 4. Water was encounter at the time of drilling. 5. The lines between strata represent approximate boundaries and transitions may be gradual. 6. Laboratory Testing Results: MC = moisture content of sample in percent of the dry weight. DD = dry unit weight of sample in pcf. -200 = percent of silt and clay fraction. +4 = percent of gravel fraction. WSS = water soluble sulfates in percent. SP = percent of swell under a 1 ,000 psf surcharge after wetting. HEPWORTH-PAWLAK WEIDEMAN COMPRESSOR STATION 214152A GEOTECHNICAL, Inc. LEGEND AND NOTES FIG. 5 1 .0 — — ---- Location Boring 3 0.0 ------- ---'--- ----'---- Depth 4 feet -1 .0 _____ ------ - _________ Lab No. Silverthorne Date Tested 3/24/2014 - -2.0 - - ----- O' Soil Type (USCS) Sand (SP) -3.Q --- -- ------------- Moisture Content 4% - I Dry Density (pet) 93.5 -5.0 ------- Wetted at (psf) 1000 Z Compro;sion Upon Loading a .d Wetting Result (%) -3.50 Q .6.0 ----- - - ------ -------- w -7.0 -------- ------ - -------- IY M -8.0 ---------- ------ ..- -.- --. - -- 0 -9.0 ------- ------ ------ -10.0 ------- — ---- ---------- -11.0 --------- —.—._...---- -..------- -12.0 ------- ------ ------- 0.1 1 10 100 APPLIED PRESSURE (KSF) H WEIDEMAN COMPRESSOR STATION 214 152A SWELL-COMPRESSION TEST RESULTS FIGURE 6 HEPWORTH-PAWLAK GEOTECHNICAL Gradation Analysis US Standard L Sieve Sizes US Standard Sieve Numbers Hydrometer Anatysis COBBLES GRAVEL SAND SILT AND CLAY 100% - - - -, - - -� I - I I s i 80% _ ' _-- I<.- - - - 1 II 2 t ' si I I 3 _I_. L�, _._I 1 , I I t , _ .°' a I of g k I , ' 1 i l i i I I 1 0% 1 I I I I 390.625 78.125 15.625 3.125 0.625 0.125 0.025 0.005 0.001 Particle Size Diameter in Millimeters —Gradation Curve -- 3 " Sieve -00.--3/4" Sieve --= No. 4 Sieve No. 200 Sieve Particle Size Distribution Cobbles: 1 0% _ Gravel: 3% _ Sand: _ 90% _ Silt & Clay: 7% Grain Size (mm) Sieve Size % Passing Location: B-1 152.4 6" 100% Depth: 14' 101.6 4" 100% Classification: Slightly Silty Sand (SP-SM) 76.2 3" 100% Dry Density : 117.2 pcf 50.8 2" 100% Moisture Cont: 3.0% 38.1 1.5" 100% 25.4 1" 100% 19.1 3/4" 100% 12.7 1/2" 100% 9.52 3/8" 100% 4.76 # 4 97% 2.38 # 8 89% 1.19 # 16 77% 0.59 # 30 53% 0.297 # 50 26% 0.149 #100 13% 0.074 #200 7% 'tech WEIDEMAN COMPRESSOR STATION FIGURE 7 214 152A GRADATION TEST RESULTS HEPWORTH-PAWLAK GEOTECFiiVICAI. Gradation Analysis fUS Standard Sieve Sizes US Standard Sieve Numbers Hydrometer Analysis COBBLES GRAVEL SAND SILT AND CLAY 100% 80% - . - - • - - - - o, u wt 60% --_ - _ — - - .71 �o a 40% - -- 200/0 — - —_ . — - - 0% - t -- - - - - - 390.625 78.125 15.625 3,125 0.625 0,125 0.025 0.005 0.001 Particle Size Diameter in Millimeters Gradation Curve 3 " Sieve - 3/4" Sieve No. 4 Sieve No. 200 Sieve Particle Size Distribution Cobbles: 0% Gravel: 5% Sand: _ 71% _ Silt & Clay: 24% Grain Size (mm) Slave Size % Passing Location: B-6 152.4 6" 100% Depth: 19' 101.6 4" 100% Classification: Slightly Gravelly, Silty Sand (SM) 76.2 3" 100% Dry Density: 124.8 pcf 50.8 2" 100% Moisture Cont: 5.4% 38.1 1.5" 100% 25.4 i" 100% 19.1 3/4" 100% 12.7 1/2" 100% 9.52 3/8" 98% 4.76 # 4 95% 2.38 # 8 85% 1.19 # 16 72% 0.59 # 30 58% 0.297 # 50 42% 0.149 #100 31% 0.074 #200 24% �H♦�tGC�I WEIDEMAN COMPRESSOR STATION 214 152A � FIGURE 8 HEPWORTH•PAWLAKGEOTECHNICAL GRADATION TEST RESULTS Gradation Analysis US Standard Sieve Sizes US Standard Sieve Numbers Hydrometer Analysis COBBLES GRAVEL SAND SILT AND CLAY 100% - - - - - - , I + I ( t i i r I II ` le I • ' ll 80% . : i t s ; - t -1____ I t m i • 3 , A 60% i i i - pt i • C H fa a.. I ! A e • 4 0% 1 I l I i I I I ' l lI ( I 20% - ; , ; I I , I I 1 I I I I ! t ' ' I I • i ! I I i t 1 I ' I t ___L_L___ 390.625 78.125 15.625 3.125 0.625 0, 125 0.025 0.005 0.001 Particle Size Diameter In Millimeters - Gradation Curve 3 " Sieve - 3/4" Sieve No. 4 Sieve No. 200 Sieve Particle Size Distribution Cobbles: 0% Gravel: 0% Sand: 86% Silt & Clay: 14% Grain Size (mm) Sieve Size 0/0 Passing Location: P-1 152.4 6" 100% Depth: 3' 101.6 4" 100% Classification: Silty Sand (SM) 76.2 3" 100% Dry Density : 110.9 pcf 50.8 2" 100% Moisture Cont: 5.4% 38.1 1.5" 100% 25.4 1" 100% 19.1 3/4" 100°/u 12.7 1/2" 100% 9.52 3/8" 100% 4.76 # 4 100% 2.38 # 8 99% 1.19 4 16 89% 0.59 # 30 73% 0.297 # 50 53% 0.149 #100 30% 0.074 #200 14% I li I GgWEIDEMAN COMPRESSOR STATION 214 152Atech FIGURE 9 HEPWORTH-PAWLAK GEOTECHNICAL GRADATION TEST RESULTS Gradation Analysis [ US Standard Sieve Sizes US Standard Sieve Numbers Hydrometer Analysis COBBLES GRAVEL SAND SILT AND CLAY 100% I - _ ________ - 80% - - - Z a) 3 E60% - - - -- - - - -- - - ..- - - - -- - - - ---- - - I i i b E II i C 40% - - -, ►--- - -- - - • -- - - -- - - - - ft 20% -- - - - - -- - 1 a - - --- - i - - - - - 390.625 78.125 15.625 3.125 0.625 0.125 0.025 0.005 0,001 Particle Size Diameter in Millimeters =Gradation Curve 3 " Sieve -- -3/4" Sieve No. 4 Sieve No. 200 Sieve Particle Size Distribution Cobbles: 0% Gravel: _ 0% _ Sand: 88% _ Sit & Clay: 12% Grain Size (mm) Sieve Size 0/0 Passing Locatbn: P-2 152.4 6" 100% Depth: 3' 101.6 4" 100% Classification: Sky Sand (SM) 76,2 3" 100% Dry Density: 113.5 pcf 50,8 2" 100% Moisture Cont: 3.5% 38.1 1.5" 100% 25.4 1" 100% 19.1 3/4" 100% 12.7 1/2" 100% 9.52 3/8" 100% 4.76 # 4 100% 2.38 # 8 98% 1,19 ## 16 85% 0.59 # 30 69% 0.297 # 50 52% 0,149 #100 29% 0.074 #200 12% 214 152AI �'teCh WEIDEMAN COMPRESSOR STATION I FIGURE 10 HEPWORTH-PAWLAK GEOTECHNICAL GRADATION TEST RESULTS i I t z O O a I a x I I O w U I m n I I Iiv) VI N V) -. - V' _ o z cg o x it o tA a U • -- •-- - x it a .. n .. V w w 4 v) Q z o z N ° S o o — U Int U ,- lei a �zy 2 o 8 8 W i-4 p .. O O r� 2U hit C a 'Q! E-, In o in Q L M PA - - - __ _ J Q ail d w - - -- -- - —i- — -, -- - CM ,F3ez, M tom. N .�-. r.4 til OZ - I - 1 - - G O Q a a a i VD CO a V) 0 . 14 w I b M V1 O O >s G' C •-+ r,i K0 t� 00 Q N Q� --4 Q' N N 't' O en a § z 8 nt g, a - N O N ON 'O N O, 00 M N 00 ^-4 M f v� U U4 re; M44 I ri -: 2 M N4 ‘D OO 4 4tri u1 r6 '2 i it) d Q o o/ ) to N Z V I I a 'S r...4 - - A C E N z g 1 N rr v+ Z' N seO\ N Cr 1:7‘ v ON N Cr w' M M z v p a — Z I co Ng. -- .- N N N M t 1 M fl to if...? g .� m ro Qa ca as m ca m co cc m m m a a Mn I i a) 4-� coce _ C in N. co r N 0 O f` CO C co co 0. O ►n O N f%- ttry�- r Cu E o N mot' 't ff- Co N (I N L - C L a) Cu r > C ih co in ti co O 0 CO co N `J 2 d J N r 0 0 0 N Cf' r O r Z i= o Q O Q ca , U E o C Z U' W o Tii I J W r Co O Vn P) 0 pp 0 co co U U d a 0 C° in co f� o co co co co r. 1n p t " cMv VI' d- i_ .`-' Icr vo co co co O 0 � 's rLii w D w ¢ N r' N (6 gct- N W co Q W 2 Z i- (a iV t=- 2 a - r.- < j o ►rai rcn- r 0 o co CO.. COo OL M M J O 2t i LT CV Ct I Z 0 o F-- _ } O W W 95 Q n a ti o 0 o o. ,in 0 c C O. Q o W Y +� a 0 co CO N 'e nor) M N J C r r L C) "E' 0 in o h in I 0 Z N a) a a O Flatirons, Inc. — Surveying & Engineering APPENDIX E Inspection Report A blank copy of the sample stormwater facility inspection report. Weideman Compressor Station E April 14, 2014 Weideman Compressor Station Stormwater Facility Inspection Inspection required every 6 months or following major precipitation event. Date: Inspection Type: Rountine Maintenance Follow Up Public Concern Last Rainfall: < 24 Hours 1 -3 Days > 4 Days Inspector: FACILITY OBJECT COMPLIANT YES NO DESCRIPTION PHOTO #s Water Quality Pond Swales Culverts Berms Entry Road Yard Area Other Items to Inspect Water Quality Pond: Check for accumlated sediment - remove as required Check level spreader - repair as required Check for debris and weeds in pond - remove immediately Check for erosion on sides/bottom/embankment - repair immediately Swales/Ditches: Check for accumlated sediment - remove as required Check for debris and weeds - remove immediately Check for erosion on sides/bottom - repair immediately Culverts: Check for accumlated sediment - remove as required Check for debris and weeds - remove immediately Berms: Check for erosion on top/bottom - repair immediately Entry Road : Check culverts under entrances - see above for requirements Yard Area: Check for uncontrolled spills - clean up immediately ..y.: . • . -.. . \ WEIDEMAN COMPESSOR STATION '�\ DRAINAGE PLANSde r 1 , A PORTION OF LAND LOCATED IN THE NORTH HALF OF SECTION 29, mi . . i . -...• \ TOWNSHIP 4 NORTH, RANGE 66 WEST OF THE 6TH P. M., . \ COUNTY OF WELD, STATE OF COLORADO t 'v \ z / . ..„‘ / "AksH.11•:•... / , / 1 • f �T ;�. I ��\.. •._ .rtt: ' i s..• ,-: z :\:•:. :., 1 , , , ..• ... / � - / . \ ,. . 4 baa in- Saw i J n v o / PEI 317E M f 1 �, �1. — Jib -j 4". 03 m r m n r -Sib. r St. I .0 W m �y' 1+ r 4. z z o ix A . 01/2 5 tn 2 I ! I/ �', \ :., \ AvrrArrFWWI i t .'• '� r. J tl le,,) r••• I N � . . Jr, ._ . 1' ' i -5 . -' ' - � � re° ^ n I 1 • ,1. \ ^ �� of a n • �, v (r(/�',' , .../ - ) it' i 0 zit: / ! jt X1 TRAVEL l �p� \ / VICINITY MAP 4" to a 1i / �/ ; SLOPE 0.46% t ' SCALE: 1'-1500' / , /1/4..' LQICTH: 21s l �.::., \ Cx 4• i1 `-' • Ito t„ ! ` •, 05 EwsrsrcH� I °St.- f/ / \ / / �' UNDEVELOPED BASIN RUNOFF SUMMARY at* / TIME OF / / �` ` BASIN AREA IMPERVIOUS IMPERVIOUS CONCENTRATION Ca Cio cm, °> (cis) °1° (as) °m (C(S) / / �' ' (cc) AREA (o°) RATIO TC (min) CC • ` X1 3.57 0.00 2% 45.5 0.09 0.17 0.37 0.4 1.0 4.4 �" 0 n/ SOIL 28 / 1i tZ/ XI OVERLAND FLOW .•r' ' '•••1-.^- _ La O S (.9 SLOPE 0.74% ; I' '1:: Legend - _ 0- < WITH / 1 ! /i••• x�s —- - EXISTING MINOR CONTOURS z // 9 /// / • .4 .4•••,::.. . ---soon-— — E)OSTING MAJOR CONTOURS U Q 0 A Mq'tlSID / // 1 //. _ �.��;. '! PROPERTY UNE Z ,',^.I.m Z - MI M1 in EXISTING MAJOR BASIN DELINEATION Q • O/ ‘ fi. -•IlC4t- % /60 �.:), tir 4C FLOW ARROW W O 2 // • // / ! / ° ' . r � °'� / DENOTES BASIN DESCRIPTION / X3 ) X.XX DENOTES BASIN / A AREA (ACRES) / iI!af' i,1. X.XX NY WW DENOTES % IMPERVIOUS / / / Sl'' WW 2 .YY DENOTES MINOR COEFFICIENT / / r •,J : / / .ZZ DENOTES MAJOR COEFFICIENT CCg s r / e„ J L.: :.i I a SOILS BOUNDARY / 47!4.14 ' / �� i T' , 301L 30 / • I / _ E T i • O 1§11 / I' / TO;/ / ••~ GRAPHIC SCALE " 1. / f /.I / A•!i /`^• e / B@CHMARK INFORMATION a a » lti a // / i/ / K. a A GPS DERIVED ELEVATION WAS ESTABUSHED AT AN ONSITE 9 y- LOT D / ! 1, !• ' / / BENCHMARK AT THE EASTERLY CORNER OF SAID LOT D, BEING A ( TN nzr ) AMENDED RECORDED / �. pr MAG NAIL IN THE DITCH ACCESS ROAD, WITH AN ELEVATION OF 1 Inch - 10 ft. EXEMPTION NO. / / 4767.55 FEET. A CHECK SHOT, 0.1't, WAS TAKEN ON NG5 POINT = "'" , 105?-29-2 / / 0 pE _ / / / ;' PLATTEVILLE AZ MK 3, BONG A NGS DISK, IN CONCRETE, P 0 01. •• • REC NO 34630934022. / / / / /� ! / ..._,...• - > / STAMPED 'PLATTEVILLE, 1935, 1978', LOCATED 6.2 MILES FROM O .*.��'�llC' • ! 03/20/2007 / / *i' Eli / SITE, WITH A PUBUSHED ELEVATION OF 4819.97 FEET (NAV088). ,• ; �V/ ... Jr. '! // //t ,-' .•, / NO DIFFERENTIAL LEVEUNG WAS PERFORMED TO ESTABUSH THIS ; „, 25620 s•_4 / // �t i .r• '• '`yFAND? -/I / , ,� M I1 /°°j ;` t� / DRAWING /� ' , / DR-1 / - ia , - / SHEET J- f /� % ," , ' / 1 OF 2 , . .,.. ., . . .....: \ WEIDEMAN COMPESSOR STATION . _. , �` \ DRAINAGE PLANS a A PORTION OF LAND LOCATED IN THE NORTH HALF OF SECTION 29, I •.> • TOWNSHIP 4 NORTH, RANGE 66 WEST OF THE 6TH P. M, A I I '�; '•`ti: \ COUNTY OF WELD STATE OF COLORADO I '• , 701.14 `r'<` ;T 1 ,•�•�j FI •`' 700.4 r, MI ^,L .•,Y •-�}.. ( y, " .1 %• `"• - \ STAGE STORAGE FOR WATER QUALITY POND "fie` a ' 1 I •.,_:'. '. it �� *`F� .• \ SURFACE AREA VOLUME BELOW 1 SITE - 1-1611141 t I + ''• `° �• ♦ • '''' ELEVATION (FT) AT AC) S(ATAGE LABEL .4) �y • STAGE STORAGE _ Al! t '''. ./+ , ♦ \~ ' _ 4759.79 0 - BOTi0M _ — _ �. J _I+ _ rN� `� I •, ;t�. Rr ♦ :,\•...,. 4760.00 229 24 1^+ _ ,� ' ,ter \ I r � i � i1 � 1 LEVEL sPaEADEx •' ` '1 �, ♦ ' , \ • • \ 4760.50 927 313 I — n.�+ .n o n o a y SEE DRAWING C-1 PROPOSED - '•\".• ;� � 1 4761.00 2,166 1,086 '' i • " • d , •: , ( )l f� EERY ♦♦,. `. �• p-• 4761.50 4,266 2,694 WOCV=2,642 CF . -1-_•P!4 `, !: • b a '!•/ • ♦ a ,.;; 4762.00 8,192 5,809 10-YR=5.067 CF �., ay ' m p E to r'1: •�.; WATER QUA1117 Para `•• \ 4762,50 14621 11 512 / "�' 1 Cr N ix 5�' 1',.i: TOP are: 7ILoO ♦ • .. : t , n v o �, 3A, . - _ . i' r.1' ;': . PROPOSED r: - °tnSWALE •7• •}• �;1 - — • - - • 1 S\?i.�; •\ .•" \ - il. hhh: /may. - ,y/'r . , �� N ` �t_� � (CURSE) `\ ��. VICINITY MAP / 1/ '•` 1. %.: ' A tP[.•1 TRAWL 2 SCALE: 1'=1500' h 4701. �+ t 470 N - N�% � 'i` :s-,MOTH: 33Y N. PANt r! CAVoL�7E a7t7I V •- M / . •�• ' 5�%r�1 .♦ C2 OVERLAND PLOW ap 4-, • , t . \ �.%4:'- 4: 1t.. \ g Q aD 7 I • s: IA `r�. SLOPE: MIR t \ t ` `- , N 470 ID • •• ��' LENOTIt 31' I `SYr l f .,.''•.� •., :1,: •, \ II LOPED 1N RUNO8UMY ce J� • IMPERERVIOUS% CNTRATION c ot flARERATIOs 3 (�)(m,n)♦ \ ,_. � ._ \ / A0. 44% 2.7 0.32 1.3� 0. 44X 2.7 0.32 1.0,♦ I ` J� . % 04oX 2.7 0.30 1.2 18 .0. 2X 3.2 0.09 0,1 02 /. A I Al TRAWL • • _ //� [[,,.. ` I —�3 `` SLOPE: 23.0x ' \ C2 0.10 0.00 29X 5.2 0.25 0.32 0.47 0.1 0.1 0.4 '�1 .` / 1 y UOUD �LENGRt 0' •, 7 C3 0.16 0.00 2X 12.7 0.09 0.17 0.37 0.0 1.0 0.4 m r . PROPOSED ` ; 1,14 "p EXCHANGER '\1P ••'' :.r \ t N J . NE-031 , /-/ • �/, ! ! ` , I 47e4 4703. �'..' \ / Lv 754. ' • Legend DESIGN POINT SUMMARY �" , ' r/ CONTACTOR , - - - EXISTING MINOR CONTOURS DESIGN ASSOCIATED TOTAL BASIN IMPERVIOUS o o ors) o cfs legitCr V-22Dt �, • �' • • — -st D EXISTING MAJOR CONTOURS a (�) Lo ( ) too ors) t4/ `� / �V i oR • — _ — — POINT BASINS AREA Coo) RATIO / CgiPFtE550R DISOH. , . .l CHANNEL 2 COALESCING �� ` �, 5000 PROPOSED MINOR CONTOUR 1 B 1.47 40% 1.2 1.8 4.9 F-2200 , t O \ O t \ r TEc ' ' t , 2 Al 1.14 44% 1.0 1.5 3.9 CC . . . �. ` DENY /` . 0000 PROPOSED MAJOR CONTOUR CONDENSER SKID CHANNEL t ••. • •.• • ti•!•• 3 A B 2.99 42% 2.5 3.8 10.1 0 Z B TRAVEL 2 / O ' LEG ` `� :y��ti s..�-Yw• PROPERTY LINE N SLOPE: 0.4aQ / UAX -UP PROP'S ' ':,}'...4••••I•1 1� 0� 0� r al d ' \ LENGTH: 341' // SOIL 29 �� C COALESCING i1LITR ��, r, PROPOSED MAJOR BASIN DELINEATION GO Z W \ / s • .C IX \ // ` A & Al 00•ERLANO RON 1 F ,�, r-; .—. _._. SCALE LL C9 �/ � SLOPE: 1.03% '� `' : ...VI, Z Q OIL TANK r• / LENGTH: 137 t " t.:•.4; , BERM 2 Q d Z Is / { / y.',:: FLOW ARROW o }� p o IL TANK / v it\ ,/ OaOENSATF % ci OVERLAND FLAW r . - r .I ; ..,/4;• < PRIYOS N TANK SLOPE: 8.2% I/ ' • • • • /1\ DESIGN POINT Z \IOC 1K-1002 • LENGTH: 10' •$ / •••'''A�:: / POMPOM' 'N , • • 76x34 AM guava ; I/�/ // DENOTES BASIN DESCRIPTION Q U� O ' A DENOTES BASIN ID kali- / AIR �� f�' /iii ; 1:::,�s A3 X.XX DENOTES BASIN AREA (ACRES) 2 C W \ • /� / / �" O• X,XX .YY WW DENOTES % IMPERVIOUS W > •\ \ ` ` 10-YEAR) � �, t L'` _. Z DENOTES MAJOR COEFFICIENT.. WW .YY DENOTES MINOR COEFFICIENT ((100-YEAR) 0 0 WATER TANK B OVERLAND FLOW 47156 • �j w SLOPE: 0.80xC3 TRAVEL 1 \\ TK-1001 SLOPE 1.10% / / i./ • LENGTH: 473' ♦ LENGTH: 143' / 11444%..... �C8innic !t r •4? /`I, O.t! .17 DOSED / ' `1 / // çt4yir, fr 4. g,ill qqEl TRAVEL a T SLOPE: 23.0x7 ` t SOIL 30 / :" o r g'� 28 r J LENGTH: a• 761.77 PROPOSED • r/ / '; , 0 5 CO l tiur CHANNEL 2 SEMI / Pyt �� 3le 6 I / it r/ �t, t 9BJpIMARIC INFORMATION 6 t'a`' 0 -' AMENDED RECORDED / / /LOT Dr //f / / A CPS DERIVED ELEVATION WAS ESTABUSHED AT AN ONSITE It EXEMPTION NO. / / i.%% • BENCHMARK AT THE EASTERLY CORNER OF SAID LOT D, BEING A ii 1057-29-2 / /SHALE /' GRAPHIC SCALE MAG NAIL IN THE DITCH ACCESS ROAD, WITH AN ELEVATION Of = me. AMRE-4022 / PROPOSED / / N /0 4767.55 FEET. A CHECK SNOT, 0.1'±, WAS TAKEN ON NGS POINT =• �' • RFOk '' REC NO 3463093 / / � T •, PLATTEVILLE AZ MK 3, BANG A NGS DISK, IN CONCRETE, ' , W 03/20/2007 ��%' 1'+'' B� STAMPED PLATTEVILLE, 1935, 1978', LOCATED 6.2 MILES FROM , •L ////.' // ''7 / ( >P 1� ) SITE, VAN A PUBUSHED ELEVATION OF 4819.97 FEET (NAVD88). { • 1 '? ; / t , /i / NO DIFFERENTIAL LEVEUNG WAS PERFORMED TO ESTABLISH THIS /a�L,� • d / 1 Inch so tt ELEVATION. • •' l, 0_;4 //� v' / ,.,F AN• F 'S / /' el . G, \\ / �o // / .; `� /c. DRAWING 4, •`t 4711E • ,, �, , 4 / DR-2 y / c3 ovESAA zoz / ;�;' ' ` / SHEET < LENGTH: 1C It' Final Drainage Report j For AKA Energy Group , LLC Weideman Compressor Station Weld County , Colorado Prepared For AKA Energy Group , LLC 13472 Weld County Road 40 Platteville , CO 80651 ( 970 ) 737 - 2601 April 14, 2014 FS# 14- 100501 Prepared By : Flatirons, Inc . Surveying , Engineering & Geomatics 655 Fourth Avenue Longmont, Colorado 80501 303-443 - 7001 FINAL DRAINAGE REPORT FOR AKA ENERGY GROUP , LLC Weideman Compressor Station WELD COUNTY, COLORADO Prepared for: AKA Energy Group, LLC 13472 Weld County Road 40 Platteville, CO 80651 (970) 737-2601 April 14, 2014 Prepared by: Flatirons, Inc. Surveying & Engineering 655 Fourth Avenue Longmont, CO 80501 FS1# 14-100501 Flatirons, Inc. — Surveying & Engineering Table of contents Certification 1 Vicinity Map 2 1 .0 Location and Description 3 Background 3 Project Location 3 Property Description 3 Project Description 4 2.0 Drainage Basins and Sub-Basins 4 Major Basin Description 4 Sub-Basin Description 5 3.0 Drainage Design Criteria 5 Regulations 5 Development Criteria Reference and Restraints 5 Hydrological Criteria 6 Hydraulic Criteria 6 4.0 Drainage Facility Design 7 General Concept 7 Specific Details 9 5.0 Conclusions 11 References 12 Appendix A A Hydrology Computations A Appendix B B Hydraulic Computations B Appendix C C Floodplain Information C Appendix D D Geotechnical Report D Appendix E E Inspection Report E Weideman Compressor Station April 14, 2014 Flatirons, Inc. — Surveying & Engineering Cer t if icat io n "I hereby certify that this report for the final drainage design of the Weideman Compressor Station was prepared by me (or under my direct supervision) in accordance with the provisions of the Weld County storm drainage criteria for the owners thereof" ' p0 RE pQ`PG4ST o coo Ili Kenneth W. Curfrnan PE, PLS / 25620 a i For and on Behalf of Flatirons, Inc. I • State of Colorado No. 25620 ••••• N • AND9NC, Akwecisalw Weideman Compressor Station 1 April 14, 2014 Flatirons, Inc. — Surveying & Engineering Vicinity Map 1: . m . 1 , •a 60 .4or. it.,J117111114 • c tel.,. iimil :Ay: v County Road 42 '�_ ; •�� ► _ . _ .45 '. - lirlbrA. it, r ft " a... i - -' Id t. ., , , 1 rut . d f .A . , SITE _tie i _ .Os .; tr. . . r te' --- 'PP / . . .. • '...1, .1 ' et .*i . //771' r--- Aill • 1 _. • 1,1 r �. 4. Ai �,l i to 7 -A .i, . . • 1 , , • )t. . . , • ic / r_. .: \ . • r C_oun'tyitoed.3as © GOOGLE 2014 ` I i o } v r (Not to Scale) A Weideman Compressor Station 2 April 14, 2014 Flatirons, Inc. — Surveying & Engineering 1 . 0 Locat ion and Descr ipt ion Background This Final Drainage Report is prepared for a Use by Special Review (USR) Permit application from AKA Energy Group, LLC of Platteville, CO for the Weideman Compressor Station. The Final Drainage Report follows the criteria set forth by Urban Storm Drainage Criteria Manuals (USDCM), Volumes 1, 2 and 3, and the Weld County Storm Drainage Criteria Addendum to the Urban Storm Drainage Criteria Manuals, Volumes 1, 2 and 3 dated October 2006. Project Location The Weideman Compressor Station is located in a portion Lot D, Amended Recorded Exemption No. 1057-29-2 AMRE 4022 described under Reception Number 3463093 in the records of Weld County, and situated in the Northwest Quarter of Section 29, Township 4 North, Range 66 West of the 6th P.M., County of Weld, State of Colorado. The property is surrounded by land designated as Agricultural Zoning. The project site and all of the surrounding land are under Weld County jurisdiction. There are no major lakes, streams, or water resource facilities within the property. A small concrete lined irrigation ditch parallels the eastern and northern project boundaries. The Farmer's Independent Ditch flows northeasterly and parallels the eastern property boundary approximately 25 feet east the property. The top of Farmer's Independent Ditch is elevated approximately 3 feet above the subject property, and water from the ditch feeds the concrete lined irrigation ditch on the north and east sides of the property. Land owned by the Boney Trust bounds the property on the north, and the Strear Farms Company owns the land that forms the eastern property boundary. The adjacent property to the south and west are portions of Lot D, Exemption No. 1057-32-2 RE 4508. Property Description The site is approximately 3.3 acres in size, and has historically been agricultural land. The land was cultivated during the 2013 growing season. The rectangular shaped property extends 500 feet in a northwest/southeast direction and 250 feet in a northeast/southwest direction. The site is relatively flat and has 3-feet of fall from the higher eastern side to the lower western side. The eastern side of the property is at an elevation of 4764, and the elevation of the western part is 4761 . The average slope across the property is 0.6%. Runoff from the site flows northwesterly to center pivot irrigated crop land adjacent to the project. The property is located one-half mile south of Weld County Road (WCR) 42 at the intersection of an undesignated 2-tract dirt road and the Farmer's Independent Ditch service road. The service road for the Farmer's Independent Ditch intersects WCR 42 to Weideman Compressor Station 3 April 14, 2014 Flatirons, Inc. — Surveying & Engineering the northeast of the property and WCR 40 to the southwest. Access to the property will be from WCR 42 along the undesignated, 2-track dirt road, or from the service road that parallels the Farmer's Independent Ditch. A concrete lined irrigation ditch parallels the eastern and northern property lines. The irrigation ditch has a trapezoidal shape and is 1 .5-feet deep, 4-feet across the top, and has a 1 -foot wide flat bottom. Flows in the ditch move northerly and westerly, and the ditch is fed by an outlet structure located near the southeast corner of the property connected to the Farmer's Independent Ditch. The top of the west and south sides of the concrete lined ditch are elevated 9 to 12-inches above the natural ground surface. Runoff from the property does not enter the ditch, and water in the ditch is conveyed away from the property to the north. The soil covering the site is Julesburg Sandy Loam. The soil is divided between Map Unit 29 and Map Unit 30. Both units are comprised of the Julesburg Sandy Loam, with Unit 29 associated with slopes of 0% to 1%, and Unit 30 associated with slopes of 1% to 3%. Unit 30 soils cover a 100-foot strip of land along the eastern property line, and the remainder of the site is covered with Unit 29 soils. Both Julesburg Sandy Loam soils are well drained and assigned to Hydrologic Group `B' by the United States Department of Agriculture (USDA) National Resources Conservation Service (NRCS). Project Description The Weideman Compressor Station is a natural gas facility. Buried pipelines connected to local infrastructure are used to feed the compressor station, and the compressed natural gas from the station will be delivered through other buried pipes. The proposed development will add five compressors and associated infrastructure to the property. The portions of the site that are not be used for appurtenances or buildings will be covered with a crushed recycled concrete surface. The proposed drainage concept is to replicate historic drainage patterns while utilizing a water quality pond situated at the northwestern edge of the property. The layout of the proposed improvements will not adversely impact the drainage concept, and increased runoff from the site will be allowed to infiltrate in the surrounding farm fields. 2 . 0 Drainage Basins and Sub -Basins Major Basin Description The property is located in the South Platte River Basin approximately 2 miles southeast of river. The South Platte River flows to the northeast, and the land between the river and the site is irrigated agricultural land. The excess runoff from the site will infiltrate in downstream agricultural fields to the west of the site. Runoff from the site will not flow directly to the river. The Farmers Independent Ditch, which is located uphill from the site meanders in a northeasterly direction above the South Platte River delivering irrigation water to farms. Weideman Compressor Station 4 April 14, 2014 Flatirons, Inc. — Surveying & Engineering According to the FEMA Food Insurance Rate Map; Community Panel No. 080266-0750 C, Dated September 28, 1982, the Weideman Compressor Station property is located in Zone C, Areas of minimal flooding. Sub-Basin Description Historically one sub-basin, X1 , defines the existing, onsite drainage basin. Runoff from Basin X1 sheet flows across the property in a northeasterly direction and drains to cultivated farm fields located west of the site. Offsite surface runoff flowing towards the property from the east is intercepted by the concrete lined irrigation ditch and conveyed around the property. Refer to drainage exhibit DR- 1 in the back of this drainage report for the delineation of existing drainage basin. 3 . 0 Drainage Design Cr it er is Regulations This final drainage report is prepared with criteria set forth in the Weld County Storm Drainage Criteria (WCSDC) Addendum to the Urban Storm Drainage Criteria Manual (USDCM), and Volumes 1 , 2, and 3 of the Urban Storm Drainage Criteria Manual. Spreadsheets supplied by Urban Storm Drainage website and developed by Flatirons, Inc. were used to calculate runoff, water quality capture volume, open channels, and culverts. No deviations from the either the WCSDC or the USDCM are required for the installation of the drainage improvements, except detention, which is not proposed for the site. The site is surrounded by farm fields that create a buffer that extends nearly one-half mile in all directions around the site. Runoff from the site will flow northwesterly onto an irrigated farm field where it will infiltrate. The area of the field to the northwest of the compressor station is approximately 160 acres, and the proposed development site contains less than 4 acres. Assuming the compressor station is part of the 160 acres of farm field, and the proposed development is 42% impervious. The imperviousness of the farm field will increase by less than 1 .5% due to the development of the site. A water quality pond will be constructed at the northwest corner of the compressor site in lieu of a detention pond. The water quality pond will treat the runoff from the developed site before releasing it over a level spreader and to the farm field to the northwest of the property. Development Criteria Reference and Restraints There is neither a project master plan, nor a regional drainage master plan for the site. The site is located on a relatively flat, undeveloped piece of land with no existing structures. Overhead utility lines and power poles are situated along the eastern side of the property. There are no existing buried utilities on the site; however, buried pipelines will be installed as part of the proposed improvements for the property. Weideman Compressor Station 5 April 14, 2014 Flatirons, Inc. — Surveying & Engineering Hydrological Criteria This drainage report was prepared using the 10-year event for the minor storm in accordance with Section 7. 1 of the Weld County Storm Drainage Criteria Addendum to the Urban Storm Drainage Criteria Manuals, Volumes 1 , 2 and 3; and the 100-year event for the major storm. The design rainfall was obtained from NOAA's Precipitation Frequency Data Server website. The values are based on National Oceanic and Atmospheric Administration (NOAA) Atlas 14, Volume 8, Version. The latitude and longitude of the site, 40.2833° North and 104.8011 ° West, was used to obtain the point frequency rainfall for the project. The minor storm ( 10-year) precipitation depths are 1 .39 inches for the 1 -hour event, 2.01 inches for the 6-hour event, and 2.75 inches for the 24-hour event. The major storm (100- year) precipitation depths are 2.73 inches for the 1 -hour event, 3.94 inches for the 6-hour event, and 4.75 inches for the 24-hour event. The Rational Method as outlined in the USDCM, Volumes 1 and 2 was used for calculating peak runoffs for the drainage report. Proprietary spreadsheets developed by Flatirons, Inc. based on the formulas developed in the USDCM were used for runoff calculations and to calculate the Water Quality Capture Volume (WQCV). Copies of the spreadsheets can be found in Appendix A and Appendix B. The Detention Basin Volume Estimating Workbook spreadsheet, version 2.32, distributed by the Urban Drainage and Flood Control District (UDFCD) was used to calculate stage- storage volume for the water quality pond. Hydrological calculations for this report are based on UDFCD spreadsheets that are available to the public. Proprietary spreadsheets from Flatirons Inc. based on formulas developed for the Rational Method by UDFCD were also used. Hydraulic Criteria The drainage facilities that will be used to convey and treat storm water runoff on the site are based on parameters developed in the USDCM and WCSDC literature. There are no inlets or storm sewers on the site. Runoff is conveyed on the surface of the proposed site, except where a culvert is required under the project entry. No check or drop structures are included as part of the drainage facilities for the site. Open channels are designed to carry the 100-year flows with at least a 0.5-foot freeboard. The side slopes of the channels are 4 to 1 , and the channels are considered to be riprap lined excavated channels that are straight, uniform and clean. The Manning's "n" value for such a channel is 0.025 for capacity checks and 0.018 for stability checks. The Hydraflow Express Extension for AutoCAD Civil 3D 2013 was used for open channel calculations. Minimum culvert capacity is based on the developed 100-year storm, and the maximum headwater to diameter ratio (HW/D) is 1 .0 for the 10-year storm and 1 .5 for the 100-year Weideman Compressor Station 6 April 14, 2014 Flatirons, Inc. — Surveying & Engineering storm. Both reinforced concrete and corrugated metal pipe were considered, but CMP was ultimately chosen. The Manning's "n" value for CMP is 0.025. No flared end sections are proposed for the culvert. The Hydraflow Express Extension for AutoCAD Civil 3D 2013 was used for culvert calculations. The applicant is proposing to construct a linear shaped water quality pond located at the northwest corner of the property in lieu of a detention pond. Storage in the water quality pond will be comprised of the volume of the open channels that surround the property. Runoff from the site will be conveyed to the water quality pond and released to the same cultivated field to which it has historically flowed. The subject site is surrounded by agricultural fields and runoff generated from the site will be directed to the farm fields. The area of the farm fields to the northwest of the compressor station is approximately 160 acres, and the proposed development site contains less than 4 acres. Assuming the compressor station is part of the 160 acres of farm field, and the development is 45% impervious. The imperviousness of the farm field will increase by less than 1 .5% due to the development of the site. The water quality pond will provide the required Water Quality Capture Volume (WQCV). All water in the water quality pond including the WQCV below the elevation of 4761 .50 will be allowed to infiltrate. The pond will empty based on location specific infiltration rates given in the Geotechnical Engineering Study prepared by HP Geotech, dated April 11 , 2014. An additional one-foot of freeboard is included in the pond above the elevation of the level spreader. All hydraulic calculations for this report are based on spreadsheets, and methods that are available to the public. The calculations and results can be found in the appendix. 4 . 0 Drainage Facil it y Design General Concept The drainage patterns of the existing onsite basin will not be significantly altered by the site improvements. Historically, the property of the Weideman Compressor Station has been irrigated agricultural land that was cultivated as recently as the 2013 growing season. The proposed drainage concept for the Weideman Compressor Station is to replicate historic drainage patterns. Onsite flows will be directed to the water quality pond at the northwest corner of the project which is the natural low spot of the site. From the water quality pond, runoff will be allowed to sheet flow over a level spreader and into the surrounding farm fields. The existing drainage basin is designated Basin X1 , and it contains the total developed site. The area of Basin X1 is 3.57 acres, and the 10-year and 100-year peak flows are 1 .0 cfs and 4.4 cfs respectively. Drawing DR-1 , found in the back of this report, shows the drainage patterns and tabulates the drainage calculations for historic conditions. The developed site is divided into two drainage basins, designated Basin A and Basin B. Each basin is approximately 1 .5 acres in size, and both basins drain to the 2-feet deep swale Weideman Compressor Station 7 April 14, 2014 Flatirons, Inc. — Surveying & Engineering that surrounds the onsite pad. The peak 10-year flows for Basins A and B are 2.0 cfs and 1 .8 cfs, respectively. The peak 100-year flows are 5.2 cfs for Basin A and 4.9 cfs for Basin B. Surface runoff will be allowed to sheet flow from the middle of the property toward the open channels that surround the property. The open channels are 2-feet deep with 4 to 1 side slopes. The high point of the open channels is near the midpoint of the eastern side of the property. The open channels are designated Channel 1 and Channel 2. Channel 1 runs along the north property line, and Channel 2 runs along the south project boundary. From the high point, the open channels flow to the north and south along the eastern edge of the property. The open channels then continue to the west along the north and south property boundaries of the site. Upon reaching the western edge of site, the north channel (Channel 1 ) enters the northern side of the water quality pond located at the northwest corner of the property. The southerly channel (Channel 2) flows to the north and directs flows to an 18- inch CMP culvert under the entry road. The culvert is designated Culver 1 and it conveys the water in the swale into the south end of the water quality pond. The water quality pond will only treat onsite generated flows. Three small developed basins, designated Cl , C2, and C3, are situated around the periphery of Basins A and B. Basins Cl , C2, and C3 are located on the outside slope of the 2-foot berm that surrounds the site, and contain 0.32 acres, 0. 10 acres, and 0. 16 acres, respectively. The peak 10-year flows for Basins Cl , C2, and C3 are 0.2 cfs, 0. 1 cfs, and 0. 1 cfs. The peak 100-year flows for the basins are 0.8 cfs, 0.4 cfs, and 0.4 cfs. Runoff from the basins will be allowed to sheet flow off the berms and flow toward the northwest following natural drainage patterns. Basin Al is a sub-basin of Basin A and was defined to estimate the peak flows that are conveyed by the northerly swale that surrounds the onsite pad. The area of Basin Al is 1 . 14 acres and the peak 10-year and 100-year flows are 1 .5 cfs and 3.9 cfs, respectively. Drawing DR-2, located in the back of this report, shows the drainage patterns, site improvements, and tabulates the drainage calculations for developed conditions. Basin Summary Basin Area (ac.) Impervious `% Tc (min.) Qto (cfs) Qioo (cfs) X1 3 .57 2 45.5 1 .0 4.4 A 1 .52 44 12.7 2 .0 5 .2 Al 1 . 14 44 12 . 7 1 .5 3 .9 B 1 .47 40 12 . 7 1 . 8 4.9 Cl 0.32 2 13 .2 0.2 0. 8 C2 0. 10 29 5 .2 0. 1 0.4 C3 0. 16 2 12 . 7 0. 1 0.4 "fable 1 Weideman Compressor Station 8 April 14, 2014 Flatirons, Inc. — Surveying & Engineering No offsite runoff is conveyed across the site. The runoff that approaches the site is prevented from entering the site by a 2-foot high berm that will be built on the periphery of the developed site. The berm is set a minimum of 8 feet outside of the open channels that surrounds the onsite pad. The top of berm is elevated at least 2-feet above the flowline of the swale around the onsite pad and has side slopes set at 4 to 1 . The berm does not exist at the entry road, but the high point of the entry road is set at an elevation that is equal to the surrounding berm. The proposed hydraulic structures for the developed site includes open channels (Channels 1 and 2) that surround the property, an 18" CMP culvert (Culvert 1) to convey flows under the entry road, and a level spreader that will release the flows from the developed site. Open Channel Summary Description Ditch Design Max. Water Max. Depth Peak Q100 Depth** Velocity*** Freeboard (ft) (cfs) (ft) (fps) (ft) Channel 1 2 .0 3 .9 0.67 2 . 8 1 .3 Channel 2 2.0 4.9 0.79 2 .5 1 .2 Table 2 * * Based on design channel with a manning's n of 0.025 and the minimum channel slope. * * *Based on design channel with a manning's n of 0.018 and maximum channel slope Culvert Summary Description Culvert Design Max. Water Max. Diameter Peak Q100 Depth Velocity Slope (in) (cfs) (in) (fps) (%) Culvert 1 18 4.9 12.9 3.61 1 .00 Table 3 Specific Details All drainage improvements for the expansion property are in compliance with the Weld County Storm Drainage Criteria Addendum and the Urban Storm Drainage Criteria Manuals, Volumes 1, 2, and 3. No drainage problems were encountered during the design of the expansion property improvements. Weideman Compressor Station 9 April 14, 2014 Flatirons, Inc. — Surveying & Engineering Five natural gas compressors and associated infrastructure will be constructed on the site. The compressors and associated infrastructure are assigned an imperviousness of 90. The site will be leveled and surfaced with a crushed recycled concrete product which is assigned an imperviousness of 40. Undeveloped portions of the site will be assigned an imperviousness of 2. The weighted average of the imperviousness was used to assign runoff coefficients for each delineated basin that contained more than one type of imperviousness. The calculations for the weighted averages can be found in Appendix B. Detention is not proposed for the site. The site is surrounded by agricultural fields that are irrigated with center pivots. The farm fields create a buffer that extends nearly one-half mile in all directions around the site. Runoff from the site will flow northwesterly into an irrigated farm field where it will infiltrate. A water quality pond will be constructed at the northwest corner of the site in lieu of a detention pond. The water quality pond will treat the runoff from the developed site before releasing it over a level spreader and into the farm fields to the west of the property. Water in the pond below the elevation of 4761 .50 will be allowed to infiltrate. Calculations indicate the required detention volume for the 10-year storm is 5067 cubic feet, which is less than the volume of the water quality pond. The maximum depth of water in the water quality pond is 2.21 feet, and based on the geotechnical report, the water quality pond will be constructed in loose silty sand. The water quality pond contains 5809 cubic feet, and the required WQCV is 2642 cubic feet. The infiltration rate of the soil at the southwest corner of the property, which is near the pond, is 60 minutes per inch or 1 -inch per hour based on the geotechnical report. Based on the recommended infiltration rate, it will 26.5 hours for the full pond to infiltrate. Calculations indicate the required detention volume for the 10-year event is 5067 cubic feet, and the required detention volume for 100-year event is 9085 cubic feet. Water Quality Pond Stage Storage Table Elevation Area at Elevation Volume Below Stage Comments (st) (ci) 4759.79 0 0 Bottom of Pond 4760.00 229 24 4760.50 927 313 4761 .00 2166 1086 4761 .50 4266 2694 WQCV Elev = 4761 .50 4762.00 8192 5809 Level Spreader = 4762 .00 9762.50 14,621 11 ,512 Table 4 Access to the drainage facilities will be easily accessible from the onsite pad. There are no anticipated issues accessing the drainage facilities for maintenance purposes. The water quality pond, open channels, berms and culvert are adjacent to the onsite pad. Maintenance Weideinan Compressor Station 10 April 14, 2014 Flatirons, Inc. — Surveying & Engineering will include keeping culverts, swales, and pond free of accumulated sediment, obstructions, and debris, keeping berms and embankments erosion free, and inspecting the yard for uncontrolled spills. All onsite drainage facilities will be private, and the plant operator will be responsible for the maintenance of onsite drainage facilities. The plant operator will inspect offsite drainage patterns and flows to make sure unforeseen offsite drainage issues don't have an adverse impact on plant operations. Inspections will take place at least every six months or following major precipitation events. Copies of the inspections shall be kept on file at the site and made available upon request to those authorized to review the inspections reports. An inspection log can be found in Appendix E. 5 . 0 Concl usions The Final Drainage Report has been prepared in compliance with the criteria set forth by Urban Storm Drainage Criteria Manuals (USDCM), Volumes 1 , 2 and 3, and the Weld County Storm Drainage Criteria Addendum to the Urban Storm Drainage Criteria Manuals, Volumes 1 , 2 and 3 dated October 2006. It is intended to be submitted as part of, and in support of a Weld County Use by Special Review Permit application for AKA Energy Group, LLC of Platteville, CO for the Weideman Compressor Station. This proposed development is located in the middle of farm fields and will not have any negative impacts on the upstream or downstream properties, or adversely affect adjoining property owners. The site is surrounded by agricultural land, and there are no structures that could be damaged by surface runoff immediately downstream from the property. Weideman Compressor Station 11 April 14, 2014 Flatirons, Inc. — Surveying & Engineering Refer en ces - Weld County Strom Drainage Criteria Addendum to the Urban Storm Drainage Criteria Manuals Volumes 1 , 2, and 3 October 2006 Weld County Public Works Department. - Urban Storm Drainage Criteria Manual Volumes 1 and 2 June 2001 ; Revised April 2008 Urban Drainage and Flood Control District - Urban Storm Drainage Criteria Manual Volume 3 - Best Management Practices November 2010 Urban Drainage and Flood Control District - FEMA Flood Insurance Rate Map September 28, 1982 Community Panel No. 080266-0750 C - USDA Natural Resources Conservation Service National Cooperative Soil Survey http://websoilsurvey.nres.usda.gov/app/ - NOAA National Weather Service Precipitation Frequency Data Server Hsdc.nws.noaa.gov/hdsc/pfds - Hepworth-Pawlak Geotechnical, Inc. Geotechnical Engineering Study Proposed Addition to the Weideman Compressor Station Located Approximately on '/4 Mile South and '/2 Mile East of Intersection of County Road 27 and County Road 42, Weld County, Colorado, April 11 , 2014. Weideman Compressor Station 12 April 14, 2014 Flatirons, Inc. — Surveying & Engineering Appendix A Hydrology Computations > Land Use Assumptions o NOAA Rainfall intensity maps o NRCS soils maps and descriptions > Historic Runoff o Runoff Coefficient vs. Watershed Impervious Tables o Runoff coefficients determination o Time of Concentration calculations (Tc) o Peak Q calculations > Developed Runoff o Runoff Coefficient vs. Watershed Impervious Tables o Runoff coefficients determination o Time of Concentration calculations (Tc) o Peak Q calculations o Design point calculations Weideman Compressor Station A April 14, 2014 Precipitation Frequency Data Server http://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=40.2833&l0... .0,0 OF NOAA Atlas 14, Volume 8, Version 2 �v ,� g Location name: Platteville, Colorado, US** et noes \ •• 44-:=. • Latitude: 40.2833 , Longitude: -104.8011° sliP fi�o �� Elevation: 4762 ft* 4 ? P 44..0* * source: Google Maps ,"�. POINT PRECIPITATION FREQUENCY ESTIMATES Sanja Perica, Deborah Martin, Sandra Pavlovic, Ishani Roy, Michael St. Laurent, Carl Trypaluk, Dale Unruh, Mchael Yekta, Geoffery Bonnin NOM, National Weather Service, Silver Spring, Maryland PF tabular I PF graphical I Maps & aerials PF tabular PDS-based point precipitation frequency estimates with 90% confidence intervals (in inches)1 Average recurrence interval (years) Duration 1 2 5 10 25 50 100 200 500 1000 5-min 0.238 0.288 0.386 0.481 0.635 0.772 0.924 1 .09 1.34 1.55 (0.190-0.301) (0.229-0.364) (0.306-0.489) (0.379-0.613) (0.492-0.871) (0.578-1.07) (0.664-1.31) (0.750-1.59) (0.881-2.01) (0.980-2.33) 10-min 0.349 0.422 0.564 0.705 0.930 1 .13 1 .35 1 .60 1.97 2.27 (0.278-0.441) (0.336-0.533) (0.448-0.716) (0.555-0.898) (0.721-1.27) (0.846-1.56) (0.973-1.92) (1.10-2.33) (1 .29-2.95) (1.44-3.41) 15-min 0.426 0.515 0.688 0.859 1 .14 1 .38 1 .65 1 .95 2.40 2.77 (0.339-0.538) (0.410-0.650) (0.546-0.873) (0.677-1.09) (0.879-1 .55) (1.03-1 .90) (1.19-2.34) (1.34-2.85) (1.57-3.60) (1.75-4.16) 30-min 0.571 0.688 0.918 1.15 1 .51 1 .84 2.21 2.62 3.22 3.72 (0.455-0.721) (0.547-0.869) (0.728-1.16) (0.903-1.46) (1.17-2.08) (1.38-2.54) (1.59-3.13) (1.80-3.82) (2.11-4.83) (2.35-5.60) 60-min 0.706 0.839 1.11 1 .39 1 .85 2.26 2.73 3.26 4.04 4.70 (0.563-0.892) (0.668-1.06) (0.881-1.41) (1.09-1 .77) (1 .44-2.55) (1.70-3.14) (1.97-3.89) (2.24-4.77) (2.66-6.08) (2.97-7.08) 2-hr 0.842 0.991 1 .30 1 .63 2.18 2.69 3.26 3.90 4.87 5.68 (0.676-1.05) (0.795-1.24) (1.04-1.64) (1.30-2.06) (1.72-2.99) (2.04-3.69) (2.37-4.59) (2.71-5.66) (3.24-7.24) (3.63-8.45) 3-hr 0.921 1 .07 1 .40 1 .75 2.35 2.90 3.52 4.24 5.30 6.20 (0.744-1.15) (0.866-1.34) (1.13-1.75) (1.40-2.20) (1 .86-3.20) (2.21-3.96) (2.58-4.94) (2.96-6.10) (3.55-7.84) (3.99-9.15) 6-hr 1 .08 1 .25 1 .62 2.01 2.66 3.26 3.94 4.71 5.86 6.83 (0.879-1.33) (1.02-1 .54) (1.32-2.00) (1.62-2.50) (2.13-3.58) (2.51-4.40) (2.92-5.45) (3.33-6.70) (3.96-8.55) (4.44-9.96) 12-hr 1 .27 1 .50 1 .94 2.37 3.06 3.66 4.33 5.07 6.15 7.04 (1.04-1.54) (1.23-1.83) (1.59-2.37) (1.93-2.91) (2.44-4.01) (2.83-4.84) (3.22-5.86) (3.60-7.06) (4.19-8.81) (4.63-10.1) 24-hr 1.51 1 .78 2.28 2.75 3.46 4.08 4.75 5.49 6.55 7.42 (1.25-1.82) (1.48-2.15) (1.88-2.76) (2.25-3.34) (2.78-4.46) (3.18-5.30) (3.56-6.34) (3.93-7.53) (4.50-9.23) (4.93-10.5) 2-day 1 .74 2.07 2.65 3.17 3.93 4.56 5.23 5.94 6.94 7.74 (1.45-2.07) (1.73-2.47) (2.20-3.17) (2.62-3.81) (3.16-4.95) (3.57-5.82) (3.94-6.84) (4.29-8.00) (4.81-9.62) (5.20-10.8) 3-day 1.90 2.23 2.82 3.35 4.12 4.75 5.43 6.15 7.16 7.97 (1.59-2.25) (1.88-2.65) (2.36-3.36) (2.78-4.00) (3.33-5.15) (3.74-6.02) (4.12-7.05) (4.47-8.22) (4.99-9.84) (5.39-11.1) 4-day 2.02 2.36 2.96 3.49 4.27 4.91 5.59 6.31 7.33 8.14 (1.71-2.39) (1.99-2.79) (2.48-3.50) (2.91-4.15) (3.46-5.31) (3.88-6.18) (4.26-7.22) (4.60-8.39) (5.13-10.0) (5.53-11.2) 7-day 2.31 2.69 3.35 3.92 4.73 5.39 6.06 6.78 7.75 8.52 (1.96-2.70) (2.29-3.16) (2.83-3.94) (3.29-4.62) (3.85-5.80) (4.28-6.70) (4.65-7.73) (4.97-8.88) (5.47-10.5) (5.84-11.6) 10-day 2.55 2.98 3.69 4.29 5.14 5.80 6.48 7.18 8.13 8.86 (2.18-2.97) (2.54-3.47) (3.14-4.31) (3.63-5.04) (4.20-6.24) (4.63-7.15) (4.99-8.19) (5.29-9.33) (5.76-10.9) (6.11 -12.0) 20-day 3.25 3.76 4.58 5.25 6.18 6.89 7.59 8.31 9.24 9.95 (2.80-3.75) (3.23-4.33) (3.92-5.29) (4.48-6.10) (5.08-7.38) (5.54-8.35) (5.89-9.44) (6.18-10.6) (6.61-12.2) (6.94-13.3) 30-day 3.81 4.38 5.29 6.04 7.05 7.82 8.57 9.32 10.3 11.0 (3.30-4.36) (3.79-5.02) (4.57-6.08) (5.18-6.97) (5.83-8.35) (6.31-9.40) (6.69-10.6) (6.97-11.8) (7.40-13.4) (7.73-14.6) 45-day 4.48 5.15 6.21 7.07 8.22 9.07 9.90 10.7 11.8 12.5 (3.90-5.10) (4.48-5.86) (5.39-7.09) (6.10-8.10) (6.82-9.65) (7.37-10.8) (7.77-12.1) (8.06-13.4) (8.51-15.2) (8.84-16.5) 60-day 5.02 5.79 7.01 7.98 9.27 10.2 11 .1 12.0 13.1 13.9 (4.39-5.68) (5.06-6.56) (6.10-7.96) (6.91-9.11) (7.71-10.8) (8.32-12.1) (8.75-13.5) (9.06-15.0) (9.52-16.8) (9.86-18.2) 1 Precipitation frequency (PF) estimates in this table are based on frequency analysis of partial duration series (PDS). Numbers in parenthesis are PF estimates at lower and upper bounds of the 90% confidence interval. The probability that precipitation frequency estimates (for a given duration and average recurrence interval) will be greater than the upper bound (or less than the lower bound) is 5%. Estimates at upper bounds are not checked against probable maximum precipitation (PMP) estimates and may be higher than currently valid PMP values. Please refer to NOAA Atlas 14 document for more information. Back to Top PF graphical 1 of 4 3/31/2014 12:02 PM Precipitation Frequency Data Server http://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html'?lat=40.2833&l0... PDS-based depth-duration-frequency (DDF) curves Latitude: 40.2833°, Longitude: -104.8011° 14 r r r r r r i t i r - Average recurrence 12 interval (years) 10 1 a • 2 cu 8 — 5 o — 10 0 6 , , , -- - 25 y • -- 50 v 4 - 100 °- • - 200 _.------------- -- ---:: :H . 500 1000 • c c c c c L I. I.... I.- >. >, >. >. >, >. >, >. >. E E E E rL.'r r er i L v •D •n 43 v -0 -(v -n v v , i p LA m 6to I-1 N N &1 4 N o N m 6 Duration 14 r i i • 12 . . . . • �. • 10 • Duration r 4Is 116. — 5-min — 2-day 8 : — 10Hnin — 3-day 15 min — 4-day • 30-nUn 7-day 60-mrn 10-day 4 • �� - — 2-hr — 20-day — 3-hr — 30-day it T — 12-hr — 60-day i- -1 0 - I _ t I I 1 24-ter 1 2 5 10 25 50 100 200 500 1000 Average recurrence interval (years) NOAA Atlas 14, Volume 8, Version 2 Created (GMT): Mon Mar 31 18:00:57 2014 Back to Top Maps & aerials Small scale terrain JI{UII,UIUiI Rawlins 7 Medicine Bow I National Forest Li, ., t.er iP r . elk r ----Sidney • , - t� Cheyenne �- . . .. •.-: _ Ill .,_.► •e- Sterling t'. 1t Fort-Collinsc.) a- 1 . -� - , . - Greeley • : ,it*: •/ ..1 "1 arc . t OVPIc d.Lit liPrnW ; : Y. ,- !Boulder II OM v -I 'IS Shiauone4Ldr_e :1% 50 km y ap ditip4activiepoogie 2 of 4 3/31/2014 12:02 P Precipitation Frequency Data Server http://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat--40.2833&l0... 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I Googl till2 Imagery © rzer _ 9 Y l� letrias 3 of 4 3/31/2014 12:02 P _USDA United States A product of the National Custom Soil Resource Department of Cooperative Soil Survey, Agriculture a joint effort of the United Report for States Department of 4 NRCS Agriculture and other Weld County , Federal agencies, State Natural agencies including the Colorado , Resources Agricultural Experiment Conservation Stations, and local Service participants Southern Part ,', '.0s. ... .4 om `'�` ,:. i i 2"-- , -- --s) "1 F�l ryr Ji�`� !� , ir / � !0{ J ��11,f."d��tI{�43/, 1 .t loll S�t / 1 �� t r t )r fry - ; V, ` .-'011i�F .' ,_ .. i. I : HV4 - <Y. ` . . 7ly,. r/i I 4' 'I _ 4 :- DI l I I I I I 8.000ft i , a a March 26, 2014 Preface Soil surveys contain information that affects land use planning in survey areas. They highlight soil limitations that affect various land uses and provide information about the properties of the soils in the survey areas. Soil surveys are designed for many different users, including farmers, ranchers, foresters, agronomists, urban planners, community officials, engineers, developers, builders, and home buyers. Also, conservationists, teachers, students, and specialists in recreation, waste disposal, and pollution control can use the surveys to help them understand, protect, or enhance the environment. Various land use regulations of Federal, State, and local governments may impose special restrictions on land use or land treatment. Soil surveys identify soil properties that are used in making various land use or land treatment decisions. The information is intended to help the land users identify and reduce the effects of soil limitations on various land uses. The landowner or user is responsible for identifying and complying with existing laws and regulations. Although soil survey information can be used for general farm, local, and wider area planning, onsite investigation is needed to supplement this information in some cases. Examples include soil quality assessments (http://www.nres.usda.gov/wps/portal/ nrcs/main/soils/health/) and certain conservation and engineering applications. For more detailed information, contact your local USDA Service Center (http:// offices.sc.egov.usda.gov/locator/app?agency=nres) or your NRCS State Soil Scientist (http://www.nres.usda.gov/wps/portal/nres/detail/soils/contactus/? cid=nres142p2_053951 ). Great differences in soil properties can occur within short distances. Some soils are seasonally wet or subject to flooding. Some are too unstable to be used as a foundation for buildings or roads. Clayey or wet soils are poorly suited to use as septic tank absorption fields. A high water table makes a soil poorly suited to basements or underground installations. The National Cooperative Soil Survey is a joint effort of the United States Department of Agriculture and other Federal agencies, State agencies including the Agricultural Experiment Stations, and local agencies. The Natural Resources Conservation Service (NRCS) has leadership for the Federal part of the National Cooperative Soil Survey. Information about soils is updated periodically. Updated information is available through the NRCS Web Soil Survey, the site for official soil survey information. The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, age, disability, and where applicable, sex, marital status, familial status, parental status, religion, sexual orientation, genetic information, political beliefs, reprisal, or because all or a part of an individual's income is derived from any public assistance program. (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means 2 for communication of program information (Braille, large print, audiotape, etc.) should contact USDA's TARGET Center at (202) 720-2600 (voice and TDD). To file a complaint of discrimination, write to USDA, Director, Office of Civil Rights, 1400 Independence Avenue, S.W., Washington, D.C. 20250-9410 or call (800) 795-3272 (voice) or (202) 720-6382 (TDD). USDA is an equal opportunity provider and employer. 3 Contents Preface 2 Soil Map 5 Soil Map 6 Legend 7 Map Unit Legend 8 Map Unit Descriptions 8 Weld County, Colorado, Southern Part 10 11—MLRA 67B - Bresser sandy loam, 0 to 3 percent slopes 10 29—Julesburg sandy loam, 0 to 1 percent slopes 11 30—Julesburg sandy loam, 1 to 3 percent slopes 12 References 14 4 Soil Map The soil map section includes the soil map for the defined area of interest, a list of soil map units on the map and extent of each map unit, and cartographic symbols displayed on the map. Also presented are various metadata about data used to produce the map, and a description of each soil map unit. 5 Custom Soil Resource Report 3 so Soil Map IV a a o 516200 516300 516400 516500 516600 516101 SI6800 516900 517000 517100 517200 517300 517400 517500 517600 517700 517800 0 40? 17'IS"N a a 40? 17'18"N Ysr, N T a a I o r- .7 n !/ O N Y� T c 1 c d T QN T T g o in N 30 i 'per N T 11 T "- $ N a 1 4-rrI• • A 7 Cp O 1-. 1 T II Si r` r Y -. cn P N " -r a• .,1 ' \ o - - til g a • - ♦ At 7 ea _ _ 1{ _ • _ __ C N '° ac a -r T 40? 16'43"N 40? 16'43"ti 516200 5)6300 5)6400 516500 516600 516700 516800 516900 517000 517100 517200 517300 517400 517500 .517600 517700 517800 3 3 V. Y el b Map Scab: 1:7,660 ifprinted on Alandscape(11"x 8.5")sheet. t- 4. hitters g N 0 100 200 400 600 E Feet U 350 700 1400 2100 Map projection: Web tv rcator Corner coordinates: WGS84 Edge tics: UIMZone 13N N'GS84 6 Custom Soil Resource Report MAP LEGEND MAP INFORMATION Area of Interest(AOI) Spoil Area The soil surveys that comprise your AOI were mapped at 1:24,000. Area of Interest(AO') Stony Spot Soils Warning: Soil Map may not be valid at this scale. in Very Stony Spot I Soil Map Unit Polygons Wet Spot Enlargement of maps beyond the scale of mapping can cause .ms. Soil Map Unit Lines misunderstanding of the detail of mapping and accuracy of soil line • Other Soil Map Unit Points placement. The maps do not show the small areas of contrasting Special Line Features soils that could have been shown at a more detailed scale. Special Point Features Blowout Water Features Streams and Canals Please rely on the bar scale on each map sheet for map ® Borrow Pit measurements. Transportation Clay Spot Rails 0 Source of Map: Natural Resources Conservation Service Closed Depression ..s Interstate Highways Web Soil Survey URL: http://websoilsurvey.nrcs.usda.gov X Gravel Pit US Routes Coordinate System: Web Mercator (EPSG:3857) Gravelly Spot Major Roads Maps from the Web Soil Survey are based on the Web Mercator O Landfill Local Roads projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the A Lava Flow Background Albers equal-area conic projection, should be used if more accurate a Marsh or swamp - Aerial Photography calculations of distance or area are required. * Mine or Quarry This product is generated from the USDA-NRCS certified data as of • Miscellaneous Water the version date(s) listed below. O Perennial Water Soil Survey Area: Weld County, Colorado, Southern Part v Rock Outcrop Survey Area Data: Version 12, Jan 3, 2014 + Saline Spot Soil map units are labeled(as space allows)for map scales 1:50,000 Sandy Spot or larger. Severely Eroded Spot Date(s)aerial images were photographed: Apr 22,2011—Apr 13, O Sinkhole 2012 itt Slide or Slip The orthophoto or other base map on which the soil lines were Sodic Spot compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be cvidcnt. 7 Custom Soil Resource Report Map Unit Legend Weld County, Colorado, Southern Part (CO618) Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI 11 MLRA 67B - Bresser sandy 8.3 2.8% loam, 0 to 3 percent slopes 29 Julesburg sandy loam, 0 to 1 215.8 72.4% percent slopes 30 Julesburg sandy loam, 1 to 3 74.2 24.9% percent slopes Totals for Area of Interest 298.2 100.0% Map Unit Descriptions The map units delineated on the detailed soil maps in a soil survey represent the soils or miscellaneous areas in the survey area. The map unit descriptions, along with the maps, can be used to determine the composition and properties of a unit. A map unit delineation on a soil map represents an area dominated by one or more major kinds of soil or miscellaneous areas. A map unit is identified and named according to the taxonomic classification of the dominant soils. Within a taxonomic class there are precisely defined limits for the properties of the soils. On the landscape, however, the soils are natural phenomena, and they have the characteristic variability of all natural phenomena. Thus, the range of some observed properties may extend beyond the limits defined for a taxonomic class. Areas of soils of a single taxonomic class rarely, if ever, can be mapped without including areas of other taxonomic classes. Consequently, every map unit is made up of the soils or miscellaneous areas for which it is named and some minor components that belong to taxonomic classes other than those of the major soils. Most minor soils have properties similar to those of the dominant soil or soils in the map unit, and thus they do not affect use and management. These are called noncontrasting, or similar, components. They may or may not be mentioned in a particular map unit description. Other minor components, however, have properties and behavioral characteristics divergent enough to affect use or to require different management. These are called contrasting, or dissimilar, components. They generally are in small areas and could not be mapped separately because of the scale used. Some small areas of strongly contrasting soils or miscellaneous areas are identified by a special symbol on the maps. If included in the database for a given area, the contrasting minor components are identified in the map unit descriptions along with some characteristics of each. A few areas of minor components may not have been observed, and consequently they are not mentioned in the descriptions, especially where the pattern was so complex that it was impractical to make enough observations to identify all the soils and miscellaneous areas on the landscape. The presence of minor components in a map unit in no way diminishes the usefulness or accuracy of the data. The objective of mapping is not to delineate pure taxonomic classes but rather to separate the landscape into landforms or landform segments that have similar use and management requirements. The delineation of such segments 8 Custom Soil Resource Report on the map provides sufficient information for the development of resource plans. If intensive use of small areas is planned, however, onsite investigation is needed to define and locate the soils and miscellaneous areas. An identifying symbol precedes the map unit name in the map unit descriptions. Each description includes general facts about the unit and gives important soil properties and qualities. Soils that have profiles that are almost alike make up a soil series. Except for differences in texture of the surface layer, all the soils of a series have major horizons that are similar in composition, thickness, and arrangement. Soils of one series can differ in texture of the surface layer, slope, stoniness, salinity, degree of erosion, and other characteristics that affect their use. On the basis of such differences, a soil series is divided into soil phases. Most of the areas shown on the detailed soil maps are phases of soil series. The name of a soil phase commonly indicates a feature that affects use or management. For example, Alpha silt loam, 0 to 2 percent slopes, is a phase of the Alpha series. Some map units are made up of two or more major soils or miscellaneous areas. These map units are complexes, associations, or undifferentiated groups. A complex consists of two or more soils or miscellaneous areas in such an intricate pattern or in such small areas that they cannot be shown separately on the maps. The pattern and proportion of the soils or miscellaneous areas are somewhat similar in all areas. Alpha-Beta complex, 0 to 6 percent slopes, is an example. An association is made up of two or more geographically associated soils or miscellaneous areas that are shown as one unit on the maps. Because of present or anticipated uses of the map units in the survey area, it was not considered practical or necessary to map the soils or miscellaneous areas separately. The pattern and relative proportion of the soils or miscellaneous areas are somewhat similar. Alpha- Beta association, 0 to 2 percent slopes, is an example. An undifferentiated group is made up of two or more soils or miscellaneous areas that could be mapped individually but are mapped as one unit because similar interpretations can be made for use and management. The pattern and proportion of the soils or miscellaneous areas in a mapped area are not uniform. An area can be made up of only one of the major soils or miscellaneous areas, or it can be made up of all of them. Alpha and Beta soils, 0 to 2 percent slopes, is an example. Some surveys include miscellaneous areas. Such areas have little or no soil material and support little or no vegetation. Rock outcrop is an example. 9 Custom Soil Resource Report Weld County, Colorado, Southern Part 11—MLRA 67B - Bresser sandy loam, 0 to 3 percent slopes Map Unit Setting Elevation: 4,050 to 6,800 feet Mean annual precipitation: 12 to 18 inches Mean annual air temperature: 45 to 55 degrees F Frost-free period: 135 to 190 days Map Unit Composition Bresser and similar soils: 90 percent Minor components: 10 percent Description of Bresser Setting La ndform: Terraces Landform position (three-dimensional): Tread Down-slope shape: Linear Across-slope shape: Linear Parent material: Coarse sandy alluvium derived from igneous, metamorphic and sedimentary rock Properties and qualities Slope: 0 to 3 percent Depth to restrictive feature: More than 80 inches Drainage class: Well drained Capacity of the most limiting layer to transmit water (Ksat): Moderately high to high (0.60 to 2.00 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency ofponding: None Calcium carbonate, maximum content: 10 percent Maximum salinity: Nonsaline (0.0 to 0.1 mmhos/cm) Available water capacity: Low (about 5.8 inches) Interpretive groups Farmland classification: Prime farmland if irrigated and the product of I (soil erodibility) x C (climate factor) does not exceed 60 Land capability classification (irrigated): 4e Land capability (non irrigated): 4c Hydrologic Soil Group: B Ecological site: Sandy Plains (R067BY024CO) Typical profile 0 to 9 inches: Sandy loam 9 to 25 inches: Sandy clay loam 25 to 30 inches: Sandy loam 30 to 79 inches: Loamy sand Minor Components Truckton Percent of map unit: 5 percent La ndform: Terraces 10 Custom Soil Resource Report Landform position (three-dimensional): Tread Down-slope shape: Linear Across-slope shape: Linear Ecological site: Sandy Plains (R067BY024CO) Vona Percent of map unit: 5 percent Landform: Stream terraces Landform position (three-dimensional): Tread Down-slope shape: Linear Across-slope shape: Linear Ecological site: Sandy Plains (R067BY024CO) 29—Julesburg sandy loam, 0 to 1 percent slopes Map Unit Setting Elevation: 4,700 to 4,800 feet Mean annual precipitation: 15 to 19 inches Mean annual air temperature: 48 to 52 degrees F Frost-free period: 145 to 155 days Map Unit Composition Julesburg and similar soils: 85 percent Minor components: 15 percent Description of Julesburg Setting Landform: Terraces Down-slope shape: Linear Across-slope shape: Linear Parent material: South platte river alluvium Properties and qualities Slope: 0 to 1 percent Depth to restrictive feature: More than 80 inches Drainage class: Well drained Capacity of the most limiting layer to transmit water (Ksat): High (2.00 to 6.00 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency ofponding: None Available water capacity: Moderate (about 6.5 inches) Interpretive groups Farmland classification: Prime farmland if irrigated and the product of I (soil erodibility) x C (climate factor) does not exceed 60 Land capability classification (irrigated): 2s Land capability (non irrigated): 3e Hydrologic Soil Group: B Ecological site: Sandy Plains (R067BY024CO) 11 Custom Soil Resource Report Typical profile 0 to 12 inches: Sandy loam 12 to 27 inches: Sandy loam 27 to 60 inches: Sand Minor Components Edgar Percent of map unit: 4 percent Remmit Percent of map unit: 4 percent Valent Percent of map unit: 4 percent Vona Percent of map unit: 3 percent 30—Julesburg sandy loam, 1 to 3 percent slopes Map Unit Setting Elevation: 4,700 to 4,800 feet Mean annual precipitation: 15 to 19 inches Mean annual air temperature: 48 to 52 degrees F Frost-free period: 145 to 155 days Map Unit Composition Julesburg and similar soils: 90 percent Minor components: 10 percent Description of Julesburg Setting Landform: Terraces Down-slope shape: Linear Across-slope shape: Linear Parent material: South platte river alluvium Properties and qualities S lope: 1 to 3 percent Depth to restrictive feature: More than 80 inches Drainage class: Well drained Capacity of the most limiting layer to transmit water (Ksat): High (2.00 to 6.00 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency ofponding: None Available water capacity: Moderate (about 6.5 inches) Interpretive groups Farmland classification: Prime farmland if irrigated and the product of I (soil erodibility) x C (climate factor) does not exceed 60 12 Custom Soil Resource Report Land capability classification (irrigated): 2e Land capability (nonirrigated): 3e Hydrologic Soil Group: B Ecological site: Sandy Plains (R067BY024CO) Typical profile 0 to 12 inches: Sandy loam 12 to 27 inches: Sandy loam 27 to 60 inches: Sand Minor Components Remmit Percent of map unit: 5 percent Valent Percent of map unit: 5 percent 13 References American Association of State Highway and Transportation Officials (AASHTO). 2004. Standard specifications for transportation materials and methods of sampling and testing. 24th edition. American Society for Testing and Materials (ASTM). 2005. Standard classification of soils for engineering purposes. ASTM Standard D2487-00. Cowardin, L.M., V. Carter, F.C. Golet, and E.T. LaRoe. 1979. Classification of wetlands and deep-water habitats of the United States. U.S. Fish and Wildlife Service FWS/OBS-79/31 . Federal Register. July 13, 1994. Changes in hydric soils of the United States. Federal Register. September 18, 2002. Hydric soils of the United States. Hurt, G.W., and L.M. Vasilas, editors. Version 6.0, 2006. Field indicators of hydric soils in the United States. National Research Council. 1995. Wetlands: Characteristics and boundaries. Soil Survey Division Staff. 1993. Soil survey manual. Soil Conservation Service. U.S. Department of Agriculture Handbook 18. http://www.nrcs.usda.gov/wps/portal/nrcs/ detail/national/soils/?cid=nres 142p2_054262 Soil Survey Staff. 1999. Soil taxonomy: A basic system of soil classification for making and interpreting soil surveys. 2nd edition. Natural Resources Conservation Service, U.S. Department of Agriculture Handbook 436. http://www.nrcs.usda.gov/wps/portal/ nrcs/detail/national/soils/?cid=nrcs142p2_053577 142p2_053577 Soil Survey Staff. 2010. Keys to soil taxonomy. 11th edition. U.S. Department of Agriculture, Natural Resources Conservation Service. http://www.nrcs.usda.gov/wps/ portal/nres/detail/national/soils/?cid=nres 142p2_053580 Tiner, R.W., Jr. 1985. Wetlands of Delaware. U.S. Fish and Wildlife Service and Delaware Department of Natural Resources and Environmental Control, Wetlands Section. United States Army Corps of Engineers, Environmental Laboratory. 1987. Corps of Engineers wetlands delineation manual. Waterways Experiment Station Technical Report Y-87-1. United States Department of Agriculture, Natural Resources Conservation Service. National forestry manual. http://www.nrcs.usda.gov/wps/portal/nrcs/main/national/ landuse/forestry/pub/ n d u se/forestry/pub/ United States Department of Agriculture, Natural Resources Conservation Service. National range and pasture handbook. http://www.nres.usda.gov/wps/portal/nres/ detail/national/landuse/rangepasture/?cid=stelprdb1043084 14 Custom Soil Resource Report United States Department of Agriculture, Natural Resources Conservation Service. National soil survey handbook, title 430-VI. http://www.nrcs.usda.gov/wps/portal/ nrcs/detail/soils/scientists/?cid=nrcs142p2_054242 i l/soi is/scie ntists/?cid=nres 142 p2_054242 United States Department of Agriculture, Natural Resources Conservation Service. 2006. Land resource regions and major land resource areas of the United States, the Caribbean, and the Pacific Basin. U.S. Department of Agriculture Handbook 296. http://www.nres.usda.gov/wps/portal/nres/detail/national/soils/? cid=nrcs142p2_053624 United States Department of Agriculture, Soil Conservation Service. 1961. Land capability classification. U.S. Department of Agriculture Handbook 210. http:// www.nres.usda.gov/Internet/FSE_DOCUMENTS/nres142p2_052290.pdf 15 DRAINAGE CRITERIA MANUAL (V. 1 ) RUNOFF Table RO-5— Runoff Coefficients, c Percentage Imperviousness Type C and D NRCS Hydrologic Soil Groups 2-yr 5-yr 10-yr 25-yr 50-yr 100-yr 0% 0. 04 0. 15 0.25 0. 37 0.44 0.50 5% 0.08 0. 18 0.28 0.39 0.46 0.52 10% 0. 11 0.21 0.30 0.41 0.47 0.53 15% 0. 14 0.24 0.32 0.43 0.49 0.54 20% 0. 17 0.26 0. 34 0.44 0. 50 0.55 25% 0.20 0.28 0.36 0.46 0. 51 0.56 30% 0. 22 0. 30 0. 38 0 .47 0.52 0.57 35% 0.25 0.33 0.40 0.48 0.53 0.57 40% 0.28 0.35 0.42 0. 50 0.54 0.58 45% 0. 31 0.37 0.44 0.51 0. 55 0.59 50% 0.34 0.40 0.46 0. 53 0.57 0.60 55% 0. 37 0.43 0.48 0. 55 0.58 0.62 60% 0.41 0.46 0. 51 0. 57 0.60 0.63 65% 0.45 0.49 0.54 0. 59 0.62 0.65 70% 0.49 0.53 0. 57 0.62 0.65 0.68 75% 0. 54 0.58 0.62 0.66 0.68 0.71 80% 0.60 0.63 0.66 0.70 0.72 0.74 85% 0.66 0.68 0. 71 0. 75 0. 77 0.79 90% 0.73 0.75 0.77 0.80 0.82 0.83 95% 0.80 0.82 0.84 0.87 0.88 0.89 100% 0.89 0.90 0.92 0.94 0.95 0.96 TYPE B NRCS HYDROLOGIC SOILS GROUP 0% 0.02 0.08 0. 15 0.25 0.30 0.35 5% 0.04 0. 10 0. 19 0.28 0.33 0.38 10% 0.06 0. 14 0.22 0. 31 0.36 0.40 15% 0.08 0. 17 0.25 0. 33 0.38 0.42 20% 0. 12 _ 0.20 0.27 0. 35 0.40 0.44 25% 0. 15 0.22 0.30 0.37 0.41 0.46 30% 0. 18 0.25 0.32 0. 39 0.43 0.47 35% 0.20 0.27 0.34 0.41 0.44 0.48 40% 0.23 0.30 0. 36 0.42 0.46 0.50 45% 0.26 0.32 0.38 0.44 0.48 0.51 50% 0.29 0. 35 0.40 0 .46 0.49 0.52 55% 0.33 0.38 0.43 0.48 0.51 0.54 60% 0. 37 0.41 0.46 0. 51 0.54 0.56 65% 0.41 0.45 0.49 0. 54 0.57 0.59 70% 0.45 0.49 0. 53 0. 58 0.60 0.62 75% 0.51 0.54 0.58 0.62 0.64 0.66 80% 0. 57 0. 59 0.63 0.66 0.68 0.70 85% 0.63 0.66 0.69 0.72 0.73 0.75 90% 0. 71 0 . 73 0. 75 0 . 78 0.80 0.81 95% 0.79 0.81 0.83 0.85 0.87 0.88 100% 0. 89 0.90 0.92 0 .94 0.95 0.96 2007-01 RO-11 Urban Drainage and Flood Control District r r:N To C in it d• C X th z O @ C a) •.—�+ Q X N •-`1, (/) r.... ^` aL+ . x EC C C E Q) I— a 0. t (rte' >, .C U C W 00 + •�/) ^ C U 0 _ g (NI 0@ U (9 o c Co CfT2 o O J �. to CO i To :e.g. E 0 H N D E —c— !Pt .@ a O E U ~ „ Q Jr_ W N J it C O <O CO I: O I co U N 0 N a N O u) N > O C Tr = Q (6 a) R > Q co• a)2) V c`0 = c CO > > } u CCS p w ~ # 7 o Cti c �o V < U) u a u N @ d >. S H — — 3 C = �•V N co W J co Y "a -0 N a) N O p C >- U o aa) a@i a) Y CO '. CO Z U •N U t COal Z O II 2Lt CtfV O W N 0 0 C I^ > 0) a t w. Q) Q O)CD m ~ E O ur O a = HU) ZU' a. Cr - - O + D C c a. 0 O L N !Y O O II Z N > a) 0 to 26 0 C 00 ^ J �+ L co O Q) O Q) = a r o O C it Q Q. y — )•' — O ro cii I I -E to a •� H > 0 C M O D- a) W C Q '0- En d ; U W ,__, •r E �. 0vi E @ 0) 0 Q W C' W I- 3 0 O x O U C N C C Z_ d 4. O co co O co N L Q O. d H — -a 3 a) N O O z a) L .Q c c D O = to O J uJ (�j '� et C H e (,) `� O d 0 — `. c co 0 co g a L O ca C a) cA C ~ co o X `. c m a 0 c •- d -1 a J H E6 C � C � o m .c 2 ^ M D Eo E o 4 t -- d W (D d c O II 3 " a) 0 .0 m --,2,- � o E U r >s _ r r 0 U , 0 c >, t L o •O cc 7 > V) Ch W Q •C `- N . 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V U J CO ' U C� O O O O O O O O O O O O r r 0 N _ E } u d LL O cs a) a) N Non d• cO 0o N to tb O M co o L r @ en U O O O O O r r r N N N N in r iz 1— •c N Q C co7 7 O O O O O O O O O O O O r N M '--' O C D OTo "ci E — — II oC E E C O N to o to o to o to O Un O >, 01 F- io O N O ,,'� U) 7 7 rrNNMM � zfLU N O• U O U O E E o o v re c_ c O V C CC E E CU) O f- to O .0 C Q) a) C• uO d• L 0 , .C .C _ U) I-- I- i — — 0 N C Q) o) N O c o Q) J t O N in (` t t4 O co QL V M M x o a to Z to ca C Q) E 2 Q Q co to Q) a o II C 0 — O O Q) Q 2 G 2 p a) r y:r. a C 0 Q) N Q) N N to O co E CK E E o E til 0 0 d) Cl.) Q) Q) Q) Q) Q) Q) Q) a) O IL W V II II ii ti c a� Tij CI. aaaaaaaaa a. C To 2 0 U Q > > 0 0 0 0 0 0 0 0 0 0 L m co II cD Q) Q) Q) Q) Q) Q) Q) a) O) O) Q) Q) C C C O — -a -a > > > > > > > > > > 0 u,(7) ;o ;_, 0 O1 � � � 0 0 CD O � � � � � CD� � r N r to r 0 MU) m X co X I LCD -. DRAINAGE CRITERIA MANUAL (V. 1 ) RUNOFF Table RO-5— Runoff Coefficients, c Percentage Imperviousness Type C and D NRCS Hydrologic Soil Groups 2-yr 5-yr 10-yr 25-yr 50-yr 100-yr 0% 0. 04 0. 15 0.25 0. 37 0.44 0.50 5% 0.08 0. 18 0.28 0.39 0.46 0.52 10% 0. 11 0.21 0.30 0.41 0.47 0.53 15% 0. 14 0.24 0.32 0.43 0.49 0.54 20% 0. 17 0.26 0. 34 0.44 0. 50 0.55 25% 0.20 0.28 0.36 0.46 0. 51 0.56 30% 0. 22 0. 30 0. 38 0 .47 0.52 0.57 35% 0.25 0.33 0.40 0.48 0.53 0.57 40% 0.28 0.35 0.42 0. 50 0.54 0.58 45% 0. 31 0.37 0.44 0.51 0. 55 0.59 50% 0.34 0.40 0.46 0. 53 0.57 0.60 55% 0. 37 0.43 0.48 0. 55 0.58 0.62 60% 0.41 0.46 0. 51 0. 57 0.60 0.63 65% 0.45 0.49 0.54 0. 59 0.62 0.65 70% 0.49 0.53 0. 57 0.62 0.65 0.68 75% 0. 54 0.58 0.62 0.66 0.68 0.71 80% 0.60 0.63 0.66 0.70 0.72 0.74 85% 0.66 0.68 0. 71 0. 75 0. 77 0.79 90% 0.73 0.75 0.77 0.80 0.82 0.83 95% 0.80 0.82 0.84 0.87 0.88 0.89 100% 0.89 0.90 0.92 0.94 0.95 0.96 TYPE B NRCS HYDROLOGIC SOILS GROUP 0% 0.02 0.08 0. 15 0.25 0.30 0.35 5% 0.04 0. 10 0. 19 0.28 0.33 0.38 10% 0.06 0. 14 0.22 0. 31 0.36 0.40 15% 0.08 0. 17 0.25 0. 33 0.38 0.42 20% 0. 12 _ 0.20 0.27 0. 35 0.40 0.44 25% 0. 15 0.22 0.30 0.37 0.41 0.46 30% 0. 18 0.25 0.32 0. 39 0.43 0.47 35% 0.20 0.27 0.34 0.41 0.44 0.48 40% 0.23 0.30 0. 36 0.42 0.46 0.50 45% 0.26 0.32 0.38 0.44 0.48 0.51 50% 0.29 0. 35 0.40 0 .46 0.49 0.52 55% 0.33 0.38 0.43 0.48 0.51 0.54 60% 0. 37 0.41 0.46 0. 51 0.54 0.56 65% 0.41 0.45 0.49 0. 54 0.57 0.59 70% 0.45 0.49 0. 53 0. 58 0.60 0.62 75% 0.51 0.54 0.58 0.62 0.64 0.66 80% 0. 57 0. 59 0.63 0.66 0.68 0.70 85% 0.63 0.66 0.69 0.72 0.73 0.75 90% 0. 71 0 . 73 0. 75 0 . 78 0.80 0.81 95% 0.79 0.81 0.83 0.85 0.87 0.88 100% 0. 89 0.90 0.92 0 .94 0.95 0.96 2007-01 RO-11 Urban Drainage and Flood Control District Area-Weighting for Impervious Calculation Project Title: Weideman Drainage (Developed) Catchment ID: Basin A Illustration st3 y LEGEND: _ _ •� T Flow Direction 4 • `'l3Wr Catchm ent Subarea 3 Boundary Instructions: For each catchment subarea, enter values for A and C. Subarea Area Impervious Product ID acres A I CI input input input output Gravel 1 .39 40.00 55.60 Roof 0. 13 90.00 11 .70 Sum: 1 .52 Sum: 67.30 Area-Weighted Runoff Coefficient (sum CA/sum A) = 44.28 Area-Weighting for Impervious Calculation Project Title: Weideman Drainage (Developed) Catchment ID: Basin Al Illustration st3 y LEGEND: _ _ •� T Flow Direction 4 • `'l3Wr Catchm ent Subarea 3 Boundary Instructions: For each catchment subarea, enter values for A and C. Subarea Area Impervious Product ID acres A I CI input input input output Gravel 1 .04 40.00 41 .60 Roof 0. 10 90.00 9.00 sum: 1 .14 Sum: 50.60 Area-Weighted Runoff Coefficient (sum CA/sum A) = 44.39 Area-Weighting for Impervious Calculation Project Title: Weideman Drainage (Developed) Catchment ID: Basin B Illustration st3 y LEGEND: _ _ •� T Flow Direction 4 • `'l3Wr Catchm ent Subarea 3 Boundary Instructions: For each catchment subarea, enter values for A and C. Subarea Area Impervious Product ID acres A I CI input input input output Gravel 1 .46 40.00 58.40 Roof 0.01 90.00 0.90 Sum: 1 .47 Sum: 59.30 Area-Weighted Runoff Coefficient (sum CA/sum A) = 40.34 Area-Weighting for Impervious Calculation Project Title: Weideman Drainage (Developed) Catchment ID: Basin Cl Illustration sts\Nse3t y LEGEND: _ _ •� T Flow Direction 4 • �r ��3 Catchment Subarea 3 Boundary Instructions: For each catchment subarea, enter values for A and C. Subarea Area Impervious Product ID acres A I CI input input input output Undeveloped 0.32 2.00 0.64 sum: 0.32 sum: 0.64 Area-Weighted Runoff Coefficient (sum CA/sum A) = 2.00 Area-Weighting for Impervious Calculation Project Title: Weideman Drainage (Developed) Catchment ID: Basin C2 Illustration sts\Nse3t y LEGEND: _ _ •� T Flow Direction 4 13Wr Catchment Subarea 3 Boundary Instructions: For each catchment subarea, enter values for A and C. Subarea Area Impervious Product ID acres A I CI input input input output Gravel 0.07 40.00 2.80 Undeveloped 0.03 2.00 0.06 Sum: 0.10 sum: 2.86 Area-Weighted Runoff Coefficient (sum CA/sum A) = 28.60 Area-Weighting for Impervious Calculation Project Title: Weideman Drainage (Developed) Catchment ID: Basin C3 Illustration sts\Nse3t y LEGEND: _ _ •� T Flow Direction 4 • �r ��3 Catchment Subarea 3 Boundary Instructions: For each catchment subarea, enter values for A and C. Subarea Area Impervious Product ID acres A I CI input input input output Undeveloped 0. 16 2.00 0.32 sum: 0.16 sum: 0.32 Area-Weighted Runoff Coefficient (sum CA/sum A) = 2.00 M C h h h N O ~ o_ M N C) O) oo t? d C O (O O y_ H r � r � Or a 0 In el Tr OC2O M x O U o.j r r N _ Co•h h I- N N .., 8 L I� ti ti (0 O P.-. C c "i E- v a) �0 V ~ E N N N M O N } — C (O (O a a a a C W N O C - O N en m — 2 .ars U a a 'C 000000 CD O MMMMMM w U `� ≤ '- a) CC W V J t ti r- M O O, co r Ll C I� n r N- N-. 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V V NNN a) f0 OO (LO .� (aO E ID ID 0C E E a E c co c >) 9 a) o o d a) a) a) a) O a) O N 0 y LL W u E 3 Q Q C W a) a) ado. n O. 0. aaa CL. C C (0 m 2 V II 11 ` 11 ❑ > > 0 0 0 0 0 0 0 0 0 r r N CO '(/j r r N M m I U U Q Q •o o m > a) >0 CD> o a> CD CD 0)> > > coo Q Q m U U U O Q Q m U U U m o Cop 4..' C a C > > > > > > > > > 0 co OJ m C C a) CD CD a) d CD a) CD CD Co CO 0 m u) 0 J ❑ ❑ ❑ ❑ ❑ ❑ ❑ ❑ ❑ ❑ ❑ r H CL D Design Point Summary Design Associated Total Basin Impervious Q5 (CFS) O10 (CFS) O100 (CFS) Point Basin Area (ac) Ratio 1 B 1 .47 40% 1 .2 1 .8 4.9 2 Al 1 . 14 44% 1 .0 1 .5 3.9 3 A & B 2.99 42% 2.5 3.8 10. 1 Flatirons, Inc. — Surveying & Engineering Appendix B Hydraulic Computations ➢ Culverts o Culvert sizing calculations ➢ Open Channels o Open channel sizing calculations ➢ Water Quality Capture Volume o WQCV calculations ➢ Water Quality Pond o Stage storage volume calculations o Infiltration calculations Weideman Compressor Station 13 April 14, 2014 Culvert Report Hydraflow Express Extension for AutoCAD® Civil 3D® 2013 by Autodesk, Inc. Thursday, Apr 10 2014 Culvert 1 Invert Elev Dn (ft) = 4759 .79 Calculations Pipe Length (ft) = 61 .00 Qmin (cfs) = 4 . 90 Slope (% ) = 1 . 00 Qmax (cfs) = 4. 90 Invert Elev Up (ft) = 4760 .40 Tailwater Elev (ft) = Normal Rise (in ) = 18 . 0 Shape = Circular Highlighted Span (in ) = 18 .0 Qtotal (cfs) = 4 . 90 No . Barrels = 1 Qpipe (cfs) = 4. 90 n-Value = 0. 024 Qovertop (cfs) = 0 . 00 Culvert Type = Circular Corrugate Metal Pipe Veloc Dn (ft/s) = 3.61 Culvert Entrance = Projecting Veloc Up (ft/s) = 3 .62 Coeff. K, M , c,Y, k = 0 . 034 , 1 . 5 , 0 .0553 , 0 .54, 0. 9 HGL Dn (ft) = 4760. 87 HGL Up (ft) = 4761 .47 Embankment Hw Elev (ft) = 4761 . 77 Top Elevation (ft) = 4763. 00 Hw/D (ft) = 0 . 91 Top Width (ft) = 23 . 00 Flow Regime = Inlet Control Crest Width (ft) = 1 . 00 Elev 'ft Culvert 1 Hw Depth (ft) 4764.0D 3.60 4763.0D - T 2.60 e' 4762.00 1.60 4761.00 _ 0.60 4760 CO -0 40 4759.00 - I 4_ 4758.00 • _ _ IC tE 25 30 35 40 45 EC EE _D _ ._ s HGL Embank Rer. .. Channel Report Hydraflow Express Extension for AutoCAD® Civil 3D® 2013 by Autodesk, Inc. Thursday, Apr 10 2014 Channel 1 -capacity Triangular Highlighted Side Slopes (z: 1 ) = 4 . 00, 4. 00 Depth (ft) = 0 .67 Total Depth (ft) = 2 . 00 Q (cfs) = 3 . 900 Area (sqft) = 1 .80 Invert Elev (ft) = 4600 . 00 Velocity (ft/s) = 2 . 17 Slope (% ) = 0 .64 Wetted Perim (ft) = 5. 52 N-Value = 0. 025 Crit Depth , Yc (ft) = 0 . 57 Top Width (ft) = 5 .36 Calculations EGL (ft) = 0 .74 Compute by: Known Q Known Q (cfs) = 3 . 90 Elev (ft) Depth (ft) Section 4603.00 3.00 4602.50 2.50 4602.00 - 2.00 4601 .50 1 .50 - 4601 .00 1 .00 4600.50 - 0.50 4600.00 0.00 4599.50 - -0.50 0 2 4 6 8 10 12 14 16 18 20 Reach (ft) Channel Report Hydraflow Express Extension for AutoCAD® Civil 3D® 2013 by Autodesk, Inc. Thursday, Apr 10 2014 Channel 1 -stability Triangular Highlighted Side Slopes (z: 1 ) = 4 . 00, 4. 00 Depth (ft) = 0 . 59 Total Depth (ft) = 2 . 00 Q (cfs) = 3 . 900 Area (sqft) = 1 .39 Invert Elev (ft) = 4600 . 00 Velocity (ft/s) = 2 . 80 Slope (% ) = 0 .64 Wetted Perim (ft) = 4. 87 N-Value = 0. 018 Crit Depth , Yc (ft) = 0 . 57 Top Width (ft) = 4.72 Calculations EGL (ft) = 0 .71 Compute by: Known Q Known Q (cfs) = 3 . 90 Elev (ft) Depth (ft) Section 4603.00 3.00 4602.50 - 2.50 4602.00 - f 2.00 4601 .50 -' - 1 .50 / 4601 .00 1 .00 77 4600.50 0.50 4600.00 0.00 4599.50 - -0.50 0 2 4 6 8 10 12 14 16 18 20 Reach (ft) Channel Report Hydraflow Express Extension for AutoCAD® Civil 3D® 2013 by Autodesk, Inc. Thursday, Apr 10 2014 Channel 2 -capacity Triangular Highlighted Side Slopes (z: 1 ) = 4 . 00, 4. 00 Depth (ft) = 0 .79 Total Depth (ft) = 2 . 00 Q (cfs) = 4 . 900 Area (sqft) = 2 . 50 Invert Elev (ft) = 4600 . 00 Velocity (ft/s) = 1 . 96 Slope (% ) = 0 .40 Wetted Perim (ft) = 6. 51 N-Value = 0. 025 Crit Depth , Yc (ft) = 0 .63 Top Width (ft) = 6.32 Calculations EGL (ft) = 0 . 85 Compute by: Known Q Known Q (cfs) = 4 . 90 Elev (ft) Depth (ft) Section 4603.00 3.00 4602.50 - 2.50 4602.00 - 2.00 4601 .50 - 1 .50 4601 .00 1 .00 4600.50 - 0.50 4600.00 0.00 4599.50 - -0.50 0 2 4 6 8 10 12 14 16 18 20 Reach (ft) Channel Report Hydraflow Express Extension for AutoCAD® Civil 3D® 2013 by Autodesk, Inc. Thursday, Apr 10 2014 Channel 2 -stability Triangular Highlighted Side Slopes (z: 1 ) = 4 . 00, 4. 00 Depth (ft) = 0 .70 Total Depth (ft) = 2 . 00 Q (cfs) = 4 . 900 Area (sqft) = 1 . 96 Invert Elev (ft) = 4600 . 00 Velocity (ft/s) = 2 . 50 Slope (% ) = 0 .40 Wetted Perim (ft) = 5.77 N-Value = 0. 018 Crit Depth , Yc (ft) = 0 .63 Top Width (ft) = 5 .60 Calculations EGL (ft) = 0 . 80 Compute by: Known Q Known Q (cfs) = 4 . 90 Elev (ft) Depth (ft) Section 4603.00 3.00 4602.50 - 2.50 • 4602.00 - 2.00 4601 .50 - 1 .50 'l 4601 .00 1 .00 4600.50 0.50 4600.00 0.00 4599.50 - -0.50 0 2 4 6 8 10 12 14 16 18 20 Reach (ft) Area-Weighting for Impervious Calculation Project Title: Weideman Drainage (Developed) Catchment ID: Basin A, B, C1 , C2, and C3 Illustration 3A_ s • y LEGEND: _ _ •� T Flow Direction 4 `'13r°ea3 Cat ChM ent Subarea 3 Boundary Instructions: For each catchment subarea, enter values for A and C. Subarea Area Impervious Product ID acres A I CI input input input output A 1 .52 44.00 66.88 B 1 .47 40.00 58.80 O1 0.32 2.00 0.64 C2 0. 10 29.00 2.90 C3 0. 16 2.00 0.32 Sum: 3.57 Sum: 129.54 Area-Weighted Runoff Coefficient (sum CA/sum A) = 36.29 o O a in cp o O a) en CO > > O as 0 CO w -- cn co ( o 0 4I O (6 r v N U N V O 0E- > > O 0 C ca o ct O O o ≥ ^ O O O N ea r :it' 0U .7i. o I` O " CO O T I — To > rip ti > = "C) D RS o + 4- N p C a O > U (Jr C1 o 0 a. H 0 a)N D CB M qt Cr O . N ; co __ a .a V 5 L a a) O O a) o 2 > ( ) O 2 = — o — a CO O O CO CO 0 O c0 O a = O o a) o co C Lo 0 O O E > " O E.) L CU 0 cti ca co rn o ✓ L o i O 0 f CO d - N CD 2 V r O V 2 O o a) r o co E -. O Q = N Y o 0 > O C coco O co co 0 �.+ " O74:5a E Ln = -- O a) o a) co ^ c0 a) a) U -a Ti O L O E o ~ a) CO ca = o o p o o C C) > r n -- > o II Lo Q 4_ 0 N U co M r o O N Y < o .- O 47- o o up M N O i D C ' w O O o O _ o Q 0 0 o M CC U E 6 O9 -a E R9 E o uO W O w -c o CO co Q D CCD ti rn N L O I- N ci3 a) (I) co CO U ~ o 6 ts i i o o >' t/) i @ Li)• o w Q O O O I— Q c7 u) 0 i Y o o cn o L O II r ,-- Y Q) a c > Y O a cn= ii a) o O U °' E > • N C -o = a) = > M a) co C O a O Q)Ec -c 0 11. a) i > COL O a) 0 E Cn * a) in 4 n_ STAGE-STORAGE SIZING FOR DETENTION BASINS Project: Weideman Compressor Station Basin ID: Water Qualtiy Pond Dam -__Side Slope Z Silt Slope Z Dam Side Slept x AFlow Fbw Dam L F,_HA . W [1> + wif 411I--- w i C 4 D v Side Slope Z odePe x < L > < L > Side Slope Z <-> L Design Information (Input): Check Basin Shape_ Width of Basin Bottom, W = ft Right Triangle OR... Length of Basin Bottom, L = ft Isosceles Triangle OR... Dam Side-slope (H:V), 4 = ft/ft Rectangle OR... Circle / Ellipse OR... Irregular (Use Overide values in cells G32:G52) MINOR MAJOR Storage Requirement from Sheet 'Modified FAA': acre-ft. Stage-Storage Relationship: Storage Requirement from Sheet 'Hydrograph': acre-ft. Storage Requirement from Sheet 'Full-Spectrum': _acre-ft. Labels Water Side Basin Basin Surface Surface Volume Surface Volume Target Volumes for WQCV, Minor, Surface Slope Width at Length at Area at Area at Below Area at Below for WQCV, Minor, & Major Storage Elevation (H:V) Stage Stage Stage Stage Stage Stage Stage & Major Storage Stages ft ft/ft ft ft ft2 ft2 User ft3 acres acre-ft Volumes (input) (input) Below El. (output) (output) (output) Overide (output) (output) (output) (for goal seek) 4759.79 (input) _ 0 0.000 0.000 Bottom 4760.00 0.00 0.00_ 229 _ 24 0.005 0.001 4760.50 0.00 0.00 927 313 0.021 0.007 4761.00 0.00 0.00 2,166 1,086 0.050 0.025 WQCV =4761.50 4761.50 0.00 0.00 4,266 2,694 0.098 0.062 WQCV=2642 cf Level Spreader 4762.00 0.00 0.00 8,192 5,809 0.188 0.133 10 yr=5067 cf 4762.50 0.00 0.00 14,621 11,512 0.336 0.264 #N/A #N/A #N/A #N/A #N1A #N/A #N/A #N/A #N/A #N/A #N/A #N/A, #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N1A #N/A #N/A #N/A #N/A #N/A #N/A #N/A, #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A - #N/A #N/A #N/A #N/A #N/A #N/A 100501-UD-Detention_v2.33.:ls, Basin 4/10/2014, 3:19 PM STAGE-STORAGE SIZING FOR DETENTION BASINS Project: Basin ID: STAGE-STORAGE CURVE FOR THE POND 4762.79 - 4762.29 • • 4761 .79 S G) 4761 .29 - C) a, as in 4760.79 - - 4760.29 - ♦ 4759.79 • 0.00 0.05 0.10 0.15 0.20 0.25 0.30 Storage (acre-feet) A 100501-UD-Detention v2.33.xls, Basin 4/10/2014, 3:19 PM Flatirons, Inc. — Surveying & Engineering Appendix C Floodplain Information Attached is copy of the FEMA Floodplain Flood Insurance Rate Map of the Area Weideman Compressor Station C April 14, 2014 Weideman Compressor Station — Water Quality Ponds Draw Down Calculations Infiltration rates based on the Geotechnical Engineering Study; Proposed Addition to the Weideman Compressor Station; April 11 , 2014; HP Geotech Inc. WATER QUALITY POND Infiltration Rate = 60 min/in Depth of Pond at 100-year water surface elevation Top of Pond = 4762.00 Bottom of Pond = 4759.79 Depth of Water = 4762.00 — 4759.79 = 2.21 ft. = 26.5 in. Pond Draw Down = Depth of Water * Infiltration Rate = (26.5 in.)*(60 min/in) = 1590 min. = 26.5 hr 0 0 ta O U O) J /s Q �i w DC L.3 (NJ v y m E W � oo c —' NC3 p� O N V co z co cp WI 2 —' to l0 O. c w C O OC a W �' = O IS: oo = E -c1°o ooE - isi oo aal Z -J � � !V o ULII o i F'd tt'Y J Wr N a.az W 0 y @ \\F__ H CC laa O O Q O. CC N `� C O N O E CZZO o Z 4 El g 0 "-ILim (1. cC o = n Z O p� o - a. U ,2 0 0 ; t$ a H a'i O w = � Oa '- V 0 s d z a `I�' a V ^ z N C2 J $ E O 0 p at el. Wp (� z LW 03 47, O '��7 NN CO EOLL Q 1 Z sumo ammi O o 6 cc LI O. N O c o Q § 4� t C caj W N O J _co LL E C N D a0 -c 2 +• NH r-6 O 2 E N .C T LL .C N• a a. C .C N a N -C l6 — _L-' N : E —� r --- —_______ — —_---- o c o \ \� -- - ~I !~ II � y = � E Ii II J " ° E — ) re)C N N N N O O2 I I 3 `Oa V c 0 w Q (4 W 2 V O 0 N •••••4J 0z to :\,. ..‘.,,, (...-, tO i 0DN 0 N > z9 a •., Q O in 'N''.----\ \ . < \.\ N . � D 0 N J7 to N>:',-, Jb K.N.----. 4• •Vm �ify I IN ) I I it I % L ( I I I \ ® El __ 1 o �._ t o { I Flatirons, Inc. — Surveying & Engineering Appendix D Geotechnical Report Attached is a copy of the Geotechnical Engineering Study prepared by HP Geotech, dated April 11 , 2013 . Weideman Compressor Station D April 14, 2014 HcpWorth-PaA►k C'ietnechnical. Inc. 1030' South Progresc Wad Geetech Parker, C..11L,raK1t, SOI 34 Phone: 303-841 .7110 Fax: 3t,3-S41 -75 56 email: hNL.t 2 «hhiNet)rcch.com GEOTECHNICAL ENGINEERING STUDY PROPOSED ADDITION TO THE WEIDEMAN COMPRESSION STATION LOCATED APPROXIMATELY ON 1 /4 MILE SOUTH AND 1/2 MILE EAST OF INTERSECTION OF COUNTY ROAD 27 AND COUNTY ROAD 42, WELD COUNTY, COLORADO JOB NO. 214152A APRIL 11 , 2014 PREPARED FOR: FLATIRONS, INC. ATTN: KEN CURFMAN, P.E., P.L.S. 955 FOURTH AVENUE LONGMONT, COLORADO 80501 TABLE OF CONTENTS PURPOSE AND SCOPE 1 PROPOSED CONSTRUCTION 1 SITE CONDITIONS 2 FIELD EXPLORATION 2 SUBSURFACE CONDITIONS 2 SEISMIC DESIGN 3 DESIGN RECOMMENDATIONS 3 SPREAD FOOTING FOUNDATION 3 MAT FOUNDATIONS 5 DEEP FOUNDATIONS 5 FOUNDATION AND RETAINING WALLS 6 FLOOR SLABS 7 PERIMETER DRAIN SYSTEM 8 INFILTRATION TESTING 8 SITE GRADING 8 SURFACE DRAINAGE AND MAINTENANCE 9 CONTINUING SERVICES 10 LIMITATIONS 10 FIGURE 1 SITE LOCATION FIGURE 2 BORING LOCATIONS FIGURES 3 - 4 BORING LOGS FIGURE 5 LEGEND AND NOTES FIGURES 6 SWELL/COMPRESSION TEST RESULTS FIGURES 7 - 10 GRADATION ANALYSES RESULTS TABLE 1 SUMMARY OF LABORATORY TEST RESULTS TABLE 2 INFILTRATION TEST RESULTS PURPOSE AND SCOPE This report presents the results of a subsoil study for proposed expansion to Aka Energy Group's Weideman Gas Compression Station located about 1 /4 mile south and 1/2 mile east of the intersection of County Road 27 and County Road 42 in Weld County, Colorado. The project site location is shown on Figure 1 . The purpose of the study was to evaluate the subsurface conditions, provide foundation type and construction recommendations for a compressor station and determine infiltration rates for a storm water detention/retention pond. A field exploration program consisting of 8 borings was conducted to obtain information on the subsurface conditions. Samples of the subsoils obtained during the field exploration were tested in the laboratory to determine their classification and other engineering characteristics. Infiltration rates were determined for detention/retention pond design. The results of the field exploration and laboratory testing were analyzed to develop recommendations for foundation types, depths and allowable pressures for the proposed addition foundations. This report summarizes the data obtained during the study and presents our conclusions, design recommendations and other geotechnical engineering considerations based on the proposed construction and the subsoil conditions encountered. PROPOSED CONSTRUCTION The proposed Weideman compressor station is shown on Figure 2. The new construction will include the installation of 6 Exterran C-Series compressors near the north end of the site, the construction of a storm water detention/retention pond located to the south of the site, and a storage tank bay near the southeast corner. Several other appurtenant structures will be located within the site. Specific loads were not provided, but we assume structure gravity loads range from light to moderate, typical of this type of construction. Job No. 214152A 1GL-Gt1 April 1 l , 2014 SITE CONDITIONS The site is approximately 1/4 mile south and 1/2 mile east of the intersection of County Road 27 and County Road 42, Weld County, Colorado. Adjacent parcels have been cropped and irrigated. The ground surface is relatively flat. Access to the site was gained by way of an unpaved road leading to the area. A small ditch exists on the north side of the proposed construction. Vegetation in the area of the proposed construction consisted of harvested corn. FIELD EXPLORATION The field exploration for the project was conducted on March 24, 2014. A total of 8 borings were drilled at the locations shown on Figure 2 to evaluate the subsurface conditions in the area of the proposed construction. The borings were drilled with a truck mounted CME-55 drill rig equipped with an automatic hammer, and were logged by a representative of Hepworth-Pawlak Geotechnical, Inc. Samples of the soils were taken with a nominal 2-inch ID California spoon sampler. The sampler was driven into the subsoils at various depths with blows from a 140-pound hammer falling 30 inches. This test is similar to the standard penetration test described by ASTM Method D-1586. The penetration resistance values are an indication of the relative density or consistency of the subsoils. Depths at which the samples were taken and the penetration resistance values are shown on the Boring Logs, Figures 3 and 4. The samples were returned to our laboratory for review by the project engineer and testing. SUBSURFACE CONDITIONS Below about 1 foot of top soil, the soils consisted of silty sands to the maximum depth drilled of 25 feet. Based on blow counts, the sands were loose to dense. In Borings B-1 , B-2, and B-4, groundwater was encountered near the bottom of the borings at the time of drilling and was found at depths ranging from 19 to 20 feet when measured the following day. Borings B-3, B-5, B-6, P-1 , and P-2 were dry both at the time of drilling, and when measured the following day. Groundwater levels are expected Job No. 214152A 2 Gettech April 11 , 2014 to fluctuate due to seasonal, climatic, or other factors including irrigation of the adjacent land. Laboratory testing included natural moisture content, unit weight, swell/compression, gradation analysis, and water soluble sulfate concentration. The sample of silty sand from Boring B-3 at 4 feet exhibited a vertical compression is 3 .5 percent when wetted under a 1 ksf surcharge, indicating the soil is not expansive. Gradation analysis results of sand samples are shown on Figures 7 to 10. The concentration of water-soluble sulfates was found to range between nil and 0.005 percent in the samples tested. Sulfate concentrations below 0. 1 percent represent a negligible degree of sulfate attack on concrete, and therefore no special recommendations regarding cement type are required. Type I/II is recommended for this project due to its ready availability and common use in this area. SEISMIC DESIGN The following parameters are based on the 2009 International Building Code. 0.2 second spectral response acceleration Ss = 0.206 g [Fig. 1613 .5(1 )] 1 .0 second spectral response acceleration S1 = 0.054 g [Fig. 1613 .5(2)] Site Class = D Site coefficient Fa = 1 .6 Table 1613 .5.3(1 ) Site coefficient F, = 2.4, Table 1613 .5.3(2) DESIGN RECOMMENDATIONS Based on the soils encountered in our investigation, it is our opinion that shallow foundations bearing on compacted fill are adequate for the proposed structures at this site, but understand that deep foundation may be desired, particularly for use with the compressors. Recommendations for both foundation types have been provided. SPREAD FOOTING AND RETAINING WALL FOUNDATIONS Relatively loose sands were encountered at the anticipated depth of the foundations, and therefore excavation, moisture conditioning, and re-compaction of the onsite soils to a depth of 2 feet below the foundations is recommended. Soils should be compacted to at Job No. 214152A 3 Gt ech April 11 , 2014 least 98 percent of the maximum standard proctor density (ASTM D698A) . Additionally, the following recommendations should be followed for the construction of footing foundations. 1 ) Footings placed on the undisturbed native silty sand or compacted fill should be designed for an allowable bearing pressure of 1 ,500 psf. Based on experience, we expect settlement of footings designed and constructed as discussed in this section will be less than 1 inch total and about 34 inch differential. 2) Loose or disturbed soil below the proposed footing area should be removed and replaced compacted to at least 98 percent of the standard Proctor (ASTM D698) density, and within 2 percent of the optimum moisture as described in the SITE GRADING section. 3) Footings should have a minimum width of 16 inches for continuous walls and 24 inches for isolated pads. 4) The lateral resistance of foundation or retaining wall footings 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 bottom of the footings can be calculated based on a coefficient of friction of 0.35. Passive pressure of compacted backfill against the sides of the footings can be calculated using an equivalent fluid unit weight of 350 pcf. The coefficient of friction and passive pressure values recommended above assume ultimate soil strength. Suitable factors of safety should be included in the design to limit the strain which will occur at the ultimate strength, particularly in the case of passive resistance. Fill placed against the sides of the footings to resist lateral loads should be compacted and moisture conditioned in accordance with the specifications listed in the SITE GRADING section. 5) All exterior footings and footings beneath unheated areas should be provided with adequate soil cover above the bearing elevation for frost protection. Placement of foundations at least 36 inches below exterior grade is typically used in this area. 6) Continuous foundation walls should be reinforced top and bottom to span local anomalies, such as by assuming an unsupported length of at least 12 feet. 7) Foundation excavations should not be wetted or dried excessively. The foundation soils should be tamped to compact loose soil prior to placing forms for footings. Job No. 214152A 4 Cc tech April 11 , 2014 8) A representative of the geotechnical engineer should observe the footing excavations prior to forming to evaluate bearing conditions. MAT FOUNDATIONS Reinforced concrete mats may be used to support some equipment. A modulus of vertical subgrade reaction of 100 pci can be used for the design of mat foundations bearing on at least 2 feet of moisture conditioned onsite silty sand re-compacted to at least 98 percent of the standard proctor density (ASTM D698). A maximum allowable bearing pressure of 1 ,500 psf may be used. If these recommendations are followed, settlement of large mats is expected to be less than about 1 inch. The Base of the mats should be constructed below frost level. Alternatively, edge thickened mats extending below the frost level may be used. Any loose or disturbed soil below the proposed footing area should be removed and replaced compacted to at least 98 percent of the standard Proctor (ASTM D698) density, and within 2 percent of the optimum moisture as described in the SITE GRADING section. A representative of the geotechnical engineer should observe the footing excavations prior to forming to evaluate bearing conditions. DEEP FOUNDATIONS 1 ) Drilled piers used to support structures may be designed for an allowable end bearing pressure of 8,000 psf at depths of 15 feet or greater. Side shear may be calculated based on 500 psf for the portion of the shaft below 5 feet. 2) A minimum pier length of 15 feet is recommended. To avoid caving, casings may be required during construction. Due to the soils type and the groundwater level at the time of drilling, construction of piers extending deeper than about 20 feet below existing grade may be difficult. A minimum diameter of 18 inches is recommended. 3) Piers should be designed to resist lateral loads assuming a modulus of horizontal subgrade reaction of 20 pci for loose sand and 60 pci for medium dense sand. The modulus value given is for a long, 1 foot wide pier and must be corrected for pier size. Job No. 214152A 5 c tech April 11 , 2014 The following LPILE values have been provided for the soil types encountered. LPILE PARAMETERS Soil Type Total Unit k Friction Cohesion, c Weight (pci) Angle, (psi) so (pci) (degrees ) Loose Silty Sand 0.064 20 30 N/A N/A Medium dense to dense 0.070 60 32 N.A N/A Silty Sand 4) Concrete utilized in the piers should be a fluid mix with sufficient slump so that concrete will fill the void between the reinforcing steel and the pier shaft. 5) Pier shafts should be properly cleaned prior to the placement of concrete. 6) Free water was encountered in the borings drilled at the site, and seepage in the pier shaft will likely be encountered during drilling. Dewatering equipment may be required to reduce water infiltration into the pier shaft. If water cannot be removed prior to placement of concrete, the tremie method should be used after the hole has been cleaned of spoil. In no case should concrete be placed in more than 3 inches of water unless the tremie method is used. 7) A representative of the geotechnical engineer should observe pier drilling operations FOUNDATION AND RETAINING WALLS Foundation walls and retaining structures which are laterally supported and can be expected to undergo only a slight amount of deflection should be designed for a lateral earth pressure computed on the basis of an equivalent fluid unit weight of at least 55 pounds per cubic foot (pcf) for backfill consisting of the on-site sand soils. Cantilevered retaining structures which are separate from the structure and can be expected to deflect sufficiently to mobilize the full active earth pressure condition should be designed for a lateral earth pressure computed on the basis of an equivalent fluid unit weight of at least 35 pcf for backfill consisting of the on-site sand soils. Light compaction equipment should be used within 3 feet from the wall surface to avoid wall movement. Job No. 214152A 6Get tech April 11 , 2014 All foundation and retaining structures should be designed for appropriate hydrostatic and surcharge pressures such as adjacent footings, traffic, construction materials and equipment. The pressures recommended above assume drained conditions behind the walls and a horizontal backfill surface. The buildup of water behind a wall or an upward sloping backfill surface will increase the lateral pressure imposed on a foundation wall or retaining structure. A drain system, weep holes or geosynthetic composite drain board should be provided to prevent hydrostatic pressure buildup behind walls. FLOOR SLABS The natural on-site silty sand is suitable to support lightly to moderately loaded slab-on- grade construction. The following details should be followed for slab on grade floors. Some movement, up to about one inch, could occur. If no movement is tolerable then a • structurally supported floor should be considered. Where possible, floor slabs should be separated from all bearing walls and columns with expansion joints which allow unrestrained vertical movement. 1 ) Floor slab control joints should be used to reduce damage due to shrinkage cracking. Control joint spacing is a function of slab thickness, aggregate size, slump and curing conditions. The requirements for concrete slab thickness, joint spacing and reinforcement should be established by the designer based on experience, recognized design guidelines and the intended slab use. Placement and curing conditions will have an impact on the final concrete slab integrity. 2) If plumbing lines are below or penetrate the slab, they should be tested before operation. Where plumbing lines enter through the floor, a positive bond break should be provided. Flexible connections should be provided for slab-bearing mechanical equipment. Flexible connections should allow for at least 1 inch of vertical movement. 3) Depending on the floor covering, a vapor retarder may be needed below the slab. However the vapor retarder may affect the concrete curing. Considerations and recommendations for the installation of vapor retarders below concrete slabs are outlined in section 3 .2.3 of the 2006 report of the American Concrete Institute (ACI) Committee 302, "Guide for Concrete Floor and Slab Construction (ACI 302. 1R-04)". Job No. 214152A 7Gettech April 11 , 2014 PERIMETER DRAIN SYSTEM It is our understanding that below grade levels are proposed for the construction of this site, and therefore, a perimeter drain system is not necessary. If below grade levels are considered, we should be contacted to provide additional recommendations. PERMEABILITY TESTING Two shallow holes P1 and P2 were drilled to depths of 3 to 3'A feet to conduct in-place permeability tests in the area of the proposed detention/retention ponds. The shallow holes were filled with water the day they were drilled and the permeability was measured the following day. Detailed test results are presented on Table 2. Based on the measured rates, we recommend using a coefficient of permeability of 7 X 104 cm/s (60 min/inch) for design purposes. SITE GRADING General The following recommendations should be followed for grading, site preparation, and fill compaction. 1 ) All import and onsite backfill should be approved by the geotechnical engineer. 2) Where fill is to be placed, loose or otherwise unsuitable material, including topsoil and vegetation should be removed prior to placement of new fill. 3) Soils should be compacted with appropriate equipment for the lift thickness placed. 4) The following compaction requirements should be used: TYPE OF FILL MOISTURE CONTENT SOIL TYPE - Compaction Percent PLACEMENT (ASTM D698 — Standard Proctor) Under Foundations -2% to +2% of Optimum On site sands or structural import 98% Foundation Wall Backfill -2% to +2% of Optimum Suitable Onsite or Import Fill min — 95% Below Concrete Flatwork, -2% to +2% of Optimum Slab-on-Grade and Pavement Suitable Onsite or Import Fill min — 95% Landscape Areas -2% to +2% of Optimum Onsite or Import Fill — 90% Utility Trenches As they apply to the finished area Excavation The soils can be excavated with conventional equipment to the proposed grades. Job No. 214152A 8Get tech April 11 , 2014 Suitability of On-site Soil The on-site sand soils can be used as fill on all areas of the site, provided that the above listed moisture and compaction specifications are followed. All fill should be processed so that it does not contain fragments larger than 3 inches in diameter. Imported Structural Fill If imported structural fill is required, a granular material, such as a CDOT Class 5 or 6 aggregate should be used. Imported structural fill should consist of minus 4-inch material having less than 35 percent passing the No. 200 sieve, a liquid limit less than 30, and a plasticity index less than 15 . Structural fill placed below footings should be compacted to at least 98 percent of the maximum standard Proctor density (ASTM D698) at moisture content within 2 percent of optimum. Drainage Good surface drainage should be provided around all cuts and fills to direct surface runoff away from these areas. Slopes and other stripped areas should be protected against erosion by paving, re-vegetation or other means. SURFACE DRAINAGE AND MAINTENANCE The success of foundations, slab-on-grade, and concrete flatwork is contingent upon keeping the bearing soils at approximately constant moisture content, and by not allowing surface water a path to the subsurface. Positive surface drainage away from the structure must be maintained at all times. Landscaped areas should be designed and built such that irrigation and other surface water will be collected and carried away from foundation elements. The ground surface surrounding the exterior of the structure and any overlying pavements should have a positive slope away from foundation walls on all sides. We recommend a minimum slope of 6 inches in the first 10 feet in unpaved areas and a minimum slope of 3 inches in the first 10 feet in paved areas. A swale should be provided at the base of cut slopes that are adjacent to the building. For entrance areas, ADA criteria may apply, and should take precedence over the above recommendations. Job No. 214152A 9 Gettech April 11 , 2014 Proper compaction of exterior backfill is necessary in maintaining a long-term positive slope away from the structures. Areas of settlement of the exterior backfill after construction should be backfilled immediately to maintain positive slopes away from the structure. All roof downspouts and drains should discharge well beyond the limits of all backfill. CONTINUING SERVICES Two additional elements of geotechnical engineering service are important to the successful completion of this project. 1 ) Consultation with design professionals during the design phases. This is important to ensure that the intentions of our recommendations are properly incorporated in the design, and that any changes in the design concept properly consider geotechnical aspects. 2) Observation and monitoring during construction. A representative of the Geotechnical engineer from our firm should observe the exposed foundation excavation prior to placement of structural fill. We should observe and test placement of structural fill under foundations to judge whether the proper placement conditions have been achieved. We recommend observation and inspection of the underdrain system, damp proofing, installed vapor retarders under floor slabs and crawlspaces. LIMITATIONS This study has been conducted in accordance with generally accepted geotechnical engineering principles and practices in this area at this time. We make no warranty either express or implied. The conclusions and recommendations submitted in this report are based upon the data obtained from the exploratory borings drilled at the locations indicated on Figure 2, the proposed type of construction and our experience in the area. Our services do not include determining the presence, prevention or possibility of mold or other biological contaminants (MOBC) developing in the future. If the client is concerned about MOBC, then a professional in this special field of practice should be consulted. Our findings include interpolation and extrapolation of the subsurface conditions identified in the borings and variations in the subsurface conditions may not Job No. 214152A 10 C1'tecY1 April 11 , 2014 become evident until excavation is performed. If conditions encountered during construction appear different from those described in this report, we should be notified so that re-evaluation of the recommendations may be made. This report has been prepared for the exclusive use by our client for design purposes. We are not responsible for technical interpretations by others of our information. As the project evolves, we should provide continued consultation and field services during construction to review and monitor the implementation of our recommendations, and to verify that the recommendations have been appropriately interpreted. Significant design changes may require additional analysis or modifications to the recommendations presented herein. We recommend on-site observation of excavations and foundation bearing strata and testing of structural fill by a representative of the geotechnical engineer. Respectfully Submitted, HEPWORTH - PAWLAK GEOTECHNICAL, INC. Cuong Vu, Ph.D., P.E. Reviewed by _era r le.�_. 4. � Il ir O • • 6 0 ; Arben Kalaveshi, P.E. o� secj %p ', • O • • 4596e • D •O4-//-/4 •:4 AGNAL "9° Job No. 214152A 11 G�c�tech April 11 , 2014 -7. • - ,fr--. -47w----- ' 77 _ . �` fJ�'w-r- '� -�v IL! ��+ •r •■ ■ ``1 j p'�^ i•�M 7(J �lVt C.. ►h 4743 4742 --'// es,7 t )tr ( 1• f v $ f Well �' // r 4748 I , l i 1 r a • 0 1 9 ' 475 •• ells 21 I I • ` 1 R 4i•J.� , ovoj150 Ial I.,- Li/ 11 1 n II N P u t a ' Ir 0 ti I 11 tie sr u to ' a) •.• II`aTSa R a is I • • 48 +. 17 Y APPROXIMATE SITE LOCATION t° I ' I i o ttiV , 1 , •...., / fr: r Y t • DITCH y---"r'-' 7, ', 47'55 Akioa• i . • a.!•-14.4 0 I . . > 1N I • a le:;. •l ii' -- • == • 1 ai■ •a J•. P • 30f 1 :4762 9 a e ' ? ; :- ',j ski " -" " ) . \ 'j i Is I o /Thlt i Y.Y.■ ii ' ' r' (Di + ) ,�)jf _ _ ».... - •" 11C2`('St V '■ f 4 ' .r7' 'J- • 8M i ' ,IP; 1. f 2 F: 4754 a I v r n • _ k 4 6J !•. 1417 -. �1; sr c ) 0" r 1e -. gO� • o -. QivQ / 18 ��' PI � n I ll,T I f 7 / I GIN all fr' _Well ii It' a 4-7587 l rr- d 1 7 J f' / ( 72 dam . . i its r ' - I �4' _'�. �, if • — , ..- / r ; . J t I;I 4777 ---_- -- 0774 - - - -__._.�- -._ 41 kJ _ f = _ e / 0 1000' 2000 r-` l ji‘ r° 1 o 0 : a I r." SCALE: 1" = 2000' _ I .,w&I �� a r"� r is I 1\ HEPWORTH-PAWLAK WEIDEMAN COMPRESSOR STATION 214152A GEOTECHNICAL, Inc. SITE LOCATION FIG. 1 .li.N -— ' I I I '- _ I - _ _ . '- _ �._.1 • aaa I a. • --' -•_ e a rr! w, _ _ .,-i_•-..-._._... .__r_._•r_•.•-ts.y:.n 'z_.-•.•-•.. •• \. O. I 46,p a3i • l [""°—J •,� i uewm B15.11 l 1 at mu Y4 1 fi' • • B-1 B-2 B-3 B-4 n1 ? R i • i1'c • • 4; 6t- um. , + thi—• #) an. # Ill! I i r y . . 1 41. II rtl i 1 ' Ilk \• , i S 1 •a., , 1 a I 1 S! , , 1 i 1 1 1 { I 1 K .37.). ,. i i ' 1 PM PR I r 0- 1 , 1 warp 1 \I", •, '`',\lam\\``t[C� \. \‘..„,NC. - - - - - l 1 • ! 1 % : .1/4„' <,, (-.5 . : II .-•flvt!f?tOs 11 0 20' 40' I SCALE: 1 " = 40' HEPWORTH-PAWLAK WEIDEMAN COMPRESSOR STATION 214152A GEOTECHNICAL, Inc. BORING LOCATIONS FIG. 2 B-1 B-2 B-3 BA 0 0 - • • 9/12 5/12 6/12 7/12 • MC = 9.2 MC = 5.7 MC = 10.2 /� DD = 121 .6 •/ DD = 108.7 DD = 119.3 6/12 5/12 /� 8/12 . 6/12 - 5 • • MC = 4.1 MC = 3.9 d MC = 3.9 . • • MC = 4.3 5 SP - 35 DD = 109.6 WSS ,10.0 DD = 111 .4 - WSS = 0.005 • - �▪ .", 7 7 _ - 21/2 28/12 10/12 11/12 - 10 MC = 3.1 • MC = 1 .6 ' • MC = 6.2 10 • DD = 116.6 • DD = 117.1 DD = 121 .6 - ///7 .200 - 3 7 /7••N 41/12 23/127 21/12 35/12 - 15 / MC =3.0 15 Li • DD = 117.2 ,T� a +4 = 3 �� • - Q Q - 200 =7 • _ 0 7•• 1 12/12 122/127 21/12 14/12 - 20 7-: : : MC = 2.8 20 DD = 119.5 - • -200 = 11 _ 26/12 . 31/12 - 25 / - • 25 30 30 HEPWORTH-PAWLAK WEIDEMAN COMPRESSOR STATION 214152A GEOTECHNICAL, Inc. BORING LOGS FIG. 3 B-5 B-6 P-1 P-2 0 0 . 7/12 / 10/12 / / - 7- MC = 8.8 7:/__ / DD = 109.5 _ -/ ,T� 7/12 7/12 - /• • 8/12 6/12 . • MC = 5.4 MC = 3.5 - DD = 110.9 110.9 DD = 113.5 5 MC = 4.1 MC = 4.3 +4 = 0 +4 = 0 5 DD = 112.4 •- DD = 112.0 -200 = 14 -200 = 12 77 11/12 / 13/12 10 / '� /• . 10 / /. 7.4. . u_ ..ei /- - O 22/12 � 27/12 - O 15 / 15 /: r I - 28/12 26/12 - 20 MC = 5.4 20 DD = 124.8 +4 = 5 - -200 = 24 25 25 HEPWORTH-PAWLAK WEIDEMAN COMPRESSOR STATION 214152A GEOTECHNICAL, Inc. BORING LOGS FIG. 4 LEGEND Top soil, sand, silt, some clay, corn and grass, moist, brown. / SAND (SM, SP-SM), silty, loose to dense, fine to medium, moist, light brown, dark brown to brown. 17/12 Indicates 2" I . D. California sampler. 17/12 indicates 17 blows of a 140 lb hammer falling 30" were required to drive the sampler 12 inches. Indicates depth of free waterlevel at the day of drilling 1 Indicates depth of free water level and 1 day after drilling NOTES: 1 . Borings were drilled on March 24, 2014 with a truck mounted CME-55 rig powering 4-inch diameter continuous flight augers. 2. Locations of borings shown on Figure 2 are approximate. 3. Borings were plotted by depth. 4. Water was encounter at the time of drilling. 5. The lines between strata represent approximate boundaries and transitions may be gradual. 6. Laboratory Testing Results: MC = moisture content of sample in percent of the dry weight. DD = dry unit weight of sample in pcf. -200 = percent of silt and clay fraction . +4 = percent of gravel fraction. WSS = water soluble sulfates in percent. SP = percent of swell under a 1 ,000 psf surcharge after wetting. HEPWORTH-PAWLAK WEIDEMAN COMPRESSOR STATION 214152A GEOTECHNICAL, Inc. LEGEND AND NOTES FIG. 5 1 .0 Location Boring 3 0.0 ------' ------ ------' Depth 4 feet -1 .0 _narini•Ilimaisennomemeanionaml Lab No. Silverthorne Date Tested 3/24/2014 o-2 .0 — -----� ------ ----- Soil Type (USCS) Sand (SP) -3 .0 --- --- ----- Moisture Content 4% Dry Density (pcf) 93.5 Wetted at (ps f) 1000 z ComprF3sion Upon Loading a )d Wetting Result (%) -3.50 /O// _6.0 --------- ------ ------- VJ W -I .0 ------- ------ ------r _8 .0 ~-------- ------ ------- O -9.0 ------- ------ ------- -10.0 ------Mal - -------- -ern --- -11 .0 ------- ------ ------- -12.0 - - - 0. 1 1 10 100 APPLIED PRESSURE (KSF) HIP 214 152A G tech WEIDEMAN COMPRESSOR STATION FIGURE 6 HEPWORTH-PAWLAK GEOTECHNICAL SWELL-COMPRESSION TEST RESULTS Gradation Analysis US Standard Sieve Sizes US Standard Sieve Numbers Hydrometer Analysis COBBLES GRAVEL SAND SILT AND CLAY 100% , I i I I 1 i i 80% i I I ! , I , 4-0 i i I ► I � m f 1 t • I c , I f y I I I ns i 40% I ' I I I I ? I a } I I I I i I 20% I - . - - I T 3 I , I � , I f 1 j ! ( 0% i , I . 1 I _ I I I A, ! f 390.625 78.125 15 .625 3.125 0.625 0. 125 0.025 0.005 0.001 Particle Size Diameter in Millimeters eGradation Curve 3 " Sieve e 3/4" Sieve No. 4 Sieve -No. 200 Sieve Particle Size Distribution Cobbles: 0% Gravel: 3% Sand: 90% Silt & Clay: 7% Grain Size (mm) Sieve Size 0/0 Passing Location : B- 1 152.4 6" 100% Depth : 14' 101.6 4" 100% Classification : Slightly Silty Sand (SP-SM) 76.2 3" 100% Dry Density : 117 .2 pcf 50.8 2" 100% Moisture Cont: 3 .0% 38.1 1.5" 100% 25.4 1" 1000/0 19.1 3/4" 100% 12.7 1/2" 100% 9.52 3/8" 100% 4.76 # 4 97% 2.38 # 8 89% 1.19 # 16 77% 0.59 # 30 53% 0.297 # 50 26% 0.149 #100 13% 0.074 #200 7% 1-1 PC 214 152A Gee tech WEIDEMAN COMPRESSOR STATION FIGURE 7 HEPWORTH-PAWLAKGEOTECFINICAL GRADATION TEST RESULTS Gradation Analysis US Standard Sieve Sizes US Standard Sieve Numbers Hydrometer Analysis COBBLES GRAVEL SAND SILT AND CLAY 100% - - - - 80% --- -- - T.— s o) .F) .10 60% -- rn c IA 4.1 a c u40% --L. cu a 20% • - 0% --- - - 390.625 78.125 15 .625 3. 125 0.625 0.125 0.025 0.005 0.001 Particle Size Diameter in Millimeters Gradation Curve 3 " Sieve - 3/4" Sieve No. 4 Sieve No. 200 Sieve Particle Size Distribution Cobbles: 0% Gravel: 5% Sand: 710/0 Sitt & Clay: 24% Grain Size (mm) Sieve Size % Passing Location: B-6 152.4 6" 100% Depth: 19' 101.6 4" 100% Classification : Slightly Gravelly/ Silty Sand (SM ) 76.2 3" 100% Dry Density: 124.8 pcf 50.8 2" 100% Moisture Cont: 5 .4% 38.1 1.5" 100% 25.4 1" 100% 19.1 3/4" 100% 12.7 1/2" 100% 9.52 3/8" 98% 4.76 # 4 95% 2.38 # 8 85% 1. 19 # 16 72% 0.59 # 30 58% 0.297 # 50 42% 0.149 #100 31% 0.074 #200 24% 214 152A G ( 'tech WEIDEMAN COMPRESSOR STATION FIGURE 8 HEPWORTH-PAWLAK GEOTEC HN!CAL GRADATION TEST RESULTS Gradation Analysis US Standard Sieve Sizes US Standard Sieve Numbers Hydrometer Analysis COBBLES GRAVEL SAND SILT AND CLAY 100% -- --47 ' i i I I 80% — — — - - I_ ---- — +- .c en .45 >" 60% - - —r— vi r ro a I c I S 40% -- - - — a t 1 I i i 20% -- - -- , - _ + I I I 0% f ' - - 390.625 78 . 125 15 .625 3. 125 0.625 0. 125 0.025 0.005 0.001 Particle Size Diameter in Millimeters — Gradation Curve 3 " Sieve 3/4" Sieve No. 4 Sieve - No. 200 Sieve Particle Size Distribution Cobbles: 0% Gravel: 00/0 Sand: 86% Sitt & Clay: 14% Grain Size (mm) Sieve Size %o Passing Location : P- 1 152.4 6" 100% Depth : 3' 101.6 4" 100% Classification : Silty Sand (SM) 76.2 3" 100% Dry Density : 110.9 pcf 50.8 2" 100% Moisture Cont: 5 .4% 38.1 1.5" 100% 25.4 1" 100% 19.1 3/4" 100% 12.7 1/2" 100% 9.52 3/8" 100% 4.76 # 4 100% 2.38 # 8 99% 1. 19 # 16 89% 0.59 # 30 73% 0.297 # 50 53% 0. 149 #100 30% 0.074 #200 14% fri WEIDEMAN COMPRESSOR STATION 214 152AI Geet ch GRADATION TEST RESULTS FIGURE 9 HEPWORTH-PAWLAK GEOTECHNICAL Gradation Analysis US Standard Sieve Sizes US Standard Sieve Numbers Hydrometer Analysis COBBLES GRAVEL SAND SILT AND CLAY 10 0% r- - - -- - - -- 80% — — r rn w .a 60% -- - -- - - C' c in R a 3J c u 40% — -- L 20% 0° - - - — /o f •--, —z— , 390.625 78 . 125 15 .625 3. 125 0.625 0. 125 0.025 0.005 0.001 Particle Size Diameter in Millimeters • Gradation Curve - 3 " Sieve - 3/4" Sieve No. 4 Sieve No. 200 Sieve Particle Size Distribution Cobbles: 0% Gravel: 0% _ Sand: 88% 1 Silt & Clay: 12% Grain Size (mm) Sieve Size 0/0 Passing Location: P-2 152.4 6" 100% Depth : 3' 101.6 4" 100% Classification : Silty Sand (SM) 76.2 3" 100% Dry Density : 113 .5 pcf 50.8 2" 100% Moisture Cont: 3 .5% 38.1 1.5" 100% 25.4 1" 100% 19.1 3/4" 100% 12.7 1/2" 100% 9.52 3/8" 100% 4.76 # 4 100% 2.38 # 8 98% 1 .19 # 16 85% 0.59 # 30 69% 0.297 # 50 52% 0.149 #100 29% 0.074 #200 12% I-11P WEIDEMAN COMPRESSOR STATION 214 152A eeteCh GRADATION TEST RESULTS FIGURE 10 HEPWORTH-PAWLAK GEOTECHNICAL i z a c F O c.,,. a - Ca Cr Q Z1 i w 4$ 41 .C .y .N .y ,y .y : V) V) V) V) V) V) C C C C v R Qf RS g a! CS V) Ca V) V) V) V) Z Z cd in U Z a O 0. v (1.1 • .. U w w Z En p )—( z a Z o t Cl) O O O v U Z Wch crl ¢ O p w' E.L. a o 0 V O N o O O W - z w 3 O W kel * a 3 0 WQ M w x gK a Lo Cn G W X F a Q a x 03 >. [- o en d' '"I- N 1 q�-+ •-- N —. .-. U Z _ _ O Q ¢ ? O N 0 00 00 O 00 Cn g CID C7 - . s••4 w O ^ N Q o en In O O O O. c E ..) F O U Z 2 O N No N h .O •— M Li "t �O h 'Cr CO 00 ON to 2 r cz ci) s N .-. .-. p p .-. ... N O N a .� .-. .-. a z o 3 E O a.) o U N F-4 a) g te F z N .41- cn C8 0 U W o N O O� �O O� 00 M N ao "4 en Q O O . . O: 4M M M s- 2 M N tt \o 00 f 4 l/1 M C o N (N1z g Oa) cCI)c v-) o > o. :�13 c o C" "' Z F c13 N '� ON N d' ON N �• O� `d' O` N 1 ti' O� en en 43) 1Z > 4. N 0_ Q v # Z Z z E U v Cn O0 K v N N N M en en <t to 'V 'o N CO O O Co m CO m m m m m m m m m m m m m a cL. ,..7 Ca _ a) (15 cc C in N- o r N •ct co I%-- CO CO O O inO ti N- r r C6 -- C'7 O O N LLc) r ca OO 4 E co N 4 ct' ti co N Co N C a) (6 > C C2 �O N.. N. CO o o O CO ON o .c - Z O " N r O O o N 4 r o r z 0 F O Q 0 J H U E O C Z W CI) w F- CI) (Oct I J I-1-1 .C z CO o Ln r CO 0 CO O CO CO U W Q. a) C in LO N- O o CO CO CO N- LO W W O C cc N ft' 't Vt 't r d- ":t- CO CC O Q ❑ 4- U a) O W U) Z oN r N -6 N W CO O o 2 Z F- Q as N J (a I__ ° a OD co O Lo r o O co o co Q C co O in N- O CO N- CO CO N-- W O C v cc) Vt Vt Vt V m tri r M i LI m 03 I z o > w H - >- CC CD O w z o 0 W c E R O o o O o c:). o o W Q CJ) a) r O r Q) CO N 6 Y C CO CO CO N tt CO CO CO N = < J C r 1 - +-' a) O LC) Q) o N Q) .-- in Vt O I Z r N _O a_ d O I Flatirons, Inc. — Surveying & Engineering Appendix E Inspection Report A blank copy of the sample stormwater facility inspection report. Weideman Compressor Station E April 14, 2014 Weideman Compressor Station Stormwater Facility Inspection Inspection required every 6 months or following major precipitation event. Date: Inspection Type: Rountine Maintenance Follow Up Public Concern Last Rainfall: < 24 Hours 1 -3 Days > 4 Days Inspector: FACILITY OBJECT COMPLIANT YES NO DESCRIPTION PHOTO #s Water Quality Pond Swales Culverts Berms Entry Road Yard Area Other Items to Inspect Water Quality Pond : Check for accumlated sediment - remove as required Check level spreader - repair as required Check for debris and weeds in pond - remove immediately Check for erosion on sides/bottom/embankment - repair immediately Swales/Ditches: Check for accumlated sediment - remove as required Check for debris and weeds - remove immediately Check for erosion on sides/bottom - repair immediately Culverts: Check for accumlated sediment - remove as required Check for debris and weeds - remove immediately Berms: Check for erosion on top/bottom - repair immediately Entry Road : Check culverts under entrances - see above for requirements Yard Area: Check for uncontrolled spills - clean up immediately TRAFFIC NARRATIVE Wiedeman Compressor Station Aka Energy Group Upon completion of construction , the Wiedeman Compressor Station will operate as an unmanned facility . Vehicles accessing this site on a daily basis , once construction has been completed , will be three to four half ton or one ton company pickup trucks . Once a month a Waste Management truck will visit the site to remove general refuse from the waste dumpsters . Two contract maintenance employees may visit the site twice a month . Once a week the Porta-a-pottie service company will visit the site . Once a year the used oil will be removed by Mesa Environmental . Traffic leaving the site will proceed north onto County Road 42 and travel west until it intersects with Highway 60 . 60% will proceed south while the remaining 40% will proceed north . Traffic entering the site will proceed west onto County Road 42 from Highway 60 . Approximately 60% will enter the site from Highway 60 to CR 42 and approximately 40% will enter onto C . R . 42 from C . R . 29 . A traffic study was not required due to the rural location of the site . TRAFFIC CONTROL PLAN — AKA ENERGY GROUP, LLC / Wiedeman Compressor N NOTE : Sign spacing will be determined according to Table 6H-3 in the Manual on Uniform Traffic Control Devices (MUTCD). Road Work Ahead Weld County Road 42 Road Work Ahead Summary of Signs 2 — 48"x48" Road Work Ahead �p COO l - ea\ Weld County Public Works Dept. st 1111 H Street ACCESS PERMIT ,0 ,i, , P.O. Box 758 0,;w:` iGreeley, CO 80632 APPLICATION FORM �(/C v 9e Phone: (970)304-6496 Fax: (970)304-6497 Applicant Property Owner (If different than Applicant) Name S\ oe. S2.4kb Name Icrri, lAj e&e'tg,n Company Ate► Ene r3% 610(1.0 t i �k, Address I a tag CAZ. 42. Address i%1-192- Gk. 1-tQ City Ploi eustle, State CO Zip a0C.5 ( City PloWe.vle- State Co Zip 9Oc5( Phone (MO- ? (s - oiy G,W Business Phone cvflO- ri3)- ,Ol Fax Fax cl-10- t13n - 0155 E-mail E-mail % 4m @ ck1e.q Qne rcatc.) . COK\ A = Existing Access A= Proposed Access aex)cznS , PC-5 eC\Wta\ ,co Parcel Location & Sketch The access is on WCR t-12 Nearest Intersection: WCR 1-12. & WCR 2°1 WCR y2 Distance from Intersection 2.CIA 0 c:::et* B A Parcel Number 1M'r12g2CX)Qa -7 C5- Section/Township/Range 2.c2t - r-1 - t it v cc Is there an existing access to the property? YE NO N ` 3 Number of Existing Accesses : e-c. blaua1Oc. RitAcka Road Surface Type & Construction Information Asphalt Gravel x Treated Other WCR LAO Culvert Size & Type E4It kb au-csS \Ms vw CUlkAL 't Materials used to construct Access C,1as5 Co G +aalostse,. y .2 Construction Start Date s , ly Finish Date 61 -30 / t4 Proposed Use u Temporary (Tracking Pad Required)/ $75 ❑ Single Residential/$75 o Industrial/$150 el,cl, Small Commercial or Oil & Gas/$75 o Large Commercial/$150 o Subdivision/$150 ❑ Field (Agriculture Only)/Exempt Is this access associated with a Planning Process? u No c<USR n RE ❑ PUD u Other Required Attached Documents - Traffic Control Plan -Certificate of Insurance - Access Pictures (From the Left, Right, & into the access) By accepting this permit, the undersigned Applicant, under penalty of perjury, verifies that they have received all pages of the permit application; they have read and understand all of the permit requirements and provisions set forth on all pages; that they have the authority to sign for and bind the Applicant, if the Applicant is a corporation or other entity; and that by virtue of their signature the Applicant is bound by and agrees to comply with all said permit requirements and provisions, all Weld County ordinances, and state laws regarding facilities construction. Signature Printed Name %p,je . Szmtot Date y/O/f'r A ICA energy group, Mc t i ft lr. :in tit( , rr u-lir ul tril->i ) April 10, 2014 Weld County Public Works Dept. 1111 H Street P.O. Box 758 Greeley, CO 80632 RE: Access Permit Application Township 4 North, Range 66 West, 6t1' P.M. Section 29: Lot A & D of AMRE-4022, being part of the N'/2 Weld County, Colorado To whom it may concern: Aka Energy Group, LLC has entered into an agreement with Terry Wiedeman to access a proposed unmanned natural gas compressor station located in Lot D of AMRE-4022. A USR pre-application meeting has been held for this proposed facility and this access application will be submitted with the USR application. This is an existing agricultural access that will be used mutually by Aka Energy Group, LLC to access the compressor site and allow the landowner to access his farmland. The access road will have class 6 road base or crushed concrete spread on the surface for tracking control making it an all season road. Currently there is no culvert in place at the existing access due to the flat nature of the area and existing irrigation ditches nearby, it is not anticipated to add one because of this. The access road will be used by two company vehicles twice a day, Monday through Friday to take readings and perform routine maintenance. The Gilcrest / Platteville FPD has inspected the proposed access and has signed a letter stating it is wide enough for all emergency equipment to access the compressor site in the event of an emergency. I have included a copy of that letter for review. Two trees in photo three will cut down to improve access to the site. Enclosed is an exhibit of the access road and compressor site for review. Please contact me if you have any questions or concerns. Best regards, Donald P. Evans Contact Agent, Hill Land Services, Inc. Representing Aka Energy Group, LLC (970)-227-9682 devans.pfs@gmail.com EXHIBIT "A" uljcc� 42, LOCATED IN SECTION 29, TOWNSHIP 4 NORTH, RANGE 66 EST OF THE 6TH PRINCIPAL MERIDIAN, COUNTY OF WELD, STATE OF COLO DO SHEET 1 OF 1 - p 3 �-S�_ - `-P�_ 251 17 261k Ot262 I 1 r 129-12 TOLLGATE 3-S 3-S- I I l / I1 DERREK I LOT t f\ X11 iRCE. 1.102-2-•-- / I • I I / � I • I III / II I• 5 MCLEOD 1 iet, COMP , ��t' / � 'cc,, v v / ' • 29-13 MCLEOD III / • 1 MATTIE • • S \ / Cl. • I-- • •� O. • •) S29 7 . \ T4N • • R66W `'' n LOT D 1'Ak ,w$ V" 'N1 ( 5 �1vc`J.„)i AMENDED RECORDED 5A- 0 EXEMPTION NO. c' ' 8 1057-29-2 AMRE-4022 �� t— REC NO 3463093 CD 03/20/2007 Y Li • i, 29-1 WIEDEMAN 29-1 MCLEOD rr A / O •, I ) / 1� / I� O) - . I:n 0 200 `I Flatirons, Inc. JOB NUMBER: 14-62,997l1! DRAWN BY: T. COLVIN Surveying, Enginee ing & Gcannlies DATE: MARCH 5, 2014 1 Inoh m 40011. -. ';'it +' 3825 IRIS AVE, STE 395 „ ; 4 BOULDER, CO 80301 ` ' THIS IS NOT A "LAND SURVEY PLAT" OR *IMPROVEMENT SURVEY PLAT" AND THIS EXHIBIT IS .� PH: (303) 443-7001 NOT INTENDED FOR PURPOSES OF TRANSFER OF TITLE OR SUBDIVISIONS OF LAND. RECORD FAX: (303) 443-9830 INFORMATION SHOWN HEREON IS BASED ON INFORMATION PROVIDED BY CLIENT. )i u•nc Ploiirmtc/nc.cant 4:1:� .w`r. � / Ajr, •'rci ij:: ' 'I • L,_ O " •.4; 4#� �i,`�' ei .+i�y � f ► y aft 4 ere: ( 0,1?51 0!• • �, ` # 1147..; 4Prit , p mil! t ! "rniet , .... ,., ► - . t 14 + ♦ .,• ti 1 8al gliir rwil•ossCsr ref 4 4F. 9 I • • ' 05.-r lei.- 11 .� - •�.•� ` _t •ter Y ty ♦ I r• • It. • A. s.` �••?...' r .•t' •► 1 • - its- ' It !talk ^• . • • • •."•••••!•• . . • ''� '•� 1w • «• •` • l•• e��j a �s•;r jtAa1'I " ,fir • '• 7 v _ • �/J� X11' r t 2 irs, e. yt/ „4 i 414%. J• y1 i ; h C. • siiit •2fy rte. 3'� _ � : ' •� • ' 47` • 4 f ► • t ,.- - ', w , .yam . 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F , ...._,..... • 1 • { , . . ,� may.. r• .. • /. +j - . !•. . . - 001°.... _- v - - _ ... - ..-. .• - , .1. a •. l s It.' It ^ Nor•-. '•t y .. y{Yt rF , .�I�Y - ;'.+ �•- • ,. '•� or L • w r a A 11..' _ '4N.e ' '. Rv ,� .+ s' .LM1M' 'r2-' s i. .y S� ,-. �. Yom♦ ►. _ .-. _ �.. ♦. y �,. �. . 6. t Y a,r . e r • y. P: !! w. ,rl��i ' .1 ' .. • I - • tw• . ter • - .y} S. - l.' �; •� - a . >� �e -f. �.wT tip. .wr ♦ -:a + �� ' {• ' f� is �� , - %,- 1. •T -•• - ' S. ' - e/.• \ . }. , •! r - is 1 • - I v - ..... .. • - a • • y. 4-, • 1:41, 4k ' 4 1 4 - - • t • 'M,1- -- -5 -r t' rr•♦ . . .1 • 1 '>r. Ivy •-'1 - ?-4 _ _ .. .. • r Itl' ,Easio: ..., wog. L I 2We p e • • ' - r ' Si • ,> -�� Vii' ' - - - A 7' .4;',E...2,_.-� --.447 .as. _.t --. .,1 1..ltir .^ ---..a... ! March 26„ 2014 Access Road Width Approval USR 14-0064 To Whom it May Concern: 1 personally inspected the proposed access road to the Wiedeman compressor site under USR 14- 0064 on 1< ,-e,„ 4. a 7 , 2014. The 14 foot width of the road easement from County road 42 south to the compressor site is wide enough for emergency equipment to access the proposed natural gas compressor site. I have no concerns or issues at this time. Sincerely, 1 j Signed 7-7 Ave) f) e// £.. ` Printed Title Platteville / Gilcrest FPD EXHIBIT "A" LOCATED IN SECTION 29, TOWNSHIP 4 NORTH, RANGE 66 WEST OF THE 6TH PRINCIPAL MERIDIAN, COUNTY OF WELD, STATE OF COLORADO SHEET 1 OF 1 - =l -- $ ----J. - __ _-- - _4 _ IF-pm—..—.— - P ' - ' tor—3—S 3-S 251 4 I I1 k i 26 262 129-12 TOLLGATE 3-S 3-S I 7 • 11 1 DERREK I • I I / I I . 1 / I _ / l II / 5 MCLEOD I I • I I / • I 1 / 1 29-13 MCLEOD • / 1 MATTIE • • • LL • N. (.. / S29 T4N R66W • LOT D AMENDED RECORDED EXEMPTION NO. 1057-29-2 AMRE-4022 ;. REC NO 3463093 03/20/2007 29-1 WIEDEMAN • 29-1 MCLEOD A / t � � / 0 200 400 Flatirons, Inc.JOB NUMBER: 14-62,997 Surveying, Engineering & Genmalirc DRAWN BY: T. COLVIN DATE: MARCH 5, 2014 1 inch in 4O01t. 3825 IRIS AVE, STE 395 BOULDER, CO 80301 THIS IS NOT A "LAND SURVEY PLAT" OR "IMPROVEMENT SURVEY PLAT" AND THIS EXHIBIT IS PH: (303) 443-7001 NOT INTENDED FOR PURPOSES OF TRANSFER OF TITLE OR SUBDIVISIONS OF LAND. RECORD FAX: (303) 443-9830 INFORMATION SHOWN HEREON IS BASED ON INFORMATION PROVIDED BY CLIENT. ww„•-/yrtriron.rinc.ro,n Hello