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HomeMy WebLinkAbout17 - Design Report - S 11th Extension - Water, Wastewater Extension WATER & WASTEWATh;r------- -- EXTENSION DESIGN REPORTS FOR: SOUTH 11th AVENUE EXTENSION BOZEMAN, MT Prepared By: MADISON ENGINEERING Madison Engineering 895 Technology Drive, Suite 203 Bozeman, MT 59718 (406) 586-0262 APRIL 2017 WATER MAIN EXTENSION DESIGN REPORT FOR: SOUTH 11th AVENUE EXTENSION BOZEMAN, MT Madison Engineering 895 Technology Blvd Ste 203 Bozeman, MT 59718 (406) 586-0262 APRIL 2017 Water Design Report SOUTH IITH AVENUE EXTENSION WATER SYSTEM DESIGN REPORT A. General This design report will give an overview of the existing water distribution system, as well as the proposed water main extension for S. I Ith Avenue between Opportunity Way and Alder Creek Subdivision in Bozeman (See Location Map). Improvements are anticipated to be constructed during the summer of 2017. Once the water main is constructed and approved, the main will become a part of the City of Bozeman(COB) system. The following references were used in the preparation of this report: a. COB Design Standards and Specifications Policy, 2004. Addendum#5 b. COB Modifications to Montana Public Works Standard Specifications (MPWSS). c. DEQ Circular No. 1 d. City of Bozeman Zoning Map e. City of Bozeman Water Facility Plan f. 2012 International Fire Code B. Existing Water Supply The existing water distribution system, to serve the main extension consists of a 12" stub at S 11 th Ave and Opportunity Way and an existing 12" stub in S 11 th Ave in the Alder Creek Subdivision, north of Brookdale Drive. The following information regarding pressures of the existing system were obtained from the COB: Hydrants 2146 & 1932 (S. 1 lth Ave & Brookdale Drive) - South End of Main Static Pressure: 54 psi Pitot Pressure: 42 psi Residual Pressure: 50 psi Hydrant Discharge: 1090 gpm during test, 2.5" port Distribution Main Capacity—Maximum flow at minimum residual pressure Q,=Qt[(P,,—Pm)/(Ps—Pr)]0.54 Qr= 1,090[(54—20)/(54—50)]0.54 Qr=3,462 gpm at 20 psi Qt= Hydrant Discharge During Test Qr= Fire Flow at Minimum Residual Pressure P,= Static Pressure Pm = Minimum Residual Pressure Pr = Residual Pressure Pt= Pitot Pressure 1 lth Ave Extension Water Design Report Page I of 2 C. Proposed Water System The proposed South I Ph Water Main Extension will consist of approximately 2,037 linear feet of 12" DI water main and connect to the existing COB water distribution system at three (3) locations: Opportunity Way, Graf Street (currently under construction), and the existing stub in S llt" Ave in the Alder Creek Subdivision, north of Brookdale Drive. The proposed main will connect to the existing stubs with new gate valves. Two (2) water services and two (2) fire services are proposed between Opportunity Way and Arnold Street to serve the Residential Emphasis Mixed Use (REMU) zoned property, west of S 1lt". Five (5) 8" DI stubs will be installed off of S 1lt" Ave to serve the future residential areas between Graf Street and Opportunity Way. 12" inch DI stubs will be installed at Arnold Street, per the COB Water Facility Plan. All stubs will terminate with a blow-off assembly for flushing. The proposed water main extension is sized in accordance with COB Water Facility Plan The layout of the proposed water main meets the COB design criteria and will be located within the proposed roadway easement. Multiple fire hydrants are proposed on this extension and meet the spacing requirements set forth by the COB. Fire hydrants are not necessary on the extension south of Graf St as there are existing hydrants at the intersections of S. 11th Ave and Brookdale Drive. D. Capacity Analysis The proposed main extension as well as the 12" stub at Arnold St are designed per the COB Water Facility Plan in order to create a looped distribution system and provide redundancy. Therefore, a capacity analysis of the 12" extension is not necessary. The 8" stubs at the local street are sized to meet the minimum standards for residential areas and will be looped in as the Allison Subdivision is developed. E. Conclusion The proposed water main was designed per the COB Water Facility Plan. This project will require the approval of the City Engineer and MDEQ. Appendix 1. City of Bozeman Water Facility Plan, Figure 1 11 th Ave Extension Water Design Report Page 2 of 2 Appendix Y. �,, }!� Jar j-• j ,;ii. �- IL !`jik 1 ,.; r•. ALLEN DR � � ,,, 7- �• G OPP©RT6NITY VWAY W ' "FUTURE 12"1 M - - WATER MAIN 416 NmLiJ5 �- �• 1 - • �� «_ �J�1 FtA F S T ,.1 s- .�W ! ., � -• � - . _aC.. T �A.�r�:.J1.1:4•ii�I' i!',' _ � � �r I h--- �1 Q l3wPoKDAL d(ACM p ORrLu j �AL•'OER CREEK, R7 14 AD - O\ ENGINEERING � � S 11th Avenue 12"Water Main Extension Distribution Main Capacity @ Residual Pressure Fire Flow at Minimum Residual Pressure Prepared by: Madison Engineering Qr= Qt[(Ps—Pm)/(Ps—Pr)]0,54 Qr 1,090 ( 54 - 20)/( 54 - 50 )0 54 Qr == 3462 gpm Static Pressure: 54 psi Pitot Pressure: 42 psi Residual pressure: 50 psi Minimum Residual pressure: 20 psi Huydrant Discharge During Test: 1090 gpm Qt= Hydrant Discharge During Test Qr= Fire Flow at Minimum Residual Pressure PS= Static Pressure Pm= Minimum Residual Pressure Pr = Residual Pressure Pt= Pitot Pressure GWADISON ENGINEERING\PROJECTS\2015\15-148 Graf Street Extension\Design Report\S l l th Ave WHOLE\Water\Distrib Main Cpcty g residual AS Page I of I Wastewater Design Report SOUTH 11TH AVE EXTENSION WASTEWATER SYSTEM DESIGN REPORT A. General This report will give an overview of the existing wastewater collection system, as well as the proposed wastewater collection system crossings for the extension of S llth Ave. The proposed sanitary sewer mains will serve the development of future phases of Allison Subdivision, west of S 1 lth Avenue, which is zoned R-1 (Residential Single Household). This report will provide a description of the proposed wastewater collection system and design parameters. Once the wastewater system is constructed and approved, the system will become a part of the City of Bozeman system. The following references were used in the wastewater facilities design and capacity analysis: a. COB Design Standards and Specifications Policy, 2004. Addendum#5 (8/23/13) b. COB Modifications to Montana Public Works Standard Specifications(MPWSS). c. City adopted MPWSS and Adopted Addenda d. COB Wastewater Facility Plan, 2015 e. WQB Circular No. 2 f. City of Bozeman Zoning Map The procedures and parameters outlined in the COB Design Standards and Specifications Guide were used in the design of the sewer infrastructure for the proposed development. B. Capacity Analysis The proposed wastewater collection system will provide service to future phases of Allison Subdivision, west of South 1 lth. Manholes are proposed in S 1 lth Ave at the intersection of Arnold and a future E-W local street. Each manhole will have 8" PVC sanitary sewer stubs extending eight feet beyond the right-of-way to the east and west. When the sanitary sewer mains are built out in the future they will be extended within the future right-of-ways to the east and west, and the effluent will travel to the east to the existing sanitary sewer system. The capacity requirement of the proposed stubs were determined based on the upstream demand, future lots of Allison Subdivision, west of S 1 lth. The wastewater demands were estimated on a per acre basis for R-1 zoning. The City of Bozeman's Design Standards specify an average daily flow rate of 730 gal/acre/day for R-1 development, obtained from Table V-1. The proposed sewer mains have been sized to flow at no more than 75-percent of full capacity at peak hour conditions of full build out, and a Manning coefficient of 0.013 was used for PVC pipe. Table 1 Wastewater Calculations Wastewater Area Sewer Loading Served Average Flow Peaking Peak Flow Peak Flow Main d/acre acres Rate d Factor Rate d Rate cfs Local Street 730 24.8 18,104 4.14 74,951 0.116 Arnold 730 1 18.3 13,359 4.19 1 55,974 1 0.087 S 11`h Ave Extension Wastewater Design Report Page 1 of 3 A peaking factor was calculated based on the following formula: Qmax/Qave= (18 + P0-5) / (4 +P0,5) (P = Population/thousands) The calculated peaking factors are included in the appendix of this report. The peak flow rate anticipated from the development was calculated by multiplying the average flow rate by the peaking factor. The peak flow rate was then converted from gpd to cfs. In addition to the wastewater generated from the development, a 150 gpd/acre infiltration rate is required and added to the Peak Flow rate. Table 2 Infiltration Rate Area Infiltration Peak Flow Peak Flow Sewer Served Rate Infiltration Peak Flow Rate Rate Main acres d/acre) Rate d Rate d W 1/I d W 1/I cfs Local St. 24.8 150 3,720 74,951 78,761 0.122 Arnold 18.3 150 2,745 55,974 58,719 0.091 The sewer main sizes for both streets will be 8-inch based on minimum required pipe size. An 8- inch PVC sewer main at minimum slope of 0.4%, and a C factor 0.013, has a capacity of 0.64 cfs at 75% of full flow capacity, which has adequate capacity for the proposed peak flows of 0.122 cfs and 0.090 cfs for the local Street and Arnold Street crossing, respectively. Calculations are provided in the appendix of this report. C. Proposed Collection System With the extension of S 11 ch Ave, two (2) 48" manholes with 8" sanitary sewer main stubs extending east and west will be installed in Arnold Street and a Local Street intersections. In the future, when the lots west of S I lth Ave are developed as part of Allison Subdivision, the mains will be extended to serve these lots. PVC pipe meeting COB specifications will be used for all sewer mains. The sewer main will maintain a minimum separation of 10-feet horizontally and 18-inches vertically from any proposed or existing public water mains. D. Downstream Capacity Analysis It is anticipated that the City of Bozeman sanitary sewer system has enough capacity to accommodate the main extension. A capacity letter from a City Engineer is attached per DEQ requirements. E. Conclusion As outlined above, 8-inch sanitary sewer mains in Arnold Street and local Street. At the South 11th crossings, will have the capacity for the effluent generated from the future phases of Allison S 11`h Ave Extension Wastewater Design Report Page 2 of 3 Subdivision, west of South 11th Avenue. This project will require the approval of the City of Bozeman and MTDEQ. Appendix 1. Calculations 2. Sanitary Sewer Drainage Areas Exhibit S 11 h Ave Extension Wastewater Design Report Page 3 of 3 Appeindix Wastewater Design S 11th Ave Extension Peaking Factor Street: Local Street Contributing Area: 24.8 acres Zoning Acres Units/Acre Density Total (residents/unit) Population R1 24.8 3.9 2.11 204 Peaking - Q(max) = 18 +P 0.50 P =Population/thousands =204/1000 =0.204 Factor Q(ave) 4 +P 0.50 Peaking Factor = 4.14 Street: Arnold Contributing Area: 18.3 acres Zoning Acres Units/Acre Density Total (residents/unit) Population R1 18.3 3.9 2.11 151 Peaking = Q(max) = 18 +P 0.50 P =Population/thousands = 151/1000 =0.151 Factor Q(.e) 4 +P 0.50 Peaking Factor = 4.19 Wastewater Design S 11th Ave Extension Estimated Flow Rate Street: Local Street Contributing Area: 24.8 acres Wastewater Loading: 730 gpd/acre Average Flow Rate: 18,104 gpd Peaking Factor: 4.14 Peak Flow Rate: 74,951 gpd Peak Flow Rate: 0.116 cfs Infiltration Rate: 150 gpd/acre 3,720 gpd 0.006 cfs Peak Flow Rate w I/I: 78,671 gpd Peak Flow Rate w I/I: 0.122 cfs Street: Arnold Contributing Area: 18.3 acres Wastewater Loading: 730 gpd/acre Average Flow Rate: 13,359 gpd Peaking Factor: 4.19 Peak Flow Rate: 55,974 gpd Peak Flow Rate: 0.087 cfs Infiltration Rate: 150 gpd/acre 2,745 gpd 0.004 cfs Peak Flow Rate w I/I: 58,719 gpd Peak Flovtate w I/I: 0.091 cfs 8-inch PVC Pipe Capacity Project Description Friction Method Manning Formula Solve For Discharge Input Data Roughness Coefficient 0.013 Channel Slope 0.40000 % Normal Depth 5.58 in Diameter 8.00 in Results Discharge 0.64 ft'!s Flow Area 0.26 ft' Wetted Perimeter 1.32 ft Hydraulic Radius 2.37 in Top Width 0.61 ft Critical Depth 0.38 ft Percent Full 69.8 % (93%full flow capacity x 75%flow depth) Critical Slope 0.00748 ft/ft Velocity 2.45 ft/s Velocity Head 0.09 ft Specific Energy 0.56 ft Froude Number 0.66 Maximum Discharge 0.82 ft'!s Discharge Full 0.76 fN/s Slope Full 0.00278 ftift Flow Type SubCrftical GVF Input Data Downstream Depth 0.00 in Length 0.00 ft Number Of Steps 0 GVF Output Data Upstream Depth 0.00 in Profile Description Profile Headloss 0.00 ft Average End Depth Over Rise 0.00 % Normal Depth Over Rise 69.75 % Downstream Velocity Infinity ft/s Bentley Systems,Inc. Haestad Methods So18tadlOpfftewMaster V8i(SELECTseries 1) [08.11.01.03] 411112016 9:20:06 AM 27 Slemons Company Drive Suite 200 W Watertown,CT 06795 USA +1-203-756.1666 Page 1 of 2 Sanitary Sewer Drainage Areas Exhibit • I � I� I o B" SANITARY t /I 1 �� SEWER MAIN IN�' I 1 8" SANITARY SEWER ARNOLD i1 Ijl i _ ` MAIN IN S(ACEN7r.` NHbiE TIN 1 I II I SIITNAL I 1 DRAWN BY:JLS REVIEWED BY:CGB PROJECT ENGINEER:CGB DESIGNED BY: COB DRAINS TO A HOLD ST m H E" Q 18.3 AC DA A� DRAINS TO NAVDIS LOCAL STREET 24.8 AC I t I H z 1 u� m I - r I I � 1 � z I I QM � 1 zo � � W a � � I ,cam Q N o { xQ � I I i t UQ w �o a A .0 i I � .0 1 SHEET SSLO x DTITA E _ I 1 SXN,TrARY seWLx SOUTH lip AVENUE IMPROVEMENTS � PROJECT: 5-119,i SANrrARY SENVER DIULNAGL\R,AS � DATE: APRIL 201 7 n