The URL can be used to link to this page

Home My WebLink About043 Utility Design Report Stockman Bank Drive-Through 22056 Bozeman, Montana, 59718 Utility Design Report 3/15/2023 March 15, 2023 Project No. 22056 SEWER AND WATER DESIGN REPORT STOCKMAN BANK DRIVE-THROUGH BOZEMAN, MONTANA SITE NARRATIVE The purpose of this report is to summarize the design of the future sanitary sewer and water service installations associated with the Stockman Bank Drive-Through project in Bozeman, Montana. The water service line will connect to an existing stub and the sanitary sewer service will connect to the existing main located to the south of the project area. The following report will summarize the water and sewer service design and capacity calculations for the proposed Stockman Bank Drive-Through project. SITE DEVELOPMENT PLAN The proposed project consists of one building, a parking lot and four drive-through lanes. This project is located at the corner of West Mendenhall Street and North 8th Avenue in Bozeman, Montana, see Appendix A. SEWER The proposed sewer service includes the installation of approximately 107-feet of 4-inch PVC sewer line. The water service will tie-in to an existing 6-inch sanitary sewer main located in the alley south of the project. Capacity calculations were conducted per the City of Bozeman Design Standards and Specifications Policy dated March 2004, updated May 2017 and Circular DEQ 4. Capacity spreadsheets are in Appendix B. The 4-inch sewer service capacity at 75 percent full is 91-gal/min using the minimum pipe slope of 0.02 ft/ft. The project area is zoned B2-M, Community Business District-Mixed. It is assumed that there will be approximately four employees in the building. Per Table 3.1-1 in Circular DEQ 4 for an office building the typical wastewater flow is 13 gpd/person. The typical wastewater flow for the building is as follows: P:22056_Utility_Design_Report 2 (03/15/2023) NH/RPE/bc Sanitary Sewer Average Day Demand = 13 gpd/person * 4 employees = 52 gpd Peak flow calculations for the proposed sanitary sewer service was completed to find the overall peak flow in the 4-inch sewer service exiting the development. The average daily flow exiting the development was estimated at 0.04 gal/min. A peaking factor of 4.24 was then applied for a peak hourly flow rate of 0.15 gal/min. An infiltration flowrate of 0.05 gal/min was then used to calculate a total peak hourly flow rate with infiltration of 0.21 gal/min, which is significantly less than the 4- inch capacity of 91 gal/min stated above. WATER The proposed water system consists of approximately 104-LF of new 3/4-inch diameter water service. The proposed 3/4-inch diameter service will tie-in to an existing 3/4-inch service stub which is connected to the existing 6” water main in North 8th Avenue. Cushing Terrell calculated the peak hour water demand to be 8 gpm based on the plumbing code and proposed fixture units (See Appendix C). There will be no sprinkler system in the building so fire sprinkler demand was not calculated. CONCLUSION Based on the assumptions provided above, the proposed 4-inch sanitary sewer and 3/4-inch water service installations will provide the required capacity for the proposed Stockman Bank Drive- Through. Please contact Bobby Egeberg, PE for any questions pertaining to this report by email, begeberg@sandersonstewart.com or by phone 406-922-4308. APPENDIX A Site & Utility Plan Stockman Bank 22056 FOR SP2 REVIEWNORTH020SCALE: 1" = 20'401020 PARKING CALC: REQUIRED:8 STALLS (WEST LOT ON-SITE PARKING)EXISTING:22 STALLS (UNDERGROUND ON-SITE PARKING)17 STALLS (STANDARD ON-SITE PARKING)PROPOSED:53 STALLS TOTAL1 STALL (ADA ON-SITE PARKING)5 STALLS (ALLEY ON-SITE PARKING)FILE: PROJECT NO: CAD: QUALITY ASSURANCE: DRAWING HISTORY DATE DESCRIPTION SECTION 12, TOWNSHIP 02S, RANGE 05E SITE PLAN STOCKMAN BANK DRIVE-THROUGH SPRINGBROOK ADD LOTS 1-12, 16 E 20' OFF LOT 17 BLK 2 CONDO MASTER BOZEMAN, MTC3.0RPE 22056_SITE_PROD.DWG DME 08/11/2022 100% CD - - - - - - - - - - - - -- 22056 EXISTING BUILDING = 27,333 SFPROPOSED DRIVE-THROUGH BUILDING = 660 SFTOTAL BUILDING = 27,993 SF (23,794 SF AT 85% REDUCTION)REQUIRED PARKING = 23,794 / 1000 X 2 = 47.6 (47 MIN) FOR SP2 REVIEWNORTH020SCALE: 1" = 20'401020INLET AND MANHOLE STRUCTURE SIZING SCHEDULESTRUCTURE IDSTRUCTURE TYPEDIAMETER (FT)SDMH ASTORM DRAIN MANHOLE4SDMH BSTORM DRAIN MANHOLE4SDMH CSTORM DRAIN MANHOLE4SDI ASTORM DRAIN INLET3SDI BSTORM DRAIN INLET3SDI C STORM DRAIN INLET3FILE: PROJECT NO: CAD: QUALITY ASSURANCE: DRAWING HISTORY DATE DESCRIPTION SECTION 12, TOWNSHIP 02S, RANGE 05E UTILITY PLAN STOCKMAN BANK DRIVE-THROUGH SPRINGBROOK ADD LOTS 1-12, 16 E 20' OFF LOT 17 BLK 2 CONDO MASTER BOZEMAN, MTC5.0RPE 22056_UTILITY_PROD.DWG DME 08/11/2022 100% CD - - - - - - - - - - - - -- 22056 APPENDIX B Sanitary Sewer Demand Calculations Stockman Bank 22056 Project: 22056 Stockman Bank Drive-up Date: 3/14/2023 Capacity Calclulations 4" Pipe Flowing Full Capacity 0.27 cfs 4" Pipe Flowing Full Capacity 121 gal/min Q/Qfill @ 75% full, 0.75 per nomograph Capacity @ 75% full 91 gal/min City of Bozeman Sanitary Sewer System Design Criteria DESIGNATION People Demand Office 4.0 13 gpd/person Total Demand 52 gal/day 0.04 gal/min Peaking Factor (per DEQ circular 2 formula)4.24 Peak Hourly Flow 0.15 gal/min Infiltration at 150 gal/acre/day 75 gal/day Infiltration gal/min 0.05 gal/min Total Peak Hourly Flow plus Infiltration 0.21 gal/min Result Q/Qfull based on peak hour 0.00 Percent Full for 4" From Nomograph at peak hour 2% Service Area APPENDIX C Water Demand Calculations Stockman Bank 22056