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Home My WebLink About004_UtilityDesignReport ALTOS PHOTONICS Project # 24141.01 Bozeman, MT OCTOBER 2024 October 2024 Project No. 24141.01 SEWER AND WATER DESIGN REPORT ALTOS PHOTONICS BOZEMAN, MONTANA 59715 SITE NARRATIVE The purpose of this report is to summarize the design of the future sanitary sewer and water service installations associated with the Altos Photonics project in Bozeman, Montana. The water service lines will connect to the existing main and the sanitary sewer services will connect to an existing service line and the existing main located south of the project area in East Tamarack Street. The following report will summarize the water and sewer design capacity calculations for the proposed Altos Photonics project. SITE DEVELOPMENT PLAN The proposed project consists of one building, a parking lot, and associated landscaping. This project is located at the corner of North Rouse Avenue and East Tamarack Street in Bozeman, Montana, see Appendix A. SEWER The proposed sewer service includes the installation of approximately 12-feet of 6-inch PVC sewer line. The sewer service will tie-in to an existing 6-inch sanitary sewer service that is tied to an existing 30-inch sanitary sewer main located in East Tamarack Street. An additional proposed sewer service includes the installation of approximately 152-feet of 4-inch PVC sewer line. The additional sewer service will also tie-in to the existing 30-inch sanitary sewer main located in East Tamarack Street. Capacity calculations were conducted per the City of Bozeman Design Standards and Specifications Policy dated March 2004, updated March 2020 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 0.0200 ft/ft. The 6-inch Sewer and Water Design Report Page 2 of 3 October 2024 sewer service capacity at 75 percent full is 257 gal/min using the minimum pipe slope of 0.0200 ft/ft. The project area is zoned NEHMU, Northeast Historic Mixed-Use. It is assumed that there will be approximately eleven 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. It is assumed that there will be a coffee shop located in the northwest corner of the building. It is assumed that there will be approximately two employees and 270 customers per day. Per Table 3.1-1 in Circular DEQ 4 for a coffee shop, the typical wastewater flow is 10 gpd/person per employee and 6 gpd/person per customer. The typical wastewater flow for the building is as follows: Sanitary Sewer Average Day Demand = 13 gpd/person * 11 employees = 143 gpd Sanitary Sewer Average Day Demand = 10 gpd/person * 2 employees + 6 gpd/person * 270 customers = 1,640 gpd Peak flow calculations for the proposed sanitary sewer services were completed to find the overall peak flow in the 4-inch and 6-inch sewer services exiting the development. The average daily flow exiting the 6-inch service was estimated at 0.10 gal/min. The average daily flow exiting the 4-inch service was estimated at 1.06 gal/min. A peaking factor of 4.24 was then applied for a peak hourly rate of 0.42 gal/min for the 6-inch service and 4.48 gal/min for the 4-inch service. An infiltration flowrate of 0.05 gal/min was then used to calculate the total peak hourly flowrate with infiltration of 4.53 gal/min for the 4-inch service and 0.47 gal/min for the 6-inch service, which is significantly less than the 4-inch capacity of 91 gal/min and 6-inch capacity of 257 gal/min stated above. WATER The proposed water system consists of approximately 42-LF of new 1-inch diameter water service. The proposed 1-inch diameter service will tie-in to an existing 8-inch water main in East Tamarack Street. Sanderlin and Edden calculated the peak hour water demand to be 54 gpm based on the plumbing code and proposed fixture units (See Appendix C). Sanbell utilized City of Bozeman provided available fire flow test data from three hydrants located near the proposed development. The static pressure provided from the model was 147 psi. The hydrants can produce approximately 10,400 gpm with a residual pressure of 20 psi. The International Fire Code for 2021 specifies 20 psi as the minimum residual pressure required at full flow. Sewer and Water Design Report Page 3 of 3 October 2024 The building construction type for the Altos Photonics building is V-B, so the required fire flow without automatic sprinklers is 3,250 gpm, per Appendix B of the 2021 International Fire Code. Since the building will be equipped with an automatic sprinkler system, the required demand can be reduced by 75% which is 812.5 gpm. The fire flow cannot be reduced below 1,500 gpm, so 1,500 gpm is the required fire flow for the building. The existing hydrants near the development can profide approximately 10,400 gpm at 20 psi residual pressure so they can provide more than the required 1,500 gpm need for the proposed building. See Appendix C for a summary of the hydrant test data. CONCLUSION Based on the assumptions provided above, the proposed 4-inch sanitary sewer service, 6-inch sanitary sewer service, 1-inch domestic water service, and 4-inch fire service installations will provide the required capacity for the proposed Altos Photonics building. Please contact Chad Schreiner, PE for any questions pertaining to this report by email, cschreiner@sanbell.com or by phone 406-922-4303. APPENDICES Appendix A – Site and Utility Plan Appendix B – Sanitary Sewer Demand Calculations Appendix C – Water Demand Calculations ALTOS PHOTONICS Project # 24141.01 APPENDIX A SITE AND UTILITY PLAN CP#1 CP#2 CP#3 CP#4 BUILDING GRIDLINE SETTING OUT POINTS POINT # 1 2 3 4 NORTHING 123542.43 123543.30 123458.67 123459.30 EASTING 383968.47 384028.46 383985.68 384029.67 ELEVATION 0.00 0.00 0.00 0.00 DESCRIPTION GRIDLINE 1/A1 INTERSECTION GRIDLINE 5/E INTERSECTION GRIDLINE 5/A1 INTERSECTION GRIDLINE 3.1/E INTERSECTION FILE:PROJECT NO:CAD:QUALITY ASSURANCE:DRAWING HISTORYDATE DESCRIPTION906 N. ROUSE AVESITE AND UTILITY PLANALTOS PHOTONICSNORTHERN PACIFIC ADD., BLOCK 116, LOTS 19-24BOZEMAN, MTC3.1 RPE24141_SITE_PROD.DWGCS10/04/2024SITE PLAN SUBMITTAL--------------24141.01 NORTH 0 10 SCALE: 1" = 10' 20510 P:\24141_01_411_e_tamarack_site_plan_&_inf_plan\CADD_C3D\production_dwg\24141_SITE_PROD.dwg, 24x36-SITE, 10/4/2024 10:43:59 AM, cschreiner, 1:1 ALTOS PHOTONICS Project # 24141.01 APPENDIX B SANITARY SEWER DEMAND CALCULATIONS Project: 24141.01 Altos Photonics Date: 10/02/2024 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 Coffee Shop Employee2 10 gpd/person Customer 2706 gpd/person Total Demand 1640 gal/day 1.14 gal/min Peaking Factor (per DEQ circular 2 formula)4.24 Peak Hourly Flow 4.83 gal/min Infiltration at 150 gal/acre/day 75 gal/day Infiltration gal/min 0.05 gal/min Total Peak Hourly Flow plus Infiltration 4.89 gal/min Result Q/Qfull based on peak hour 0.05 Percent Full for 4" From Nomograph at peak hour 19% Service Area Project: 24141.01 Altos Photonics Date: 10/02/2024 Capacity Calclulations 6" Pipe Flowing Full Capacity 0.80 cfs 6" Pipe Flowing Full Capacity 357 gal/min Q/Qfill @ 75% full, 0.75 per nomograph Capacity @ 75% full 268 gal/min City of Bozeman Sanitary Sewer System Design Criteria DESIGNATION People Demand Office 11 13 gpd/person Total Demand 143 gal/day 0.10 gal/min Peaking Factor (per DEQ circular 2 formula)4.24 Peak Hourly Flow 0.42 gal/min Infiltration at 150 gal/acre/day 75 gal/day Infiltration gal/min 0.05 gal/min Total Peak Hourly Flow plus Infiltration 0.47 gal/min Result Q/Qfull based on peak hour 0.00 Percent Full for 6" From Nomograph at peak hour 1% Service Area ALTOS PHOTONICS Project # 24141.01 APPENDIX C WATER DEMAND CALCULATIONS Project Name:Altos 9/24/2024 SE Engineers PO Box 1491 Three Forks, MT 59752 406-600-8796 Based on Water Supply Fixture Units (WSFU) and Minimum Fixture Branch Pipe Size;Table A 103.1 of UPC 2021 Flush Valve = 0, Flush Tank = X 0 Static Pressure in Main (PSI)80 Elevation Rise (FT) 60 Meter Loss (PSI) 7 Backflow Preventor Loss (PSI) 8 Minimum Available Water Pressure (PSI) 39.2 Minimum Required Fixture Pressure (PSI) 15 Maximum Length 250 Developed Length Factor 1.5 Total Developed Length 375 Fixture Qty FU Total FU Sink 0 2 0 Clothes Washer 0 0 0 Dishwasher (Domestic) 2 1.5 3 Drinking Fountain 0 0.5 0 Drinking Fountain Assembly 0 0.75 0 One Hose Bibb 1 2.5 2.5 Each Additional Hose Bibb 2 1 2 Kitchen Sink (domestic) 2 1.5 3 Laundry Sink 0 1.5 0 Lavatory 7 1 7 Mop Basin 1 3 3 Shower per shower head 2 2 4 Bath/ Shower 0 4 0 3/4" fill bath/ shower 0 10 0 Urinal Public (1.0 GPF) 7 2.5 17.5 Restaurant 0 75 0 Water Closet Public (1.6 GPF gravity) 7 2.5 17.5 Water Closet Public (1.6 GPF Flushometer tank) 0 2.5 0 Water Closet Public (1.6 GPF Flushometer valve) 0 5 0 Water Closet Assembly (1.6 GPF gravity) 0 3.5 0 Water Closet Assembly (1.6 GPF Flushometer tank) 0 3.5 0 Water Closet Assembly (1.6 GPF Flushometer valve)0 6 0 59.5 54 6.88 2 5.59 5.01 Water Flow Velocity (FPS) Calculated Main Friction Loss (PSI/100ft) Project Information Total Water Demand Total FU Total GPM Allowable Friction Loss Per 100 Feet (PSI) Water Main Sizing (Input By User)