The URL can be used to link to this page

Home My WebLink About23O - Water Report (full)Water Engineering Report Page 1 of 4 ATWELL SUITES – BOZEMAN, MT WATER MAIN EXTENSION BOZEMAN, MT WATER ENGINEERING REPORT JUNE 2024 1.1.1 General Information a.There are existing City of Bozeman water mains located along the eastern, western, and southern boundaries of the proposed development. Refer to the City of Bozeman infrastructure map for additional information. Existing water mains are detailed below: Internal Water Main (West side of site) = 8” DIP Baxter Lane (South of site) = 12” DIP Simmental Way (East of site) = 12” DIP Existing gravity sewer mains in the vicinity of the project are also included within the infrastructure map. Internal Sewer Main = 8” PVC Baxter Lane = 24” ACP Simmental Way = 24” ACP The subject property is undeveloped and a new water main will be installed to serve the new hotel and a new fire hydrant. b.A public water main will be extended from the City’s existing system to serve a new hotel project within the undeveloped property. The total developed area to be served by the water main extension is approximately 2.3 acres. c.The proposed utility extensions are being completed by the following entity: Bozeman 7 RE LLC PO Box 6000 Butte, MT 59701 d.Professional Engineer’s Seal: Kevin J. May, 38402PE 1.1.2 Extent of Water Works System a.The project will include the installation of approximately 270 lineal feet of 8” Class 51 ductile iron water main to supply water to the hotel and a new fire hydrant, connecting to the existing City of Bozeman water main located west of the new hotel building. A new domestic water line and fire service will be installed along with the water main install. The public water main extension includes all appropriate fittings, valves, fire hydrant, and other appurtenances. b.The proposed extension will consist of a public water main within the subject site to serve the hotel development. The proposed water main extension is relatively independent in nature to serve the development. Neighboring undeveloped properties have direct access to existing Water Engineering Report Page 2 of 4 water mains; therefore, provisions for extending water service beyond the subject property are not anticipated to be necessary. c.As noted above, future service requirements beyond the subject property are not warranted due to the areas being previously developed or in the direct vicinity of existing water infrastructure. 1.1.3 Alternate Plans No alternate plans are under consideration at this time. 1.1.4 Site Conditions Onsite soils generally consist of 6-7 feet of lean clays overlaying sands and gravels. The topography of the site is relatively flat with gentle slopes from south to north. Based on the geotechnical investigation completed onsite, groundwater is anticipated to be approximately 4-feet deep and has the potential to impact water main installation. The site is scheduled to include substantial structural fill placement to raise the grades, meaning the water main installation is anticipated to be completed at the approximate groundwater elevation. If groundwater is encountered, the contractor will be responsible for all dewatering permitting and coordination, if necessary. The project site is not located within a mapped floodplain. Refer to the plan and profile sheets for additional information. 1.1.5 Water Use Data a.The proposed water main extension will provide domestic water service to the proposed hotel building. With respect to design flows for the hotel, we refer to Circular DEQ 4, Table 3.1-1. The typical wastewater flows/water usage from a hotel is estimated at 48 gpd/guest. At capacity, we anticipate the hotel 104-room hotel will have 208 guests (two people per room). The average daily usage is calculated as 208 guests x 48 gpcd, plus 12 employees @ 10 gpcd equaling 10,104 gpd or an average daily flow of 7.0 gpm. Using a peaking factor of 4.133 (Per DEQ 2 Equation 10-1), the peak hourly flows are anticipated as 29.0 gpm. Based on the attached fixture unit count provided by the Mechanical Engineer and attached calculation, peak instantaneous demand is calculated as 89.5 gpm. The proposed 8” water main will adequately service the needs of the hotel development. The service line and fire protection lines were sized to adequately supply the development based on the design flows anticipated. b.As the land for development is vacant, there is no current water demand in the proposed project area. As stated above, daily domestic water usage is calculated as 10,104 gpd or 7.0 gpm with a peak hourly flow rate of 29.0 gpm. Maximum daily water use is anticipated at 23,239 gpd (16.1 gpm) based on a max day peaking factor of 2.3 per City of Bozeman Design Standards Section V.4. Irrigation water usage at the site is anticipated to be 6,300 gpd at a peak rate of approximately 25 gpm per the landscaping design completed by Steiner Thuesen. The peak fire flow required for the new fire hydrants is 2,000 gpm. Water Engineering Report Page 3 of 4 c.Water is supplied by the City of Bozeman’s municipal system from an existing 8” DIP water main (which is ultimately served via a 12” DIP water main within Baxter Lane). Hydrant flow modeling on the hydrants surrounding the development was completed and revealed an estimated static pressure of 103.2 psi with an estimated yield of approximately 7,400 gpm with 20 psi residual remaining in the system. Please reference attached hydrant flow results as provided by the City of Bozeman for additional information. As shown within the attached hydraulic calculations, existing yield will be adequate for the proposed development. d.None. e.N/A. 1.1.6 Flow Requirements a.The City of Bozeman-provided hydrant flow data demonstrates that pressures and water flows for the area are adequate for the development. See attached hydrant flow model results. Static pressures for the site are approximately 100 psi. Pressure loss associated with domestic and irrigation water usage will be negligible and system pressures will remain well above 20 psi during the normal usage events as detailed in the attached hydraulic calculations. b.Emergency fire flow requirements for the proposed development will include a minimum of 2,000 gpm for the new fire hydrant. Pressure drops associated with emergency fire events will not reduce the residual water pressure within the system below 20 psi as required by Circular DEQ 1. Refer to hydrant flow model provided by the City of Bozeman in addition to the attached hydraulic calculations. As shown within the calculations, the 2,000 gpm fire flow demand coupled with the peak instantaneous demand and peak irrigation use (conservatively modeled as 2,200 gpm), yields head losses of approximately 11 psi and an anticipated residual pressure of approximately 81 psi. Additionally, as shown in the ultimate hydrant capacity calculations, a 4,700 gpm ultimate capacity is anticipated with 22.3 psi residual pressure, yielding a 4,585 gpm hydrant flow when added to the 90 gpm peak instant domestic use and 25 gpm peak irrigation use. 1.1.7 Sources of Water Supply Water is supplied by the City of Bozeman’s existing municipal water system. No additional sources to be developed for this project. 1.1.8 Proposed Treatment Processes Water is supplied from the City’s existing water mains. No additional treatment works are deemed necessary for the water system. 1.1.9 Sewage system available A gravity sewer main is in place west of the proposed hotel building as well as within the existing Baxter Lane right-of-way south of the property. The sewer mains convey waste to the City’s wastewater treatment plant. The existing mains located west and south of the development are owned and operated by the City of Bozeman. The hotel project will discharge to the existing sewer Water Engineering Report Page 4 of 4 main via a new sewer service. No adverse impacts to the existing wastewater infrastructure are anticipated with this project. 1.1.10 Waste Disposal No impacts to waste disposal are anticipated. 1.1.11 Automation N/A 1.1.12 Project sites The water main extension is required in order to supply water to the proposed hotel building and necessary fire hydrant. Since an existing water main is located within close proximity to the site, no other sites or sources for water supply were considered. 1.1.13 Financing Project funding for the water main extension will be provided by the owner of the subject property as listed above. 1.1.14 Future extensions As detailed above, future extensions of this water main are likely not warranted as surrounding properties have already been developed or have direct access to existing City of Bozeman infrastructure. 1.2 Engineering Plans and Supporting Documents Contract documents, consisting of construction drawings, plan & profile sheets, construction details, and technical specifications for the water line extension project are submitted herewith for review. 23O - Atwell Suites - Bozeman, MT Wastewater Generation & Water Use Calculations 6/11/2024 Information (wastewater generation/water use): 104-Room hotel @ 2 guests per room & 48 gpd/guest:9984 gpd 12 Employees @ 10 gpd/employee 120 gpd Total Domestic Use:10104 gpd Additional Water Use from Irrigation (see below) Estimated Population = 220 persons± Wastewater Generation (Per DEQ 4 - Table 3.1-1) Hotel Guests + Employees =10104 gpd (Average Daily Use) Max Daily Water Use =23239 gpd*(*Max Day Factor = 2.3 per CoB Design Standards Section V.4) Overall Domestic Flow Rates (WW Generation & Domestic Water Use) Average Flow Rate 7.0 gpm Peak Hourly Flow Rate 29.0 gpm Max Day Domestic Water Use 16.1 gpm* @ 220 persons, peaking factor =4.133 Assume water usage is similar to WW generation with additional Landscape Irrigation Avg. Domestic Use Irrigation Use (see below) Water Consumption =10,104 gpd +6300 gpd =16404 gpd (summer) Landscaping Water Usage 39100 sf landscaping area 6300 gpd (Average irrigation use per day) 25 gpm (peak irrigation demand) Note: Refer to Steiner Thuesen Landscaping Design for additional information Peak Instantaneous Demand - Refer to Additional Calculations & Mechanical Eng. Fixture Unit Analysis Peak Instant Demand:89.5 gpm 𝐷𝐷𝑃 2 𝐷𝑞𝑛 10 −1:𝐷𝑒𝑞𝑖𝑔𝑛𝑃𝑒𝑎𝑘𝐻𝑛𝑢𝑞𝑘𝑦𝐷𝑘𝑛𝑢 𝐷𝑒𝑞𝑖𝑔𝑛𝐴𝑢𝑒𝑞𝑎𝑔𝑒𝐷𝑘𝑛𝑢=(18 +𝑃) (4 +𝑃) 23O - Atwell Suites - Bozeman, MT Water System Head Loss and Pressure Info 6/19/2024 BSCE - Kevin May, P.E. Peak Fire Flow Hydraulic Modeling Hazen Williams Head Loss Equation Hydrant Flow Testing Results (From CoB @ Hydrant #2477) Ex. Hydrant Static Pressure 103.2 psi 8" Water Main from Ex. Hydrant 2477 to Dead End Residual Pressure 91.54 psi (@ 2,200 gpm) Diameter 8 in Note: Res. Pressure from CoB Hydrant Curve Data Ch 130 Q 2200 gpm 4.902 cfs Peak Design Head Loss (Domestic + Fire)Flow Requirement: Length 320 ft 25.3 ft Estimated Fire Demand: 2,000 gpm Velocity 14.05 ft/s 11.0 psi Peak Instant Domestic Flow Rate: 90 gpm hf/1000'79.05 ft Peak Irrigation Flow: 25 gpm Total Demand: 2,115 gpm; therefore, 2,200 gpm = conservative Total Head Loss within new piping @ 2,200 gpm=25.3 ft *Length Calcs 11.0 psi New Onsite Piping = 271' Estimated Residual Pressure @ Hydrant 2477 Connection:91.5 psi Dist from Hyd 2477 to new connect = 49' Estimated Residual Pressure @ new hydrant =80.6 psi Total Flow Length for Calc = 320' Estimated Residual Pressure exceeds 20 psi; therefore, acceptable per DEQ 1 Section 8.2.1 Ultimate Hydrant Capacity Hydraulic Modeling Hazen Williams Head Loss Equation Hydrant Flow Testing Results (From CoB @ Hydrant #2477) Ex. Hydrant Static Pressure 103.2 psi 8" Water Main from Ex. Hydrant 2477 to Dead End Residual Pressure 67 psi (@ 4,700 gpm) Diameter 8 in Note: Res. Pressure from CoB Hydrant Curve Data Ch 130 Q 4700 gpm 10.472 cfs Peak Design Head Loss (Domestic + Fire) Length 320 ft 103.0 ft Velocity 30.02 ft/s 44.7 psi hf/1000'321.98 ft Total Head Loss within new piping @ 2,200 gpm=103.0 ft 44.7 psi Estimated Residual Pressure @ Hydrant 2477 Connection:67.0 psi Estimated Residual Pressure @ new hydrant =22.3 psi Estimated Residual Pressure exceeds 20 psi; therefore, acceptable per DEQ 1 Section 8.2.1 Facility Name Building address or number Residential or Non-Residential Minimum Pressure (psi) Fixture Value Number of Subtotal Fixture or Appliance (at 60 psi)Fixtures Fixture Value Toilet (tank)2.5 104 260 Toilet (flush valve)26.25 4 105 Urinal (wall or stall)16 0 Urinal (flush valve)20 1 20 Bathtub, Bath/Shower 4 24 96 Shower (single head)2 80 160 Sink (lavatory)1 107 107 Bar Sink & Hand Sink 2 106 212 Scullery & Pot Sink 2 1 2 Service Sink / Mop Sink 3 2 6 Bathtub 8 0 Clothes Washer 4 2 8 Hose connections (with 50 ft of hose) 1/2 in.2.5 4 10 5/8 in.9 0 3/4 in.12 0 Miscellaneous Bedpan washers 10 0 Drinking fountains 2 0 Dental units 2 0 Combined Fixture Value 986 Demand (gpm)121 Pressure Adjustment Factor 0.74 Total Adjusted demand (gpm)89.5 Water Demand Estimate Using Fixture Values (Based on AWWA M22 Manual, Second Edition) Atwell Suites - Bozeman N. 19th Ave & Baxter Lane - Bozeman, MT