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HomeMy WebLinkAbout12 - Design Report - Town Pump - Baxter & 19th - Water Water Main Extension Engineer's Report Town Pump — Baxter Lane and North 19t" Avenue February 2012 Submitted to: City of Bozeman Engineering Department 20 East Olive Bozeman, MT 59715 Montana Department of Environmental Quality Permitting and Compliance Division Public Water and Subdivisions Bureau PO Box 200901 Helena, MT 59620-0901 Prepared by: Stahly Engineering and Associates 7585 Shedhorn Drive Bozeman, MT 59718 (406) 522-9526 ���INEEAf� STAH LY �`'t 9ffocraz�.S`� � � Engineer's Report Contents Note: The Engineer's Report format for the Town Pump Water Main Extension follows DEQ-1 organization. Additional information required by the City of Bozeman Design Standards is added where required. Report Narrative 1.1.1 General information 1.1.2 Extent of water works system 1.1.3 Alternate plans 1.1.4 Site conditions 1.1.5 Water use data 1.1.6 Flow requirements 1.1.7 Sewage system available 1.1.8 Sources of water supply 1.1.9 Proposed treatment processes 1.1.10 Waste disposal 1.1.11 Automation 1.1.12 Project Sites 1.1.13 Financing 1.1.14 Future Extensions Figures and Tables Figure 1. Vicinity Map (included separately) Figure 2. Water Distribution System Map (included separately) Table 1. Estimated Water Use Water Mains 1 3/22/2012 1.1.1 General Information The proposed new Town Pump is located within the City of Bozeman at 5851 East Baxter Lane. The site is comprised of Lot 1 B of Gardner Simmental Plaza Subdivision owned by Town Pump with a total acreage of 4.03 acres. The site is currently occupied by the existing Anderson Pre- cast building and storage yard. The current building will be demolished prior to construction of the proposed Town Pump. The property owner's contact information is: Town Pump, Inc. c/o Dan Sampson, Construction and Development Manager 600 South Main Street Butte, MT 59701 Water supply and wastewater treatment will be provided by the City of Bozeman's municipal systems. The system owner's contact information is: City of Bozeman Public Service Department Debra Arkell, Director PO Box 1230 Bozeman, MT 59771-1230 The location of the proposed Town Pump is shown on the Vicinity Map in Figure 1 included separately at the back of this report. 1.1.2 Extent of Water Works System Water supply to the existing structure at the site is provided from an existing 12" water main in Baxter Lane. This main will supply the proposed town pump with water supply via a 4"fire service line and a 2" domestic service line. A 1" water line will run from the building to the RV dump location for use at that location. An 8" water main extension is proposed on the east side of the property and extends approximately 285 feet to the north from the existing 12" main located in Baxter Lane. This extension will end with a fire hydrant. The proposed water supply layout can be seen on Figure 2 attached to this report. Additional fire hydrants are located at the southeast corner of the intersection of Baxter Lane and North 19t" Avenue and the Southwest corner of the intersection of Baxter Lane and Commerce Way. Existing pressure conditions were obtained from the City of Bozeman's Water Facility Plan. Water junction J-1661 in the model indicates a steady state pressure of 107 psi. Extension from this junction to the north 285 Water Mains 2 3/22/2012 feet will have little influence on this steady state pressure and this steady state pressure indicates water pressure and flow are sufficient for this extension. 1 .1.3 Alternate Plans Due to the project's location within the City of Bozeman, extension of public mains was the only water supply alternative. 1 .1.4. Site Conditions The site is typical of Bozeman with fine grained soils overlying gravel deposits. Geotechnical borings have determined the depth to gravel ranges from 5 to 6 feet. Estimated depth to groundwater obtained from the geotechnical borings is 3 feet. If mains are installed during high groundwater times dewatering may be required. 1.1.5. Water Use Data Water use for the proposed Town Pump was estimated using Table 5-1 of DEQ-4 for stores. Estimates on customer volume and employee counts were based on previous similar Town Pump stores. Estimated water usage for the proposed Town Pump is in Table 1 below. The City of Bozeman water system model indicates the system is capable of supplying this proposed use and this lot is included in the service are in the City of Bozeman Water Facility Plan. TABLE 1. Estimated Water Use-Town Pump User Class Proposed Town Pump Customer volume 500 -Average Day Flow d/customer 3 Subtotal Inmate Water Use 1,500 Staff Population 25 -Average Day Flow d/sta 10 Subtotal Staff Water Use 2,500 -Average Day Flow d 4,000 -Peaking Factor to Maximum Day 2.5 Maximum Day Flow d 10,000 Maximum Day Flow m 6.9 -Peaking Factor to Maximum Hour 3.0 Maximum Hour Flow m 8.3 Water Mains 3 3/22/2012 Fire flow requirements are based on the Uniform Fire Code. The hydrant flow is determined using Table H.5.1 of the Uniform Fire Code. An 8,200 sq ft Type V-B building requires a fire flow of 2,500 gpm. The fire department is allowing a 75% reduction due to the fire sprinkler system down to the minimum required fire flow of 1,500 gpm. The total fire flow required from the hydrants and sprinkler system is 1500gpm. 1 .1.6. Flow Requirements The water main extension for the proposed Town Pump is 285 feet long. Because of the size and pressures (107 psi steady state) in the existing 12" water main, a hydraulic analysis was not performed. The head loss through the pipe extension and hydrant assembly will not significantly change from the existing conditions. 1.1.7. Sewage System Available Sewer service will be provided by city mains. The proposed Town Pump will be connected to existing sewer mains located in Baxter Lane. Where new water and sewer mains are parallel a 10-foot separation will be provided between pipes. Where water mains cross sewer mains 18" of vertical separation will be provided. 1.1.8. Sources of Water Supply This section is not applicable. 1.1.9 Proposed Treatment Process This section is not applicable. 1 .1.10 Waste Disposal This section is not applicable. 1.1.11 Automation This section is not applicable. 1.1.12 Project Sites This section is not applicable. Water Mains 4 3/22/2012 1 .1.13 Financing This section is not applicable. 1.1 .14 Future Extensions This section is not applicable. Water Mains 5 3/22/2012 Town Pump - Baxter Lane and North 19th Avenue Water Extension Capacity Calculations Total Area Served= 6.31 acre (Includes future development) Community Commercial(Table V-2)= 2400 gal/acre/day Irrigation Demand(assume 1 acre at IVday)= 18.82 gal/min Total Daily Flow= 42245 gal/day Total Daily Flow= 1760 gal/hr Total Daily Flow= 29.3 gal/min Max Day Flow(2.3.1)= 67.5 gal/min Required Fire Flow(IFC 2009)= 1500 gal/min (min allowed w/sprinklers) Total Max Day Plus Fire Flow= 1567.5 gal/min 8-inch Extension Calculations at Total Max Day Pius Fire Flow Use Hazen-Williams Velocity in 8-inch pipe at 1568 gpm= 10.0 fUsec less than 15 ft/sec so ok Hydrant Flow test from City of Bozeman Static Pressure= 102.0 psi Flow(4.5"nozzle)= 2000.0 gpm Residual Pressure at flow= 92.0 psi Head Losses(at fire hydrant flow test flow rate) hs -2.5 ft hf= 23.8 ft hm 1.6 ft ht,ta= 22.9 ft Residual Pressure from hydrant flow test= 92 psi 212.3 ft Redisdual Pressure at End Fire Hydrant at 2000 gpm= 82.1 psi e i 2 0 2 0 Shaping Our Future Together CITY OF BOZEM HYDRANT PRESSURE/FLOW REQUEST FORM Date: 4/5/12 Location H drant Static Pressure Pito Pressure Residual Pressure Commerce Way 440 13.5# Baxter Lane 1256 102# 92# Requested By:Ryan Ritter Fax#emailed Nozzle Size Flowed:4.5" Done By: ES/JB Comments: 2000 GPM 1178 1714 1158 1159. 11,56 __12 1161 1 i 171'.-4,4 2193 210 —_-- — 1137 1958 441 2059 2192 2191 15 2060 " 1591 1593 1957 2062