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HomeMy WebLinkAbout14_Cannery District Sewer Engineers Report_3-31-2020 Sewer Engineer’s Report Cannery District PUD Building ‘J’ Update March 2020 For Submittal to: City of Bozeman Engineering Department 20 East Olive Bozeman, MT 59715 Prepared by: Stahly Engineering and Associates 851 Bridger Drive, Suite 1 Bozeman, MT 59715 (406) 522-9526 Sewer Engineer’s Report 1 3/27/2020 Engineer’s Sewer Report Contents Note: The Engineer’s Report format for the Cannery District’s Sewer report follows DEQ-2 organization. Additional information required by the City of Bozeman Design Standards is added where required. Report Narrative Chapter 10 – Engineering Reports & Facility Plans 11.1 Engineering Report 11.11 Problem Defined 11.12 Design Conditions 11.13 Impact on Existing Wastewater Facilities 11.14 Project Description 11.15 Design Criteria 11.16 Site Information 11.17 Environmental Impacts Figures and Tables Figure 1. Vicinity Map Figure 2. Sewer Site Plan (included separately) Table 1. Cannery District Sewer Flow Estimates Table 2. Capacity of 8” and 10” SDR 35 PVC Sewer Main Appendices A Table 1. Estimated Water Use Sewer Engineer’s Report 2 3/27/2020 11.1 Engineering Report The Cannery District is a multi-phase development located in the City of Bozeman on the north side of East Oak Street and Rouse Avenue, north of the Gallatin County Fairgrounds. The existing property consisted of several parcels of land totaling approximately 12.22 acres. The development consists of four phases. The first phase, which was completed in 2016, consisted of remodeling four existing buildings originally constructed as part of the original pea canning operation in 1917. Phases 2, 3 and 4 involve the construction of six new buildings on the Cannery District property. Phases 2 and 4 improvements were completed in 2018, Phase 3 improvements are currently under construction and are anticipated to be completed in the summer of 2020. The final site building, Building ‘J’, will begin construction in the fall of 2020 after plan approval from the City. In addition to Building ‘J’, the Northwest Parking Lot will be constructed as a site plan modification to Building O. Construction of the Northwest Parking Lot is planned to happen in the summer of 2020. This report addresses the sewer improvements associated with the final building construction of the Cannery District PUD (Building ‘J’) and compares the originally estimated sewer demands with the demands based on actual uses of the built-out development. The wastewater flows Building ‘J’ project was accounted for in the design of all four phases of the Cannery District PUD. The developer’s contact information is: Cannery District Partners, LLC 113 East Oak Street, Ste 4A Bozeman, MT 59715 Water supply and wastewater treatment will continue to be provided by the City of Bozeman’s municipal systems. The system owner’s contact information is: City of Bozeman Public Service Department PO Box 1230 Bozeman, MT 59771-1230 The location of the Cannery District is shown on the Vicinity Map in Figure 1. See Figure 2 for the overall sewer system plan. Sewer Engineer’s Report 3 3/27/2020 Figure 1. Vicinity Map, Bozeman, Montana 11.11 Problem Defined City of Bozeman sewer mains were constructed in 1917 to serve the original buildings. The previously constructed Phase 1 and 2 sewer upgrades replaced these original sewer mains and provide the backbone of the infrastructure needed to serve the remaining Cannery District phases. The remaining Building ‘J’ requires only additional sewer services. The location of the previously constructed sewer mains, and proposed sewer services are shown in Figure 2, which is included separately. 11.12 Design Conditions The initial sewer flow estimated contributed by the Cannery District was determined using wastewater flow rates for zoned undeveloped areas from the City of Bozeman Design Standards and Specifications Policy, Table V-1. Table V-1 shows a flow rate of 2,000 Gal./Acre/Day for zoning designation B- 2. This water use estimate using this flow rate resulted in a design peak hour flow of 212 gpm. Since the Cannery District is largely built out, and the specific uses of the proposed Building ‘J’ are known, water usage for this building and the entire development was determined using the following values for average water use rates: Office/Retail 10,000 gal/yr/1,000 sf Restaurant 165,000 gal/yr/1,000 sf Residential 89 gal/day/person Sewer Engineer’s Report 4 3/27/2020 The wastewater flow estimates are shown in Table 1. The revised estimated sewer flows, based on actual developed uses, is reduced to 185 gpm, versus the originally estimated 212 gpm. Table 1: Cannery District Sewer Flow Estimates Cannery District Water Use Cannery District Northside PUD Total w/ Northside Phase 1 Phase 2 Phase 3 Phase 4 All Phases Acreage (acres) 3.761 3.29 3.237 1.946 12.234 3.024 15.254 Design Water Use Rate (gpd/acre)* n/a n/a n/a n/a n/a 2,000 n/a Design Daily Water Use (gpd)* 9,710 1,068 8,248 1,636 20,662 6,048 26,710 Design Peaking Factor (Ave Day to Peak Hour) 10 10 10 10 10 10 10 Design Peak Hour Flow (gpm) 67 7 57 11 143 42 185 * See detailed water use estimates organized by phase and buildings based on actual use areas in Appendix. The previously constructed Phase 1 sewer network consists of both 8” and 10” SDR 35 PVC sewer mains. 8” SDR 35 PVC sewer mains installed at the minimum slope of 0.4% have a flow capacity of 312.8 gpm using 75% of the flow depth of the pipe as required by the City of Bozeman Design Standards and Specifications Policy. 10” SDR 35 PVC sewer mains installed at the slope of 0.3% have a flow capacity of 491.2 gpm using 75% of the flow depth of the pipe. See Table 2 below for the parameters used in the flow calculation. Table 2: Capacity of 8” and 10” SDR 35 PVC Sewer Main Capacity of 8" and 10" SDR 35 PVC Sewer Pipe Status Existing &Proposed Proposed Location Cannery District Cannery District Pipe Material 8" SDR 35 PVC 10" SDR 35 PVC Pipe Diameter (in) 8 10 Minimum Pipe Slope (ft/ft) 0.004 0.003 Coefficient of Roughness (n) 0.013 0.013 Depth in Pipe at 75% Full (in) 6 7.5 Depth of Flow (ft) 0.5 0.625 Pipe Radius (in) 4 5 Pipe Radius (ft) 0.33 0.42 Wetted Perimeter 1.40 1.75 Area of Flow (ft2) 0.28 0.44 Hydraulic Radius 0.20 0.25 Velocity (ft/sec) 2.48 2.49 Maximum Pipe Flowrate (gpm) 312.8 491.2 Peak Hour Flow (gpm) 185 185 Peak Flow % of Max Capacity 59.29% 37.76% Sewer Engineer’s Report 5 3/27/2020 The existing 8” and 10” sewer mains constructed in previous phases has enough capacity to convey the peak flows from all four phases of the Cannery District, as well as flows from the existing Northside PUD. 11.13 Impact on Existing Wastewater Facilities Most of the sewer network for the Cannery District was completed during previous phases. The proposed Building ‘J’ does not include any main extensions but requires new sewer services. During construction of Building ‘J’, existing sewer services within the Cannery District and Northside PUD will remain in service. 11.14 Project Description Cannery District Building ‘J’ located in the PUD Phase 2 area is the final building to be constructed in the development. The construction of Phases 1 and 2 has provided most of the infrastructure needed to serve the Cannery District development. The proposed BLDG J 6” sewer service will be connected to the previously-installed 8” main located west of the proposed building. The existing 8” main flows north to the existing 10” main which then flows west to connect to the offsite sewer main located in Rouse Avenue (see Figure 2). 11.15 Design Criteria The Cannery District sewer main extensions were designed in accordance with Montana Department of Environmental Quality Circular 2, Montana Public Works Standards and Specifications, City of Bozeman Modifications to Montana Public Works Standards and Specifications, the Uniform Plumbing Code, and the City of Bozeman Wastewater Facility Plan. 11.16 Site Information A Geotechnical Report was prepared by Allied Engineering Services, Inc. for the Cannery District site. The report identified the site to contain fine grained soils overlying gravel deposits. Geotechnical borings have determined the general soil profile consists of 1.5 to 7.0 feet of fine grain silt and clay overlying alluvial gravel. Estimated depth to groundwater obtained from the geotechnical borings is 6.5 -11 feet. If mains are installed during high groundwater times dewatering may be required. 11.17 Environmental Impacts Continued use and new extensions of City of Bozeman municipal sewer mains has the least environmental impact. No new environmental impacts will be caused by these sewer main extensions. Figure 2 Sewer Site Plan O A K S T R E E T STORMWATERRETENTION BASIN/SNOW STORAGE 3 0 S P A C E S 4 0 S P A C E S 15 SPACES 22 SPACES22 SPA C E S 2 0 S P A C E S 9 S P A C E S 6 S P A C E S 8 S P A C E S 23 SPACES13 SPACES 1 1 S P A C E S WATERTOWER BLDG O B L D G H BLDG N BLDG G B L D G F B L D G K B L D G J B L D G C B L D G D B L D G B B L D G A 3 2 S P A C E S 2 9 S P A C E S PARKING PLAZA14 SPACESEXISTINGFAIRGROUNDSACCESS ROUSE AVE R A I L T R A I L T R A S H T R A S H T R A S H 2 0 ' R O W F O R O A K STORIESUSE DESIGNATIONGROSSAREA(SF)PHASE 4BLDG N5,412210,296OFFICE B L D G E 1 0 S P A C E S 5 SPACES 22 SPACESTOWER TRAIL 8 SPACES17 SPACES S T O R M W A T E R B I O S W A L E / S N O W S T O R A G E PHASE/BUILDINGPHASE 1BLDG E9,231428,333RETAIL, RESTAURANT, OF F I C E BLDG F12,0201&215,751RETAIL, BREWERY, OFFIC E BLDG G13,7601&219,324OFFICEBLDG H1,6001&22,100OFFICE FOOT-PRINT(SF)PHASE 2BLDG K8,9621+MEZZ11,838MEDICAL & OFFICE N O R T H S I D E P U D ( E X I S T I N G ) BIOSWALEBIOSWALE P A T I O PATIO P A T I O B I O S W A L E BIOSWALE MAINT. C L A N E D LANE A LANE B L A N E G LA N E A LANE C LANE E LANE109 E. OAK 1 2 8 5 N . R O U S E 105 E. OAK 107 E. OAK 1 1 5 E . O A K 1 1 1 E . O A K 1 1 7 E . O A K 1 2 3 7 N . R O U S E 1 2 5 1 N . R O U S E P R O P E R T Y L I N E 1 2 0 3 N . R O U S E 1 1 3 E . O A K PROPERTY LINE 2 1 1 E . O A K P R O P E R T Y L I N E P R O P E R T Y L I N E PATIO P R O P E R T Y L I N E OAK STREETBLDG J8,8751&213,602OFFICE TRASH B L D G M 1 1 S P A C E S B L D G L 1 3 S P A C E S 1 6 S P A C E S 1 1 S P A C E S 1 3 S P A C E S 9 S P A C E S 9 S P A C E S 2 7 S P A C E S R A I L T R A I L L O A D I N G R A I L T R A I L PHASE 3BLDG L17,784460,966OFFICE w/RESIDENTIAL A B O V E BLDG M8,1652+BSMT22,176OFFICE w/BASEMENT STO R A G E P A R K I N G P L A Z A 2 0 S P A C E S E L A N E F L A N E 2 3 1 E . O A K 2 2 1 E . O A K 5 S P A C E S 1 0 S P A C E S RESERVED RESIDENTIALPARKING RESERVED RES.PARKING R E S E R V E D R E S . P A R K I N G R E S E R V E D R E S I D E N T I A L P A R K I N G R E S E R V E D R E S . C O M P A C T . P A R K I N G L O A D I N G BLDG O8,9501&318,524OFFICE, RESTAURANTTOTAL94,759202,910 ROUSE AVENUE (MT 86) I N T E R S T A T E 9 0 R O W B N S F R O W 1 1 S P A C E S R E S E R V E D R E S . P A R K I N G 24 SPACES I N T E R S T A T E 9 0 R O W E X I S T I N G S E W E R M A I N S A N D S E R V I C E S 30' WIDE W A T E R - SEWER E A S E M E N T S N O R T H S I D E P U D S E W E R S E R V I C E S R U N N I N G T H R O U G H T H E C A N E R Y D I S T R C T 3 0 ' W I D E W A T E R - S E W E R E A S E M E N T S 30' WIDE WATER-SEWER EASEMENTS C O N N E C T B L D G J T O E X I S T I N G S E R V I C E S T U B EXISTING SE W E R MAINS AND S E R V I C E S E X I S T I N G S E W E R M A I N S A N D S E R V I C E S P R O F E S S I O N A L E N G I N E E R S & S U R V E Y O R S BUILDING JCANNERY DISTRICT PH 2211 EAST OAK STREET S T A H L Y E N G I N E E R I N G & A S S O C I A T E S CANNERY DISTRICT PARTNERS, LLC S E W E R S I T E P L A N F I G U R E 2 Appendix TABLE 1: Detailed Cannery District Water Usage 5/15/2020 Cannery District Phase 1 Area **Peak Hr Flow Use by Building (gsf)gpd/1000 sf GPD (ac-ft/yr)(gpm) Cannery Building (Bldg E) Office/Retail 16,897 30 507 0.57 3.5 Restaurant/Bar 7,663 500 3,832 4.29 26.6 Building Common Area 3,773 30 113 0.13 0.8 Subtotal 28,333 4,452 4.99 30.9 Cannery Complex (Bldg F) Office/Retail 7,621 30 229 0.26 1.6 Restaurant/Bar 7,505 500 3,753 4.20 26.1 Building Common Area 625 30 19 0.02 0.1 Subtotal 15,751 4,000 4.48 27.8 Canning Warehouse (Bldg G) Office/Retail 14,041 30 421 0.47 2.9 Restaurant/Bar 1,365 500 683 0.76 4.7 Building Common Area 3,066 30 92 0.10 0.6 Subtotal 18,472 1,196 1.34 8.3 Boiler House (Bldg H) Office 2,100 30 63 0.07 0.44 Total of Phase 1 9,710 10.88 67.43 Cannery District Phase 2 Area **Peak Hr Flow Use by Building (gsf)gpd/1000 sf GPD (ac-ft/yr)(gpm) Building J Office 13,602 30 408 0.46 2.8 Subtotal 13,602 408 0.46 2.8 Building K Office 3,245 30 97 0.11 0.7 Gym 4,607 100 461 0.52 3.2 Building Common Area 3,391 30 102 0.11 0.7 Subtotal 11,243 660 0.74 4.6 Total of Phase 2 1,068 1.20 7.4 Cannery District Phase 4 Area **Peak Hr Flow Use by Building (gsf)gpd/1000 sf GPD (ac-ft/yr)(gpm) Bldg N Office/Retail 8,712 30 261 0.29 1.8 Building Common Area 1,584 30 48 0.05 0.3 Subtotal 10,296 309 0.35 2.1 Bldg O Office/Retail 14,378 30 431 0.48 3.0 Restaurant/Bar 1,642 500 821 0.92 5.7 Building Common Area 2,504 30 75 0.08 0.5 Subtotal 18,524 1,327 1.49 9.2 Total of Phase 4 1,636 1.83 11.4 Cannery District Phase 3 Area **Peak Hr Flow Use by Building (gsf)gpd/1000 sf GPD (ac-ft/yr)(gpm) Bldg L Office/Retail 14,926 30 448 0.50 3.1 *Residential 7,142 8.00 49.6 Subtotal 7,590 8.50 52.7 Bldg M Office 21934 30 658 0.74 4.6 Total of Phase 3 8,248 9.24 57.3 TOTAL ALL PHASES 20,662 23.14 143.5 *Residential Use calculated using 89 gal/person/day, 80.25 estimated people **Peaking Factor used for Avg Day to Peak Hour 10 Average Water Use Average Water Use Average Water Use Average Water Use