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HomeMy WebLinkAboutSanitary Report SANITARY SEWER REPORT FOR THE PROPOSED STERLING HEIGHTS APARTMENTS B&A#11533 LOCATED IN: College Station, Texas First Submittal: 4/15/2015 Second Submittal: 5/22/15 Prepared By: Sam J. Vernon, P.E. OF * I '' *1# ' SAM J. VERNON Bleyl &Associates �l 99353 1722 Broadmoor Ste. 21010tt'•,�c �O•:• � Bryan,Texas 11 v '•• SNS• �_� Phone: 979.268.1125 1 ONALE Ss� �'_ Fax: 979.260.3849 ��'��'~~'" t 5\111.\1# TABLE OF CONTENTS SANITARY SEWER DESIGN REPORT 3 Introduction 3 Analysis of proposed systems 3 Exhibit 1: Site Plan 5 Page 2 of 4 SANITARY SEWER DESIGN REPORT Introduction The proposed site will consist of 0.937 AC of multi-family residential development. The proposed Sterling Heights Apartments will contain 24 units and 40 total bedrooms. Wastewater from the site will be collected into a cleanout which connects to a proposed 6" sanitary sewer service. The proposed service will tie into an existing 6" sanitary sewer line that runs eastward along the rear of the property. The location of the proposed service is shown in the site plan attached in Exhibit 1. Analysis of Proposed Systems As discussed in the introduction, wastewater from the site will be collected into the existing 6" sanitary sewer line south of the site. The flow generation for the system was calculated using the fixture unit method, as outlined in the BCS Unified Design Guidelines, which specifies a load factor per fixture. This factor is then multiplied by the number of fixtures to find the total number of fixture units. Table II in the BCS Unified Guidelines was used to find the total number of gpm per fixture. The contribution of flows within the proposed site was determined using the method shown below: Sterling Heights Fixtures • 24 kitchen sinks @ 2 units per each • 40 showers/baths @ 2 units per each • 40 toilet © 2 units per each • 40 vanity sinks @ 2 units per each • 24 washing machines © 4 units per each • 24 dishwashers @ 2 units per each Total proposed flow: Total fixture units: 432 Total peak flow: 125gpm/500units (Table II of BCS Unified) = .25gpm per fixture unit=.25(432) = 108 gpm = 0.24 cfs Manning's equation was used to calculate the capacity of the proposed 6" sanitary sewer service line. The slope of the service line was designed at 1%. Page 3 of 4 Capacity of 6" PVC S=1.0%: Manning's equation parameters • n=0.013 7rD2 7x(0.5)2 • Area =A= 4 = 4 =0.196 ft2 iirDz • Hydraulic Radius = RH = A 4 _ D =9:-5 = 0:-5 =0.125 ft P,, nD 4 4 • Slope = 0.01 ft/ft Q = 1.486xAxR3 xSy Q= 1.486x0.196x0.1252 3 x0.012 =0.56 cfs 0.013 Table 1: Impact of proposed flow — 6" service line Total capacity 0.56 cfs Proposed flow 0.24 cfs Proposed excess capacity 0.32 cfs As shown in the calculations above the proposed sanitary sewer service line has adequate capacity to serve Sterling Heights. Using these flows, the City can verify the capacity of the existing 6" sanitary sewer line to serve the proposed development. Page 4 of 4 EXHIBIT 1: SITE PLAN SANITARY SEWER REPORT FOR THE PROPOSED STERLING HEIGHTS APARTMENTS B&A#11533 LOCATED IN: College Station, Texas First Submittal: 4/15/2015 Prepared By: Sam J. Vernon, P.E. OF N i .. T�c''r ��It Bleyl &Associates 5 • ' '••s 11 1722 Broadmoor Ste. 210 * �� •':*�j Bryan, Texas Phone: 979.268.1125 a SAM J. VERNON Fax: 979.260.3849 141%. 99353 9ENS 'G.#v i TABLE OF CONTENTS SANITARY SEWER DESIGN REPORT 3 Introduction 3 Analysis of proposed systems 3 Exhibit 1: Site Plan 5 Page 2 of 4 SANITARY SEWER DESIGN REPORT Introduction The proposed site will consist of 0.937 AC of multi-family residential development. The proposed Sterling Heights Apartments will contain 24 units and 40 total bedrooms. Wastewater from the site will be collected into a cleanout which connects to a proposed 6" sanitary sewer service. The proposed service will tie into an existing 6" sanitary sewer line that runs eastward along the rear of the property. The location of the proposed service is shown in the site plan attached in Exhibit 1. Analysis of Proposed Systems As discussed in the introduction, wastewater from the site will be collected into the existing 6" sanitary sewer line south of the site. The flow generation for the system was calculated using the land use determination method, as outlined in the BCS United Design Guidelines, which specifies a residential population factor of 2.67 capita per unit. This factor is then multiplied by the residential average flow generation per capita of 100 GPD. The contribution of flows within the proposed site was determined using the method shown below: Sterling Heights • 2.67 persons per unit • 100 gallons per day per person • 24 units • Peaking Factor = 4 Total proposed flow: /2 67 personx 100 gPd \ _/267 gpd x 24 units Residential lot average flow: unit person1 v unit =6,408gpd=4.45 gpm Total peak flow: 4.45 gpm (4) = 17.8 gpm = 0.04 cfs Manning's equation was used to calculate the capacity of the proposed 6" sanitary sewer service line. The slope of the service line was designed at 1%. Page 3 of 4 Capacity of 6" PVC a(7. S=1.0%: Manning's equation parameters • n=0.013 • Area =A= 2 = r(05)2 = 0.196 ft2 4 7602 • Hydraulic Radius = RH =A = 4 = D = 0_5 = 0.125 ft PW 7rD 4 4 • Slope = 0.01 ft/ft 1.486xAxR� xSY Q= Q_ 1.486x0.196x0.125Y x0.01% =0.56 cfs 0.013 Table 1: Impact of proposed flow — 6" service line Total capacity 0.56 cfs Proposed flow 0.04 cfs Proposed excess capacity 0.52 cfs As shown in the calculations above the proposed sanitary sewer service line has adequate capacity to serve Sterling Heights. Using these flows, the City can verify the capacity of the existing 6" sanitary sewer line to serve the proposed development. Page 4 of 4 EXHIBIT 1: SITE PLAN