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2020 Eugene Wastewater Master Plan Chapter 4: Design Criteria 33 <br />commercial and industrial) should be used when available. Flow rates are provided for both gross and <br />net acres. Gross areas are for the entire development site, including street areas. Net areas are for lots <br />and development areas only and assume 25 percent of the gross area is used for streets. <br />Table 4-3: Summary of Design Wastewater Flow Rates for New Developments <br /> Gross Acre Design Net Acre Design <br />Land Use Category Base flow Rate <br />(Gal/Acre/Day) <br />Base flow Rate <br />(Gal/Acre/Day) <br />Low-Density Residential 600 750 <br />Medium-Density Residential 1605 2000 <br />High-Density Residential 3230 4040 <br />Neighborhood Commercial Facilities 1360 1700 <br />Community Commercial Center/Mixed Use 2000 2500 <br />Major Retail Center 2560 3200 <br />Campus Industrial 3040 3800 <br />Light-Medium/Special Heavy Industrial 3040 3800 <br />Heavy Industrial 1520 1900 <br />Park and Open Space Consult park master plan for use intensity <br />Government and Education/University Research 2680 3350 <br />Peak Flow Factor (PFF) <br />The peak flow factor simulates the peak hourly base wastewater flow rate that occurs during the day. <br />The PFF varies between 3.5 and 1.5, depending on the total average dry-weather flow from the basin <br />area. The PFF can be calculated from the following equation: <br />Peak Flow Factor = 25 - 20.2 (ADWF)0.0165 <br />where ADWF is the total average dry-weather flow from the basin or study area, expressed in 1000s of <br />gallons per day. <br />Example: Total ADWF for the basin is 600,000 gal/day <br /> PFF = 25 - 20.2 (600)0.0165 <br />= 25 - 20.2 (1.11) = 2.55 <br />Infiltration/Inflow - New Development Areas <br />For new development, an allowance is made for peak infiltration at the following rates: <br />Peak Infiltration Rates <br /> Type of Land Use Gal/Gross Acre/Day Gal/Net Acre/Day <br /> All Types 2,000 2,500 <br />