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Final Report <br />City of Paris, Texas <br />Wastewater Collection System Capacity Analysis <br />and the nighttime minimum flow rates are fundamental to the calculation <br />of WWP and RDII. <br />The formula used for the determination of WWP is as follows: <br />Wastewater Production =(Average Dry Weather F[ow - Average Dry <br />Weather Minimum) / Wastewater Production Factor <br />or <br />WWP = (ADWF-ADMF) / R'WP Factor <br />Where the WWP factor varies from 1.0 to 0.75 and averages to 0.88 for <br />predominately residential basins. This factor is dependent on the land use <br />in the area and may require adjustment to reflect nighttime activities if the <br />actual flows measured indicate it. <br />Base Inflow and Infiltration <br />Base Inflow and Infiltration is the flow that exists in the system at all <br />times that is not a direct result of water usage. This flow is considered to <br />be constant and enters from such sources as cracked pipe below dry <br />weather groundwater levels and may occur from irrigation drainage or <br />faulty plumbing. This flow may represent a considerable operational cost <br />but it is very difficult to identify and eliminate. <br />The amount of Base Inflow and Infiltration in a metered basin is <br />calculated from the previous formulas rearranged: <br />Base Inflow and Infiltration = Avg. Dry Weather Flow - Wastewater Production <br />or <br />BI/I = ADWF - WWP <br />Typical components of flow in the Average Dry Weather Day are shown <br />in Figure 2. <br />7 <br />