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DUBLIN SAN RAMON SERVICE DISTRICT REGIONAL CONNECTION FEES Surveys have shown that District -wide in the commercial sector, under utilization of capacity may exceed 20% in normal times; in the current economic situation, under utilization is undoubtedly higher'. In addition, the last two years has been drought years with upwards of 16% water conservation which translates to some reduction in wastewater flow. The District must reserve treatment capacity for existing customers that purchased capacity but is not currently using the capacity. An under utilization of 20% under current conditions is reasonable or the current ADWF that the District is required to accommodate is 13.1 mgd. Currently, the District uses 220 gallons per day (gpd) per DUE to convert DUE to flow. Shown in Figure 3 is the annual average gpd per DUE from 1997 to 2009. In the most recent years, the unit flow has been less than 220 gpd which is to be expected because of the sudden economic downturn, the current drought conditions and a large number of DUEs that have been purchased that are not yet flowing. Because of thesc reasons, 220 gpd for a DUE is still a valid conversion for estimating future flow. Figure 3 DUE Flow History 250 225 a rn 200 uJ o 175 —i 150 1996 1998 2000 2002 2004 2006 2008 2010 Year Not only must the District treat all the wastewater that may reach the WWTP from connected customers, an adequate portion of the WWTP capacity has to be reserved for customers that have purchased capacity but have not yet connected to the system. As of January 1, 2010, the number of DUES sold but not connected is approximately 1,000. This is equivalent to another 0.2 mgd of plant capacity that is already allocated. Therefore, as of January 1, 2010, the existing plant flow for projection purposes is 13.3 mgd. FUTURE AVERAGE DRY WEATHER FLOW (ADWF) "Sewer Allocation Analysis Andrew Cussen and Rhodora Biagtan; September 2007. BLACK VEATCH 23 MAY 2010