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INFORMATION SHEET MUSCO FAMILY OLIVE COMPANY AND THE STUDLEY COMPANY WASTEWATER TREATMENT AND LAND DISPOSAL FACILITY SAN JOAQUIN COUNTY FLOW LIMITATION As part of the RWD, the Discharger was required to submit a water balance to demonstrate that it has adequate treatment, storage, and disposal capacity for its requested flow rate. The current WDRs contain an implied flow rate of 500,000 gpd,while the revised TSO allow a weekly flow limit of 820,000 gpd. The RWD contained a water balance with a flow rate of 1,000,000 gpd. Staff carefully reviewed the initial water balance, and spent many hours talking with the Discharger's consultants about our concerns. The consultants have since submitted several revised water balances. One major revision had to do with the capacity of the storage pond (which is currently under construction). The original water balance used a storage capacity of 114 million gallons, but the Discharger now estimates that the pond's actual capacity will be only 84 million gallons. The most recent water balance was submitted with the 8 August 2002 response to the tentative WDRs. In general, the water balance fails to demonstrate adequate wastewater storage and application capacity for the requested a flow rate of 800,000 gpd. Evaluation of the water balance is complicated by the poor data regarding stonnwater runoff and tailwater generation rates. However, because the Discharger can stop operations and limit wastewater flow if needed to prevent overflows of wastewater from the storage pond, staff are recommending the Discharger be allowed the requested flow limit—with some additional restrictions. In the discussion below, the water balance is reviewed and the additional restrictions are described. Water Balance Review In preparation of the tentative WDRs, the Discharger has submitted water balances prepared by Kennedy Jenks. Since the original water balance was submitted in the 30 April 2002 RWD, two conference calls to discuss the contents of the water balances have been held. In addition, the Discharger has revealed the actual size of the wastewater storage pond to be 84.1-million gallons (Mgal) (nearly 30-Mgal less than originally stated). This evaluation focuses on Table 2 "Water Balance for 100 Year Rainfall Event Climate Conditions". The water balance addresses some of staff's concerns regarding previously submitted water balances but fails to demonstrate adequate storage capacity for the wastewater flow rate as proposed. In general, the water balance is overly optimistic—especially considering the problems the Discharger has experienced with controlling tailwater at the site. However,because of the nature of the olive processing activities, the facility can stop production if necessary and wait for better climatic conditions. The water balance indicates wastewater will be stored during the winter months of December, January, and February and applied to land application areas the rest of the year. During the months when wastewater is stored, stormwater that falls on upland application areas is proposed to be bypassed past the storage pond. (Stormwater that falls on the main facility will continue to be discharged to the storage pond). However, the Discharger has not proposed criteria for bypassing stormwater. As written,the tentative WDRs prohibit bypass until the Discharger provides acceptable criteria to show that wastewater will not be present in the stormwater. The ability to bypass wastewater is a critical assumption in the water balance and may impact the Discharger's ability to operate.