SITE INFORMATION AND CORRESPONDENCE

Home Browse Search

INFORMATION SHEET • • - 16 - MUSCO FAMILY OLIVE COMPANY AND THE STUDLEY COMPANY WASTEWATER TREATMENT AND LAND DISPOSAL FACILITY SAN JOAQUIN COUNTY This Discharge Specification prescribes a maximum BOD loading of 300 lbs/acre on any one day, and 100 lbs/acre/day as a 7-day (weekly) average. The weekly average loading limit of 100 lbs/acre/day is based on U.S. Environmental Protection Agency Publication (USEPA) guidelines provided in Pollution Abatement in the Fruit and Vegetable Industry— Wastewater Treatment (USEPA 625/3-77-0007) (hereafter Pollution Abatement). Although the RWD states that the yearly average BOD loading will be less than 70 lb/ac/day, a review of the most recent self-monitoring report(May 2002) shows that the Discharger may not be able to meet the daily or weekly limitations. The Discharger has already proposed to install aerators in its ponds; this step may be all that is necessary to meet the BOD effluent limitation. If not then the Discharger will need to take other steps to improve its treatment system. It is not appropriate to relax the BOD loading rate as staff are still receiving odor complaints. Land Application Area Specification D.19 Land Application Area Specification D.15 requires that effect wastewater application on the soil shall not exceed the buffering capacity of the soil profile. The Discharger has described the disassociation of the bicarbonate ion under certain soil pH conditions but has failed to describe the pH at which the disassociation is anticipated to occur. Pollution Abatement recommends a wastewater pH range of 6.4 to 8.4 for irrigation and Effluent Limitation CA requires wastewater discharged to the land application areas to not have a pH of less than 6.5 or greater than 8.5. This limitation alone cannot ensure that soil pH conditions will be optimal for land treatment and preventing leaching of metals, so Land Application Area Specification D.19 requires that the discharge not exceed the soil pH buffering capacity. Land Application Area Specification D.20 This specification is needed because wastewater application near the property boundary has resulted in nuisance odors for residents. The Discharger's Odor Minimization Report described elimination of standing water in the irrigation checks. Because the soil permeability is so low, staff believe any application of wastewater at the irrigation checks will result in standing water. To prevent anaerobic conditions and associated odor problems in the treatment and storage ponds, this Order also requires the dissolved oxygen content in the upper 12 inches of any liquid impoundment to be maintained at no less than 1.0 mg/L. Technical Reports Required by the Provisions The Discharger is required to submit a workplan for characterization of groundwater quality and percolate quality at the land treatment units (land application areas). The groundwater well workplan will allow fi:rther evaluation of groundwater conditions upgradient and downgradient of the newly constructed 84- million gallon storage pond and in the land application areas. In addition, installation of lysimeters are required to determine the quality of the percolate at the bottom of the land treatment units (at a depth of five feet). Lysimeters shall be installed in both the land application areas and in an area where no land application of wastewater has occurred. The Discharger is required to submit a BPTC Salinity Source Reduction Plan because the available data on groundwater quality,wastewater quality, and crop uptake indicates the wastewater application could impact groundwater quality. This Workplan must contain plans to reduce the concentration of TDS constituents, organic constituents, and hydraulic loading. The Discharger is required to submit an assimilative capacity report for the LTUs (land application areas).