SITE INFORMATION AND CORRESPONDENCE

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WASTE DISCHARGE REQUIREMENTS ORDER NO. • MUSCO FAMILY OLIVE COMPANY AND THE STUDLEY COMPANY to- WASTEWATER TREATMENT FACILITY SAN JOAQUIN COUNTY 46. As the Discharger has not provided other groundwater data regarding the quality of groundwater, or a more comprehensive database of source water, the above data may be presumed to be representative of the quality of background water in the underlying aquifer. Absent information to the contrary, shallow aquifers if present must be assumed to be in hydraulic continuity with deeper zones. Data substantiates that underlying groundwater is of poor but useable quality. It is unlikely that shallow groundwater is of higher quality. 47. These WDRs require continued groundwater monitoring to fully evaluate the impacts of the Discharger's past and future disposal practices. However, it is not appropriate to follow the Discharger's recommendation to conduct a year of monitoring to determine if there are groundwater impacts, and then design effluent limits based on the groundwater data. In the last year, the Discharger has substantially increased its wastewater flow and strength, and has begun applying wastewater to a larger area. These recent changes may not yet be reflected in the groundwater quality. In addition, the RWD clearly shows that the Discharger intends to apply significantly more salt than will be taken up by the crops; therefore, these WDRs contain limits to prevent impacts to the underlying groundwater. SITE SPECIFIC CONDITIONS 48. Local land use consists of industrial, residential, and agricultural operations. The site is located on an alluvial fan that generally slopes to the northeast. Topography varies from steep to nearly level. 49. The land application areas are located outside the 100-year flood zone. 50. The average annual total precipitation for this area of San Joaquin County is 11.3 inches. The 100-year annual total precipitation for this area is 27.5 inches. The peak monthly 100-year precipitation of 5.9 inches occurs in March. 51. Surface water drainage from the facility is to the Sacramento San Joaquin Delta. 52. Shallow soil samples were collected in the land application areas in November 1999 and April 2001 as part of the 6 April 2001 Soil Salinity Assessment required by C&A Order No. 5-00-717. The samples were collected to evaluate the wastewater application impact to soil quality. Analysis indicted that 22-percent of samples collected in the Field 55 East and Field 55 West(a total of 55 acres)may be impacted by the wastewater application and 28-percent of the samples collected in Field 95 (95 acres)may be impacted. The report stated that the high concentration of sodium in the wastewater has the potential to reduce the already low permeability of the soil. SPECIAL CQNSIDERATIONS FOR FOOD PROCESSING WASTE 53. Excessive application of food processing wastewater to land application areas can create objectionable odors, soil conditions that are harmful to crops, and degradation of underlying groundwater by overloading the shallow soil profile and causing constituents of concern (organic carbon, nitrate, dissolved solids, and metals) to percolate below the root zone.