SITE INFORMATION AND CORRESPONDENCE 1980-1999

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Discharger is in violation of its odor control prohibition in its existing permit and likely to violate the same prohibition in its new permit. We suspect the Discharger is also in violation of the dissolved oxygen limit of 1 mg/l for the ponds. Daily testing for dissolved oxygen and pH (to reveal septic conditions) should be included in the permit to demonstrate compliance with the requirement of Pond Specifications C-2 and C-4. DeltaKeeper is concerned by the prospect of the Discharger expanding its irrigation area by 500 acres to the south of its current border. Approval of the increased acreage should be delayed until compliance is demonstrated. G. Monitoring for Biosolids. The Tentative Permits states that wet biosolids are currently handled by periodic blending with reclamation water and distributed via a ditch to fields for application by flood irrigation. DeltaKeeper is informed that,historically, the Discharger has collected supernate from the sludge lagoons and mixed it with reclamation water for irrigation. Periodically, sludge is dredged from the lagoons, dried and then land applied. The supemate contains high concentrations of metals and other priority pollutants. The Tentative Permit contains limits on land application concentration and loading rates. It is not clear that monitoring is required for the supemate. The Discharger will need to conduct flow monitoring if accurate pollutant loadings are to be calculated from the sludge lagoon supernate. DeltaKeeper believes that flow monitoring needs to be required for the wet biosolids that are blended with the reclamation water and distributed for application by flood irrigation. DeltaKeeper notes that Specification E-3 states that "[d]ischarge of waste classified as `hazardous' under Section 2521, Chapter 12 of Title 23 or `designated', as defined in Section, 13173 of California Water Code is prohibited." However,we could find no monitoring requirements that compel the Discharger to test the biosolids/sludge lagoon supernate for hazardous waste characteristics. How does the Regional Board intend to determine compliance with this limitation if testing is not conducted? The determination of hazardous waste characteristics and their soluble threshold limit concentrations (STLC)cannot be determined by priority pollutant analysis. The Discharger must perform a hazardous waste characterization test(STLC) on their biosolids/supemate. The literature reports that volatile acids increase when a digester experiences upsets and interference (becomes sour"). We recommend pH testing on the digestor supernate to detect upset/possible interference conditions in the digestor. When an upset condition is detected by a low pH reading,the Discharger should be required to test for priority,pollutants and hazardous waste characteristics (STLC) on the lagoon supemate nad wet biosolids. Again,testing is driven by conditions that have a reasonable potential to cause pollutant excursions. DeltaKeeper,Tentative NPDES Permit,Lodi, 17 December 1999,Page 12.