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WASTE DISCHARGE REQUIREMENTS
<br /> CITY OF STOCKTON 1
<br /> REGIONAL WASTEWATER CONTROL FACILITY
<br /> SAN JOAQUIN COUNTY LATE REVISIONS
<br /> 43. The previous Order established secondary technology-based effluent limitations for total
<br /> suspended solids (TSS) at 30 mg/1 as a monthly average, 45 mg/1 as a weekly average,
<br /> and 60 mg/I as a daily maximum. This Order retains the existing monthly, weekly, and
<br /> daily maximum TSS effluent limitations. This Order contains a provision to allow for the
<br /> permit to be reopened to consider modifying TSS limitations after the DO TMDL is
<br /> finalized.
<br /> 44. As discussed in Section 8.2 of the Fact Sheet, the Discharger has developed several
<br /> models to assess available dilution and mixing zones. Some model information is useful
<br /> for estimating the relationship between different rainfall year types. However, due to
<br /> inherent inaccuracies in model estimates verses real-time data, and the impaired condition
<br /> and presence of endangered species in the SJR, the Regional Board finds that it is not
<br /> appropriate to use the submitted models to determine dilution. The evaluation of actual
<br /> flow measurement during above average wet years, with conservative assumptions for
<br /> critical dry year conditions, is more dependable and protective.
<br /> DISINFECTIONXILTRATION
<br /> 45. The Regional Board has found, in Finding No.10, the SJR has the beneficial uses of
<br /> domestic supply, agricultural supply, and body contact and non-body contact water
<br /> recreation, and that at times there is little or no dilution. Recreational uses identified in
<br /> the immediate vicinity of the RWCF outfall include boating, water skiing,jet skiing,
<br /> swimming, and fishing(both fish and invertebrates). A number of agricultural intakes
<br /> have been identified through a search of the SWRCB, Water Rights Division database.
<br /> Within an approximate two-mile radius of the outfall there are approximately ten riparian
<br /> users, including the Stockton Golf and Country Club, which draws as much as 1.15 cubic
<br /> feet per second of SJR water near Smith Canal for irrigation of its golf course and
<br /> landscaping. Additionally, subsistence and snorts fishine%shellfish bar-vesting is prevalent
<br /> in the immediate vicinity of the RWCF outfall
<br /> To protect these beneficial uses, the Regional Board finds that the wastewater must be
<br /> disinfected and adequately treated to prevent disease. The principal infectious agents
<br /> (pathogens) that may be present in raw sewage may be classified into three broad groups;
<br /> bacteria,parasites and viruses. These pathogens include Entamoeba histolytica, Giardia
<br /> lambia, Balantidium coli, Ascaris lumbricoides, Ancylostoma duodenale, Necator
<br /> americanus, Ancylostoma, Strongyloides stercoralis, Trichuris trichiura, Taenia,
<br /> Entrobius vermicularis, Echinococcus granulosus, Shigella, Salmonella typhi,
<br /> Salmonella, Vibrio cholerae, Escherichia coli, Yersinia enterocolitica, Leptospira,
<br /> enteroviruses (71 types), poliovirus, echovirus, coxsackie virus, hepatitis A virus,
<br /> adenovirus (31 types), rotavirus, and parvovirus (2 types). In addition, Giardia and
<br /> Cryptosporidium have become more of a concern to health officials, drinking water
<br /> purveyors, and the public in recent years.
<br /> After consultation ota ff eeiisulted with the California Department of Health Services
<br /> (DHS) regarding this project,and-DHS recommended the wastewater be treated to
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