Laserfiche WebLink
necessitate the ratepayers to bear potentially multi-million dollar costs even though there <br /> is no benefit to public health associated Nvith this requirement. Accordingly, a more <br /> restrictive averaging period is inappropriate and unnecessary, based on all information in <br /> the record, including DHS' own evaluation of the range and variability of effluent quality <br /> that poses no threat to contact recreational uses. <br /> 9. The Stockton Studv Conclusions are Applicable to Lodi <br /> In previously issued permits (e.�., City of Stockton), the Regional Board has <br /> determined that it was both reasonable and appropriate to allow the permittee to <br /> investigate whether more restrictive DHS recommended coliform limitations are <br /> necessary to protect public health. In particular, Stockton evaluated the DHS claim that a <br /> specific level of"viral reduction" is required to protect public health and that such <br /> reduction is only demonstrated when a 2.2 MPN/100 ml total coliform is present. The <br /> level of viral reduction is specifically related to an assumed high level of virus in the <br /> influent and an assumed level of vines removal through the treatment plant. These <br /> conservative assumptions may or may not be correct for any given plant. In fact, given <br /> the multiple conservative assumptions used, it is highly probable that municipal facilities <br /> not achieving a 2.2 MPN/100 ml coliform limitation fully meet DHS' intended objective <br /> for the level of virus that will not impair contact recreation uses. <br /> The Comprehensive Health Risk Assessment Final Report prepared by the City of <br /> Stockton (the "Stockton Study"), which was conducted with the approval of DHS, <br /> concluded that 2.2 MPN/100 ml is not necessary to protect public health and that DHS' <br /> assumptions on plant performance and vines levels were misplaced. Stockton found that <br /> actual virus levels in the effluent were much lower than assumed by DHS even with total <br /> coliform levels well above 2.2 MPN/100 ml and therefore, there is no significant risk to <br /> public health present. DHS had simply over-estimated the risk presented by municipal <br /> effluents, regardless of the dilution available. <br /> The Stockton Study demonstrated that many people engaged in the type of <br /> recreational activities that are more likely to result in immersion or ingestion such as <br /> - swimming, water-skiing, sailing and jet-skiing. Few if any people use Dredger Cut in <br /> NPDES Permi(Comments Exhibit 2 Page 19 12/17/99 <br />