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recalculation of these criteria (excluding the trout data) will result in a higher chronic <br /> water quality standard about 10 ug/1). The acute criteria would also increase <br /> q Y ( <br /> significantly as a result of deleting rainbow trout from the database. Furthermore, the <br /> federal criteria are expressed as free cyanide, not total. The available data do not indicate <br /> that free cyanide levels are above the criteria; thus the more restive limitation should be <br /> deleted. <br /> Finally, dilution is clearly present in Dredger Cut and should be considered in <br /> developing appropriate effluent limits. The dilution that occurs over the tidal cycle is <br /> approximately a factor of two (2). (Finding 22.) Any limitation calculated for the <br /> discharge should reflect this condition which directly impacts instream compliance with <br /> the objectives. <br /> The City requests that the Regional Board provide a schedule of compliance in the <br /> Permit that provides time for the City to (1) collect sufficient data and (2) evaluate with <br /> the Regional Board the need for water quality-based effluent limitations for cyanide. <br /> Until completion of this process the City should be required to monitor only. <br /> Zinc <br /> The City objects to the effluent limitations for zinc for reasons including the <br /> following: <br /> • The Delta zinc criteiia are not applicable to Dredger Cut. _ <br /> • No valid, representative, reliable data for making a reasonable potential <br /> determination, and the lack of clean techniques and dissolved/total metal data. <br /> • No reliable effluent data indicating that dissolved levels exceed criteria in <br /> - Dredger Cut and the assumed hardness is inappropriately low. <br /> Organisms most sensitive to zinc (i.e., daphnids) were subject to whole <br /> effluent toxicity ("WET") test with no toxicity exhibited; therefore, no <br /> exceedance of the narrative criteria exists. <br /> As with cyanide, the Regional Board is attempting to apply an objective to Lodi's <br /> discharge that is not applicable. The zinc criteria specified in the Basin Plan expressly <br /> apply to specific waters. Dredger Cut is not within those waters. As such, it is an <br /> NPDESPermitComments Exhibit 2 Page 4 12/17/99 <br />