SITE INFORMATION AND CORRESPONDENCE_CASE 2

Home Browse Search

Response to Written Comments -17- 24 April 2007 City of Tracy WWTP San Joaquin County Request: These wording changes should be made to the end of the first sentence in Provisions VI.CA.b.i. and V1.CA.c.i. to make it clear that final limits do not apply where interim limits under a compliance schedule are imposed. RESPONSE: The discharge must be capable of complying with the final effluent limitations for copper and aluminum before increasing the discharge flow rate to Old River. Allowing the discharge to exceed the water quality-based effluent limitations for these constituents would not be in compliance with Resolution 68-16. CITY OF TRACY - NPDES COMMENT #29: Provision VI.C.4.c. Compliance Schedules. Phase 2-4 Improvements. The Regional Board should modify the language to state that 'The permitted average daily discharge dry weather flow may increase to 16 mgd upon compliance" with the stipulated conditions. Further, the permit should define average dry weather flow as the flow for three consecutive dry weather months in a calendar year. RESPONSE: See response to CITY OF TRACY — NPDES COMMENT #27 CITY OF TRACY - NPDES COMMENT #30: Provisions VI.C.4.d.i. and f., Pages F-8 Compliance Schedules for Final Effluent Limitations for Copper and Aluminum. The City contends that tying compliance with the copper and aluminum limits to the date of the Phase I improvements is not justified since these improvements are not designed specifically to address either copper or aluminum removal, only tertiary treatment and nitrification/denitrification, although the tertiary filters will likely provide some additional metals removal. The City also contends that Antidegradation is not a proper justification for the shortened compliance schedules. Request: Remove the language `or upon compliance with Special Provisions VI.C.4.b., whichever is sooner,"from Provision VI.CA.d.i. and f. , and footnote 3 on page 28 of the Permit, and make corresponding changes to the Fact Sheet. Change compliance date for aluminum to May 3, 2017 to be consistent with the Basin Plan compliance schedule. RESPONSE: The discharge must be capable of complying with the final effluent limitations for copper before increasing the discharge flow rate to Old River to be in compliance with Resolution 68-16. In the proposed Order we were requiring compliance with the aluminum effluent limitations before allowing an increase in flow for the same reason. However, since aluminum in the receiving water exceeds the effluent aluminum, Resolution 68-16 does not apply. Therefore, a late revision is proposed to allow the discharge flow to increase to 10.8 mgd prior to compliance with the effluent limitations for aluminum. Regional Water Quality Control Board, Central Valley Region Board Meeting—3/4 May 2007 Item#17