SITE INFORMATION AND CORRESPONDENCE

Home Browse Search

u RESPONSE TO WRITTENCOMMENTS -23- City Of Stockton-Regional Wastewater Control Facility NPDES No. CA0079138 26 April 2002 Board Meeting yield valid results for mercury. Mercury samples need to be grab samples only, to provide as little external influence (interference) as possible on the mercury test result. The general statement after ti.e notes states :gat the discharger shall monitor and record all data for all the constituents listed above on the first day after each such intermittent discharge. This statement does not adequately cover the RWCF facility. The RWCF can store water as mentioned above and does not have to continuously discharge should the operators determine it is in the best interest of the City to stop discharging. This may occur more than once in any given week. The City should meet the effluent test requirements as listed in the sampling frequency and this general statement should be eliminated. RWQCB Response: All of these changes were already made to the tentative order as a result of the City's 9 May 2001 comments. Stockton Comment No. VI.B (Three Species Chronic Toxicitv Monitoring): Several minor points need to be made here. This section does not specify the routine testing frequency in Phase L, except for individual species repeat testing when TUc>1. Is this monthly? This section does not differentiate between Phase I and Phase lI and the follow-up testing requirements are not clear. If routine tests are reported within 30 days, how are follow-up test results reported? RWQCB Response: Comment noted. The tentative order has been modified to clarify the testing procedures. Stockton Comment No. VLC (Water Supply Monitoring): This section requires a sampling station be established where a representative sample of the municipal water can be obtained. This is very difficult, if not impossible at the RWCF site. The City's water utility and the California Water Service Company are already required by law to furnish each customer an annual comprehensive water quality summary report that provides all of the information requested in this section. RWQCB Response: Comment noted. The tentative order has been modified to allow the City to use the water supplier's reports for their water supply monitoring. Stockton Comment No. VII. (Costs): The costs associated with achieving the various more restrictive permit limitations for coliform, ammonia, and nitrogen removal are extremely high, on the order of$100 million. RWQCB Response: The cost estimates provided in the City's comment letter appear to be reasonable. It is noted, however, that the estimates are not based on existing flows, but instead allow for growth. Conceivably, the costs would be somewhat less if based on current flows. VIII. Board's Re ; ' s Incomplete