SITE INFORMATION AND CORRESPONDENCE 1980-1999

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The Regional Board required the City of Stockton to employ continuous online devices to monitor dissolved oxygen,pH,temperature, electrical conductivity and turbidity in Smith Canal for dissolved oxygen problems similar to those found in White Slough. DeltaKeeper recommends that similar continuous monitoring be required for receiving water stations R-1, R-2, R-3 and R-4. How frequently did the Discharger monitor during critical pre-dawn time frames? Did the Discharger monitor the dissolved oxygen sags following chemical weed control efforts? Has the Discharger made an effort to ascertain the effects of illegal dairy waste dumping? Relative to the amount of data obtained, the cost of continuous monitoring equipment is minimal. DeltaKeeper requests that the Regional Board require the Discharger to conduct metals and priority pollutant analyses concurrently with effluent metal and priority pollutant analyses. This would establish the effect of effluent discharges on receiving waters. Sample type (composite or grab) should be the same for effluent and receiving water sampling. This requirement should be clearly specified in the Receiving Water Monitoring section. Again,exceedances of a water quality standard should trigger a requirement for additional monitoring. J. Monitoring Wells. We are concerned that groundwater may be impaired below and around the holding ponds and sludge lagoons from percolation of pollutants from these locations. These ponds are the largest volume source of pollutants and have the longest holding times. Consequently, areas surrounding the holding ponds and sludge lagoons have the greatest exposure. DeltaKeeper requests that additional monitoring wells be located immediately adjacent to the holding ponds and sludge lagoons on the down-gradient side. K. Priority Pollutants. The Tentative Permit lacks a technical description defining priority pollutants. Does the phrase priority pollutants mean all pollutants listed in the National Toxics Rule or all pollutants listed in the California Toxics Rule or all priority pollutants listed under 503 of the Clean Water Act? Does priority pollutants as defined in the Tentative Permit include MTBE or tributyltin? We believe the Discharger should sample for all pollutants that have an established water quality standard, as listed in the National Toxics Rule. When the California Toxics Rule is enacted all additional pollutants (if any)should be included. "Priority pollutants" sampling should be conducted for four consecutive days on a quarterly basis. This would provide more accurate data to determine compliance with loading for four day averaging criteria. Should any pollutant be found to exceed a water quality standard, the Discharger should be required to re-sample within 30 days for that pollutant and report the results DeltaKeeper,Tentative NPDES Permit,Lodi, 17 December 1999,Page 14.