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is still nitrifying 70%. The extra nitrification is causing the chlorine demand to increase and the related increases in coliform concentration in the effluent. The settleable matter concentration at the time of the inspection was 0.1 ml/1 . The permit limit is 0.2 ml/1 . This example of the plant upset being caused by an industrial discharger reinforces the necessity for an adequate pretreatment program. A pretreatment program is being developed for the City of Manteca by James Montgomery Engineers. 4. Currently the plant is discharging to the irrigation fields since the settleable matter and coliform concentrations exceed the permit limits. Normal discharge at this time of the year is to the San Joaquin River as there is no demand for the water at the irrigation locations. 5. We discussed the proposed plant expansion and related permit renewal with Mr. Shannon. In general , staff informed him that there are several items that will need to be developed prior to completing the draft requirements and/or will be required to be submitted in the permit. Those items are as follows: a. The renewed permit is requested to include an increase in allowed discharge to 6.95 mgd. The potential impact from the increased discharge to the San Joaquin River has not been determined. A stream impact study will be necessary prior to completion of the draft permit. This study should focus on dissolved oxygen concentrations, BOD in the discharge and river, and ammonia toxicity of the discharge to the aquatic species in the river. The analysis should be made for the worst case instances. For example, during low flow periods. b. The current permit allows for disposal requires that the irrigation fields be used to their maximum. Prior to start-up of the plant expansion, a technical report will be required that details the rates of wastewater application to the land, related crop requirements, nutrient requirements, BOD removal capacity, heavy metal accumulation rates, and application and runoff control techniques. C. The current permit allows for disposal of sludge as approved by the Executive Officer. Current practice is to use the sludge as a fertilizer on the irrigation fields. A study will need to be performed as to the application of the sludge at agronomic rates. Exceedances of agronomic rates would make the irrigation fields land disposal units that would be regulated under Chapter 15. d. A ground water monitor system is presently monitored. The ground water elevations will be required to be measured in the new permit to allow a determination of ground water flow directions and possible impacts from the treatment plant disposal practices. e. An effluent toxicity monitoring program will be required under the renewed permit. 6. Mr. Shannon explained that a portion of the plant capacity is dedicated to the City of Lathrop. A portion of the expansion is also dedicated to Lathrop. The flow from Lathrop enters the treatment plant after the bar screens. Mr. Shannon would like to see flow equalization basins provided in the expansion. This would help the plant run more efficiently and would allow a uniform blending of the Lathrop and Manteca flows.