WORK PLANS - Laserfiche WebLink

Home Browse Search

Mr. George Lockwood September 7, 2004 Page 4 City Responses to Regional Board Staff's Comments on Report Recommendations 1. Digital data recorders are recording groundwater elevations every 60 minutes. Comment: While it may be highly technical to view hourly or diurnal fluctuations of groundwater elevations, this much data seems to be overpowering and without much report evaluation and justification. The quarterly gradient and direction are not calculated as required by the Monitoring Report Program No. 5-00-031. City Response: One of the data issues raised in the October 2000 Groundwater Evaluation Report was the highly variable values for groundwater elevations and nitrate concentrations. One of the conclusions of that Report was that the close proximity of some of the monitoring wells to canals and ditches may be significantly influencing the data being collected. The increased frequency of data collection was intended to provide some confidence in the quarterly data collected as part of the City's permit requirements. This data has been helpful. It does not appear that changing conditions in the canals and ditches are significantly influencing the data being collected. The City has recently reduced the frequency of groundwater level data collection to twice daily. Future quarterly and annual reports are to address this topic and are to include a calculated flow gradient and a discussion of flow direction. 2. The City should implement changes to its effluent management practices to avoid nitrogen overloading. Comment: After concluding the facility has had no impact on groundwater, the report recommends a review and changes to operations. The recommendation to avoid nitrogen overloading should be standard practice. The report should consider Specific Conductivity, which is already monitored, and should consider adding Total Coliform Organisms to the effluent monitoring also. City Response: The intent of Conclusion 9 was to state that based on the nitrate information collected and evaluated, it appeared that City operations had not had a significant impact on downgradient water quality. It does appear that water quality beneath limited portions of City property has been impacted, but the data did not clearly demonstrate that the City has impacted the downgradient water quality. This issue will be discussed further later in this letter. The City agrees that avoiding nitrate overloading should be standard practice, and the City is continually refining its management efforts to improve its operations. See City Response to Board Staff's Comment 5. The City has evaluated the Specific Conductivity and Total Coliform Organisms data. Those evaluations will be discussed later in this letter. LLOCKWOOD NPDESPERMIT.DOC