Status Report on Watermaster’s Water Quality Management Activities May 20, 2003

Watermaster’s Activities to Characterize Water Quality through OBMP Watermaster initiated comprehensive water quality monitoring program: – Samples 200 to 300 wells annually in southern Chino Basin; 205(j) Groundwater Quality Study; Hydraulic Control Monitoring Program – Obtains water quality data for non-ag pumpers from the pumpers, DHS and others – Obtains reports and data from RWQCB, DHS, DTSC, Counties and others

Watermaster’s Activities to Characterize Water Quality through OBMP Maintains a comprehensive data base Geologic data from wells Groundwater level and quality Migrating from MS Access-based to EQUIS SQL- based system Has developed a comprehensive geographical information system for characterizing groundwater conditions in the Chino Basin

Watermaster’s 2002/2003 Monitoring Program General minerals/general physical Perchlorate 1,2,3-Trichloropropane Wells within or near VOC plumes Following analytes where not previously sampled in 1999/2000: – hexavalent chromium – Si, Sr, Ba – coliforms

Watermaster’s Recommendation for On- Going Monitoring Conclusion/recommendation of the 205(j) Final Technical Memorandum: – Continued monitoring of water levels and water quality influent to the desalter well fields is critical to optimizing the performance of these treatment facilities. – Water levels should be measured at least annually. – All private wells should be sampled for general mineral and general physical parameters at least once every three years. – Sampled for other contaminants (volatile organic chemicals [VOCs], perchlorate, etc.) at least once every six years.