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California Renal Water Quality CAL Board Central Valley Region z Robert Schneider Chair Terry Tamminen Sacramento Main Office (r Arno`d-Schwarzenegger Secretary for Internet Address: http://www.smeb.ca.gov/rwgcb5 Governor Environmental 11020 Sun Center Drive#200 Rancho Cordova,CA 95670-6114 Protection Phone(916)464-3291 Fax(916)464-4797 SEP 2 8 2004 ENVIRONNIENI hLALM PERMIT/SER;!I-ES 27 September 2004 Mr. Robert Mihalovich ChevronTexaco Environmental Management Company 6001 Bollinger Canyon Road, Rm K2072 San Ramon, CA, 94583-2324 TRANSMITTAL OF DRAFT MONITORING AND REPORTING PROGRAM, KOPPEL STOCKTON TERMINAL, 2025 W. HAZEL TONAVE, STOCKTON, SAN JOA QUIN COUNTY The Koppel Stockton Terminal (Koppel) has been remediating nitrate and ammonium pollution in soil and groundwater with phytoremediation since 2000. We reviewed the progress of the treatment program as documented in the following reports prepared by Koppel's consultant, CH2MHil1: • April 2003 2002 Annual Groundwater Monitoring Report • October 2003 2003 Semi-Annual Groundwater Monitoring Report • April 2004 Three-Year Evaluation and 2003 Annual Groundwater Monitoring Report (Evaluation Report) Koppel planted a one-acre phytoremediation test plot in 1998, and planted trees over 80% of the remaining 12-acre site in 2000. The areas that are not planted accommodate the warehouse and vehicle movements accessing the warehouse and track scale. The Evaluation Report states that many of the .poplar trees originally planted have succumbed to damage inflicted by the Western Poplar Clearwing Moth. Koppel has replaced these trees with a variety of fast-growing trees that are more resistant to the clearwing moth. The original test grove suffered the most damage, and this plot was completely replanted in 2003. The data from groundwater monitoring wells in the test plot show a steady decline in nitrogen concentrations in groundwater beginning the spring after the test plot was planted and continuing until about fall 2002, when concentrations began increasing. The increase corresponds to the period of declining tree health. The nitrate concentrations are expected to again decline when the replacement trees get established. With one exception, all other wells in or downgradient of the planting areas show continuing declines in nitrogen concentrations. The exception is KP-3,which increased from about 20 mg/1 to about 400 mg/1 in 2002. As with the original test grove, the poplars in the western portion of the plot containing KP-3 also suffered serious losses and the western portion was replanted in 2003. Groundwater sampling events conducted in fall of 2003 and spring of 2004 show nitrogen again declining in KP-3. California Environmental Protection Agency �p*Recycled Paper