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i, 45-80' sand layer is bounded to the North by CPT#5. The 45-80' sand layer is bounded to the Nortb/East (bearing of gradient) by MW-11. To the East, MW-10 continues to show hydrocarbon contamination and the 45-80' sand layer is unbounded to the East. The clays and silts below 80' are bounded on the West and on the South by the bearing of the gradient and on the North by CPT-3 and on the East by MW-8D. The plume definition of the clays and silts below 80' is completed. Status of Investigation and Interim Remediation In the course of investigating the limits of the plume an additional tank was found across Lafayette Street in the City of Stockton Right-of-Way. The agencies administering the City and State right-of-way would not allow additional investigation on land in their control for fear of being exposed to clean up liabilities. Cal-Trans eventually allowed one time push bore sample collection with CPT#3,4,5 and 6, but would not allow a permanent monitoring well. The investigation continued on lands held by Olivarez, but the zero line has not obtained to the East and the N1E. Since additional off site investigation was not allowed and the zero line could not be detern-iined, groundwater extraction well EW-1 was installed to pull water back through the original path of least resistant with the intention of making the wells that were installed the zero line. EW-1 is targeting the 45-80' sand layer were the mass of contamination is concentrated. The pump and treatment system ran for 16 months from 10111107 to 217109 until financial resources were exhausted. The financial resources were consumed by accelerated system testing and carbon filter breakthrough due to the system bringing in an unknown plume of TBA (tert- Butyl Alcohol). Carbon filters are not effective on TBA and the discharge permit has zero tolerance for fuel additives like TBA. Prior to the start of the pump and treat system the 0-80' screened monitoring wells were non-detect for TBA for four years in a row with only one hit in MW-1 and MW-3R. TBA was not expected to be a problem. The policies of the agencies administering the City and State right-of-way have changed since 2000 and have allowed installation of MW-10 and i l in 2010. MW-10 shows persistent TBA contamination and has revealed the source of the TBA plume. Foothill Engineering has designed a 2,500gal linearly progressive, submerged, fixed film, aerobic bio-reactor intended to treat the break through concentrations from the carbon filters, The bio-reactor is sized with the intention to handle all the direct raw water discharge from EW- 1. Only a pilot test will reveal the site specific capacity. Activated carbon is the only bullet proof system. A tertiary and safety net carbon filter will always be required. 1). Mass Remaining Mass remaining is best estimated with full delineation of the plume and well data from a single point in time. This site has not identified a fixed area yet. MW-10 and MW-11 has enlarged the