SITE INFORMATION AND CORRESPONDENCE

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Mr. Robert Brod 0 - 2 - 0 11 July 2012 Of the 19 floor samples, 4 contained nitrogen concentrations that were between 123 mg/kg and 163 mg/kg, one contained 425 mg/kg, and one contained 537 mg/kg. In these excavations with elevated nitrogen concentrations, the soil was saturated with groundwater and additional excavation was not required by Central Valley Water Board staff. In a 2006 soil investigation, John Deere found dieldrin and DDT in sample boring SB-14, near the boundary between the northern and southern property boundaries. Although this area was not included in the excavation, the DDT concentration of 117 ug/kg is below the California Human Health Screening Level (CHHSL) of 1,600 ug/kg for residential land uses, and the dieldrin concentration of 62 ug/kg is below the CHHSL of 130 ug/kg for industrial land uses. In a letter dated 31 January 2007, Central Valley Water Board staff determined that these compounds were not constituents of concern at this site. Therefore, Central Valley Water Board staff concur with John Deere that soil containing elevated concentrations of constituents of concern has been removed to the maximum extent practicable. Groundwater Monitoring Three monitoring wells remain at the site. Monitoring wells MW-2 and MW-4 are on the northern property, and MW-3 is on the southern property. John Deere should sample these remaining monitoring wells at least semi-annually. When John Deere can demonstrate that concentrations of constituents of concern in groundwater are below the water quality objectives, or exhibit a declining trend that suggests that water quality objectives could be met in a reasonable amount of time, then John Deere may propose that the site be closed. If Central Valley Water Board staff concur, then it will request that John Deere provide a draft fact sheet notifying the public that the Central Valley Water Board is considering the site for closure. This fact sheet will provide a 30-day public review period. At the close of the public review period, Central Valley Water Board staff will consider the comments, and make a recommendation to the Executive Officer. If the Executive Officer issues a Conditional No Further Action letter, then John Deere must destroy the monitoring wells to receive the final closure letter. Conclusion John Deere Landscapes has completed soil remediation at the former Lesco facility. When groundwater monitoring demonstrates that water quality objectives have been met or will be met in a reasonable time, it may request that the Central Valley Water Board consider the site for closure. Central Valley Water Board staff appreciate the magnitude and the thoroughness of the excavation and the accompanying report. If you have any questions, you may contact me by telephone (916)) 464-4680 or by email at aterrell(a)waterboards ca oov. AMY'TERRELL Private Sites Cleanup Unit cc: Mr. Harlin Knoll, San Joaquin County Environmental Health Dept., Stockton Mr. Matt Scheeline, ERM-West, Inc., Sacramento Mr. Jeff Kaspar, Deputy Port Director, Port of Stockton, Stockton Ms. J. Devon Brown, Carmichael Ms. Carolyn Sanguinetti, Stockton Mr. John Sulpizio, West Sacramento