SITE INFORMATION AND CORRESPONDENCE_FILE 1

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J. R. Simplot, Lathrop -5- 1 August 2007 San Joaquin County installation. After our review of the Detection Monitoring Program, we have the following comments: 1) As I discussed over the telephone with you on 23 March 2007 and again on 25 May 2007, 1 generally concurred with J. R Simplot's proposal to install three new shallow monitoring wells (A, B and C) in the vicinity of the UN-32 tank. However, the Detection Monitoring Program stated, "...we will install two new monitoring wells, up- gradient from the point of release, and a background well." Based on your Attachment 1 showing the locations of the proposed monitoring wells and the generalized groundwater flow direction to the north-west, I believe that you meant to describe two of the monitoring wells (A and B) to be installed downgradient from the point of release. Please confirm the proposed locations and intentions for the monitoring wells in a specific well installation work plan. Please submit this Work Plan to the Regional Water Board by 12 September 2007. 2) Section 3.0 of the Detection Monitoring Program states "...samples show that there was some impact from a leak but it appears to be diminished to the point of not being a concern for further migration to ground water."This statement was not substantiated by the inclusion of data. Therefore, upon completion of the UN-32 tank assessment work, including the proposed installation of three monitoring wells, please include all of the assessment data to date, a discussion of the results, conclusions and recommendations from a properly licensed (professional) individual in the State of California (See Sections 6735, 7835 and 7835.1 of the California Business and Professions Code). Surface Release of Dilute Ammonia Sulfate Solution On 14 February 2007, you reported a surface spill of approximately 100,000 gallons of dilute ammonia sulfate solution to me by phone. The spill occurred as a result of a broken sight glass on the side of a process tank. Based on initial reports, approximately 90 to 95 percent of the spill was contained on-site and pumped into one of the on-site lined surface impoundments. Approximately 5,000 to 10,000 gallons of this solution was reported to have flowed off-site in an unlined ditch along Howland Road to the east of the facility. From this event, an unknown quantity of solution flowed under Howland Road through a culvert and discharged to surface soils located on the east side of Howland Road just before the Union Pacific Railroad's tracks. J. R. Simplot initiated immediate cleanup of the impacted soil material in front of their facility by excavating and blending that material that was determined to be suitable for use as filler material for their fertilizer. On 23 March 2007, J. R. Simplot submitted an email to the Regional Water Board staff that included preliminary assessment results and remedial work performed on the ammonia sulfate spill and proposed additional assessment work to further define the extent of soil impacts along both sides of Howland Road. A figure provided as an attachment with the email termed the area of impact as the "Mother Liquor Spill Location" (MLSL area). Regarding this correspondence, Regional Water Board staff has the following comments: 1) We appreciate J. R. Simplot's taking the initiate to clean up and investigate the ammonium sulfate spill in an expedited manner. However, in the future, we require that all cleanup and investigative activities be described in a work plan prepared by