SITE INFORMATION AND CORRESPONDENCE

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Ms. Jeanne Zolezzi April 12, 1996 Page 2 of 4 Conclusions The most significant conclusion drawn from the existing data is that the pickling operations conducted on the western portion of the subject parcel have not significantly impacted local groundwater quality and are not the source of the widespread poor quality groundwater in the area. As noted in Attachment I the property has been used for food processing since approximately 1977. Adjacent properties have been utilized for food processing for over 35 years. In terms of potential for impacts upon the underlying first groundwater the subject site is substantially less significant. This is due to the shorter operational duration, but also because the total volume of high TDS water stored/discharged on the Teichert property was significantly less at any given time (relative to adjacent sites), and there has been no discharge to subsurface drains or sewers on the subject site (unlike the adjacent London Produce property). Other properties in this general area of Stockton have also discharged waste water related to food processing which probably contributed to the poor shallow water quality. Finally, a large topographic depression is shown on the Stockton quad map in the area directly across (north) the railroad tracks from the subject site, which probably served to collect runoff from the many industrial operations (including the railroad) in the area. Infiltration from this natural collection area would be consistent with the widespread poor quality groundwater. Further supporting this conclusion are the results of sampling at the site which have shown well MW-6 (furthest well on the parcel from London Produce and outside of the former pickling operational area) to have the highest levels of TDS and chloride on the property. This is significant since the levels in wells MW-7 and MW-8 (within the former pickle tank area) have TDS/chloride levels and chemical 'signatures' very similar to the Roek well located approximately 2000 feet to the west. By contrast, well MW-9 located on the adjacent Teichert parcel to the east, which is over 300 feet from the area of food processing operations has a chemical 'signature' essentially the same as MW-6. These chemical signatures are derived from major ion analysis using the computer program WATEVAL and relate directly to the source of the constituents detected in the water samples (Attachment II). The WATEVAL analysis clearly shows a similar source relationship between wells MW-6 and MW-9 which is distinct from wells MW-7, MW-8 and the distant Roek well. It is significant that the two wells on the property furthest from the pickling operations have the highest chloride, and that unlike the other three wells chloride is the dominant anion. Similarly it is highly significant that the Roek well, located approximately 2000 feet regionally upgradient has an almost identical major ion chemistry as the two on-site wells located in the pickling operation area. This clearly indicates the water samples from wells MW-7 and MW-8 reflect the poor regional background quality of the shallow water bearing zone in the Stockton area.