SITE INFORMATION AND CORRESPONDENCE

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I WATER QUALITY OBSERVATIONS 1) All wells: Cl > Na indicating possible cationic'exchange, which would occur with a brine. Note that this includes the background well(102 S. Wilson Way). This appears to be a regional characteristic as a result of impact'by gasfield brines, deltaic/seawater encroachment and agribusiness discharge. 2) All wells:,proportion of Mg relative to Ca + Mg is greater than 40%, possibly indicating a seawater-like component of contribution;(encroaching deltaic water, connate waters from gas wells). 3) All wells including the background well have similar relative proportions of cations in decreasing order: Ca Mg Na + K 4) Wells MW7 and MW8 (in the former picklingoperations area) and the background well (located approximately 2000 feet west of the property) have similar relative proportions of anions, in decreasing order: HCO3 Cl SO4 J 5) Wells MW6 and MW9 (most distant onsite wells from former pickling operations) have similar relative proportions of anions, which are in a different decreasing order of importance: Cl RR HCO3 1 SO4 i 6 Absolute ionic concentrations in all wells are e'nerall similar with the exception of g � Y P chloride, which is somewhat elevated in MW6 and MW9. These two wells are not located in the area of former pickling operations. No clear trend of increasing chloride concentrations is evident in either of these wells. ` Conclusions are that shallow groundwater exhibits high background levels of objectionable analytes including TDS and chlorides. These background concentrations are a result of encroaching deltaic waters impacted by leaching of saline soils as well as regional impact from improperly abandonend gas wells and agribusiness operations in general. Impact from site operations is deminimis. I gromdze\teichert\sitehist 4 j �E