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Musco Family Olive Company - 16 - 12 December 2006 gradient of 0.02 ft/ft, perpendicular to the shallow zone. Time Series plots for TDS and general minerals are presented in Appendix E. Well MW18 Well MW-18 was installed in June 2005 and has a limited data set for comparison. Well MW-18 is considered the up-gradient well and is located near the southeastern corner of Pond B, installed to a depth of approximately 100 feet bgs. When reviewing the analytical data for the COCs it is not readily apparent if groundwater in the vicinity of well MW-18 has been impacted by process wastewater. Chloride and sodium concentrations are below the interim standards yet are elevated above the Regional Well concentrations. TDS concentrations appear consistent but when compared to the Regional Well, are elevated by approximately 450 mg/L. Although bicarbonate concentrations in the deep wells are low compared to the shallow wells, well MW-18 has the highest bicarbonate concentration among the deep wells (238 mg/L to 390 mg1L) used to monitor water quality. The average bicarbonate concentration in well MW-18 is .530 mg/L, as shown in Table 8, and is 250 mg/L higher than the bicarbonate concentration in the Regional Well. Well MW-18 is located adjacent to the Title 27 surface impoundments and the drainage swale that has been impacted by spray irrigation and - wastewater leaking from the Reservoir and 1-million gallon pond. Groundwater in the deep zone flows across MW-18 from the drainage swale toward the northwest. Other deep wells do not exist to monitor water quality up-gradient (southeast) of the deep wells. However, the Regional Well is located southeast and when the CDCs are compared it appears the deep water bearing zone in the vicinity of well MW-18 has been impacted by wastewater. Well MW-12 Well MW-12 is near the northeastern corner of Pond B and is installed in the same water- bearing zone as well MW-18. TDS and chloride concentrations are above the interim standards and these concentrations including sodium are above the Regional Well concentrations. TDS and chloride exhibit slight increasing trends over time. Sulfate also appears to be.elevated in well MW-12 compared to deep wells MW-4, MW-8, and the Regional Well. Well MW-12 is cross-gradient to deep groundwater flow according to Potentiometric maps provided by Musco. Based on a review of well logs and DTW recorded in wells MW-12 and MW-18, it is apparent the water-bearing zones observed in these wells are connected and are likely communicating across the site. Higher TDS and sulfate values seen in MW-12 could indicate another source is affecting groundwater in this area. Concentrations of bicarbonate detected are above the Regional Well and have varied in concentration over time. Well MW-4 and MW-8 Well MW-4 is located adjacent to the 1-million gallon pond and monitors the deep groundwater in this area. Well MW-8 is north of MW-4. Both wells are located in non-spray application areas and have relatively good deep groundwater quality. Review of the water chemistry from these wells indicates they are sulfate dominant with both having near the same sulfate signature. The chloride, sodium, and bicarbonate concentrations in both wells appear similar