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Soil Suitability&Nitrate Loading Study Page 6 <br /> Proposed Oak Farm Vineyards Expansion,Lodi CA <br /> Project No. 670AC <br /> June 17,2013 <br /> 4.0 GROUNDWATER RESOURCES <br /> 4.1 Depth and Flow of Groundwater <br /> According to the maps contained in the San Joaquin County Flood Control and Water <br /> Conservation District report entitled "Spring 2003 Groundwater Report", (Appendix B) the <br /> depth to first groundwater in this area lies at a depth of about 15 feet below ground level <br /> (+10 Ft above MSL)and flows toward the northeast, however a geotechnical boring (Section <br /> 5.1) reached 24 feet without encountering groundwater. The actual depth to water is <br /> probably about 35 feet. The direction of flow may fluctuate, but is expected to be generally <br /> northwest. <br /> 4.2 Known and Potential Groundwater Contamination <br /> There are many possible sources of groundwater contamination including leaking storage <br /> tanks, surface releases of hazardous materials, over-use of agricultural chemicals, leakage <br /> from dairy lagoons, and septic sewage seepage. A detailed investigation of potential <br /> groundwater contamination was beyond the scope of this investigation however, the State <br /> Water Board's "GeoTracker" website httn:/rseotracker.swrcb.ca.govi was searched to help <br /> identify possible sources of nearby groundwater contamination. No such sites were <br /> identified within one mile of the site. No nearby dairy lagoons or other common potential <br /> sources of contamination were noted in the air photo either. <br /> Nitrate from waste disposal must be considered as possible sources of groundwater <br /> contamination at this site. In this case, excluding the existing on-site systems, two <br /> apparently up-gradient residential septic systems lie within t/4 mile. These systems are not <br /> believed likely to represent a significant detriment to groundwater quality under the site. <br /> 4.3 Water Well Sampling and Analysis <br /> One water on-site water well is expected to supply the new wine production and tasting room <br /> facility as well as the existing special events facility. <br /> Geo-Phase Environmental, Inc. sampled the well(on April 15, 2013 The well sample was <br /> collected from a spigot just downstream of the pump.near the wellhead. The water had been <br /> running for some time prior to collecting the sample, thus helping to assure that the sample <br /> was fresh and representative of groundwater conditions. The water was collected directly <br /> into I-liter amber glass jars and 40-ml VOA phials. The sample was immediately seated, <br /> labeled and place in a cooler chilled to 4 degrees C. The sample was then transported to <br /> Argon laboratories, a State certified analytical laboratory in Ceres, CA under chain-of- <br /> custody protocol. The-chain-of-custody and laboratory data sheets are attached(as Appendix <br /> D. The sample was tested for the presence of the agricultural fumigant 1,2-dibromo-3- <br /> chloropropane (DPL and for total nitrate. The water well sample did not contain <br /> detectable lev of DBgF, This compares with an EPA maxi ble drinking water <br /> concentration o fTmg/L. The total nitrate concentration 26 m=mg/L <br /> million) <br /> as compared to the maximum allowable drinking water concen <br /> 2937 Veaeman Ave.,413240 Geo-Phase Emir»nmcntal Inc. Phone: (209)569-0293 <br /> Modesto,CA 95356 Fax: (209)569-0295 <br />