Laserfiche WebLink
F <br /> 3rd Quarter 1995, Quarterly Monitoring Report <br /> Former PureGroBrea Facility <br /> 1905 North Broadway Avenue,Stockton,California <br /> Sierra-Pacific Project No.94-055.04 <br /> I <br /> The unlined Stockton Diverting Canal, which is located about 500 feet northeast of the <br /> Broadway ag-chem site at its nearest point, is oriented N 62° W (Figure 2). A normal drawn <br /> to the center-line of the canal, which would correspond to the theoretical direction of surface- <br /> water infiltration and associated ground-water flow, is S.28° W. The predicted ground-water <br /> flow direction (S 28° W), based on the hypothetical effect of infiltration from the Stockton <br /> Diverting Canal, corresponds exactly with the calculated flow direction of S 28° W. <br /> The Stockton Diverting canal was still flowing at a modest flow rate in September 1995.. <br /> j Springtime flows were substantially greater, perhaps by a factor of 100. <br /> 4.0 CONCLUSIONS <br /> • Based on field observations, existing file data, and the latest analytical results, the following <br /> tentative conclusions have been reached: <br /> Ground water at the Broadway Avenue site has flowed generally west-southwest for the <br /> past two years. Variations in water levels and flow directions appear to reflect seasonal <br /> precipitation and significant ground-water recharge from the Stockton Diverting Canal. <br /> Ground water flow is now shifting to the west as infiltration from the Stockton Diverting <br />_._ canal diminishes. <br /> A.' 1,2-DCP has been detected in ground water samples taken from monitoring wells MW-1, <br /> MW-2, MW-5, and MW-6,with highest concentrations in MW-2 and MW-5. The source <br /> of shallow 1,2-DCP concentrations appears to be the north (Brea)• evaporation pond <br /> area. <br /> -A Nitrogen appears to be present in ground water as ammonium (NH4) and nitrate (NO3). <br /> The regional background appears to exceed 18 mg/8 nitrates. Nitrates-appear to be <br /> entering the shallow ground water from various locations,.including off-site sources. <br /> A No petroleum hydrocarbons or volatile halogenated hydrocarbons (eg. 1,2-DCP) were <br /> detected in ground-water samples from MW-ll... The ag-chem plume does not extend <br /> south to MW-11. <br /> Sierra-Pati,fic Groundwater Consultants 5 <br />