Laserfiche WebLink
r s <br /> Second-Quarter 1992 Groundwater Monitoring Report <br />• Tri-Valley Growers, 'Thornton,California <br /> July 8, 1992 <br /> W2102 <br /> Groundwater samples were collected from monitoring wells MW1 and MW6 on June 8, 1992 <br /> after stabilization of pH, electrical conductivity (EC) and temperature The monitoring wells <br /> were purged using dedicated submersible pumps Well purge logs are included in Attachment <br /> 1 Samples were analyzed for benzene, toluene, ethylbenzene, xylenes (BTEX), and total <br /> petroleum hydrocarbons as gasoline (TPHG), by EPA methods 8020 and modified 8015, <br /> respectively <br /> i <br /> No dissolved gasoline hydrocarbon constituents were reported above detection limits in <br /> monitoring wells MW1 or MW6. <br /> Influent and effluent samples from the pumping well (MW4) were <br /> analyzed for BTEX and <br /> TPHG during the June 8 sampling event Analytical results indicate an increase in TPHG and <br /> BTEX levels in the influent sample collected during this sampling round Analytical results <br /> indicated no break-through in either carbon filter 1 (TVGT EFF1C) or carbon filter 2 (TVGT <br /> EFF2C) during this sampling round Influent BTEX and TPHG concentrations over time are <br /> plotted on Figures 5 and 6. <br /> Laboratory analyses were performed by RESNA Environmental Laboratory (DHS certification <br /> #1211) The analytical results are summarized in Table 2; the laboratory reports and chain-of- <br /> custody documentation are presented in Attachment 2 <br /> RESNA personnel will continue with the quarterly monitoring program which will include a <br /> report detailing system performance. We will continue to monitor system performance and <br /> adjust pumping rates as necessary <br /> i <br /> • QM061992 SAY 2 <br />