ARCHIVED REPORTS_XR0012756 - Laserfiche WebLink

Home Browse Search

- r f Ms. Mary Meays San Joaquin Coanty Re: Tri-Valley Growers, Thornton, CA RESNA WATERWORK CORP. August 9, -� INDUSTRIES Page 2 rOF" tft� CE No dissolved petroleum hydrocarbon constituents w,-ce detected above AUG 15 1991 detection limits in monitoring wells Mwl, MW2, MW3, MW5 or MW6. in MWl ove limits Oil and grease was not d Lines er total cted bpetroleum hydrocarbons in the ENVIRONMENTAL HEALTH (Table 3). The zero PERMIIT/SERVICES groundwater is plots ed in Figure 7. Influent and effluent samples from the pumping well (MW4) were also August 9, 1991 21 and on June 19. The influent analyzed for BTEX and TPHG on May cease (TOG). sample was also analyzed for total oil and g TEX levels and a slight rise Analytical results indicate Intdrop i sBcol.lected. No break-through Ms. Mary Meays in TPHG levels in -the San Joaquin County Public Health Services from carbon filter 1 (EFFC1) or 2 (EFFC2) occurred during the Environmental Health Division sampling rounds. Sampling wus done using dedicated pneumatic pumps each well. P.O. Box 2009 in eApplied An Laboratory Stockton, CA 95201 Laboratory analyses were per`ormed by Pp marized in Table 3 and the (DHS cert. `#1211). The ain- of- custody docume tation are presented laboratory repors are sum ts and ch Re: 1991 Second Quarter Report/Remediation System Start-up . in Attachment 2. Activities, Tri-Valley Growers, 26200 Nowell Road, # '� start-ug reflect a depression Thornton, CA ; i Gradient maps created after system created by pumping of the groundwater in monitoring well Mnd ' A cone of depression around the pumping well and Dear Mary: (Figures 4-6). trated in are the area of influenceresults are ssumma zed inhTable 2. maps. The groundwater monitoring This letter report updates the activities at Tri-Valley Growers' ? at a throughput of between 1.8 and 2 Thornton plant (Figure l) during the second quarter of 1991, i The system continues to pump tura exhibited in Activities during the quarter included monitoring of groundwater, is greater than the liters per minute. The zone o£ influence (capture) sampling for dissolved hydrocarbons from the five monitoring wells test data (presented in gradient data and presented on the gradient map tura on site, start-up an:'] operation of the remediation system, analysis theoretical value estimated from 1991)- correspondencePThe zone of cap of samples from the treatment system influent (well MW4) and carbonrate from the pumping rate used in filter effluent {Figure 2}. Remediation, system operation began on dated January 7, May 13, 1991. reflects the increase in pumping mWl and the capture zone calculations. bYonitoring w resp lMW of hthe are downgradient 120 feet and 127 feet, yl Groundwater monitoring was conducted in April and May (before and pumping well exhibit a clear influence from pumping- pumping after system start--up), In comparison to previous groundwater P 9 'torso program terl m ons. g elevation data water table levels rose approximately .90 feet in with the quarterly performance. April and dropped WaterWork staff will continue w� system p pped from .50 to 1.5 feet in May (Table 1). The which will include a report detailing groundwater elevation contour map for April (Figure 3) shows the monitoring will include analysis for BTEX and TPHG from direction of groundwater flow is in a southwesterly direction at a Quarterly g magnitude of 0.006 ft ft. all wells and remediation system influent and effluent, aninue to d will g ft/ MWl- Weor ft. include analysis fncont ceTandfadjustlpumping rateill as necessary. Groundwa';er samples were collected from five monitoring wells an monitor system performs June 13 1 I ....... 99 ..._af.ter.__stabilization_of___pH,.._.electrical-conductivity ................ (EC) and temperature (well purge logs, Attachment 1). Samples were analyzed for benzene, toluene, ethylbenzene, xylenes (STEX), and TVGLR731.Up total petroleum hydrocarbons as gasoline (TPHG), by EPA methods 8020/8015. in addition, monitoring well MW1 was sampled for total oil and grease (TOG) by EPA method 5520 C&F. TVGLA7v1.vr 3 1710 MAIN STREET . ESCALON,CA 95320 . (209)836-3507 2350-A WALSH AVENUE • SANTA CLARA,CA 95051 • (408)496-1249