Laserfiche WebLink
NOW <br /> and constructed in accordance with San Joaquin Local Health <br /> t District requirements. Drilling, will be conducted by <br /> Osterberg and Stewart under C57 license, using a hollow stem <br /> auger drill rig. The proposed well locations, presented on <br /> Figure 2, include one well adjacent to the leak point, one <br /> well..upgradient of the tank pit product•. lines,_ and. two.: veils <br /> down.. groundwater gradient from the underground tank :and <br /> product line locations: In addition, two soil borings (20 <br /> P!J foot maximum depth) all be drilled to assess the extent of <br /> f soil surface contamination near the leak point (Figure 2) . <br /> The wells will be constructed of two inch diameter F480 PVC <br /> well screen/casing and completed as shown on Figure 4. The <br /> !'R soil borings will be abandoned by filling with cement grout <br /> in accordance with County Regulations. <br /> A 2. Drill cuttings will be logged continuously for <br /> M characterization of contamination and soil type by Unified <br /> Soil Classification System. Descriptions of soils <br /> encountered and monitoring well construction details will be <br /> recorded on a boring/well log and Included within the <br /> assessment report. Cored soil samples will be collected <br /> above the water table at five foot intervals and below the <br /> �'. water table at select intervals for determination of soil <br /> type. Composite samples 'of the 10 and:'20 foot samples in <br /> the soil borings will be .tested. -Boll'samplaa from.10 and`- <br /> r 20 foot depths. will be'. t sted in the ' 'monitoring - <br /> :well-� boring . located. adjacent . :to the leak point:. The three <br /> perimeter borings/wells will have the �10 and 20 foot samples <br /> tested. Soil sampling will be conducted in accordance with <br /> Water Work's Soil Sampling Protocol. Laboratory analysis of <br /> soil samples will be conducted for benzene, toluene, ethyl <br /> benzene, xylenes (HTEK), and total petroleum hydrocarbons <br /> (TPH) by EPA method) 8015/8020. Sequoia Analytical, a state <br /> �s certified laboratory, will be used to perform the analyses. 5 <br /> All excavated soils will be placed on plastic sheeting, <br /> covered with same and remain on site until laboratory <br /> i results are received. Thereaster, a proposal for treatment ; <br /> r, or disposal of the excavated material will be prepared. <br /> r„ <br /> 3. The wellheads will be surveyed to a common datum and <br /> ' groundwater levels will be monitored to determine the site <br /> specific groundwater gradient. Free product thickness, if f... <br /> any, will be monitored using . an interface probe. The <br /> �,. monitoring will be conducted in accordance with WaterWork's <br /> Groundwater Monitoring Protocol (Appendix I). <br /> 1 i <br /> 4. Subsequent to installation, water samples will be <br /> " collected from the monitoring wells after purging a minimum t <br /> of four well volumes (casing and sandpack) • The purged <br /> 5 - <br /> water remain- on -site, 1n secured 55 gallon drums (DOT- 17-E) <br /> until laboratory results are received. A proposal for the <br /> treatment or disposal of the water produced during well <br /> development and sampling will be then be prepared. <br /> Collection and preservation of all water samples will be in 1 <br />