ARCHIVED REPORTS XR0007846 - Laserfiche WebLink

Home Browse Search

Ms Lori Duncan • Atigust 19, 1999 Page 2 of 3 lead The vertical extent of soil contamination in the vicinity of the former waste oil tank has been defined However, due to slow drilling progress attributed to very tight soil conditions, only three of the four proposed borings were completed and the full lateral extent of soil and groundwater contamination could not be determined The results of the investigation were presented to San Joaquin County Public Health Services, Environmental Health Division (PHS/EHD) in the Subs-►rface Investigation Summary Report (Ground Zero Analysis, May 20, 1999) By letter dated June 21, 1999 PHS/EHD commented on the report and directed the responsible party to submit a workplan for additional investigation Analytical results of the initial investigation are presented in Tables 2 and 3 Soil boring locations are shown on Figure 2 ADDITIONAL SCOPE OF WORK To further define the extent of soil and groundwater contamination at the site, Ground Zero will supervise the drilling and sampling of five additional soil borings in the vicinity of the former UST The locations of proposed borings are shown on Figure 3 Fisch Environmental (C57- 683865) will advance the borings using a truck mounted Geoprobe 5400 direct push rig It is anticipated that the borings will be drilled to depths between 25 and 30 feet, the depth to first groundwater Soil samples will be collected at 10, 15, and 20 feet below ground surface(bgs) and at total depth for logging and possible analysis Samples will be collected using a 1-inch diameter core sampler lined with clear acetate sleeves The portion of the sample to be analyzed will be immediately capped and preserved in an iced cooler at a temperature of approximately 4° Centigrade One groundwater sample will also be collected from each boring to further define the lateral extent of groundwater contamination Groundwater samples will be collected by driving the sampler to the desired depth and exposing the screen to the formation The groundwater sample will be collected using a length of 0 17 inner diameter Teflon tubing equipped with a stainless steel bottom check valve The tubing will be inserted into the probe rods and pushed to the bottom of the sampler to the desired depth The groundwater sample will be brought to the surface by gripping the top of the tubing and rapidly moving the tubing up and down creating a positive displacement effect, thereby forcing the water sample to the surface where it will be collected directly into the sample containers Due to the limited drilling access inside the building, no groundwater monitoring wells are proposed at this time Monitoring wells will be installed after the plume has been essentially defined through collection of discrete groundwater samples using the direct push drilling method, which will enable optimal placement of wells at a later date No cuttings requiring disposal will be produced using the direct push drilling method Borings will be backfilled to the ground surface with neat cement grout Up to two soil samples and one groundwater sample per boring will be submitted for analysis of total petroleum hydrocarbons as diesel (TPHD) and gasoline (TPHG) using EPA method 8015 modified, oil and grease using method 418 1 or 5520, benzene, toluene, ethylbenzene, xylenes f (BTEX) using EPA method 8020, volatile organic compounds (VOCs) including gasoline oxygenate additives using EPA method 8260, and total lead using ICP 6010 Selection of soil d,ktalgroundzelglbblyd\WPaddndm doe