WORK PLANS - Laserfiche WebLink

Home Browse Search

GEOSYNTEC CONSULTANTS ' Ms. Amy Terrell 31 January 2005 Page 5 ammonia samples are in the vicinity of or directly downgradient from the former liquid ' tank farm. However, as reported previously, a significant quantity of soil was excavated from the former tank farm area in 1991/1992 during construction of the new tank farm. This suggests that if there are any soil sources for these constituents, they ' are likely to be downgradient of the former tank farm. Higher nitrate nitrogen concentrations are found in the same areas. High nitrate concentrations were also found immediately east of the vapam tank, where high levels of ammonia were detected in soil. ' WORK PLAN ' Proposed Sampling Locations Based on the review of historical soil and groundwater data, it appears that soil ' source areas, if any, would likely be located in the following areas: 1) the equipment yard in the southwest part of the site; 2) to the north of the former liquid tank farm; 3) east of the wash pad; and, 4) east and northeast of the vapam tank. The source area ' investigation will be focused in these areas. Proposed sampling locations are shown in Figure 6. A total of 16 soil borings are proposed, including: ' • Five borings, SSI-1 through SSI-5, in the southwest yard area; • Four borings, SSI-6 through SSI-10, north-northeast of the former liquid tank ' farm; • Three borings, SSI-11 through SSI-13, east of the wash pad; and Four borings, SSI-14 through SSI-17, east and northeast of the vapam tank. Soil samples will be collected at three depth intervals at each sample location. Depth to groundwater historically has ranged from about 10.5 to 19.5 ft below ground ' surface (bgs). All samples will be collected above the water table. At each location, samples will be collected in the unsaturated soil at approximate depths of one, five, and ' ten feet bgs. P:\PRJ2003REM\Wilbur-Ellis\Wr0250(JTF)\STOCKTON\S 1.X\2005 Source Area Invest\SSI Work Plan.doc RECYCLED AND RECYCLABLE r