CORRESPONDENCE_1978-2017 - Laserfiche WebLink

Home Browse Search

30 March 2009 AGE -NC Project No. 07-1569 Page 2 of 4 area formerly used for glass disposal (Figure 2). Borings B 1 and B2 were advanced in the northern part of the former glass disposal area. Borings B3 and B4 were advanced on the floor of an excavation area, adjacent to the former glass disposal area. The excavation area was surrounded on all sides by a soil embankment. The embankment was approximately 5 feet wide at the base, and 2 feet wide at the peak, the total height of the embankment, from excavation floor to peak was approximately 10 feet. The floor of the excavation area was approximately 8 feet below surface grade. The soil borings were advanced utilizing a van mounted Geoprobe 5400 direct -push probing unit equipped with 1.25 -inch probing rods. The Geoprobe advances soil probe borings using a hydraulic hammer to drive soil sampling tools to specified depths. Borings B 1 and B2 were advanced to a total depth of approximately 24 feet below surface grade (bsg), B3 and B4 were advanced to a total depth of approximately 26 feet bsg. Soil boring locations are illustrated on Figure 2. A grab ground water sample was collected from each boring using a four -foot length of temporary PVC screen. Grab ground water samples were collected at depths of approximately 22 feet bsg (B - 1W), 24 feet bsg (B -2W), and 26 feet bsg (B -3W and B -4W). A Geoprobe push -driven water sampling device was advanced two to three feet into the water bearing zone. Samples were collected using a Geoprobe water sampling assembly fitted with a new one-half inch 0.010 -inch slotted temporary well screen. Each ground water sample was extracted using inertial action by lowering Teflon tubing through the hollow center of the push rods into the screen section. A sufficient volume of sample was collected to fill three 40-m1 EPA -approved volatile organic analysis (VOA) vials, containing approximately lml hydrochloric acid (HCL) preservative and one 1 -liter amber glass container, without preservative. Ground water sample containers were labeled with soil boring designation, date, time, and samplers initials and then placed in a chilled container. SAMPLE ANALYSIS Grab ground water samples were transported under chain -of custody to Cal Tech Environmental Laboratories (CTEL), a California Department of Health Services -certified laboratory, and analyzed for the following: • Total petroleum hydrocarbons quantified as gasolene (TPH-g) and total petroleum hydrocarbons quantified as diesel (TPH-d), in accordance with EPA Method 8015M; and • Volatile organic compounds, including benzene, toluene, ethylbenzene, and xylenes (BTEX), Advanced GeoEnvironmental, Inc.