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SOIL SAMPLING Soil samples are collected using a 2-inch-diameter by 18- or 24-inch-long modified California split-spoon sampler containing three or four 6-inch-long brass or stainless steel liners. The sampler and liners are scrubbed in potable water and Alconox or equivalent detergent and rinsed with potable — water after use at each sampling interval. At each sample depth, the sampler is driven 18 or 24 inches ahead of the augers into undisturbed soil. When the sampler is retrieved,either the lowermost or the middle sample liner is removed and the ends of the tube are covered with Teflon tape and sealed with plastic caps. The soil-filled liner is labeled with the borehole number, sample depth, site location, date, and time. The samples are placed in zip-lock bags and stored in a cooler containing ice. _ Soil from one of the liners is removed and placed in a sealed plastic bag. The soil is scanned with an OVA equipped with a flame ionization detector (FID) or photoionization detector(PID), and the readings are noted on the soil boring logs. The soil from the remaining liner(s) is examined and classified according to the Unified Soil Classification System. Soil samples are delivered, under chain of custody, to a laboratory certified by the California .. Department of Health Services (DHS) for analyses. INJECTION POINT WELL INSTALLATION The boreholes completed as injection point wells are typically constructed by installing two nested stainless steel injection points(one point for ozone and one point for hydrogen peroxide)through the inner opening of the auger. The ozone injection well point is completed with a 1-to 3-foot length of 3/4-inch-diameter well screen/diffuser at the end of the stainless steel casing. The hydrogen peroxide injection well point is completed with a 1-foot section of%2-inch-diameter stainless steel well screen. The top of the ozone diffuser is 5 feet below the base of the hydrogen peroxide screen. The ozone diffuser is installed at the bottom of the nested injection well boring. A filter pack of clean sand of appropriate size is placed in the annular space from 1 foot below to 2 feet above the ozone diffuser. The sand is placed through the inner opening of the augers as they are slowly lifted. A bentonite seal (approximately 2 feet of bentonite pellets hydrated with water) is placed above the sand pack surrounding the ozone diffuser to prevent short-circuiting. Again a filter pack of clean sand of appropriate size is placed from 1 foot below the hydrogen peroxide well screen and to a depth of 2 feet above the top of the screen. A transitional seal is completed above the sand pack by adding 2 feet of bentonite pellets and hydrating them with water. A surface seal is then created by placing neat cement grout containing less than 5 percent bentonite from the top of the bentonite seal to just below the ground surface. The injection point well is finished at the surface with a slightly raised,traffic-rated,watertight steel traffic box set in concrete. The traffic box is secured with bolts and the casing is further secured with a locking well cap. G�SHAREUWG bgy�cMurtstProto U-bjectbn PomtWell 1wallanon d c 2