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s 17 February 2012 AGE-NC Project No. 03-1100 Page 4 of 4 vacuum chamber.A vacuum pump attached to a purge port of the vacuum chamber is then used to purge the exposed soil column, through the sampling tubing and inlet port, until approximately three volumes of soil vapor or ambient air is evacuated through the sampling system. The vacuu~m chamber is then sealed and the vacuum pump is attached to a vacuum outlet port of the chamber. When vacuum is applied to the chamber, a negative pressure is created around the Tedlar bag, which inflates, allowing the soil-vapor sample to enter directly into the bag via the in port. When the sample is collected, the negative pressure in the chamber is reduced and the sample bag is sealed, labeled, log on a chain- of-custody form, and place into a dry cooler (room..temperature). Subsequently, all of the collected soil-vapor samples will be delivered to a State-certified laboratory for analysis of the chemical constituents listed in Section 2.2. After sample collection, soil-vapor from the polyethylene tubing will be monitored for the presence of volatile organics using a photo-ionization detector (PID) pre-calibrated to isobutylene. Additionally, AGE proposes to utilize 70% isopropyl alcohol (rubbing alcohol) as a leak detection tracer compound to ensure that a reliable soil-vapor sample is collected from each soil boring with no ambient air breakthrough down the probe rods. AGE will apply an appropriate amount of rubbing alcohol(approximately.8 ounces)to adequately wet a cotton towel;the wetted towel will b6lcompletely wrapped around the base of the probe rod where { it contacts the surface and the bentonite seal. Thereafter, a soil-vapor sample will be$Gho(.)d collected. Isopropyl alcohol analysis will verify the validity of each sample. 3.3. EQUIPMENT DECONTAMINATION All sampling tools used forsample collection will be thoroughly rinsed with clean water after being washed with a solution of Alconox. All down-hole drilling and sampling equipment will be pressure washed prior to starting the boring. All rinseate generated during drilling activities will be containerized in properly labeled DOT-approved 55-gallon drums, and was stored on-site in an area lacking public access. 3.4. BORING ABANDONMENT Following collection of soil-vapor samples, each borehole will be filled to the ground surface with a Portland type II cement grout. The grout mixture will consist of Type I/II portland neat cement and not more than 6 gallons of water per 94-pound sack of cement. The grout will be poured into the boring. The EHD will be given the opportunity to inspect the grout mix prior to backfilling activities. Advanced GcoEnvironmental,Inc.