Based on gas vent screening work conducted in late 2001 and early 2002, it appears that while none of the vents are very active, the most active ones are located along the west side of the cap. Specifically, gas vents GV-1, GV-4 and GV-9 had the greatest frequency of occurrence of methane. These were also the locations having the highest monitoring results (% of the lower explosive limit; LEL) over the course of the monitoring work to date. The results of all gas vent monitoring work done so far were summarized in the January 18, 2002 Summary Report of Sampling of the Neal's Landfill Gas Vent System.

We propose to install four air monitors on the top of the cap, locating each of these approximately 30-feet from one of the above gas vents. These monitors will be placed in a manner that addresses all possible wind directions. The attached site plan shows the proposed locations for the four samplers.

All four air samplers will be powered using portable generators which will be located as far from the samplers as practical.

Samples will be collected using EPA Method T-04A. This method employs a high-volume sampler and collects the sample using both a polyurethane foam (PUF) cartridge and a glass fiber prefilter. Each sample will begin at about noon on a Monday, and the final sample will be complete at approximately noon on Friday. We would like the sampling to be conducted this summer. It will be scheduled with the parties as soon as we have received concurrence with a monitoring plan.

All sixteen samples, plus two blanks, will be submitted to the laboratory for analysis. Upon receipt of the analytical results, a brief letter summarizing the results will be prepared. PCB results will be reported in ng/m3.

Other sampling techniques, including Tedlar bag sampling, were considered for the evaluation. EPA Method T-04A (PUP sampling) was selected because it provides a lower level of detection than Tedlar bags and because it provides a direct evaluation of the ambient air quality in the vicinity of the gas vents. Tedlar bags could be used to sample the gas vents but that would only provide specific data for the vents themselves and not the air quality in the surrounding area.