The Arizona Department of Transportation, the Arizona Game & Fish Department and the Arizona State Parks Board are required to conduct a study every three years on watercraft fuel consumption and recreational watercraft usage. The fuel consumption data is collected to determine the allocation of motor vehicle fuel tax to the State Lake Improvement Fund. The information on recreational watercraft usage patterns on Arizona’s lakes and rivers is necessary, in part, to determine the distribution of SLIF funds to applicants.

This Additional Site Characterization Work Plan presents a strategy for collecting site characterization information at the closed Maricopa County Cave Creek Landfill to support ongoing remedial action planning for trichloroethene-impacted groundwater underlying the site. The Work Plan supplements previous remedial investigation work plans prepared to characterize the nature and extent of site contamination.

To evaluate whether VOCs are migrating out of the landfills into the vadose zone, a soil vapor survey of the soil beneath the landfill bases was performed. Permanent vapor monitoring probes were installed and then sampled twice for VOCs. Groundwater beneath the landfills has been impactd by VOCs, namely TCE, DCE, and toluene.