Location

On 26 acres of land on the east side of Apache Lake in Maricopa County, approximately a half-mile west of Arizona Highway 88 (Apache Trail). The site is approximately 1,940 feet above mean sea-level (AMSL); normal lake elevation is reported at 1,914 feet AMSL.

Contaminants of Concern

Total Petroleum Hydrocarbon (TPH) and benzene, toluene, ethyl benzene, and xylenes (BTEX) in groundwater.  Contaminants of concern may change as new data become available.

Public Health Impact

No known risk at this time. All exposure pathways have been eliminated through remediation or restricted access/use.

Site Hydrogeology

Depth to groundwater ranges from 14 to 27 feet below ground surface, and likely fluctuates according to the rise and fall of the water level in Apache Lake. Based on the topography, and the close proximity of the lake, groundwater flow direction is likely dependent on the elevation of the lake. The groundwater elevation contour map generated from data gathered during this investigation indicates that groundwater flows to the southeast, away from the lake. Apache Lake is therefore, a “losing” lake.

Waterdog is situated on granitic bedrock and weathered granite. Based on the drilling logs, the local geology consists of approximately 4 to 7 feet of silt and/or sand, underlain by alternating weathered and less weathered granitic bedrock. The bedrock has no primary permeability and moderate to high secondary permeability from fractures.

Action Taken

In 2016 the US Air Force decided to continue using an in-situ remediation technical approach. Activated carbon and sulfate bioremediation compound injection would be tested as a remediation method. 

Groundwater monitoring and reporting would continue.

Status

By end of summer 2018, the pilot test report review will be completed.  In fall 2018, a Draft Remedial Implementation Work Plan will be submitted to ADEQ. 

By end of summer 2018, the 2016 Long-Term Monitoring Report review will also be completed.

Community Involvement Activities

There is no community involvement activity associated with this site at this time.