Cooper Road and Commerce Avenue | Site History

2019: ADEQ operated a soil vapor extraction (SVE) system and conducted regular groundwater monitoring at the site. The Proposed Remedial Action Plan (PRAP) was completed June 2019.

2018: ADEQ began drafting a site PRAP, installed three groundwater monitoring wells, operated a SVE system, and conducted regular groundwater monitoring at the site. The Feasibility Study (FS) Report was completed in April 2018.

2017: ADEQ began drafting an FS Report and conducted regular groundwater monitoring at the site.

2016: ADEQ conducted regular groundwater monitoring at the site and installed two additional groundwater monitoring wells to better define the lateral and vertical extent of contamination. Two soil borings were installed at the source area to assess volatile organic compound (VOC) concentrations in soil and soil vapor. Additionally, ADEQ conducted groundwater modeling to examine the effect of natural attenuation at the site.

2015: ADEQ released the Final Remedial Investigation (RI) Report and the FS Work Plan in July. ADEQ evaluated additional remediation alternatives and technologies available for the site. Quarterly groundwater monitoring continued at the site.

2014: ADEQ continued to monitor wells near the extraction well on a quarterly basis to monitor the effectiveness of the pump-and-treat system. In addition, the entire monitor well network at the site was sampled during the year to monitor the extent of the plume.

The groundwater pump-and-treat system was shut down in September to evaluate the need for continued operation. 

In June, the soil vapor extraction/air sparge (SVE/AS) system was shut down to evaluate the need for continued operation.

2013: ADEQ continued to operate the SVE/AS and groundwater pump-and-treat systems. 

ADEQ continued to conduct groundwater monitoring of wells near the extraction well on a quarterly basis to monitor the effectiveness of the pump-and-treat system. In addition, the entire monitor well network at the site was sampled during the year to monitor the extent of the plume.

ADEQ installed five additional shallow monitor wells near the center and in the southwest area of the groundwater plume. ADEQ also installed an additional deep monitor well, MW-119D, near Salt River Project (SRP) well 29E-1.5S located at the SRP canal and Cooper Road

2012: In June, ADEQ drilled and sampled three borings in the immediate vicinity of the main source area, the former drywell.

The sample results indicated significant amounts of Tetrachloroethene (PCE) were still present in the soils near the drywell. ADEQ installed two additional SVE wells in these borings, SVE-106 and SVE -107.

ADEQ continued to operate and maintain the SVE/AS  and groundwater pump-and-treat systems.

ADEQ continued to conduct groundwater monitoring of wells near the extraction well on a quarterly basis to monitor the effectiveness of the pump-and-treat system.  In addition, the entire monitor well network was sampled twice to monitor the extent of the plume. 

2011: ADEQ continued to operate and maintain the SVE/AS and groundwater pump-and-treat systems.

The evaluation of the capture zone of extraction well EW-101 indicated a capture zone of approximately 300 feet wide, which encompassed the source area at the location of the drywell.