East Central Phoenix - 40th Street and Indian School Road | Site History

2015: In fiscal year 2015, a total of 105 groundwater and 5 soil vapor samples were retrieved. A Remedial Investigation Report and a Feasibility Study Work Plan were finalized.

2014: In FY 2014, a total of 10 groundwater monitor wells were installed and a total of 122 groundwater samples were retrieved. A draft RI report was submitted on June 30, 2014.

ADEQ conducted groundwater sampling in 2008, using passive-diffusion bag samplers in the monitor wells. The highest concentration of tetrachloroethene (PCE) in groundwater during the October 2008 sampling event was 180 micrograms per liter (µg/l).

ADEQ installed a new well cluster (AMW9A-C) to investigate the vertical and lateral extent of the plume downgradient from the Kachina Dry Cleaners on 39th Street, north of Indian School Road. Analytical results from the well indicate that the vertical extent of the plume has been assessed, but the plume is still not laterally defined to the southwest. An additional well (AMW10A-B) was installed in Oct. 2008 on Monterosa Street, downgradient of the former Allen’s Dry Cleaners. Initial sampling results indicate the well is non-detect for PCE. In FY 2014, a total of 10 groundwater monitor wells were installed and a total of 122 groundwater samples were retrieved. A draft RI report was submitted on June 30, 2014.

2008: ADEQ installed two additional groundwater wells: one located on 39th Street north of Indian School Road and one located on Monterosa Street, south of the former Allen’s Cleaners facility. The initial groundwater samples collected from the wells had depth-specific PCE results that ranged from less than the laboratory reporting limit up to 120 µg/L.

2007: In June, ADEQ sent out notices per A.R.S. §49-287.03 initiating the remedial investigation for the site. During a routine groundwater monitoring event in the fall, the maximum PCE concentration observed throughout the site was 62 µg/L.

In December, ADEQ installed an additional groundwater well, located on 39th Street north of Indian School Road. The initial groundwater samples collected from the well had depth-specific PCE results that ranged from less than the laboratory reporting limit up to 310 µg/L.

2006: Three soil borings were drilled near the Kachina Cleaners facility to conduct a groundwater, soil, and soil vapor survey. PCE in groundwater was detected with concentrations ranging from 1.2 µg/L to 400 µg/L. Soil sample concentrations of PCE ranged from less than the laboratory limit to 0.12 mg/kg. Soil vapor concentrations of PCE ranged from less than the laboratory limit to 6.7 µg/L. ADEQ also installed a groundwater monitoring well adjacent to the Kachina Cleaners facility. The initial groundwater samples collected from the well had shallow and deep PCE concentrations that were less than the AWQS for PCE of 5 µg/L.

During a routine groundwater monitoring event, the maximum PCE concentration observed throughout the site was 78 µg/L.