Western Avenue Plume

Registry placement date: Dec. 15, 1998

Score: 51

County: Maricopa

Location: Goodyear/Avondale, bounded approximately by San Xavier Boulevard (north of Western Avenue) to the north, 3rd Street to the east, State Route 85 to the south and the Phoenix-Goodyear Airport to the west

Contaminant of concern: Tetrachloroethene (PCE)

Action taken: PCE-impacted groundwater was first discovered in the site area as part of groundwater monitoring activities conducted at the adjacent Phoenix Goodyear Airport-South Superfund Site (PGA-S) in 1993. PCE was detected in monitor wells located upgradient (east) of PGA-S. Increasing concentrations of PCE over time in these monitor wells indicated a potential upgradient source. The potential sources of PCE contamination in groundwater have been identified as former and existing dry cleaning facilities located within the site area. However, no major specific source area has been identified in upgradient areas investigated to date.

Status: ADEQ concluded that none of the facilities investigated represented a significant source of PCE to groundwater. PCE is found only in the shallow subunit A aquifer at low levels and is currently being captured by PGA-S extraction wells. No PCE source material remains and the PCE remaining in groundwater is representative of a late-stage low-concentration plume. A Record of Decision (ROD) identifying monitored natural attenuation is currently being prepared and will be issued in the near future.

Community Advisory Board (CAB): ADEQ’s WQARF process typically disbands the Community Advisory Board when the Proposed Remedial Action Plan (PRAP) and ROD notices are released. The Community Advisory Group members are still active as part of EPA’s Community Involvement Activities associated with the Phoenix Goodyear Airport-North (PGA-N) and PGA-S Superfund sites.