Superfund Site | Motorola 52nd Street

EPA #: AZD009004177

Superfund National Priority List (NPL) Status: The EPA listed this site on Oct. 4, 1989

Location: The Motorola 52nd Street Superfund Site (the site) is located in Phoenix, Arizona within the general boundaries of 52nd Street on the east, Palm Lane on the north, Seventh Avenue on the west and Buckeye Road on the south. Due to its size and to better manage cleanup efforts, the site was divided into three areas called Operable Units (OUs). The operable units, from east to west, include OU1, OU2, and OU3.

The site consists of a large area of contaminated groundwater extending from the former Motorola facility at 52nd Street and other sources west of 52nd Street, including Honeywell, the former Joray Corporation, and Arizona Public Service. ADEQ, working in concert with the U.S. Environmental Protection Agency (EPA), is the lead agency for activities in OU1 and OU2 with the exception of the vapor intrusion/indoor air investigation. The EPA is the lead agency for OU3 and vapor intrusion/indoor air investigations.

Contaminants of Concern: Volatile Organic Compounds (VOCs), including trichloroethene (TCE), 1,1,1-trichloroethane (1,1,1-TCA) and tetrachloroethene (PCE), are the main contaminants of concern (COCs) for the site. Additional COCs may be identified in one or more of the remedial investigation/feasibility studies (RI/FS) currently in progress.

Public Health Concerns: There are currently no known exposures to COCs in excess of applicable health based screening levels at the site. This includes studies conducted to date for groundwater, soil (surface and subsurface) and soil vapor intrusion.

The main exposure pathway to the COCs is through ingestion of contaminated groundwater. In Phoenix, drinking water is provided primarily through surface water sources, with only limited groundwater use from areas located outside the Motorola 52nd Street Superfund site. Interim remedial measures are in place at OU1 and OU2 to clean up groundwater and reduce migration of COCs. Remedial activities include operation of two groundwater extraction and treatment systems (GETS): one located at the former Motorola facility (OU1) and the other located at N. 20th Street and E. Washington Street (OU2). These activities are designed to mitigate the risk of exposure to the COCs through groundwater.

The EPA has also been studying the possibility that soil vapor from contaminated groundwater has migrated into buildings and has impacted indoor air. VOCs are able to easily transfer from liquid to vapor phase. TCE and PCE vapor can travel up and into surface structures, such as residential homes and commercial buildings. This exposure scenario, known as vapor intrusion (VI), is currently being studied as a part of the RI/FS process within OU1 and OU2. Based on the detection of elevated TCE concentrations in soil vapor, vapor mitigation systems were installed at specific locations to reduce exposure risk.