PUBLIC NOTICE | Availability of Proposed Remedial Action Plan for the West Central Phoenix West Osborn Complex WQARF Site

ADEQ has completed the Proposed Remedial Action Plan (PRAP) for the West Central Phoenix (WCP) West Osborn Complex (WOC) Water Quality Assurance Revolving Fund (WQARF) site in Phoenix, Arizona [Arizona Administrative Code R18-16-408(C)]. The PRAP documents the results of the remedial investigation/feasibility study (RI/FS) and identifies the proposed remedy and its estimated costs. In June 2013, ADEQ prepared two separate PRAPs for the two distinct aquifers at the site. Based on new information, ADEQ has reevaluated the 2013 proposed remedies and has published a new, comprehensive PRAP with a new proposed remedy.

Site Information

The WCP WOC WQARF site consists of two plumes located in Phoenix. The plumes are generally bounded by the Grand Canal to the north, 35th Avenue to the east, Interstate 10 to the south, and 55th Avenue to the west. The primary contaminant of concern at the site is trichloroethene (TCE), although tetrachloroethene (PCE), 1,1 dichloroethene (1,1 DCE) and chromium associated with the adjoining North Canal Plume (NCP) WQARF site have been detected within the WOC site boundary.

The proposed remedy for the site includes pump and treat and monitored natural attenuation, with contingencies for wellhead treatment, well sleeving, in-situ chemical oxidation, and additional groundwater monitor well installation. The estimated cost to implement this remedy, including contingencies, is approximately $26.9 million for a period of 30 years.

WCP WOC WQARF Site | View Site Overview >

Review Documents & Site Information

Original Published Public Notice | View > 
Proposed Remedial Action Plan | View > 

You may also review the above documentation in person at the ADEQ Record Center | Learn How >

Public Comment Period 

Dates: July 23, 2020 – Oct. 21, 2020

Comments may be submitted as follows:

     By Email | Send Email > 
     By Mail (Must be postmarked or received by Oct. 21, 2020):

       ADEQ
       Eric Mannlein
       Waste Programs Division
       1110 W. Washington Street
       Phoenix, AZ 85007