Water Quality Assurance Revolving Fund (WQARF) Site

East Central Phoenix (ECP) 40th Street and Osborn Road

Community Involvement Activities Public Health Impact Site Hydrogeology
Contacts Public Meeting Calendar Site Map
Contaminants Public Notice Calendar Site Status Update
Online Information Repository Site History

The ECP 40th Street and Osborn Road WQARF site plume is located in the 3900 block of North 40th Street near the intersection of Osborn Road. The site is bounded by Weldon Avenue to the North, 41st Street to the East, Osborn Road to the South, and 39th Street to the West; located northeast of Salt River Project (SRP) Well 17.9E-7.5N.

The plume boundaries depicted on the site map represent the Arizona Department of Environmental Quality's (ADEQ) interpretation of the data available at the time the map was constructed. The map is intended to provide the public with basic information as to the estimated extent of known contamination as of the date of map production. The actual extent of contamination may be different. Therefore, the plume boundaries may change in the future, as new information becomes available.


Site Status Update:

In fiscal year 2015, one groundwater monitor well was installed and a total of 98 groundwater samples were collected. A draft Remedial Investigation report and final Feasibility Study Work Plan was submitted on June 30, 2015.


Community Involvement Activities:

A community advisory board (CAB) was formed in November 2007. Details of CAB meeting agendas and minutes for can be viewed at the ADEQ website. These meetings are open to the public.  


Site History:

Drilling of groundwater monitor well at the ECP 40th St & Osborn Site
Drilling of groundwater monitor well
at the ECP 40th St & Osborn Site

1983 - 2002: Groundwater samples were generally collected by SRP from their well, 17.9E-7.5N, which is located west of the Osborn Road alignment and 40th Street. A sampling event, conducted in January 1998, yielded the highest detection of PCE yet observed in the SRP well, a concentration of 210 µg/L.

2000: In May, the site was placed on the WQARF Registry with a score of 30 out of a possible 120.

2003: ADEQ installed a groundwater monitoring well in the Osborn Road alignment between 39th Street and 40th Street. The initial groundwater sample collected from the well had PCE concentration that was below the AWQS of 5 µg/L. During a routine groundwater monitoring event, PCE was detected in the SRP well at a concentration of 110 µg/L.

2005 - 2006: Routine groundwater monitoring was conducted at the site. PCE was detected in the SRP well at concentrations of 41 µg/L and 28 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, PCE was detected in the SRP well at a concentration of 24 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.

2008: In the spring and winter, ADEQ installed three additional groundwater monitor wells: two were located east of 40th Street along Weldon and Whitton Avenues and one was located in the Osborn Road alignment between 39th Street and 40th Street. The initial depth-specific groundwater samples collected from the wells had PCE concentrations that ranged from less than the laboratory reporting limit to 110 µg/L.

During a routine groundwater monitoring event, PCE was detected in the SRP well at a concentration of 6.8 µg/L. The maximum PCE concentration observed throughout the site was 67 µg/L.

2014: In FY 2014, a total of 8 groundwater monitor wells were installed and a total of 99 groundwater samples were retrieved. A draft RI report was submitted on June 30, 2014.

ADEQ monitored SRP well 17.9E-7.5N and three nearby groundwater monitor wells in 2008. Sampling of the SRP well indicated a tetrachloroethene (PCE) concentration of 6.8 micrograms per liter (µg/L). The PCE results from the other wells ranged from below the Aquifer Water Quality Standards (AWQS) of 5 µg/L for PCE to 67 µg/L. In FY 2014, a total of 8 groundwater monitor wells were installed and a total of 99 groundwater samples were retrieved. A draft RI report was submitted on June 30, 2014.

2015: In fiscal year 2015, one groundwater monitor well was installed and a total of 98 groundwater samples were retrieved. A draft Remedial Investigation report and final Feasibility Study Work Plan was submitted on June 30, 2015.


Contaminants:

The current contaminant of concern in groundwater is PCE. Trichloroethene (TCE) has only been detected above the AWQS one time in November 1996 (SRP well). TCE has not been detected at any other time from the initial sampling event in 1983 to 2006. Contaminants of concern at the site may change as new data becomes available.


Public Health Impact:

There is currently no known threat of direct exposure to the public from the contamination at the site.


Site Hydrogeology:

The site is located within the West Salt River Valley sub-basin of the Phoenix Active Management Area (AMA). The Salt River Valley is an alluvial filled basin, located in the basin and range physiographic province.

Based on the boring log for SRP 17.9E-7.5N, the site is underlain by gravelly clay from ground surface to approximately 120 feet below ground surface (bgs), where bedrock is encountered. Based on measurements in 2008, depth to groundwater is approximately 32 feet bgs and flows to the southwest.


Contacts:

Name Phone/Fax E-mail
Mel Bunkers, ADEQ Project Manager (602) 771-4556*/(602) 771-4138 fax [email protected]
Wendy Flood, ADEQ Community Involvement Coordinator (602) 771-4410*/(602) 771-4236 fax [email protected]

*In Arizona, but outside the Phoenix area, call toll-free at (800) 234-5677.


Online Information Repository:

Interested parties can review site information here on this page and at the ADEQ Record Center located at 1110 W. Washington Street, Phoenix, Arizona. Please contact (602) 771-4380 or (800) 234-5677 ext. 6027714380 for hours of operation and to schedule an appointment. To review site information at a location near you, please contact the designated Community Involvement Coordinator.

Site Map

Proposed Remedial Objectives Report - Public Notice

Proposed Remedial Objectives Report

Draft Final Land and Water Use Report

60-day Public Notice regarding Draft Final Remedial Investigation Report

Draft Final Remedial Investigation Report

Map of All East Central Phoenix Plumes/Mapa de todos los penachos de East Central Phoenix

East Central Phoenix Community Involvement Plan (CIP)

Registry Report