Water Quality Assurance Revolving Fund (WQARF) Site

East Central Phoenix (ECP) 48th Street and Indian School 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 48th Street and Indian School Road WQARF site plume in Phoenix, Arizona is approximately bounded by East Monterosa Street to the north, East Fairmont Avenue to the south, North 47th Place to the east and 45th Street to the west.

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 2013 and 2014, to further delineate the soil vapor plume, ADEQ collected soil vapor samples. The soil vapor samples were collected at depths of approximately five and fifteen feet below land surface. The soil vapor concentrations of PCE ranged from less than the limit of detection of 69 micrograms per meter cubed (µg/m³) to 830 µg/m³. The results of the soil vapor sampling delineated the PCE soil vapor plume at concentrations greater than the residential indoor air screening level of 9.4 μg/m³. The soil vapor plume extended from the southwestern portion of the Arcadia. Towne Center southwest to an area near 44th Place between East Fairmount and East Indianola avenues.

In 2013 and 2014, ADEQ then went door-to-door to collect indoor air samples from residences located above the soil vapor plume to assess the potential for vapor intrusion. Thirteen residents were sampled. Additionally, ADEQ collected indoor air samples from 30 classrooms at Arcadia High School. Only one of the 13 indoor air samples collected in the residential areas contained PCE at a concentration greater than the residential indoor air screening level of 9.4 μg/m³. After confirmation sampling, results indicated PCE was less than the screening level, indicating the original sample was affected by normal household activities. PCE was not detected in any of the indoor air samples collected at Arcadia High School greater than the screening level. PCE was not detected in any indoor air samples at concentrations greater than their applicable screening levels. Due to lower than expected soil vapor and groundwater well concentrations, the new SVE system installation has been put on hold. Site investigation and groundwater well installation will continue throughout fiscal year 2016.


Community Involvement Activities:

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


Site History:

1989: This site is part of the ECP study area, which is bounded by Camelback Road to the north, McDowell Road to the south, 50th Street to the east and 20th Street to the west. Soil gas surveys were conducted at multiple facilities throughout the ECP study area to determine if a release of contaminants to the subsurface had occurred. In October, one soil vapor sample was collected adjacent to the Sandy’s Cleaners facility. The concentration of PCE detected in the soil vapor sample was 670 micrograms per liter (µg/L).

1992: Eight soil borings were drilled west of the Sandy’s Cleaners facility. The soil concentrations of PCE ranged from 0.024 milligrams per kilogram (mg/kg) to 0.440 mg/kg. A wastewater sample was collected from the facility’s lint trap in which the measured PCE concentration was 150 µg/L. ADEQ also installed two groundwater monitor wells: one directly west of the Sandy’s Cleaners facility and one northwest of SRP’s well 19.0E-8.1N. The initial groundwater sample collected from the well directly west of the Sandy’s Cleaners facility had a PCE concentration of 2,300 µg/L.

1994: One groundwater monitor well was installed southwest of the Sandy’s Cleaners facility on the Arcadia High School grounds. The initial groundwater samples collected from the well had shallow and deep PCE results that were below the AWQS of 5.0 µg/L.

During a routine groundwater monitoring event, the maximum PCE concentration observed throughout the site was 3,000 µg/L.

1996: Ten soil borings were drilled west of the Sandy’s Cleaners facility. The soil concentrations of PCE ranged from 0.0011 mg/kg to 0.2 mg/kg. Soil vapor samples that were also collected had a maximum PCE concentration of 5,600 µg/L in one boring at a depth of 15 feet bgs.

During a routine groundwater monitoring event, the maximum PCE concentration observed throughout the site was 4,000 µg/L.

1997 - 1998: The Arizona Department of Health Services (ADHS) evaluated the data collected in 1996 and provided three health consultations that determined there was no risk to employees under current use scenarios. In May, ADEQ collected grab groundwater samples from five wells. The PCE concentrations in the samples ranged from less than the laboratory reporting limit up to >2,500 µg/L.

During a routine groundwater monitoring event, the maximum PCE concentration observed throughout the site was 4,300 µg/L.

1999: In April, the site was placed on the WQARF Registry with a score of 27 out of a possible 120.

2000: ADEQ and SRP entered into a Governmental Services Contract in which ADEQ funded SRP to conduct an interim remedial action (IRA) at the site. As an IRA, SRP would design and install a SVE system to remove soil vapor contamination from the subsurface.

2001: As part of the IRA agreement, SRP installed two groundwater monitor wells east of the Sandy’s Cleaners facility and one groundwater extraction well west of the Sandy’s Cleaners facility.

2004: SRP installed two SVE wells west of the Sandy’s Cleaners facility. A non-title V Air Quality Permit from Maricopa County for their SVE system received approval.

2006: In February, SRP began operating their SVE system, which was installed west of the Sandy’s Cleaners facility. By September, the SVE system had removed approximately 248 pounds of PCE from the vadose zone. During a routine groundwater monitoring event, the maximum PCE concentration observed throughout the site was 98 µg/L.

2007: In June, ADEQ sent out notices per A.R.S. §49-287.03 initiating the remedial investigation for the site. As of the end of September, approximately 295 pounds of PCE were removed from the vadose zone by SRP’s SVE system. During a routine groundwater monitoring event, the maximum PCE concentration observed throughout the site was 100 µg/L.

2008: By the end of March, approximately 309 pounds of PCE were removed from the vadose zone by SRP’s SVE system. ADEQ installed two additional groundwater monitor wells within 47th Street, north of Indian School Road. The initial groundwater samples collected from the wells had PCE results that were equal to and below the AWQS of 5 µg/L. During a routine groundwater monitoring event, the maximum PCE concentration observed throughout the site was 33 µg/L.

2009: In January, ADEQ collected passive soil gas samples from approximately 14 sites located within North 45th Place, south of Indian School Road. By July, the SRP’s SVE system had removed approximately 310 pounds of PCE from the soil in the vadose zone. Routine groundwater monitoring was not conducted.

2010: SRP continued to operate their SVE system and as of June, approximately 314 pounds of PCE had been removed from the vadose zone soil. During a routine groundwater monitoring event, the maximum PCE concentration observed throughout the site was 370 µg/L.

48th Street and Indian School Rd. SVE System
Future site for SVE System

2011: ADEQ continued to collect passive soil gas samples from an additional 39 locations placed adjacent to the Sandy’s Cleaners facility and within North 45th Place, south of Indian School Road. The PCE mass observed in those samples ranged from less than 25 nanograms (ng) up to 3,512 ng. As a result of the PCE results, ADEQ installed 12 permanent soil vapor monitoring wells adjacent to the passive soil gas sample locations. The initial soil vapor samples collected from these wells had PCE concentrations that ranged from 16 micrograms per meter cubed (µg/m3) to 59,000 µg/m3.

SRP continued to operate their SVE system and as of December, approximately 319 pounds of PCE had been removed from the vadose zone soil. During a routine groundwater monitoring event, the maximum PCE concentration observed throughout the site was 1,400 µg/L.

2012: ADEQ installed seven SVE and six SVE observation wells adjacent to the Sandy’s Cleaners facility in preparation for the modification of SRP’s SVE system. ADEQ also conducted a SVE pilot test. The results from the test suggest that SVE would still be an effective treatment technology for the site. SRP decommissioned their SVE system in April in order for ADEQ to manage the construction, operation, and maintenance of a new SVE treatment system.

ADEQ also installed three additional groundwater monitoring wells south to southwest of the Sandy’s Cleaners facility and conducted sampling of the soil vapor monitoring wells throughout the site. Cone Penetrometer Testing (CPT) was also performed throughout the site to investigate current hydrogeologic conditions. A routine groundwater monitoring event was conducted in April.

2013: To delineate the soil vapor plume, ADEQ installed 56 temporary soil vapor wells along the northern and western parking area portions of the Arcadia Towne Center and along East Piccadilly Road, East Fairmont Avenue, East Indianola Avenue and East Clarendon Avenue (between North 43rd Place and North 44th Place). The soil vapor concentrations of PCE ranged from <11 µg/m3 to 830 µg/m3.

ADEQ went door to door to collect indoor air samples from residents located above the soil vapor plume to check for vapor intrusion. Out of 40 homes, 14 participated and granted access for their indoor air to be sampled.

2014: Groundwater monitoring and soil gas monitoring activities are currently being conducted throughout the site. Site investigation and groundwater well installation will continue throughout FY15.

As part of the early response action (ERA), Salt River Project (SRP) operated a soil vapor extraction (SVE) system. As of January 2012, approximately 319 pounds of tetrachloroethene (PCE) have been removed from the soil. In April 2012 the SVE system was dismantled by SRP in order for ADEQ to install a new system. The new SVE system is anticipated to be installed in 2015. Site investigation and groundwater well installation will continue throughout FY15 and a draft RI report will be submitted by June 30, 2015.

2015: Groundwater monitoring and soil gas monitoring activities are currently being conducted throughout the site. Site investigation will continue throughout fiscal year 2016.

In fiscal year 2015;

  • A total of 66 groundwater samples were collected.
  • A total of 33 soil gas samples were collected.

Contaminants:

The current contaminant of concern in groundwater is tetrachloroethene (PCE). 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. The Salt River Valley is an alluvial filled basin, located in the basin and range physiographic province. The site is underlain by clayey silt with trace gravel from ground surface to approximately 120 feet below ground surface (bgs). Bedrock is encountered at approximately 120 feet bgs.

Based on measurements from monitor wells during the October 2011 sampling event, groundwater is encountered at approximately 32 feet bgs and flow direction is 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

Indoor Air Assessment Fact Sheet

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