Phoenix-Goodyear Airport South
The Phoenix-Goodyear Airport (PGA) Superfund site is located approximately 17 miles west of Phoenix in Goodyear, Arizona. The site is divided into a northern portion called PGA North (PGAN) and a southern portion called PGA South (PGAS). Contamination from these two areas is not contiguous.
PGAS is in the western part of the Salt River Valley, within the City of Goodyear in Maricopa County. The boundaries are Yuma Road to the north, Litchfield Road to the east, Hwy. 85 to the south, and Reems Road to the west. PGAS is comprised of the Phoenix-Goodyear Airport (formally owned by the U.S. Navy) and the Lockheed Martin Corporation (formerly the Goodyear Aerospace Corporation and Loral Defense Systems-Arizona) and includes the groundwater contamination plume beneath the airport property and a plume extending approximately 2000 feet to the northwest of the intersection of Yuma Road and Litchfield Road beneath the agricultural fields north of the airport. The plume boundary varies and may extend beyond the site boundary, but remains part of the Superfund site in its entirety. The property where Lockheed Martin Corporation continues their operation was sold and they are now one of several tenants on the property.
Contaminated groundwater at PGAS continues to be monitored and treated by an air stripper for the Subunit A (upper aquifer) groundwater contamination beneath the airport property and by a liquid dual phase granular activated carbon system for the Northern Subunit C plume just north of the airport.
Contamination in groundwater is monitored through a network of wells that record groundwater flow patterns and incidence of trichloroethene TCE and chromium. Drinking water wells for the City of Goodyear, that are closest to PGAS, are monitored on a monthly basis to ensure that contaminants are not impacting these wells. To date, the two wells being closely monitored, COG No. 11 and COG No. 20, have not exceeded contaminant levels considered to be a threat to public health.
TCE in groundwater at the Southern Subunit C plume beneath the airport has been remediated below Maximum Contaminant Level (MCL) which is considered no longer a threat to public health.
A community advisory group (CAG) was formed in January 2001, in conjunction with PGAN and Western Avenue WQARF sites and met on a regular basis. In Fall of 2014 the CAG was disbanded with the movement of the Western Ave WQARF site to the Record of Decision phase. Historical meeting agendas and minutes can be viewed on the ADEQ web site and the meetings are open to the public.
EPA will be forming a new CAG to serve the affected community in Spring 2015. EPA publishes fact sheets that are sent to the community involvement area regarding PGAN progress, and the latest fact sheet can be viewed on the ADEQ website. An updated Community Involvement Plan was completed in July 2013 and will be updated in conjunction with the formation of the new CAG.
Goodyear Aerospace Corporation, a former subsidiary of GTRC, began operation at the airport in 1942. In 1968, the Navy transferred ownership of the facility to the City of Phoenix, and the facility became the Phoenix-Litchfield Municipal Airport. The airport was renamed the Phoenix-Goodyear Municipal Airport in 1986.
Waste from aircraft preservation and routine aircraft maintenance from cleaning and degreasing was discharged into the main drainage ditch, which eventually drained into a marsh area south of the airport. The discharged waste streams contained oil, grease, battery acids, and miscellaneous degreasing solvents. This practice continued until 1952, when the on-site sewage treatment plant was constructed.
The majority of the waste streams generated were attributed to metal treatment processes such as anodizing, degreasing, and etching. These waste streams included waste solvents TCE, chromium sludge, and processed wastewater. Prior to 1980, much of the waste generated from anodizing, metal etching, and a plastic polishing was disposed of in three on-site sludge drying beds located at the southern portion of the plant.
1942 - 1946: PGA served as the Litchfield Park Naval Air Facility since 1942. Goodyear Tire and Rubber Company began operating Goodyear Aerospace at the airport, modifying and repairing aircraft, which were then transferred to the adjoining Navel Air Facility from 1940 to 1945. In 1946, the Naval Air Facility was placed in modified maintenance status. Its primary function became the preservation and activation of military aircraft.
1968: The Navy transferred ownership of the property to the City of Phoenix.
1974: Goodyear Aerospace discontinued using TCE at PGAS.
1984: TEPA began a remedial investigation (RI) of the Litchfield Airport Area (presently known as the Phoenix-Goodyear Airport) to characterize the site, discover the extent of the contamination, and identify possible sources. From this study, the site was divided at Yuma Road into a north and a south portion.
1989: The RI/feasibility study (FS) for the site was completed in June, and a comprehensive final remedy ROD was signed in September for PGAN and PGAS.
1991: A Consent Decree (CD) for the final remedy was lodged on May 7th and entered in November, with EPA, the State, Goodyear Tire and Rubber Company, and Loral Defense Systems as signatories. This document binds Goodyear Tire and Rubber Company to remediate the Subunit B/C aquifer and contaminated soils.
1992: Goodyear Tire and Rubber Company conducted a removal action of metal contaminated soils located at the sludge drying beds. The soils containing chromium and cadmium above the Health Based Guideline Levels were stabilized, thereby eliminating the risk of exposure by ingestion and inhalation and preventing further migration to groundwater.
1993: Tetrachloroethene (PCE) was detected in PGAS Subunit A groundwater wells coming from the Western Avenue PCE Water Quality Assurance Revolving Fund (WQARF) (dry cleaning) site due east and upgradient of the PGAS plume.
1994: There are two plumes within Subunit C associated with the site, caused by conduit wells, which were promptly abandoned. Groundwater extraction and treatment of these two plumes began using granular activated carbon.
1998: In April, ADEQ approved the closure and decommissioning of the SVE system. The Vadose Zone Leaching Model was used to determine that the residual threat to the groundwater was below the maximum contaminant level. The Goodyear Tire and Rubber Company has thereby satisfied the requirements under the 1991 CD for closure of soils.
2004: An extraction well (E-102) for the northern portion (head) of the northern Subunit C plume was installed and up and running in November.
2006: Issues brought up during the FYR were addressed and work plans for a new extraction well (E-18) were approved.
2007: Due to age, Goodyear Tire and Rubber Company conducted maintenance on many components of the treatment systems. Groundwater monitoring and operation and maintenance (O&M) activities of the groundwater treatment systems continued.
2008: The O&M Manuals were updated and metals sampling rounds were conducted. Groundwater monitoring and O&M activities of the groundwater treatment systems continued. ADEQ and EPA met with the Goodyear Tire and Rubber Company to have groundwater wells installed to further delineate the Subunit C plume north of Yuma Road.
2009: Goodyear Tire and Rubber Company recommended pulsed pumping to overcome hydraulic stagnation and to address the residual contaminant mass in Southern Subunit C groundwater. A Work plan submitted to install two additional wells (GMW-21UC and GMW-22UC) to monitor TCE concentration in production well GAC-04 was submitted.
2010: Groundwater monitoring continued to track contamination at PGAS. Goodyear Tire and Rubber Company completed a pulsed pumping evaluation of the Southern Subunit C plume. Well rehabilitation was completed on three Subunit A wells (E-12, E-7, and NE-5) and on Subunit C wells I-201 and I-203. Two new Subunit C monitoring wells were installed in an effort to understand contamination in wells GAC-04 GMW 21C and 22C.
ADEQ and EPA completed the FYR for PGAS. A protectiveness determination of the remedy was not made in the report, but was deferred until further information is obtained. While the TCE plume at PGAS has been mostly delineated with COC concentrations in the plume being stable or decreasing over the last five years, the northwestern edge of the northern plume is not completely defined. Further information will need to be obtained by conducting a groundwater investigation of northern TCE plume in Subunit C. Several issues that affect long term protectiveness have also been identified: The source and extent of the TCE contamination in and around GAC-04 has not been determined and the continued occurrence of elevated chromium in the northern Subunit A plume has not been fully understood.
2011: EPA took over as lead Agency for PGAS in the fall (EPA was already the lead Agency for PGAN), which helped EPA initiate/manage the study of the area between the sites (ABS - the area between PGAN and PGAS). The ABS study was an action item from the FYR. ADEQ and EPA continued to meet with the Goodyear Tire and Rubber Company to have groundwater wells installed to further delineate the Subunit C plume north of Yuma Road.
2012: Several Subunit A monitoring wells were abandoned/replaced mostly due to a drop in groundwater elevation; making it difficult or impossible to acquire a proper groundwater sample which is needed to meet the needs of the Comprehensive Groundwater Monitoring Plan (CGMP). Goodyear Tire and Rubber Company conducted maintenance on many components of the Subunit A treatment systems. ADEQ and EPA continued to meet with the Goodyear Tire and Rubber Company to have groundwater wells installed to further delineate the Subunit C plume north of Yuma Road. GAC-04 Supply Well Investigation was completed and the final determination was to abandon the well. The well was abandoned in late fall.
2013: Well abandonment and well replacement activities continued for Subunit A along with enhancements/improvements on the treatment systems. An extraction well (E-07R) had a new pump installed. New Subunit C monitoring wells were drilled to further delineate the Northern Subunit C plume.
2014: Over 5,674 pounds of cumulative TCE mass has been removed from start up of the Subunit A treatment system in 1990 through the first half of 2014. In 2014 a new Subunit C extraction well and piping was completed in order to remove mass and contain the plume. Three new extraction wells are planned for 2014 for the Subunit A plume in order to better optimize the system and increase removal of contaminants.
The current contaminants of concern in groundwater include TCE, PCE, and chromium. Contaminants of concern at PGAS may change as new data becomes available.
Potential health risks may exist for individuals who ingest the contaminated groundwater. There are no known drinking water supply wells at PGAS. The City of Goodyear regularly monitors their drinking water supply wells, as required by law.
PGAS lies within the Basin and Range physiographic province, consisting of alluvial basins and mountain ranges. The alluvial deposits of the western Salt River Valley consist of the Upper Alluvial Unit (UAU), the Middle Fine-grained Unit, or Middle Alluvial Unit and the Lower Conglomerate Unit, or Lower Alluvial Unit (LAU).
In the vicinity of PGAS, the UAU is approximately 350 feet thick and is further divided into three subunits: Subunit A, Subunit B, and Subunit C. Subunits A, B, and C are hydraulically connected. Subunit A is composed of silty sand and gravel and extends to a depth of approximately 120 feet below ground surface (bgs). The lower half of Subunit A is saturated and is considered an aquifer. Subunit B is also comprised fluvial sedimentation consisting of sand, sandy-silt, and clay, possibly representing ancient stream deposits. Locally this horizon is thought to act as an aquitard which impedes the vertical flow of groundwater from Subunit A to C. Subunit B generally occurs at depths between 120 and 190 feet bgs. Subunit C consists of silt, sand, and gravel and occurs typically from 190 to 350 feet bgs. Groundwater contained within Subunit C is pumped for drinking water and agricultural purposes.
Groundwater flow direction within both aquifers is largely influenced by pumping as there are multiple domestic, municipal, irrigation, and remediation (extraction and injection) wells in the vicinity of PGAS. A groundwater divide occurs within Subunit A in the vicinity of Yuma Road, separating PGAN from PGAS. Subunit A within PGAS typically flows to the southwest and groundwater within Subunit C is to the west. Depth to groundwater within Subunit A is 60 to 80 feet bgs and approximately at 200 feet bgs within Subunit C.
*In Arizona, but outside the Phoenix area, call toll-free at (800) 234-5677.
Interested parties can review select site documents at the City of Goodyear Library, 250 N. Litchfield Road, Suite 185, Goodyear, AZ 85338, (602)-652-3000.
NOTE: It is anticipated that the City of Goodyear Library will be re-locating in early 2014. Please call prior to visiting to confirm location.
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.
The complete official site file can be reviewed at the EPA Region IX, Records Center, Mail Stop SFD-7C, 95 Hawthorne Street, Room 403, San Francisco, CA 94105, (415) 536-2000.