Central and Camelback
The Central and Camelback WQARF site consists of contaminated groundwater plumes located in the vicinity of Central Avenue, near Camelback Road in Phoenix, Arizona. The plumes are bounded approximately by Georgia Avenue to the north, 2nd Street to the east, Mariposa Street to the south, and 1st Avenue 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's boundaries may change in the future as new information becomes available.
A groundwater pump and treat system and a soil vapor extraction (SVE) system are operating at the southwest corner of Central Avenue and Camelback Road to remove contaminants from the groundwater and soil beneath the site. Groundwater monitoring and sampling is conducted at the site, along with monitoring and sampling of the remedial systems as required by the site permits.
ADEQ has a Poor Quality Groundwater Withdrawal Permit (PQGWP) with the Arizona Department of Water Resources (ADWR) for extraction of contaminated groundwater and an Arizona Pollutant Discharge Elimination System (AZPDES) permit for discharge of treated groundwater to Salt River Project's (SRP) Grand Canal. ADEQ has an Air Quality Permit with the Maricopa County Air Quality Department. The SVE system and the groundwater pump and treat system have removed approximately 6,800 pounds (lbs) of volatile organic compounds (VOCs), mostly tetrachloroethene (PCE), from the soil and groundwater.
A community advisory board (CAB) has been formed for this site and meets on a regular basis. This site is part of the Central Phoenix CAB, a combined CAB that meet to discuss this and other neighboring sites. Details of CAB meeting agendas and minutes can be viewed at the ADEQ website.
1999: The Southwest Corner Source Area (SCSA) portion of the site was placed on the WQARF Registry in January due to the detection of PCE in the groundwater. Concentrations were found to be as high as 20,000 parts per billion (ppb) in the area. The eligibility and evaluation score for placement on the WQARF Registry was 31 out of 120.
2000: In June, the SCSA became listed as part of the site with a score of 32 out of 120.
2001: ADEQ initiated an early response action (ERA) for the SCSA portion of the site to remediate groundwater contamination and control the migration of contamination into an underground parking garage, located on the southeast corner of Central Avenue and Camelback Road. The ERA consisted of the installation of four groundwater extraction wells, which were completed in December.
2003: The groundwater remediation system located at 21 W. Camelback Road began pumping and treating contaminated groundwater, at a rate of approximately 90 gallons per minute (gpm), on January 22nd. The treatment system removes VOCs by passing the contaminated groundwater through granular activated carbon. The treated water is discharged primarily to the SRP Grand Canal and, during canal dry-out periods, to the City of Phoenix (COP) sanitary sewer. Periodic sampling of the effluent is conducted to assure that the treated water complies with discharge standards. Eleven groundwater monitor wells were installed to delineate the extent of the PCE plume.
2004: The ERA evaluation of the Maroney's Dry Cleaners facility located at 4902 N. Central Avenue was conducted in June. Four nested soil vapor wells and one groundwater monitor well were installed during the ERA evaluation.
2005: Based on the results of an ERA evaluation, a SVE pilot test was conducted in January, and SVE was chosen as an effective remedy for the subsurface soil contamination at the former Maroney’s facility. Wells at the former Texaco station located at the corner of Central Avenue and E. Colter Street had PCE detected in groundwater samples.
2006: Two new wells were drilled at Medlock Drive and Orange Street to delineate the northern portion of the plume. ADEQ took over ownership of three COP wells at the SCSA.
2007: ADEQ began the remedial investigation (RI) to determine the nature and extent of the contamination at the Site. Per Arizona Revised Statutes § 49-287.03, notices were sent to 12 interested parties initiating the start of the RI phase of work at this Site and the surrounding community. Three new wells were drilled – two south of the site on Pierson Street and one on private property located at 15 W. Camelback Road in the proximity of the former Weiss Guys Car Wash location. The SVE system started operating in November.
2008: ADEQ installed two groundwater monitor wells in May. ADEQ detected increasing levels of PCE in CC-11 on E. Orange Drive and in the Texaco wells at 5201 N. Central Avenue.
2009: The SVE operation was altered at the end of June, to two weeks of operation and two weeks of shutdown, to monitor rebound of contaminant vapors in the subsurface.
2010: The groundwater treatment system was shut down in early January because of a restriction to discharge to the SRP canal during dry-out and cleanup of the canal. The system remained off until early March because of budget constraints. The system was operated continuously after startup in March with two of the four extraction wells in operation. The SVE system continued to operate on a two-week-on, two-week-off schedule. The SVE system was turned off from the beginning of July to early September during project contracting and funding.
2011: The groundwater remediation system was shut down in early January because of a restriction to discharge to the SRP canal during dry-out and cleanup of the canal. The system remained off until early March to allow for minor repairs, calibrations and upgrades. The system was operated continuously, after startup, with two of the four extraction wells in operation. The SVE system was operated on a two-week-on, two-week-off schedule, until December, when the system was operated continuously. A soil gas investigation was conducted in the area of the former Maroney’s Dry Cleaners building and a nested soil gas extraction well was installed.
2012: The Maricopa County Air Quality Department Air Quality Permit (Permit Number 070045 Revision 220.127.116.11) was renewed for the SVE system. The ADWR PQGWP Permit (Permit Number 59-588107.0000) was renewed. The ADEQ AZPDES Permit (Permit Number AZ0024848) was renewed. The COP Wastewater Discharge Permit (Permit Number 0710-021409) was terminated because the facility no longer discharges to the COP sewer system. The groundwater remediation system operated continuously with two of the four extraction wells in operation until June. A soil gas extraction pilot test was conducted at the newly installed soil gas extraction well. The new extraction well was connected to the SVE system after modification to the Air Quality Permit was approved by the Maricopa County Air Quality Department.
2013: Pumping equipment was removed from groundwater extraction well EW-1 and installed into well CC-5 due to sand infiltration problems with EW-1. The system was then operated full time with two extraction wells. A passive soil gas survey was conducted along Central Avenue north of Camelback Road to investigate possible releases that may have contributed to the groundwater plume north of Camelback Road. Two groundwater monitor wells were installed north of Camelback Road to better define the extent of the groundwater contaminant plume.
2014: The groundwater remediation and treatment system and the soil vapor extraction (SVE) system were operated full time with the exception of shutdown for minor repairs and granular activated carbon (GAC) change-out. ADEQ conducted a sewer line video investigation, soil investigation, and installed a groundwater monitor well to conclude the investigation of possible sources of the northern contaminant plume. The Remedial Investigation (RI) Report was finalized.
2015: The groundwater remediation and treatment system and the soil vapor extraction (SVE) system were operated full time with the exception of shutdown for SRP canal cleanup and minor repairs. The Feasibility Study (FS) work plan and FS report were completed.
The current contaminants of concern in groundwater are PCE and trichloroethene (TCE). Contaminants of concern at the site may change as new data becomes available. Other contaminants from past underground storage tank releases include: benzene, toluene, ethylbenzene, total xylenes, methyl tertiary butyl ether (MTBE), and 1,2-dichloroethane (1,2-DCA).
There is no known public health impact, since municipal groundwater in the area is not used for drinking water purposes. The area is served by the COP municipal water system or other regulated systems.
The depth to groundwater in the area is approximately 65 feet below ground surface (bgs). Water levels have declined, due to the lining of the Grand Canal, the groundwater pumping at One E. Camelback Road, and the operation of the site’s pump and treat system. Groundwater flow direction in the site area has been altered from a generally north-northwesterly flow to a generally south-southeasterly flow and is affected by pumping from the SRP irrigation wells, the groundwater pumping system at the site and the groundwater pumping system at One E. Camelback Road.
*In Arizona, but outside the Phoenix area, call toll-free at (800) 234-5677.
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.