2024: The soil vapor extraction (SVE) and ozone injection systems operated on an intermittent schedule. Both systems were shut down in June for an extended rebound monitoring period. Soil vapor rebound monitoring was performed in June, September, and December. Routine semiannual groundwater monitoring was conducted at the site.

2023: The SVE and ozone injection system operated on an intermittent schedule; soil vapor rebound monitoring was performed in accordance with the SVE operation schedule. Routine semiannual groundwater monitoring was conducted at the site.

2022: The groundwater treatment system was decommissioned and removed from the site. An in situ chemical oxidation ozone injection system and six ozone injection wells were installed as an additional component to enhance SVE system contaminant removal. The SVE and ozone injection systems operated on an intermittent schedule; soil vapor rebound monitoring was performed in accordance with the SVE operation schedule. Routine semiannual groundwater monitoring was conducted at the site.

2021: ADEQ operated the SVE system intermittently throughout the year; soil vapor rebound sampling was performed in accordance with the SVE operation schedule. Semiannual groundwater monitoring was conducted in the spring and fall. The groundwater treatment system remained offline.

2020: ADEQ re-started the SVE system in January. The system operated intermittently throughout the year; soil vapor rebound sampling was performed in accordance with the SVE operation schedule. ADEQ installed six new double nested soil vapor probes and one triple nested SVE extraction well. Semiannual groundwater monitoring was conducted in the spring and fall. The groundwater treatment system remained offline.

2019: ADEQ installed two new groundwater monitoring wells. An aquifer step test was conducted utilizing new and existing monitoring wells. Semiannual groundwater monitoring was conducted in the Spring and Fall. Soil vapor rebound sampling was performed. The groundwater treatment and SVE systems remained offline.

2018: ADEQ installed three double-nested soil vapor probes. Soil vapor rebound sampling was performed. ADEQ installed three additional groundwater monitoring wells and continued monitoring the site’s groundwater. The Southwest Corner Source Area (SCSA) groundwater treatment and SVE systems remained offline.

2017: The groundwater remediation and treatment system and the SVE system were operated part of the year. The groundwater remediation and treatment system was shutdown to facilitate an in situ bioremediation pilot test. The SVE system was operable, but temporarily shut down in preparation for a rebound test. A proposed remedial action plan was issued in June, and regular groundwater monitoring continued throughout the year.

2016: The groundwater remediation and treatment system and the SVE system operated full time, with the exception of shutdown for the Salt River Project (SRP) canal cleanup and minor repairs. Groundwater samples were collected in March 2016 and indicate continued attenuation of contaminants of concern.

2015: The groundwater remediation and treatment system and the 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.

2014: The groundwater remediation and treatment system and the SVE system were operated full time with the exception of shutdown for minor repairs and granular activated carbon 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.

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 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.

2012: The Maricopa County Air Quality Department Air Quality Permit (Permit Number 070045 Revision 1.0.0.0) was renewed for the SVE system. The Arizona Department of Water Resources (ADWR) PQGWP Permit (Permit Number 59-588107.0000) was renewed. The ADEQ AZPDES Permit (Permit Number AZ0024848) was renewed. The City of Phoenix (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.

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 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.

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.

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.

2008: ADEQ installed two groundwater monitor wells in May. ADEQ detected increasing levels of tetrachloroethylene (PCE) in CC-11 on E. Orange Drive and in the Texaco wells at 5201 N. Central Avenue.

2007: ADEQ began the 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.

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.

2005: Based on the results of an Early Response Action (ERA) evaluation, an 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.

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.

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, on January 22nd. The treatment system removes volatile organic compounds 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 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.

2001: ADEQ initiated an 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.

2000: In June, the SCSA became listed as part of the site with a score of 32 out of 120.

1999: The 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 in the area. The eligibility and evaluation score for placement on the WQARF Registry was 31 out of 120.