Objectives Remediation of Petroleum Impacted Soil and Groundwater Associated with a Former Fueling Facility as required under State Regulations.
Location 4004 South Park Ave.
Waste Acreage N/A
Operation Dates
Status Active Clean-up Site
Type Leaking Underground Storage Tank Project
Annual Budget approximately $95,000
Contact City of Tucson - Environmental Services 520-791-3175
Description The Thomas O. Price Service Center is a primary fueling facility for the City of Tucson, and has been in operation since 1972. The facility is located at the southwest corner of Ajo Way and Park Ave. (Thomas O. Price Service Center Site Map). Historically, the facility maintained 23 underground storage tanks (USTs) for gasoline and diesel. During the late 1980s, the UST system was found to have leaked an unknown amount of fuel into the soil below the fueling tanks, dispensers, and delivery piping. The tanks were emptied and removed from service in the early 1990’s. Gasoline had migrated to a clay layer 90 feet below the site (in the upper groundwater zone), and has since migrated to the north of Ajo Way and beneath Fire Station 10. Today the City operates two soil vapor extraction systems (SVE) to remove contamination from the soil, and also pumps the gasoline from the upper groundwater zone above the clay. Currently, the City monitors 67 shallow and lower groundwater monitoring and remediation wells annually to detect the gasoline and dissolved benzene in the upper groundwater zone and MTBE in both the upper and lower groundwater zones. Benzene exceeds the regulatory standard in the perched groundwater zone. All work is completed under the oversight of Arizona Department of Environmental Quality (ADEQ) Leaking Underground Storage Tank (LUST) Program accordance with the Corrective Action Plan Modification, dated February 11, 2002.
Additional Info Although groundwater contamination has been detected above state action levels, there are no Tucson Water drinking water wells nearby.
Activities Groundwater Monitoring, Soil Remediation
Last Update Monday Jul 1, 2013
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Project Details

  • Updates
  • Pictures
  • Attachments


  • November 2014
    The City submitted the annual monitoring report to ADEQ covering the January - December 2013 period. The report is available in the Reports/Attachments section of the website.
  • March-April 2014
    The City completed the annual groundwater monitoring event, including collection of 67 depth to water measurements and 44 groundwater samples. These results and remedial efforts during the 2014 calendar year will be documented in an annual monitoring report due to the Arizona Department of Environmental Quality in April/May 2015.
  • July 22, 2010
    The ADEQ approved the City’s request to revise the corrective action plan (CAP) to 1) remove nitrate/nitrite from the analyte list, and 2) begin no-purge, grab method for groundwater sample collection. Implementing both of these changes saves the City approximately $9,000 annually on direct groundwater monitoring costs, and decreases staff field time by 65%.
  • 2006, 2007, 2008
    The City installed 11 additional groundwater monitoring, soil vapor extraction, and gasoline recovery wells to assist with groundwater characterization and remediation. Today there are 56 shallow groundwater and/or remediation wells set above the clay layer, and 11 groundwater monitor wells set within the regional aquifer.
  • March 1997, January 2001, & February 2002
    Revised Corrective Action Plans (CAPs). The final clean-up plan still in effect today at PSC is vadose zone source removal by SVE (started in February 1996). At Fire Station 10 (north of Ajo Way) gasoline is removed using skimmer pumps (started in 1997) and vacuum extraction (started in October 2004).
  • April 1998
    Gasoline was discovered downgradient of PSC beneath Tucson Fire Station No. 10, north of Ajo Way.
  • February 1996
    Full scale soil vapor extraction system began operation at PSC. Prior to that, the City operated a smaller SVE system from April 1995 - February 1996 to test the feasibility of implementing this type of clean-up and as an interim remedy until the final (and bigger) system was developed.
  • February 1995
    ADEQ approved the City’s CAP to use soil vapor extraction (SVE) for soil clean-up and pump & treat for groundwater clean-up.
  • September 1993
    Consent Order signed by the City and ADEQ. The order provided the compliance schedule for the City to produce and implement soil and groundwater corrective action plans. The order was terminated in April 1997 when all objectives had been met.
  • 1989-1994
    The City initiated subsurface and groundwater investigations by taking subsurface soil samples and installing groundwater and soil vapor wells.
  • June 1989
    Fuel leakage detected at Price Service Center fueling area.