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PUBLIC NOTICE | Proposed Leaking UST Case Closure for Case File 4457.02-.03

ADEQ is considering closure of the following leaking underground storage tank (LUST) case:

LUST Case File No.: 4457.02-.03

Facility ID No.: 0-004247
Cochise County

Facility address: 
Giant #659
101 East 16th Street
Douglas, AZ 85607


This commercial property (the Site) is located at 101 E. 16th Street in Douglas. Douglas is located in southeastern Arizona in the Sulphur Springs Valley in Cochise County.  The valley extends into eastern Sonora, Mexico.  The Site is currently being operated as a retail petroleum station and convenience store.  The site is owned by Western Refining, Inc. and operates as Giant #659, a branded Chevron station.

A property transfer between Sahara Oil Company and Texaco Refining and Marketing Company in 1996 included a Preliminary Site Assessment (PSA) that included the UST system.  Nine soil borings were installed, and soil samples were collected and analyzed on site using a mobile laboratory for total petroleum hydrocarbons (TPH) and select samples were analyzed for benzene, toluene, ethylbenzene and xylenes (BTEX). TPH and/or BTEX was found in the soil at concentrations that exceeded applicable regulatory standards.

ADEQ assigned LUST release numbers 4457.01-.03 in October 1997 based on the soil data collected during the PSA. The UST system was installed in 1986 and is still in use. The UST owner/operator was identified as Texaco Refining and Marketing Company, now Shell Oil Products US (Shell).  Shell has conducted corrective actions that included soil and groundwater characterization activities. Several on site and off site monitoring wells were installed beginning in 1996.  Historic groundwater monitoring continued between 2000 and 2009 by several different consultants for Shell.  Historic volatile organic compound (VOC) concentrations in groundwater have exceeded applicable aquifer water quality standards. (AWQS). A Corrective Action Plan was submitted in 2004.

A soil vapor extraction (SVE) system was installed in 1996 and was intermittently used.  The SVE system operated until March 2010 when it was converted to dual-phase extraction (DPE).   It is not known when the system was stopped.   LUST release 4457.01 was closed in April 2010.  A pilot study was conducted to evaluate the use of carbon-based injectate (BOS 200®) in 2014, and the results appeared promising since the VOC contamination concentrations decreased in monitoring well (MW)-2 and MW-6, where the injections were done.

In February 2015, Groundwater & Environmental Services, Inc. (GES) assumed management of the site for Shell.  GES has conducted quarterly groundwater monitoring since then.  Shell submitted a Corrective Action Completion Report dated May 4, 2017. Additional groundwater sampling was conducted and Shell submitted a Corrective Action Completion Report-Addendum on April 6, 2018. MW-1 and MW-8 show benzene contamination present over AWQS.

A site specific risk assessment and detailed file/information search have been completed. Based upon the results of  remedial activities and site specific information provided by GES, the above-referenced LUST site is eligible for alternative LUST closure under Arizona Revised Statutes (A.R.S.) §49-1005(E).  Arizona Administrative Code (A.A.C.) R18-12-263.04 (A) and (B) allows case closure of a LUST site with groundwater contamination above the AWQS or Tier 1 Corrective Action Standards.

Review Document 

Review results of remedial activities and entire public notice | View/Print >

Public Comment Period 

Dates: June 18, 2018  July 18, 2018

Comments may be submitted as follows:
     By Email | Send Email > 
     By Mail (Must be postmarked or received by July 18, 2018):

       Debi Goodwin
       Waste Programs Division
       1110 W. Washington Street
       Phoenix, AZ  85007 

Documents may also be reviewed in person at the ADEQ Record Center | Learn More >