Redevelopment of Former Gasoline Service Station Property For a Major Petroleum Retailer, Harwinton, CT





CEA conducted re-development of this former retail gasoline station property which lies in a mixed commercial and residentially-zoned area of Harwinton, CT. Upon removal of three (3) underground storage tanks, demolition of the station building, and collection of post-excavation soil samples for laboratory analyses, the Site was deemed suitable for reuse based on a review of the confirmatory sampling results.


  • On November 1, 2012, two (2) 8,000-gallon steel gasoline USTs and one (1) 8,000-gallon steel diesel UST were excavated and removed at the Site by CEA. Prior to removal, the USTs were cleaned and approximately 750 gallons of rinseate were removed via a vacuum truck and transported to United Oil Recovery (United) in Meriden, CT for recycling.
  • Approximately 100 cubic yards of petroleum-impacted soils were excavated and stockpiled onsite during the removals. Post-excavation soil samples collected from the limits of the excavation were submitted for laboratory analysis of Extractable Total Petroleum Hydrocarbons (ETPH) and Volatile Organic Compounds (VOCs) via approved methods.
  • On November 9, 2012, CEA obtained a building demolition permit from the Town and subsequently demolished the former service station building and placed demolition debris in roll-off dumpsters for off-site disposal. Approximately 50 additional cubic yards of petroleum-impacted soils were excavated from beneath the former station building.
  • On November 15, 2012, the septic tank was excavated from the location west of the former station building. Six (6) post-excavation soil samples were collected upon completion of the activity and composited into one (1) soil sample which was submitted for laboratory analysis of ETPH and VOCs via approved methods.
  • On November 15 and 19, 2012, the soil excavations were dewatered into a 21,000-gallon fractionation tank on-site. Groundwater was subsequently treated and discharged. Influent and effluent groundwater treatment samples were collected on November 19, 2012 and submitted to Accutest for laboratory analysis of ETPH in accordance with CTDEEP methodology and VOCs in accordance with Connecticut RCP methodology.
  • Upon completion of excavation and demolition activities, the former building/hydraulic lift area and UST excavations were backfilled and compacted in one-foot lifts using structural gravel borrow provided by O&G Industries of Harwinton, CT. Compaction testing was performed by Tri-State Materials Testing (TSMT) of Wallingford, CT. Nuclear density tests were performed using American Society for Testing and Materials (ASTM) method reference D 6938.
  • Between November 15 and December 4, 2012, approximately 545 tons of petroleum-impacted soils were transported off-site under non-RCRA hazardous waste manifests to Phoenix for recycling.
  • On January 24, 2013, a UST Closure Report was submitted to CTDEP, on behalf of a major petroleum retailer. Based on a review of all data collected to date, the Closure Report concluded that No Further Remediation of soils was warranted or required at the Site.