Case study highlights:

  • PetroFix achieved rapid and sustained MTBE reductions below cleanup objectives
  • At only 8% of the cost of a monitoring only approach, PetroFix saved more than $1 million for this project
  • West Central Environmental Consultants (WCEC) designed the remedy using the PetroFix Design Assistant™, backed by REGENESIS technical support

This case study reviews a successful PetroFix application that placed a Washington underground storage tank (UST) site on track for closure while saving more than $1,000,000 in comparison to alternate approaches considered at the site. The site is a former service station and bulk petroleum plant in Sunnyside, Washington, where petroleum hydrocarbons were discovered leaking from USTs in the late 1990s. WCEC, an environmental consulting company highly experienced in addressing petroleum-contaminated sites, investigated the site and observed light non-aqueous phase liquids (LNAPL or free product). In response, WCEC completed interim remedial measures, including excavating grossly impacted soils and installing a free product recovery system. WCEC completed further remedial investigation over the next several years. In Situ remediation activities began in the early 2000s with the injection of oxygen enhancing amendments to stimulate biologically-mediated aerobic oxidation of petroleum hydrocarbons. Investigation and oxidation injections were expanded to address other impacted site areas in phases. Although the oxygen enhancement injections reduced the hydrocarbon mass, soil and groundwater contamination remained, including MTBE (methyl-tert-butyl-ether) concentrations exceeding the Washington Department of Ecology’s action level.