Vapor Intrusion Studies / Remediation

EEC has been on the forefront of vapor intrusion evaluation and remediation, and has been providing services at high-profile vapor-intrusion-impacted properties throughout the United States for more than 5 years. For many years, site assessment and remediation was limited to addressing two primary matrices: soil and groundwater. In recent years, however, issues related to subsurface vapors and indoor air have come to the forefront of the environmental consulting industry. This third media of concern is at the center of the regulatory debate and has been documented to be a serious health concern. EEC’s geologists, engineers, and scientists are leading the way to a greater understanding of vapor intrusion concerns and how to support our clients in mitigating these issues. EEC has been involved in projects ranging from the installation of sub-slab vapor depressurization systems to the assessment of soil vapor and indoor air for a residential development of more than 200 homes.

Services & Highlights
  • Soil vapor sampling
  • Sub-slab sampling
  • Indoor air sampling
  • Modeling
  • Risk assessment
  • Proposition 65 analysis
  • Installation of sub-slab depressurization systems


Featured Projects

Residential Vapor Intrusion Investigation

Industry: Petroleum / Legal

EEC was retained to evaluate vapor intrusion concerns for a residential neighborhood consisting of approximately 300 single-family residential homes. The neighborhood is underlain by contaminants related to three large former oil field reservoirs that were destroyed in-place. To evaluate vapor intrusion concerns, EEC conducted sub-slab vapor testing, indoor air testing, and outdoor ambient air testing, and analyzed the data to determine risk to human health. EEC provided front-line and one-to-one contact with each resident in the community and has developed an exceptional rapport with the residents.

Project Highlights
  • Residential tract with approximately 300 homes built on former crude oil storage reservoirs with 3.5 million barrel capacity
  • Installation of  sub-slab vapor probes inside residential homes under highly scrutinized conditions
  • Collection of indoor and ambient outdoor air samples
  • Extensive evaluation of environmental health risks
  • Comprehensive database containing more than 500,000 analytical results to support risk assessment and data analysis
  • High emphasis on communication with residents, community leaders, and media

Residential Petroleum Hydrocarbon Vapor Intrusion Investigation

Industry: Petroleum / Legal

EEC was retained to evaluate vapor intrusion impacts to residential homes and businesses resulting from a petroleum hydrocarbon plume estimated to contain approximately 30 million gallons of free phase petroleum hydrocarbons. The neighborhood was the location of whaling operations and petroleum refineries from the late 1800s to the late 1990s. EEC is investigating property devaluation and human health effects caused by this petroleum plume.

Project Highlights
  • Installed and sampled vapor monitoring wells throughout the community
  • Installed and sampled indoor air and sub-slab vapor points in basements and residential homes
  • Conducted ambient outdoor air monitoring, including the installation of a temporary weather station
  • Performed extensive human heath risk assessment on petroleum vapors

Petroleum Hydrocarbon Vapor Intrusion Investigation

Industry: Petroleum / Legal

EEC conducted a large-scale soil vapor intrusion investigation for a beach-side residential neighborhood to evaluate risk to the indoor breathing space as a result of multiple petroleum hydrocarbon releases from a nearby gasoline service station.  The investigation included indoor air sampling, sub-slab vapor sampling, and borehole soil vapor sampling.

Project Highlights
  • Conducted residential surveys prior to sampling indoor air
  • Conducted home inspections and an inventory of chemical and cleanser storage prior to sampling indoor air
  • Calculated risk to indoor air using Johnson & Ettinger (J&E) model based on analytical results of sub-slab and borehole soil vapor tests
  • Conducted background ambient air testing
  • Installed multiple permanent sub-slab and borehole soil vapor probes
  • Provided community updates of analytical results and expert opinion of risk to indoor breathing space

Manufactured Gas Vapor Intrusion Investigation

Industry: Manufactured Gas / Legal

EEC was retained to evaluate vapor intrusion concerns related to contaminants from a former manufactured gas plant in central Illinois. The investigation has included a detailed re-evaluation of previous site-assessment work, followed by the collection of sub-slab vapor samples and crawl space samples from residential homes within several blocks of the former facility. Laboratory testing has confirmed the presence of volatile organic compounds (VOCs). The investigation is ongoing.

Project Highlights
  • Coordination with neighborhood action alliance
  • Community meetings and interaction with City staff
  • Sub-slab and crawl space testing to evaluate vapor intrusion concerns
  • Analyses of potential human health risks
  • Prepared recommendations to the State for additional testing

Chlorinated Solvent Vapor Intrusion Mitigation

Industry: Commercial Laundry

EEC conducted a site assessment and remediation project resulting from releases of chlorinated solvents associated with dry cleaning operations. A sub-slab depressurization (SSD) and soil vapor extraction (SVE) system was installed to mitigate possible human health risks resulting from vapor intrusion within two weeks of risk identification. The indoor risk has been mitigated and source remediation is in process.

Project Highlights
  • Site assessment
  • Fast-tracked installation of sub-slab depressurization and soil vapor extraction system
  • Indoor air and soil gas sampling
  • Environmental audits
  • Multiple parties involved
  • High visibility
  • Public relations

  • Oil Field Vapor Intrusion

  • Residential Vapor Intrusion

  • Petroleum Hydrocarbon

  • Manufactured Gas Vapor

  • Chlorinated Solvent Vapor

Featured Projects - Shadow Padding

Latest News

In-Situ remediation refers to the cleanup of contamination in-place without the costly removal/ex-situ treatment of the soil and/or groundwater. In-situ remediation is often a logical choice for remediating a site due to the inherent cost savings; however, in some cases in-situ remediation is ineff...
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Office Locations

EECWorld Los Angeles OfficeLos Angeles Area Office
1 City Boulevard West Suite 1800
Orange, CA 92868
Phone: (714) 667-2300
Fax: (714) 667-2310
EECWorld Mid-Atlantic OfficeMid-Alantic Office
200 Harry S Truman Parkway, Suite 330
Annapolis, MD 21401
Phone: (410) 263-2234