Beacon passive gas sampling saves big bucks

20 October 2022


An interesting case study from Phoenix Environmental in the USA, provides insights into how Beacon’s Passive Gas Sampling can provide fast and inexpensive site evaluation data.


This brownfield property, which was vacant for seven years, consisted of 84 acres of land, a 500,000-square-foot industrial building and was previously used as an automotive part manufacturing plant. Based on prior environmental reports, numerous environmental concerns were present which were complicating its sale. These included a 250,000-gallon diesel storage tank, a 10,000-gallon solvent wastewater tank, numerous hydraulic pits and reports of spills and cleanups throughout its 30-year operation. The buyer wanted a high level of confidence the property was unaffected by environmental issues, which is where Phoenix Environmental stepped in.


Due to the number of RECs and the predicted cost to investigate using standard investigative techniques, Phoenix suggested using passive soil gas sampling techniques to rapidly evaluate the environmental issues. Passive gas sampling was to be followed up by installing 20 soil borings to assess any “hot spots.” The activities included:

  • An electromagnetic (EM) / ground penetrating radar (GPR) survey
  • Installation of 69 BEACON® Passive Soil-Gas (PSG) Samplers
  • Chemical analysis of results to ensure levels were within Tennessee Department of Environment and Conservation (TDEC) guidelines

The client indicated its risk tolerance for this site was extremely low. After discussing risks and potential liabilities with the client, Phoenix finalized the reports.


Passive gas sampling identified several areas on the site where impacts were present. These impacts were limited in nature and did not appear to be migrating offsite or to pose a concern. Due to the client’s low risk tolerance, it requested a conservative approach be taken to the impacts. Phoenix, therefore, recommended additional assessment to quantify impacts in soil, soil-gas and groundwater.

Phoenix’ recommendation to use passive soil gas sampling allowed the client to save $100,000 and allowed the client to evaluate the property adequately within its due diligence period.

For more about the best technology, techniques and data for informed decision making using Passive Soil Vapour Measurement, watch our recent webinar.