Project Portfolio

Soil Gas Monitoring
Soil Gas Monitoring Program at the Domestic Commercial Fishing Village, Honolulu Harbor, Hawaii

PCSI is supporting the Hawaii Department of Transportation, Harbors Division, through a long-term, environmental monitoring program at contaminated sites in Honolulu Harbor.  Piers 35 to 38 of Honolulu Harbor, once used for petroleum refining and storage, now house a commercial fish auction, restaurants and retail stores.  Underlying soils at the site were contaminated with petroleum releases over decades of prior use.  Natural degradation of the spilled fuels led to the formation of methane gas in the soils, creating a potential risk of explosion for buildings near the contamination.

The State hired PCSI to monitor subsurface conditions at the Harbor over a two-year span.  PCSI is responsible for periodic testing of soil gas across the 18-acre site and for testing and maintaining a system of permanent probes used to collect the soil gas.  Real-time field monitoring of soil gas, coupled with confirmatory sampling and analyses of select samples, is being conducted to track conditions over time and evaluate the impact of changes in observed conditions.

PCSI developed the Soil Gas Monitoring Plan used to evaluate the site, and coordinated approval of the Plan with the State of Hawaii Department of Health (DOH).  PCSI is also responsible for semi-annual reporting of site conditions, monitoring results, and methane migration potential for review and approval by the DOH.