Stafford County, Virginia
Project Summary
In February of 2011 Stafford County Fire and Rescue (SCFR) responded to a report of a methane release in the Woodstream neighborhood near the intersection of Woodstream and Short Branch Roads. The evening prior to the SCFR report Columbia Gas of Virginia had responded to a customer call-in reporting an odor. Columbia Gas confirmed that its gas lines were not leaking or the cause of any detected methane.
When SCFR arrived onsite, and required evacuation of certain townhouse units to protect the public until the source of the methane could be identified. Columbia Gas and Dominion Generation had cutoff utilities to seven townhouse units. Stafford County contacted Resource International for on-site assistance, and Resource provided personnel to the site within 2 hours to assist with real time methane monitoring.
Strategy and Services
Resource and SCFR, in coordination with the Virginia Department of Emergency Services, the Virginia Division of Mines, Minerals, and Energy, the United States EPA, and the Virginia DEQ, designed a field and laboratory investigation to review and rule out potential sources of the methane. Once implemented the field investigations identified the source of the methane to be natural occurrence in the soils. The soils consist of weathered rock of the Quantico Formation, a mix of slate, graphite schist, and phyllite. During the geologic formation of the Quantico Shale methane gas was entrained in the rock where if remained for millions of years until the rock was disturbed. Simple digging at the construction site release released this gas that was detectable but also dissipated into the atmosphere.
Preliminary investigation suggested that the disturbed soils would return to equilibrium and stop releasing methane. This information allowed SCFR to allow occupancy of the evacuated dwellings.
Resource followed up with a full report, including recommendations relative to future development in the area. At no time during or after this investigation was there any report of methane combustion or subsequent hazardous situation identified for the community.
