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Padding Lightly in Suisun Marsh
Suisun Marsh may be a haven for waterfowl and special-status mice and rails, but beneath its layers of life-rich muck and mud, lies a lesser-known resource-one that has recently come into great demand, thanks to the state's energy shortage. This year alone, the S.F. Bay Conservation and Development Commission (BCDC) has received nine applications and issued five permits for natural gas development in the marsh-a sharp increase from the historical pace of one application per year since the late 1960s.
Unfortunately for the marsh, reaching and extracting natural gas deposits is a complicated-and hardly environmentally benign-process. First steps involve seismic tests to develop three-dimensional maps of the geologic strata, then the drilling of 30-foot-deep holes and the setting off of explosive charges (gas locations can be determined based on the seismic energy released). Once a potential gas deposit is found, gas companies conduct exploratory drilling to determine its commercial viability. To get an even, stable surface for the drilling and equipment, they must clear vegetation and install pads and pilings. They then drill a 12-inch-wide hole down to about 1,000 feet, and from there a smaller hole down to 4,000 to 8,000 feet deep. If they find a good gas supply, the next step is to encase the hole and cement it into place. Extraction activities begin in earnest as monitoring and production equipment-including tanks for waste containment, heaters, separators, etc.-are brought to the pad. Post-extraction cleanup activities can involve both further disturbance and restoration, including the placement of large cement plugs in old wells, hole filling, equipment removal and seeding with native vegetation.
The marsh's many sensitive species-salt marsh harvest mice, California clapper and black rails, Suisun song sparrows, various species of waterfowl and shorebirds, and others-can all be disturbed by natural gas development activities, says Cal Fish & Game's Dennis Becker. "Suisun Marsh is to California what the Arctic National Wildlife Refuge is to Alaska," says The Bay Institute's Marc Holmes. "It should be preserved for wildlife; nothing else should happen there."
But drilling is going ahead. In June, BCDC staff began soliciting advice on the drilling and mitigation through meetings with federal, state, local agencies and the California Waterfowl Association. By October, BCDC had prepared a staff report on mitigation requirements.
"We're all trying to steer the gas companies away from the wetlands and to get them to use old, existing pads as much as possible," says Becker. Other mitigations include prohibiting drilling during sensitive breeding seasons and in the winter when migratory waterfowl and shorebirds cover the marsh. Adds BCDC's Michelle Levenson, "We're also encouraging them to use existing roads to build the pipes, and to camouflage their equipment." Resource agencies also want to see remote sensing used to monitor the wells to minimize traffic in and out of the marsh.
Agencies are also considering the idea of requiring gas development companies to submit one permit application for all anticipated natural gas development proposals within a given season and to monitor long-term subsidence in the marsh. "The idea is that the applicant would then have to provide a more detailed analysis of the cumulative impacts of all proposed activities," says Levenson.
Contact: Michelle Levenson (415)352-3659
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