SF CHRONICLE - 3/23/01  "NEWS BRIEFS"

A recommendation on the best way to disperse methane gas in a landfill near the 235-home Shea Homes development in Novato is due on March 30, a project manager said today. 

A consultant to the Army Corps of Engineers will submit a report to the San Francisco Bay Region's Water Quality Control Board by the end of the month, according to Jim McAlister, project manager for the Corps' Sacramento District. 

In 1999, methane gas was found beneath the landfill at the former Hamilton Air Force Base. Although the landfill was capped in 1995, the gas is spreading through the soil toward the Shea Homes development. Construction on some of the homes has ceased. 

The Corps is monitoring the gas, which is not harmful if inhaled but can be combustible if it collects in a contained area. Venting the landfill, extracting and treating the gas and pumping oxygen into the landfill are among the alternatives for removing the methane gas, McAlister said. 

McAlister said the source of the gas is unclear. Industrial, commercial and domestic waste was buried in the landfill until 1974. Petroleum solvents, pesticides, low level PCBs and some metals were buried in the landfill, McAlister said. 

"There are indications there may be more methane than originally thought. More probes are going in next week," McAlister said this morning.