Peak Underground Working Natural Gas Storage Capacity — Sep 3, 2010: “This report provides estimates of aggregate peak working gas capacity and working gas design capacity for the U.S. underground natural gas storage as of April 2010. The estimates for national and regional peak working gas capacity are based on the demonstrated maximum working gas volumes for individual active facilities from May 2005 to April 2010. Peak storage estimates are based on monthly data by field from the Form EIA-191M survey, “Monthly Underground Storage Report,” which collects data on storage volumes as of the end of the report month.”