What is the total working gas capacity in underground natural gas storage?
There are several ways that total underground working gas capacity may be measured. The Energy Information Administration (EIA) estimates that as of the end of April 2009, the aggregate peak working gas capacity for U.S. underground natural gas storage was 3.889 trillion cubic feet (Tcf). Working gas design capacity, an alternative, less conservative indicator of gas storage capacity, was 4.313 Tcf as of the end of April 2009.