WASHINGTON Regulators said on Tuesday they have asked Chesapeake Energy to give information on any hazardous substances released by a Pennsylvania natural gas well that blew out last week.
The regional U.S. Environmental Protection Agency has asked for details, including sources of the discharge and the extent of environmental damage.
"We want a complete accounting of operations at the site to determine our next steps in this incident and to help prevent future releases of this kind," said Shawn Garvin, the EPA regional administrator.
The EPA said it requested the information on Friday about fluids used at the well in hydraulic fracturing, which is also known as fracking. Pennsylvania is taking the lead in investigating the blow out.
Chesapeake said it intends to comply with EPA's request and has already communicated with the agency about its response to the incident. Chesapeake is one of the gas producers that voluntarily reveals the fracking fluids it has used at completed wells.
The EPA is conducting a two-year study on the safety of fracking and its impact on drinking water. Initial results of the peer-reviewed study are expected in late 2012.
In fracking, drillers blast water, chemicals and sand deep underground to break rocks and release natural gas.
The EPA also asked Chesapeake whether radiological compounds were present in the fluids or sediment generated as part of the development of the well and effects on any drinking water supplies.
Chesapeake, one of Pennsylvania's biggest shale gas producers, last week suspended all seven of its fracking operations in the state after the incident released thousands of gallons of drilling fluid into the surrounding area.
On Monday Chesapeake said it replaced a damaged wellhead and gained control of the well that gushed the fluids. Since the well blow out on April 19, Chesapeake shares have risen 3 percent, mirroring a similar rise in the S&P 500.
The U.S. EPA said its information request was authorized under the Clean Water Act and other statutes.
One analyst said the federal government may keep a close eye on fracking operations after Congressional hearings questioned the quality of the oversight.
"Enhanced oversight from the federal EPA is to be expected," Christine Tezak, an energy policy analyst at Robert W. Baird and Co, said in a research note on Tuesday.
(Reporting by Timothy Gardner, additional reporting by Edward McAllister in New York; Editing by Lisa Shumaker)