In questioning the delay and overall study, the letter signals Vitter plans to make good on comments that he would use his ranking-member slot to focus on fracking.
“Immediately upon its initial release, serious substantive concerns were raised, not only in regard to the quality of the science and methodology used by EPA, but also as to the findings and conclusions drawn from that flawed data and process,” Vitter said in the letter.
Fracking involves injecting a high-pressure mixture of water, sand and chemicals into tight rock formations to tap hydrocarbons buried deep underground. It has been credited with driving the domestic shale oil-and-gas boom.
The Wyoming study has served as a flashpoint in the battle between industry, and its congressional allies, and the White House on how to regulate fracking.
The Interior Department is set to finalize rules this year that will govern fracking that occurs on federal lands.
The rules will require disclosure of chemicals that companies are injecting underground. They will also establish requirements for managing so-called flowback water and ensuring well integrity to prevent fracking fluids from seeping into groundwater.
Industry and Republicans are fighting the rules. They contend that states are sufficiently managing fracking, and that federal standards would be duplicative and overly prescriptive.
But the Obama administration has said it needs to put down safety and environmental protections for a drilling method fossil fuel producers are using ever more frequently.
EPA stressed in its 2011 draft that the Wyoming fracking wells were different from many others because they were “taking place in and below the drinking water aquifer and in close proximity to drinking water wells.”
Still, environmental groups viewed the report as validation of their fears that fracking is unsafe.
The report earned a quick and harsh rebuke from the natural-gas industry and its congressional supporters.
Industry said many of the contaminants EPA found in those two Wyoming wells occur naturally. It noted that the U.S. Geological Survey (USGS) invalidated one of the two wells in a September report because its water level was too low.
EPA said at the time that the USGS findings were “generally consistent” with their own.
Vitter asked Jackson to answer why EPA “ignored multiple data sources” that mentioned naturally occurring pollutants. He also asked Jackson to explain what he called “poor quality sampling and laboratory methods.”
“The draft report’s content and conclusions, which are premature at best, suffer from criticism levied [sic] not only from other federal agencies within the administration but that are echoed by issues brought forward by State of Wyoming officials and various stakeholders,” Vitter said.
EPA is currently conducting a comprehensive national fracking study that will evaluate some of the environmental and public health matters raised in the Wyoming report. Its results are due next year.
Vitter said he is worried the agency would use the same methods it did in Wyoming in its national survey.
“Given the serious flaws in EPA’s scientific processes with regards to investigating hydraulic fracturing, how can the agency possibly plan on using this study as an authoritative document to potentially justify future regulations?” Vitter said.