A review conducted by independent nonprofit groups Environmental Integrity Project (EIP), Earthjustice, and the Stockholm Environment Institute’s U.S. Center at Tufts University, asserts that the EPA grossly overestimated the value of coal ash recycling, possibly preventing the passage of tougher regulations for the handling and disposal of fly ash and other coal combustion byproducts.

Prompted by the Tennessee Valley Authority’s massive fly ash sludge spill in 2008, the EPA’s 2010 announcement of a proposal to designate coal byproducts as hazardous waste caused an industry outcry. Opponents say the move would jeopardize several sectors that rely on recycled fly ash, an ingredient often present in building materials like wallboard and concrete. In response, the EPA’s regulatory proposal included a second option through which coal byproduct disposal would be regulated by the states.

Now, the EIP and its partners have released a new study. Using the EPA’s own empirical data, it finds that the agency’s estimate of recycling coal combustion residue results in annual life-cycle benefits at almost $23 billion is wholly inaccurate. Their analysis suggests an annual benefit of only $1.15 billion—20 times less. The group said the discrepancy arises from the government’s wish to appease industry stakeholders by pushing through weaker regulations, in light of the favorable cost-benefit analysis.

“Unfortunately, EPA and OMB just got this wrong,” said Environmental Integrity project director Eric Schaeffer in a release. “The ‘regulatory impact analysis’ prepared by EPA to support its proposal exaggerates the economic life-cycle value of coal ash recycling, which could end up stacking the deck in favor of the weaker regulatory option favored by industry.”

In the report published in late December, analysts said the EPA’s findings were faulty because they overestimated the amount of fine particle emissions prevented by recycling, and miscalculated the energy savings realized by recycling ash from cement kilns. The report also states that the agency’s numbers discount the quantifiable benefits of stricter standards, instead placing a huge dollar value on the stigma accompanying a hazardous waste designation for coal byproducts.

Stakeholders remain divided over whether a hazardous waste designation would help or hurt the industry. Though it is the only way for the EPA to obtain nationwide oversight, many use the current success and efficiency of existing state-mandated recycling programs as an argument against federal involvement.

Environmentalists, though, will see passage of weaker regulations as a win for the coal industry, arguing that another catastrophic sludge spill is imminent without stricter government controls. “It should come as no surprise that requiring safe landfills for coal ash is less costly than allowing ash dumps to contaminate water in hundreds of communities around the country,” said Earthjustice staff attorney Abigail Dillen. “What is surprising, in the face of this major public health threat, is that the books are being cooked to accommodate the coal industry.”