CO₂ a threat under Clean Water Act?

The Obama administration took another step toward regulating carbon dioxide, issuing a notice Tuesday that the Environmental Protection Agency will review whether those emissions should fall under the Clean Water Act.

The EPA earlier this year determined that C02 should be regulated under the Clean Air Act due to its impact on temperatures. But Tuesday's notice — soliciting scientific data as to what extent seas are made more acidic by C02 — could extend regulation out to U.S. waters.

The notice was in response to a petition filed by the Center for Biological Diversity, which wants the EPA to impose stricter pH criteria for ocean water quality and publish guidance to help states protect their waters from ocean acidification, which reduces pH levels.

"As more CO2 dissolves in the ocean, it reduces ocean pH, which changes the chemistry of the water," the EPA said in its notice. "These changes present potential risks across a broad spectrum of marine ecosystems."

"Preliminary projections indicate that oceans will become more acidic over time and overall, the net effect is likely to disrupt the normal functioning of many marine and coastal ecosystems," it added.

Miyoko Sakashita, a Center for Biological Diversity attorney, called acidification "likely the greatest threat to the health of our oceans."

"The federal government has finally acknowledged that ocean acidification is a threat," Sakashita added. "Now it must take the next step and fully implement the Clean Water Act to protect our nation’s waters from 'the other CO2 problem.'"

The EPA said that among the input it hopes to gather is a national study commissioned last September by the National Oceanic and Atmospheric Administration. That study is expected to take 18 months to complete.

The EPA said it hoped to make a decision within one year.

Last month, the EPA sent to the White House its recommendation that carbon dioxide be considered a pollutant under the Clean Air Act.

President Barack Obama could give the agency a green light to pursue regulating the gas, but Democrats in Congress are also moving in that direction. The administration has suggested it would prefer to have Congress deal with regulation via a system that caps emissions, then allows industry to trade allowances.

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