Development of such a rule is essential before companies can build power plants that will capture and store their carbon dioxide to limit the buildup of global warming gases.
The agency acted under the Clean Water Act because injecting carbon dioxide might push pollutants into underground drinking water supplies, according to Benjamin H. Grumbles, assistant administrator for water.
This rule paves the way for technologies that would protect public health and help reduce the effects of climate change, he said.
But before companies begin such operations on a wide scale, Congress will have to work out the liability issues and establish a price or other limits on carbon emissions, he said. Experts say that more work is also needed to cut the cost of capturing carbon dioxide from smokestacks.
The rule, which would apply to well owners and operators, would require monitoring to trace the chemical, squeezed down into liquid form. A cornerstone of this rule is that the carbon dioxide stays where it is put, and not leak or be released to the surface, Mr. Grumbles said.
If the carbon dioxide did not behave as predicted, he said, injection would be promptly stopped.
Kurt Waltzer, an expert on sequestration of carbon at the Clean Air Task Force, a nonprofit group, said the proposal was an important step but were going to need much more to move carbon capture and storage forward.
Among other steps needed, he said, was a national climate policy.