In our quest to reduce global warming we need to ensure our drinking water remains safe. The EPA agrees. In its first regulations on the burial of carbon dioxide underground, the EPA last week announced measures to protect drinking water from the gas behind the bubbles in carbonated beverages. The fledgling technology, known as carbon sequestration, is critical to reducing carbon dioxide released into the air from coal-fired power plants, one of the country’s largest sources of the greenhouse gas.
“This rule paves the way for technologies that will protect public health and reduce the effects of climate change,” said Benjamin Grumbles, an assistant administrator in the agency’s water office.
The proposal includes a new category of injection wells solely for carbon dioxide storage, and creates extensive siting, testing and monitoring requirements to prevent leaks. The EPA already regulates injection wells used to boost oil production and dispose of hazardous and non-hazardous waste.
Carbon dioxide can turn water slightly acidic at high levels. This in turn leaches toxic heavy metals and other contaminants out of the surrounding rock and into water supplies, according to scientists. Injecting carbon dioxide underground can also push other pollutants, such as saltwater, into underground aquifers.
To date, the bulk of carbon dioxide being injected underground has been done to enhance oil production. But if coal-fired power plants begin embracing carbon sequestration technology, more of the carbon dioxide that come from smokestacks is expected to be entombed in microscopic spaces in underground rock. That could be a positive development. | 
