Dominion Virginia Power has dedicated a new "scrubber" at its Chesterfield Power Station that will remove 95 percent of sulfur dioxide emissions and 90 percent of its mercury emissions. The equipment is part of $650 million in environmental investments that the company plans to make in the facility.

The system, known as "flue gas desulfurization," combines pulverized limestone with water and sprays the mixture into the exhaust gas. The mixture removes acid-rain-causing sulfur dioxide and toxic mercury from the flue gas. Byproducts include gypsum, which can be turned into drywall, and water vapor, which billows out a tall stack as a white plume. The gypsum will be barged to a company in Norfolk, which will use it to manufacture drywall.

Later, Dominion plans to install equipment to reduce particulate emissions as well as nitrogen oxide, a contributor to low-level ozone.

The Chesterfield plant has a generating capacity of 1,660 megawatts, or enough to power more than 400,000 homes at peak demand. Read more.