The Trump administration said this week it will lower American electric bills by delaying an EPA rule requiring coal-burning power plants to reduce discharges of toxic wastewater. But the EPA analysis justifying that decision paints a more complicated picture. It shows the long-term costs of allowing coal plants to continue with outdated water pollution controls could exceed potential cost savings. Coal plants draw large volumes of water to create steam to drive turbines that produce electricity. But when plants discharge that water, it carries mercury, lead, cadmium, bromide and nitrogen into rivers, lakes and streams that are also used as sources of drinking water.