Both lakes had been declining because of acid rain, the investigators found. Bruce Lake was not touched while White Deer Lake was treated with 100 tons of limestone in February, 1985.

Acid rain can increase the dangers of lakes, rivers, and streams more than you might expect. When acid rain falls to the ground and flows into the soil, it absorbs aluminum from the surrounding soil.

Normal rain falls at 5.6 on the pH scale. Acid rain, however, usually falls between 4.2 and 4.4. Any type of precipitation that has more acid in than usual is typically classified as acid rain.

Acid rain is largely behind the phenomenon, the scientists say. It’s been eating away chunks of rock, especially limestone rock, and the runoff produces carbonates that flow into rivers.

Acid rain is largely behind the phenomenon, the scientists say. It's been eating away chunks of rock, especially limestone rock, and the runoff produces carbonates that flow into rivers.

The Acid Rain Program, fully implemented under the Clean Air Act in 2010, aims to reduce these effects by regulating the output of sulfur dioxide and nitrogen oxide emissions from power plants.

The acid rain scourge of the '70s and '80s that killed trees and fish and even dissolved parts of statues on Washington, D.C.'s National Mall is back. But unlike the first round, in which sulfur ...

Normal rain falls at 5.6 on the pH scale. Acid rain, however, usually falls between 4.2 and 4.4. Any type of precipitation that has more acid in than usual is typically classified as acid rain.