From WebRef.org
Jump to: navigation, search

Abnormally acidic (low pH) precipitation (or dry deposition) resulting from emissions of sulfur and nitrogen compounds that transform during chemical processes in the atmosphere. Acid deposition can affect the chemistry of soils and acidify lakes, adversely affecting forests and fish. It does not adversely affect cropland. The Clean Air Act includes a program focused on controlling precursor emissions of acid deposition—primarily sulfur oxides from coal-fired electric utilities.