Surface waters include rivers, streams, lakes, reservoirs, and wetlands. Most of the improvement in surface water quality in Iowa over the last 25 years is directly related to pollution control programs created by the Federal Water Pollution Control Act Amendments of 1972 (commonly referred to as the "Clean Water Act"). This legislation and the control programs it established have been very successful in correcting the most serious water quality problem in the state during the first three quarters of this century: the discharge of untreated or poorly-treated wastewater from municipal and industrial wastewater treatment facilities into the state's streams and rivers. Important water quality problems, however, remain. These problems include over 150 years of alterations to streams and rivers such as channel straightening, removal of trees from stream banks, and overpasturing of livestock on stream banks. Rainfall runoff from agricultural and urban areas sometimes carries excessive amounts of sediment, plant nutrients, toxics substances, and oxygen-demanding substances that can cause serious water quality impairments to Iowa's lakes, rivers and streams. The increasing number of large, confined animal feeding operations and the pollution threat posed by disposal of animal waste presents a new water quality concern. Millions of acres of wetlands--especially in northern Iowa--were drained and converted to farm land as part of the development of intensive agricultural in the state. Today, state and federal programs exist to help protect the relatively few acres of wetlands that remain as well as the plants and animals that need wetland habitats to survive.

Groundwater is an extremely valuable natural resource in Iowa. Most public and private water supplies in the state utilize groundwater. Good quality groundwater is available in sufficient quantity to meet most water supply needs throughout the state. Naturally occurring problems with water quality and accessibility, however, prohibit use of such sources in much of the sourthern and western portions of the state. In general, natural groundwater quality is good in shallow aquifers. But, shallow aquifers are more susceptible to man-made contamination than are deeper aquifers. Naturally occurring levels of dissolved minerals and radioactive materials limit use of some groundwater, especially in deeper aquifers. Concerns with the quality of Iowa's groundwater led to the passage of the Iowa Groundwater Protection Act of 1987. This legislation established demonstration programs, well protection programs, and education initiatives, as well as initiated planning for a statewide groundwater monitoring program. The level of funding for these programs, however, has declined over the last 10 years, and some of the initiatives were not completed. Major concerns regarding groundwater involve human activities that can contaminate groundwater. Agricultural chemicals, industrial/urban sources, landfills, underground storage tanks, agricultural drainage wells, livestock wastes, and improper management of hazardous substances all contribute to groundwater degradation. The primary man-made contaminants in Iowa groundwater include nitrate, agricultural pesticides, volatile organic compounds (including fuels and solvents), metals, and bacteria.