The 40% figure is generally consistent with findings of the last decade. Runoff from agricultural lands and urban areas remains the primary source of the leading pollutants: siltation, bacteria, the nutrients phosphorus and nitrogen, and metals.

EPA Assistant Administrator for Water, J. Charles Fox, said, “It’s paramount that we clean up the nation’s remaining water pollution. Millions of Americans spend billions of dollars every year at their favourite waterways. Although most of our waterways are cleaner because of controls on direct discharges, the remaining polluted waters will only be cleaned up by addressing polluted runoff – a mix of contaminants that can include chemicals, metals, fertilisers and oily wastes.

“This summer, we will release a new program to help states address polluted runoff, so that we can once and for all restore the nation’s waterways,” said Fox. “American families deserve safer water.”

The l998 figures used reflect the states’ assessment of a third of the nation’s waterways. Among the states’ findings, over 290,000 miles of 840,000 miles of assessed rivers and streams do not meet water quality standards. States also assessed nearly half of all lakes, reservoirs and ponds, finding nearly half polluted. Of the Great Lakes, 90% of their shoreline miles were assessed; of those, 96% of the shoreline miles indicated pollution exceeding water quality standards to protect human health. Although threats remain, states found that ground water quality generally remains good and can support many different uses.

Action inspires action. Stay ahead of the curve with sustainability and energy newsletters from edie