More than half of America’s rivers and streams are now unable to support life after decades of pollution, it was revealed yesterday.
The bulk of the damage has been done by agricultural fertilizers such as phosphorus and nitrogen washing from fields into waterways.
In total, 55 per cent of rivers and streams were classified by the Environmental Protection Agency as being ‘poor’, with only a fifth in good health.
The agency sampled nearly 2,000 locations in 2008 and 2009 – from rivers as large as the Mississippi River to streams small enough for wading.
The study found more than 55 per cent of them in poor condition, 23 per cent in fair shape, and 21 per cent in good biological health.
The most widespread problem is high levels of nutrient pollution, caused by phosphorus and nitrogen washing into rivers and streams from farms, cities, and sewers.
High levels of phosphorus – a common ingredient in detergents and fertilizers – are found in 40 per cent of rivers and streams.
Another major problem is over-development, as land clearing and building along waterways increases erosion and flooding, allowing more pollutants to enter waters.
‘This new science shows that America’s streams and rivers are under significant pressure,’ said Nancy Stoner, from the EPA’s water office.
‘We must continue to invest in protecting and restoring our nation’s streams and rivers as they are vital sources of our drinking water, provide many recreational opportunities, and play a critical role in the economy.’
Conditions are worse in the East, the report found. More than 70 per cent of streams and rivers from the Texas coast to the New Jersey coast are in poor shape.
Streams and rivers are healthiest in sparsely populated Western mountain areas, where only 26 per cent were classified as in poor condition.
The EPA also found some potential risks for human health. In 9 per cent of rivers and streams, bacteria exceeded thresholds thought to endanger health.
The toxic chemical mercury was found in fish along 13,000 miles of streams at levels exceeding health-based standards.
Mercury can enter the environment from coal-burning power plants and from burning hazardous wastes. The Obama administration finalized regulations to control mercury pollution from coal-burning power plants for the first time in late 2011.