Nitrogen and Phosphorus 'Nutrients' Pollute Nation's Waterways

Capital News Service
WASHINGTON - Nitrogen and phosphorus continue to pollute waterways across the nation, according to a briefing by the United States Geological Society Friday.
Excess nitrogen and phosphorus from both agricultural and urban environments seep into groundwater and run off into streams and rivers, which empty into coastal wetlands like the Chesapeake Bay.
Nitrogen fuels the growth of algae, which -- in bloom -- blocks sunlight from underwater grasses. When nitrogen decays, it depletes the amount of oxygen in the water, according a report released Friday by the United States Geological Society.
"We're losing aquatic life because of algae in the system," said Bob Miltner, an aquatic biologist for the Environmental Protection Agency of Ohio, at the briefing.
The problem is especially acute in the Chesapeake Bay, as well as Puget Sound, Lake Erie and the Gulf of Mexico near the Mississippi River, according to the report.
And scientific modeling predicts that in years to come, algae in areas "with higher nutrients (like nitrogen and phosphorus) will be more pervasive, including around the Chesapeake Bay," said Neil Dubrovsky, chief of the Nutrient National Synthesis program of the United States Geological Survey.
Nitrogen and phosphorus pollution in the Chesapeake Bay has been fueled in recent years not just by agricultural activities, but also by rapid development and population growth.
Over the past "15 to 20 years, (we've seen) huge increases in the human population" around the Chesapeake Bay, says Jenn Aiosa, a senior scientist at the Chesapeake Bay Foundation.
"We're putting all these advanced technologies in place" to decrease the amount of nitrogen and phosphorus in the bay, "yet we're adding more polluters, so when you add those things up…it might not look like we're making a whole lot of progress" in cleaning up the Chesapeake, Aiosa added.
In the Chesapeake Bay, half of all phosphorus pollution comes from urban environments, and the other half comes from agricultural environments, said Ephraim King, director of the United States Environmental Protection Agency's Office of Science and Technology, at the briefing.
Half of the nitrogen in the bay comes from agriculture, while a third comes from the urban environment, and the rest comes from the atmosphere, he added.
Urban sources for these nutrients include wastewater treatment plants, storm-water runoff and electricity generators such as coal-fired plants, Aiosa says.
But there is hope. In addition to the new pollution diet, there have been many upgrades to sewage treatment facilities in recent years, and funding mechanisms are in place to assist with the upgrades, Aiosa adds.
And on farms, Maryland's Nutrient Management Program has been in place for the past dozen years to help ensure that "the appropriate amount of fertilizer -- and not more -- is applied" to crops, says Sue DuPont, communications director for the Maryland Department of Agriculture.