News

Computer Model Helps Minimize Water Pollution

The US Environmental Protection Agency lists stormwater as the primary cause of water pollution in the United States.
The US Environmental Protection Agency lists stormwater as the primary cause of water pollution in the United States.

Multimedia

Audio
Smitha Raghunathan

Roads, shopping centers and housing developments are generally seen as enhancing a community's quality of life. But they can also disrupt the delicate water cycle that provides food, recreation and hydration to communities.

When rain and melting snows flow over a city's streets, parking lots and sidewalks, that runoff picks up all kinds of pollutants such as residues of petroleum and pesticides, soaps and solvents, as well as pet and wildlife waste.

Too often, the run-off spills directly into local waterways. The U.S. Environmental Protection Agency, or EPA, lists stormwater as the primary cause of water pollution in the United States, and encourages local communities to develop management plans to treat run-off before it pollutes their rivers, lakes or streams.

Easy to use computer model

Bill Hunt, a professor of Biology and Agricultural Engineering at North Carolina State University, has developed an easy-to-use computer model to predict how landscape impacts water pollution.

"There are different ways of evaluating how well stormwater practices clean water … things like ponds and wetlands and permeable pavement."

The program asks users - developers or state regulators, for example - to enter a description of the local land types, such as parking lots, rooftops, roads, grasses or woods, along with any water treatment areas.

"This model essentially assesses how well (stormwater practices) work in a new way. And it's a break from the way states have done it previously."

Communities across the U.S. have become more aware of the dangers of untreated stormwater. Hunt's computer program gives them a useful new tool for addressing the problem.

The model works by using a relatively new understanding of the water filtration process. Engineers have found that wetlands, grassy fields and soil or sand filters can take in stormwater with different levels of pollution and release water with a relatively constant cleanliness. One important factor affecting the water quality is the area's temperature and rainfall, and Hunt's model is set up for the mid-Atlantic region of the United States. However, Hunt says the principles can easily be applied to other temperate climates.

Nitrogen and phosphorous

To encourage widespread use among land design firms and regulators, Hunt kept his computer model simple. It uses average yearly data in its computations, and focuses on only two major pollutants - nitrogen and phosphorous.

"If you have an imbalance, or literally too much nitrogen and too much phosphorous getting into those systems, you can essentially deplete the oxygen in that water. Which, in the end, without oxygen you have fish kills, and the like."

Phosphorous from detergents often contaminates urban stormwater, while nitrogen comes primarily from fertilizer use in agricultural areas. According to Ben Urbonas, president of the Urban Watersheds Research Institute, these nutrient contaminants tend to be more of a problem in closed water systems, like lakes, where concentrations can build up.

Wastewater first, then stormwater

In developing countries, the main source of water pollution is not stormwater, but waste water. Urbonas says communities there must focus first on developing a proper wastewater treatment system, using more complex models to plan collection and treatment.

"I think the priorities are totally skewed when people start looking at stormwater when in reality they need to be looking at what is the primary biggest culprit in what their receiving waters are being degraded by."

While many developing-world communities might not be ready for Hunt's runoff management model, Urbonas believes it is important for them to be aware of the pollutants present in stormwater even as they learn to manage their community's waste water.

A small community of design firms and regulators in North Carolina is currently testing the model, and after this trial period, it will be available free to the public on Bill Hunt's university faculty webpage.

This forum has been closed.
Comments
     
There are no comments in this forum. Be first and add one

Featured Videos

Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
Astronauts Train Underwater for Deep Space Missionsi
|| 0:00:00
...    
🔇
X
George Putic
July 30, 2015 8:59 PM
Manned deep space missions are still a long way off, but space agencies are already testing procedures, equipment and human stamina for operations in extreme environment conditions. Small groups of astronauts take turns in spending days in an underwater lab, off Florida’s southern coast, simulating future missions to some remote world. VOA’s George Putic reports.
Video

Video Astronauts Train Underwater for Deep Space Missions

Manned deep space missions are still a long way off, but space agencies are already testing procedures, equipment and human stamina for operations in extreme environment conditions. Small groups of astronauts take turns in spending days in an underwater lab, off Florida’s southern coast, simulating future missions to some remote world. VOA’s George Putic reports.
Video

Video Civil Rights Leaders Struggled to Achieve Voting Rights Act

Fifty years ago, lawmakers approved, and U.S. President Lyndon Johnson signed, the Voting Rights Act of 1965. The measure outlawed racial discrimination in voting, giving millions of blacks in many parts of the southern United States federal enforcement of the right to vote. Correspondent Chris Simkins introduces us to some civil rights leaders who were on the front lines in the struggle for voting rights.
Video

Video Booming London Property a ‘Haven for Dirty Money’

Billions of dollars of so-called ‘dirty money’ from the proceeds of crime - especially from Russia - are being laundered through the London property market, according to anti-corruption activists. As Henry Ridgwell reports from the British capital, the government has pledged to crack down on the practice.
Video

Video Hometown of Boy Scouts of America Founder Reacts to Gay Leader Decision

Ottawa, Illinois, is the hometown of W.D. Boyce, who founded the Boy Scouts of America in 1910. In Ottawa, where Scouting remains an important part of the legacy of the community, the end of the organization's ban on openly gay adult leaders was seen as inevitable. VOA's Kane Farabaugh reports.
Video

Video 'Metal Muscles' Flex a New Bionic Hand

Artificial limbs, including the most complex of them – the human hand – are getting more life-like and useful due to constant advances in tiny hydraulic, pneumatic and electric motors called actuators. But now, as VOA’s George Putic reports, scientists in Germany say the future of the prosthetic hand may lie not in motors but in wires that can ‘remember’ their shape.
Video

Video Russia Accused of Abusing Interpol to Pursue Opponents

A British pro-democracy group has accused Russia of abusing the global law enforcement agency Interpol by requesting the arrest and extradition of political opponents. A new report by the group notes such requests can mean the accused are unable to travel and are often unable to open bank accounts. VOA's Henry Ridgwell reports.
Video

Video 'Positive Atmosphere' Points Toward TPP Trade Deal in Hawaii

Talks on a major new trade agreement among 12 Pacific Rim nations are said to be nearing completion in Hawaii. Some trade experts say the "positive atmosphere" at the discussions could mean a deal is within reach, but there is still hard bargaining to be done over many issues and products, including U.S. drugs and Japanese rice. VOA's Jim Randle reports.
Video

Video Genome Initiative Urgently Moves to Freeze DNA Before Species Go Extinct

Earth is in the midst of its sixth mass extinction. The last such event was caused by an asteroid 66 million years ago. It killed off the dinosaurs and practically everything else. So scientists are in a race against time to classify the estimated 11 million species alive today. So far only 2 million are described by science, and researchers are worried many will disappear before they even have a name. VOA’s Rosanne Skirble reports.
Video

Video Scientists: One-Dose Malaria Cure is Possible

Scientists have long been trying to develop an effective protection and cure for malaria - one of the deadliest diseases that affects people in tropical areas, especially children. As the World Health Organization announces plans to begin clinical trials of a promising new vaccine, scientists in South Africa report that they too are at an important threshold. George Putic reports, they are testing a compound that could be a single-dose cure for malaria.
Video

Video 'New York' Magazine Features 35 Cosby Accusers

The latest issue of 'New York' magazine features 35 women who say they were drugged and raped by film and television celebrity Bill Cosby. The women are aged from 44 to 80 and come from different walks of life and races. The magazine interviewed each of them separately, but Zlatica Hoke reports their stories are similar.
Video

Video US Calls Fight Against Human Trafficking a Must Win

The United States is promising not to give up its fight against what Secretary of State John Kerry calls the “scourge” of modern slavery. Officials released the country’s annual human trafficking report Monday – a report that’s being met with some criticism. VOA’s National Security correspondent Jeff Seldin has more from the State Department.
Video

Video Washington DC Underground Streetcar Station to Become Arts Venue

Abandoned more than 50 years ago, the underground streetcar station in Washington D.C.’s historic DuPont Circle district is about to be reborn. The plan calls for turning the spacious underground platforms - once meant to be a transportation hub, - into a unique space for art exhibitions, presentations, concerts and even a film set. Roman Mamonov has more from beneath the streets of the U.S. capital. Joy Wagner narrates his report.
Video

Video Europe’s Twin Crises Collide in Greece as Migrant Numbers Soar

Greece has replaced Italy as the main gateway for migrants into Europe, with more than 100,000 arrivals in the first six months of 2015. Many want to move further into Europe and escape Greece’s economic crisis, but they face widespread dangers on the journey overland through the Balkans. VOA's Henry Ridgwell reports.
Video

Video Stink Intensifies as Lebanon’s Trash Crisis Continues

After the closure of a major rubbish dump a week ago, the streets of Beirut are filling up with trash. Having failed to draw up a plan B, politicians are struggling to deal with the problem. John Owens has more for VOA from Beirut.
Video

Video Paris Rolls Out Blueprint to Fight Climate Change

A U.N. climate conference in December aims to produce an ambitious agreement to fight heat-trapping greenhouse gases. But many local governments are not waiting, and have drafted their own climate action plans. That’s the case with Paris — which is getting special attention, since it’s hosting the climate summit. Lisa Bryant takes a look for VOA at the transformation of the French capital into an eco-city.

VOA Blogs