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.
Olympics Construction Scars Sacred Korean Mountaini
X
July 02, 2015 4:10 AM
Environmentalists in South Korea are protesting a Winter Olympics construction project to build a ski slope through a 500-year-old protected forest. Brian Padden reports that although there is strong national support for hosting the 2018 Pyeongchang Winter Olympics, there are growing public concerns over the costs and possible ecological damage at the revered mountain.
Video

Video Olympics Construction Scars Sacred Korean Mountain

Environmentalists in South Korea are protesting a Winter Olympics construction project to build a ski slope through a 500-year-old protected forest. Brian Padden reports that although there is strong national support for hosting the 2018 Pyeongchang Winter Olympics, there are growing public concerns over the costs and possible ecological damage at the revered mountain.
Video

Video Xenophobia Victims in South Africa Flee Violence, Then Return

Many Malawians fled South Africa early this year after xenophobic attacks on African immigrants. But many quickly found life was no better at home and have returned to South Africa – often illegally and without jobs, and facing the tough task of having to start over. Lameck Masina and Anita Powell file from Johannesburg.
Video

Video Family of American Marine Calls for Release From Iranian Prison

As the crowd of journalists covering the Iran talks swells, so too do the opportunities for media coverage.  Hoping to catch the attention of high-level diplomats, the family of American-Iranian marine Amir Hekmati is in Vienna, pleading for his release from an Iranian prison after nearly 4 years.  VOA’s Heather Murdock reports from Vienna.
Video

Video UK Holds Terror Drill as MPs Mull Tunisia Response

After pledging a tough response to last Friday’s terror attack in Tunisia, which came just days before the 10th anniversary of the bomb attacks on London’s transport network, British security services are shifting their focus to overseas counter-terror operations. VOA's Henry Ridgwell has more.
Video

Video Obama on Cuba: This is What Change Looks Like

President Barack Obama says the United States will soon reopen its embassy in Cuba for the first time since 1961, ending a half-century of isolation. VOA White House correspondent Luis Ramirez reports.
Video

Video Hate Groups Spread Influence Via Internet

Hate groups of various kinds are using the Internet for propaganda and recruitment, and a Jewish human rights organization that monitors these groups, the Simon Wiesenthal Center, says their influence is growing. The messages are different, but the calls to hatred or violence are similar. VOA's Mike O’Sullivan reports.
Video

Video US Silica Sand Mining Surge Worries Illinois Residents, Businesses

Increased domestic U.S. oil and gas production, thanks to advances known as “fracking,” has created a boom for other industries supporting that extraction. Demand for silica sand, used in fracking, could triple over the next five years. In the Midwest state of Illinois, people living near the mines are worried about how increased silica sand mining will affect their businesses and their health. VOA’s Kane Farabaugh has more in this first of a series of reports.
Video

Video Blind Somali Journalist Defies Odds in Mogadishu

Despite improving security in the last few years, Somalia remains one of the most dangerous countries to be a journalist – even more so for someone who cannot see. Abdulaziz Billow has the story of journalist Abdifatah Hassan Kalgacal, who has been reporting from the Somali capital for the last decade despite being blind.
Video

Video Texas Defies Same-Sex Marriage Ruling

Texas state officials have criticized the US Supreme Court decision giving same-sex couples the right to marry nationwide. The attorney general of Texas says last week's decision did not overrule constitutional "rights of religious liberty," and therefore officials performing wedding services can refuse to perform them for same-sex couples if it is against their religious beliefs. Zlatica Hoke reports on the controversy.
Video

Video Rabbi Hits Road to Heal Jewish-Muslim Relations in France

France is on high alert after last week's terrorist attack near the city Lyon, just six months after deadly Paris shootings. The attack have added new tensions to relations between French Jews and Muslims. France’s Jewish and Muslim communities also share a common heritage, though, and as far as one French rabbi is concerned, they are destined to be friends. From the Paris suburb of La Courneuve, Lisa Bryant reports about Rabbi Michel Serfaty and his friendship bus.
Video

Video Saudi Leaks Expose ‘Checkbook Diplomacy’ In Battle With Iran

Saudi Arabia’s willingness to wield its oil money on the global diplomatic stage appears to have been laid bare, after the website WikiLeaks published tens of thousands of leaked cables from Riyadh’s Ministry of Foreign Affairs. VOA's Henry Ridgwell reports.
Video

Video In Kenya, Police Said to Shoot First, Ask Questions Later

An organization that documents torture and extrajudicial killings says Kenyan police were responsible for 1,252 shooting deaths in five cities, including Nairobi, between 2009 and 2014, representing 67 percent of all gun deaths in the areas reviewed. Gabe Joselow has more from Nairobi.

VOA Blogs