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.
    Two-thirds of World Faces Water Shortagei
    X
    February 12, 2016 7:31 PM
    Four billion people — or two out of every three on the planet — do not have enough water to meet their basic needs. That is far greater than previously thought, according to a new study that presents a more accurate picture of the problem. As VOA's Rosanne Skirble reports, the findings will help policymakers and the public craft solutions to address the threat.
    Video

    Video Two-thirds of World Faces Water Shortage

    Four billion people — or two out of every three on the planet — do not have enough water to meet their basic needs. That is far greater than previously thought, according to a new study that presents a more accurate picture of the problem. As VOA's Rosanne Skirble reports, the findings will help policymakers and the public craft solutions to address the threat.
    Video

    Video Gateway to Mecca: Historical Old Jeddah

    Local leader Sami Nawar's family has been in the Old City of Jeddah for hundreds of years and takes us on a tour of this ancient route to Mecca, also believed to be the final resting place of Adam's wife, Eve.
    Video

    Video New Technology Aims to Bring Election Transparency to Uganda

    A team of recent graduates from Uganda’s Makerere University has created a mobile application designed to help monitor elections and expose possible rigging. The developers say the app, called E-Poll, will make Uganda's democratic process fairer. From Kampala, VOA's Serginho Roosblad reports.
    Video

    Video As Refugees Perish, Greek Graveyards Fill

    Aid workers on the Greek island of Lesbos say they are struggling to bury the increasing number of bodies of refugees that have been recovered or washed up ashore in recent months.  The graveyards are all full, they say, yet as tens of thousands of people clamor to get out of Syria, it is clear refugees will still be coming in record numbers. For VOA, Hamada Elrasam reports from Lesbos, Greece.
    Video

    Video Russia Bristles at NATO Expansion in E. Europe

    Russian Foreign Minister Sergei Lavrov is meeting Friday with the head of NATO after the Western military alliance and the United States announced plans for the biggest military build-up in Europe since the Cold War. Russia has called NATO's moves a threat to stability in Europe. But NATO says the troop rotations and equipment are aimed at reassuring allies concerned about Russia as VOA's Daniel Schearf reports from Moscow.
    Video

    Video To Fight Zika, Scientists Target Mosquitoes

    Mosquitoes strike again. The Zika virus outbreak is just the latest headline-grabbing epidemic carried by these biting pests, but researchers are fighting back with new ways to control them. VOA's Steve Baragona takes a look.
    Video

    Video Mosul Refugees Talk About Life Under IS

    A top U.S. intelligence official told Congress this week that a planned Iraqi-led operation to re-take the city of Mosul from Islamic State militants is unlikely to take place this year. IS took over the city in June 2014, and for the past year and a half, Mosul residents have been held captive under its rule. VOA's Zana Omar talked to some families who managed to escape. Bronwyn Benito narrates his report.
    Video

    Video Scientists Make Progress Toward Better Diabetes Treatment, Cure

    Scientists at two of the top U.S. universities say they have made significant advances in their quest to find a more efficient treatment for diabetes and eventually a cure. According to the International Diabetes Federation, the disease affects more than 370 million people worldwide. VOA’s George Putic reports.
    Video

    Video NATO to Target Migrant Smugglers

    NATO has announced plans to send warships to the Aegean Sea to target migrant smugglers in the alliance's most direct intervention so far since a wave of people began trying to reach European shores.
    Video

    Video Russia's Catholics, Orthodox Hopeful on Historic Pope-Patriarch Meeting

    Russia's Catholic minority has welcomed an historic first meeting Friday in Cuba between the Pope and the Patriarch of Russia's dominant Orthodox Church. The Orthodox Church split with Rome in 1054 and analysts say politics, both church and state, have been driving the relationship in the centuries since. VOA's Daniel Schearf reports from Moscow.
    Video

    Video Used Books Get a New Life on the Streets of Lagos

    Used booksellers are importing books from abroad and selling them on the streets of Africa's largest city. What‘s popular with readers may surprise you. Chris Stein reports from Lagos.
    Video

    Video After NH Primaries All Eyes on South Carolina

    After Tuesday's primary in New Hampshire, US presidential candidates swiftly turned to the next election coming up in South Carolina. The so-called “first-in-the-South” poll may help further narrow down the field of candidates. Zlatica Hoke reports.
    Video

    Video Smartphone Helps Grow Vegetables

    One day, you may be using your smartphone to grow your vegetables. A Taipei-based company has developed a farm cube — a small, enclosed ecosystem designed to grow plants indoors. The environment inside is automatically adjusted by the cube, but it can also be controlled through an app. VOA's Deborah Block has more on the gardening system.
    Video

    Video Exhibit Turns da Vinci’s Drawings Into Real Objects

    In addition to being a successful artist, Renaissance genius Leonardo da Vinci designed many practical machines, some of which are still in use today, although in different forms. But a number of his projects were never realized — until today. VOA’s George Putic reports.