When it rains… it drains

  • Published
  • By Scott Moorman
  • 96th Civil Engineer Group
EGLIN AIR FORCE BASE, Fla. --  According to the U.S. Environmental Protection Agency, stromwater runoff is the leading cause of water pollution in urbanized areas; and it's on the rise. This increase has been attributed to construction of housing and business developments, parking lots and roadways.

After heavy rain, most municipalities rely on storm sewers to divert accumulated runoff into local waterways. Much of the runoff that reaches storm drains in urban areas collect an increase in pollutant loads through oils, lawn chemicals and sediments found on impervious surfaces. And unlike sanitary sewage systems which discharge to wastewater treatment plants, nearly all stormwater systems flow untreated into the same rivers, lakes and bays used for public recreation.

Even as early as ancient Greece, civil engineers have been trying to combat the effects of stormwater runoff. Currently, the use of low-impact development, structural controls and pollution prevention strategies has helped to mitigate these effects. However, engineers can't do it alone.

"Making some minor changes to our daily activities can have a huge impact on our local waterways," said Russell Brown, 96th Civil Engineer Group's Water Quality Program manager. "Simply by checking your vehicle for leaks and recycling used motor oil and antifreeze when changing fluids is a step in the right direction."

Another of Mr. Brown's suggestions is to follow the manufacturer's instructions when applying fertilizer and garden chemicals to lawns.

"Using more than the recommended amount of fertilizer will not necessarily give you a greener yard," he said. "Quite the contrary, it can burn grasses, and residual chemicals get washed into storm drains when you water or after the next rain."

Mr. Brown said rains laced with excess fertilizer and other contaminates produce higher amounts of organic matter compared to natural occurring levels. This condition encourages the growth of algae blooms that deplete most of the oxygen in the water. When the oxygen is depleted, the bloom dies and begins to decompose, causing eutrophication.

Eutrophication is a process by which a body of water becomes rich in dissolved nutrients from fertilizers or sewage, thereby encouraging the growth and decomposition of oxygen-depleting plant life. The results can mean deadly consequences for fish and other aquatic life.

Mr. Brown also suggests several other environmentally responsible ways to prevent urban runoff pollution in the home.

"Cleaning-up after your pet, properly disposing of hazardous household waste, washing vehicles at car care facilities and keeping trash and dirt out street gutters and storm drains are also easy ways for the general public to contribute to this cause," he said.
Pet waste and failing septic systems contaminate waterways through viruses, bacteria and nutrients contained in the fecal matter. Flushing pet waste down the toilet is considered to be the best disposal method.

Because many people mistakenly believe a well manicured lawn can only be achieved through extensive watering, Mr. Brown offered some gardening tips to spruce up yards and curb water consumption.

"Water-efficient-landscaping offers many environmental benefits, but may also offer economical ones as well," he said. "For example, reduced water use means reduced water and electric bills, while carefully planted trees and plants will keep homes cooler in the summer heat."

The U.S. Geological Survey reported Americans use about 26 billion gallons of water per day, and 30 percent is for outdoor use. It is estimated that a typical suburban lawn will use 10,000 gallons of water beyond annual rainfall.

Some of the fundamentals of water-efficient landscaping include grouping plants according to water needs, using native and low-water-use plants, making sure soil is healthy, remembering to mulch and providing regular maintenance.

While automatic sprinkler systems tend to make water easier, researchers have discovered manually watering with a hose is more effective at preventing runoff by reducing water usage by up to 47 percent, according to American Water Works Association Research Foundation.

To further reduce water consumption, consider using different sources for irrigation. Rainwater can be collected from downspouts and stored in cisterns and storage tanks. Cover collection vessels to protect animals and children and prevent mosquito breeding. The AAWW Research Foundation stated homes with access to alternative sources of irrigation can reduce water bills by as much as 25 percent.

The base is also doing its part to fight stormwater pollution through public outreach and other programs.

"Eglin historically has done a good job of preventing stormwater pollution," Mr. Brown said. "We have had many initiatives and activities to get the word out, such as on Earth Day in April when displays were presented at the base schools and when volunteers placed stormwater decals throughout the Eglin community. Eglin is also subject to a wide variety of stormwater permits that if followed diligently, helps us prevent stormwater pollution."

By practicing a few environmentally sound principles, we can protect our waterways from common pollutants, and preserve a healthy ecosystem for years to come, he said.

For more on stormwater prevention, visit http://cfpub.epa.gov/npdes/stormwater/swbasicinfo.cfm.