After the Rain:
Urban Runoff

Polluted Runoff

Reporter #2

America’s fresh water supplies are under siege. When runoff from rain, snow, or irrigation moves across the land or through the ground, it picks up and carries all kinds of pollutants into our rivers, lakes, streams, and groundwater.

Some studies show that up to 80 percent of all the pollution in America’s fresh water now comes from runoff.

Reporter #2 on camera

For years, industry and inadequate wastewater treatment plants were the primary polluters of our fresh water supplies. They continue to play a role, but it may surprise you to learn that individuals are now the main problem. That’s right— you, me, our neighbors, and friends—we are the leading cause of our nation’s water quality problems.

Do you drive a car? Have you fertilized your lawn or garden lately? Do you leave pet waste where it can wash into nearby streams, storm drains, or groundwater?

Most people don’t realize these kinds of activities can pollute our fresh water supplies, but that’s exactly what’s happening.

Reporter #2

Growing towns and cities generally change the Earth’s natural processes. Pavement, buildings, and rooftops prevent precipitation from soaking into the ground. Instead, it is channeled into storm drains. This polluted runoff does not go to a wastewater treatment plant. It rarely passes through natural filters such as soil and wetlands. The reality is that urban runoff flows directly to nearby surface waters and sometimes seeps into groundwater supplies.

One-by-one, we are adding to urban runoff. Each individual’s contribution may be small, but it adds up. With hundreds, or even thousands of storm drains in a town or city, pollutants from across the landscape have a direct path into our fresh water supplies. In many cases, pollution concentrations in stormwater exceed the limits we’ve established for industries and wastewater treatment plants.

Reporter #2 on camera

It’s hard for most people to get concerned about urban runoff. That’s because most of us don’t sit around in the rain watching what goes down storm drains. But there are people who monitor the contaminants in urban runoff and their studies have identified a number of common sources that contribute to this type of pollution.

Reporter #2

Sediment is the major pollutant in most urban runoff. It usually comes from eroding soil, but vehicle exhaust, soot from chimneys, and industrial emissions also contribute to sediment pollution.

Nutrients, such as phosphorus and nitrogen, are another concern. They promote weed and algae growth in lakes and streams, which in turn depletes a water body of its life-sustaining oxygen. Common phosphorus and nitrogen sources include fertilizer, leaves, grass clippings, and vehicle exhaust.

Oxygen is also depleted by pet waste, leaves, grass clippings, and litter that end up in urban runoff. As organic matter decays in lakes and streams, it uses oxygen that fish and other aquatic life need to survive.

Bacteria is another pollution source in urban runoff. Waste from pets and urban wildlife, as well as overflows from older wastewater systems, are common sources of bacterial contamination. In many cities, bacteria levels in urban stormwater often exceed public health standards for swimming.

Finally, toxic pollutants come from a wide range of sources. These are substances that may cause death, disease, or birth defects. They also may interfere with reproduction, child development, or disease resistance.

Toxic pollutants most often found in urban runoff can be traced to automobiles, insecticides, weed killers, wood or oil burning stoves, incinerators, and insulators that once were used in electrical transformers and capacitors.

News Anchor #2

Jim, now that we’ve learned about the seriousness of the problem, I’m sure many of our viewers want to know what they can do, as individuals, to help clean up urban runoff.

News Anchor #1

Kathryn, that’s exactly why we put this next report together. It’s critical to understand that we, as individuals, can make a difference in our own homes and communities. We don’t have to give up all the conveniences of modern life, but we will need to make some changes.

Continue.

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