The Facts of Sediment

Part our quarterly Storm Water Series by Todd Sattison, WPC Program Coordinator

Sediment is the most common pollutant in rivers, streams, lakes and reservoirs, according to the Environmental Protection Agency (EPA). That’s why the city’s  Water Pollution Control (WPC) Department is focused on minimizing sediment and protecting our local bodies of water.

What is sediment?
Sediment is the loose sand, clay, silt and other soil particles that settle at the bottom of a body of water. Sediment can come from soil erosion or from the decomposition of plants and animals. Wind, water and ice help carry these particles to rivers, lakes and streams.

What produces sediment?
While natural erosion produces nearly 30 percent of the total sediment in the United States, accelerated erosion from human use of land accounts for the remaining 70 percent. The most concentrated sediment releases come from construction activities, including minor home-building projects such as room additions and swimming pools.

Problems caused from sediment pollution
Sediment pollution causes $16 billion in environmental damage annually. Sediment entering storm water degrades the quality of water for drinking, wildlife and the land surrounding streams. Here are a few specific problems caused by sediment pollution:

  • Sediment fills up storm drains and catch basins, which increases the potential for flooding.
  • Water polluted with sediment becomes cloudy, preventing animals from seeing food.
  • Murky water prevents natural vegetation from growing in water.
  • Sediment in stream beds disrupts the natural food chain by destroying the habitat where the smallest stream organisms live causing massive declines in fish populations.
  • Sediment increases the cost of treating drinking water and can result in odor and taste problems.
  • Sediment can clog fish gills, reducing the resistance to disease, lowering growth rates, and affecting fish egg and larvae development.
  • Nutrients transported by sediment can activate blue-green algae that release toxins and can make swimmers sick.
  • Sediment deposits in rivers can alter the flow of water and reduce water depth, which makes navigation and recreational use more difficult.

What you can do
Everyone can do their part to help with sediment pollution. Here are a few easy tips:

  • Sweep sidewalks and driveways instead of hosing them off. Washing these areas results in sediment and other pollutants running of into streams, rivers and lakes.
  • Use weed-free mulch when reseeding bare spots on your lawn, and use a straw erosion control blanket if restarting or tilling a lawn.
  • Notify local government officials when you see sediment entering streets or streams near a construction site.
  • Put compost or weed-free mulch on your garden to help keep soil from washing away.
  • Avoid mowing within 10 to 25 feet from the edge of a stream or creek. This will help minimize erosion and naturally filter storm water runoff that may contain sediment.
  • Wash your car at a commercial car wash or on a surface that absorbs water, such as grass or gravel.

Visit www.epa.gov/npdes/stormwater to learn more about sediment pollution. If you have questions about local storm water issues, contact Todd Sattison, WPC Program Coordinator, at 260-925-1714 or TMSattison@ci.auburn.in.us.