Stormwater is run-off from rain events and snow melt that flows over hard surfaces like pavement, roofs and sidewalks and picks up debris and pollutants in its path. This flow is directed either into a storm sewer system or can go directly into our waterways. Even if stormwater goes into a storm sewer system, it still gets discharged directly into Coeur d’Alene Lake or the Spokane River without being treated.

Chemicals, metals and trash can contaminate water and poison aquatic wildlife which can in turn harm other animals and people who eat them or ingest polluted water. A study conducted in 2011 of stormwater outfalls in CdA, revealed samples of stormwater that had zinc and lead levels that exceeded the acute and chronic exposure criteria for aquatic life as determined by the City’s Quality Asssurance Project Plan for the storm sewer system. This means that at these levels there can be unacceptable adverse affects on aquatic life including mortality, immobility, and reductions in reproduction, growth, or survival. Also, E. Coli and Coliforms were found to be above the detectable limit of the test, meaning a potential source of contamination was present. The presence of E. coli is well correlated with the presence of many waterborne microorganisms and pathogens which can cause diseases. Although E. coli itself cannot cause illness (unless introduced to an open wound or urinary tract), large amounts of E. coli found in surface water can be used as an indicator of fecal contamination from warm-blooded animals.

This list below is just a few sources of potentially harmful pollutants and their sources generally found in stormwater:

  • Pesticides are harmful to aquatic wildlife and cause irritation to humans and in high doses can have hormone disruption and can increase risk of cancer.
  • Fertilizers increase nutrient levels in water and can cause toxic algae blooms that decrease oxygen levels  and light needed for aquatic health and can cause hazards to human health, as well.
  • Oils and hydrocarbons come from leaking vehicles, industry and dumping. According to Seattle Public Utilities, “even small amount of oil can smother fish eggs and developing shellfish in our lakes and streams. Just 1 pint of oil causes a slick the size of 2 football fields.”
  • Soaps and detergents from car washing can include phosphates, which can lead to low oxygen levels in our waterways, thereby killing fish through oxygen depletion. Soaps can also include phthalates that have been linked to reproductive problems and obesity. So, it’s best not to wash your car on your driveway and let soap wash down the storm drains.
  • Industrial facilities have activities that have the potential to contaminate with an array of pollutants.
  • Copper dust is deposited on roadways from vehicle brake pads and from agricultural and manufacturing activities. This metal has effects on aquatic wildlife, especially disrupting salmonoid development and causes internal distress in humans at high levels.
  • Zinc is deposited on roadways from tire wear and galvanized buildings and fences. This metal is highly soluble in water and impairs reproduction and alter behaviors in aquatic wildlife and has adverse affects on human health.
  • Plastics, cigarette butts, anything left behind on the street will wash out to lake if not picked up.
  • Grass clippings and leaves, although natural increase the nutrients in water and reduce clarity of water.
  • Dog poop increases nutrient levels leading to oxygen depletion and fish kills. Plus it carries harmful bacteria and E.Coli.

Once again this water flows off our homes, down our streets, picks up everything in its path and goes directly to the Lake.

[big_italic]Where does this all come out?[/big_italic]

Take a look at this picture below.

Storm system outfall pipe at Sanders Beach

Storm system outfall pipe at Sanders Beach (photo courtesy of the City of CdA)

  Get the idea?

Stormwater outfall pipe at 3rd Street Boat Launch

Stormwater outfall pipe at 3rd Street Boat Launch (photo courtesy of the City of CdA)


[big_italic]What can we do?[/big_italic]

  1. Let people know that the health of Lake Coeur d’Alene is important to you and spread the message of stormwater pollution.
  2. Dump No Waste: do not pour oil, food products, hazardous waste or anything down drains. Report anyone you see doing this. See our pollution response form and emergency numbers to aid in reporting pollution. You can also volunteer for the City of CdA’s stormdrain stenciling program to paint stormdrains with the message “Dump No Waste, Drains to Lake” to spread the message of stormwater pollution and prevent dumping. Contact for more details on this program.
  3. Use fertilizers and herbicides sparingly. Follow manufacturer’s instructions for application or use safer and more environmentally friendlier methods of pest control.
  4. Do not overwater.  Soil only soaks up so much water, then the rest runs off along with any chemicals put on your lawn. In addition, overwatering is a drain on our natural resource.
  5. Wash your car at a car washing facility that recycles wash water or wash your car on your lawn. The grass will soak up and filter out the pollutants.
  6. Rake up grass clippings and leaves to keep them out of the lake. Compost or mulch the materials or rake up to dispose of properly.
  7. Drive less. If you use your car less, it will keep pollutants, that will no matter what you do still deposit on the roadway for example, zinc from tire wear, copper from brake pads, and leaks. Properly and regularly maintain your vehicle to decrease the chance of leaks and spills.
  8. Pick up your trash and dog poop. No matter how tempting it is to not pick up that steaming pile of poo, just remember if you leave it – you will be swimming in it later.
  9. Get educated. Find out what KEA is doing about stormwater, tell your city that stormwater is an important issue to you and encourage business to practice better management of their stormwater.
  10. Also a no brainer, don’t litter.

For more information about stormwater pollution and solutions, contact KEA. Or, use our Pollution Response Form to document and record and pollution incident impacting Coeur d’Alene Lake or its tributaries.

EPA Publication: After the Storm [.pdf download]

Idaho Department of Environmental Quality (DEQ): Stormwater in Idaho