Helpful Stormwater Tips

Tips On What You Can Do

If you burn fuel to heat your home, use a car, truck, bus, boat, train, or airplane, or buy products transported by any of these, you contribute to non-point source pollution. Although one person's contribution to non-point source pollution may seem insignificant, the combined effects of all DuPont residents can greatly influence water quality and quantity in our lakes, streams, wetlands, and the Puget Sound. We must work together to control non-point source pollution and strive to protect our valuable resources.

Here are some handy tips and steps that you can take to reduce non-point source pollution, reduce stormwater runoff, and make DuPont a better place to live.

Pick up after your pets

Pet waste may contain harmful bacteria and organisms (E.coli, salmonella, roundworms, etc.) that spread diseases easily. When pet waste is left on the ground, people and animals can become exposed to these diseases, which are unsafe and can cause illness. To keep our neighborhoods clean and healthy, clean up after your pets; use a plastic bag, seal it, and dispose of it in an appropriate garbage receptacle.

You can learn more about how pet waste impacts the health of our storm water systems by looking at our Pet Waste Brochure. The brochure is also available at City Hall in the lobby. 


Use pesticides and fertilizers sparingly

When too much fertilizer is used, or it is applied at the wrong time, the excess fertilizer can run off your garden and lawn and ultimately enter into nearby storm drains. If properly used, pesticides can help kill disease causing organisms, control insect pests, and eliminate weeds. If misused, however, pesticides can be harmful to humans, animals, and the environment.

Tips on pesticides and fertilizers

  • Use only when necessary
  • Do not use before a rain storm.
  • Spray or disperse on cool, windless days.
  • Follow instructions on the container.
  • Do not use products that are both "weed and feed", if you are trying to treat for one specific need.
  • Avoid spraying pesticides or fertilizers near ditches, lakes, or wetlands.
  • Dispose of lawn and garden chemicals carefully. Never dump them down the drains. If you have unused products, properly dispose of them at a household hazardous waste site.

Do not over-water your lawn
A healthy lawn usually requires only about 1 inch of water each week, or about 20 minutes of watering. For best results, water once a week to promote deep rooting rather than several light waterings, which causes shallow root growth and makes grass unable to tolerate dry periods. Also consider the weather; don't water your lawn if a 1 inch rain fall has occurred, and postpone watering if the forecast calls for heavy rain.

Other helpful tips

  • Let your grass grow longer, this promotes deep rooting and shades the soil surface which reduces evaporation and sprouting of weeds.
  • Avoid mowing during the heat of the day; freshly cut grass blades can lose water quickly and dry out your lawn.
  • Water your lawn in the early morning, watering in the evening keeps your grass wet all night which increases the risk of disease and root damage.
  • Having temporary brown outs in your lawn is ok; a few weeks of dormancy will not hurt the roots of a healthy lawn.
  • Washing your car on a city street can be harmful to storm water. You can learn more from a brochure that can be found in the DuPont City Hall or you can get a PDF copy here.

For more information on how to build and maintain a healthy yard, check out these yard care resources:


Inspect your septic systems every 3 years

Having your septic system properly maintained can help to save you money and reduce the chance of contaminating groundwater. Failing systems can be costly to repair and cause pollution of groundwater and nearby wetlands, streams, and lakes.

Tips on septic systems:

  • Tree roots can clog and damage septic systems, so only plant grass over and nearby your septic system
  • Do not park or drive your vehicles over or near a septic system, this can compact the soil and cause damage to your system.


Do not dump household hazardous wastes or used motor oil in sinks or down storm drains

When household hazardous wastes are poured down the sink, it goes through the sanitary sewage system or through your septic tank. Septic systems and sewage treatment plants are not equipped to handle hazardous waste. At treatment sewer treatment plants, the hazardous waste interferes with the biological treatment process by killing the good bacteria and contaminating the effluent that runs into our rivers and other surface waters. The biosolids that remain after the treatment process can also become contaminated, and may not be able to be reused as fertilizer.

Everything that enters into DuPont's storm drains flows directly into the stormwater system and to swales or retention/detention ponds with limited treatment. The retention/detention ponds are designed primarily to filter sediments and to hold and infiltrate stormwater to prevent local flooding. Never pour motor oil, antifreeze, fertilizer, pesticides, pet waste or other pollutants on the street or into storm drains. These pollutants can contaminate the stormwater systems and limit their effectiveness.

Additional Tips on preventing stormwater pollution at home

  • Sweep your driveways instead of hosing off to prevent pollutants from entering into storm drains
  • Fix leaking crankcases and transmissions and use drip pans to prevent spills from reaching storm drains
  • Clean up wet spills like oil by applying cat litter or another absorbent material
  • Keep your household hazardous chemicals stored in closed and labeled containers
  • Dispose of household hazardous waste at your local hazardous waste collection facility and recycle used oil at a local oil recycling center. The City of DuPont has a brochure that educates on this which can be found in the lobby at City Hall or you can find a PDF version here
  • Illegal dumping and littering can also be very harmful on the City's storm water system. A brochure is available in DuPont City Hall or you can find a PDF version here.

Remember: Only Rain Down the Storm Drain!