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Stormwater Education

Clean Water, It’s Our Future – and it starts in your neighborhood.

In the Pacific Northwest, we have treasures that are worth protecting.  Today, the main source of pollution in our local waterways comes from everyday activities that leave pollutants behind and get picked up in storm runoff and carried to our streams and waterways.  However, there are many ways to help keep our water clean. 

Everyday Activities Make A Difference

Click on the topics below to learn more about how you can prevent pollution while keeping our water safe for families, pets and wildlife.

Lawn care, landscaping, and pest control practices can be major contributors to stormwater pollution and also harm children and pets.  By working with nature in your yard and garden, you can have a great looking landscape that’s easier to care for and healthier for families, pets, wildlife and our great Northwest environment.


  • Follow the manufacturer’s directions precisely for mixing and applying herbicides, fungicides, and insecticides and use them sparingly
  • NEVER apply when it’s windy or rain is expected, or over water, within 100 feet of a well, or adjacent to streams or other waterways.
  • Sweep up spills that fall on driveways and sidewalks before they can wash off.
  • When buying fertilizers, pesticides, or other chemicals, buy only the amount you need for your project. Share the leftovers with friends or neighbors or safely dispose of them at one of the two household hazardous waste disposal stations in Clark County. Disposal is free.


When irrigation systems overwater or water sidewalks, driveways and streets, the runoff picks up pollutants and transports them to our streams via the storm sewer.  It’s also a waste of water and money.

Ensure your irrigation system is only watering the landscape where it can infiltrate into the soil.


The most effective way to manage weed infestations is to use a combination of control methods specific to the problem weed, where it is in its growth-cycle, and the location where it is growing. 

Prevention is better than control – The best control method of all is to prevent weeds in the first place. Weeds often invade due to overgrazing, bare soil, or other factors that should be corrected for the control measures to be fully effective.

Not all control methods are useful for all weed species, taking an integrated approach to weed management can greatly increase the effectiveness of your efforts. Weed control is not a one-time fix, your strategy should be practical, adaptable, cost-efficient, and effective. 

For information about rain gardens, native plants, natural gardening and much more, visit

When it rains, pet waste left on the ground from dogs, cats, horses, ducks, and other pets washes into storm drains and streams, polluting our water and posing health risks to children and pets.

Animal waste carries harmful bacteria, parasites and nutrients. Some simple clean-up and prevention measures (picking up for dogs, covering for large animals) can help keep this harmful waste from entering the nearest storm drain and stream.  


Following three simple clean water habits, can reduce the impact of our furry friends:

  1. Scoop the poop, bag it, and throw it in the trash. Even if it’s in your own backyard, harmful elements of dog waste can remain on for months and stormwater can carry it across yards.  Composting and flushing is not recommended because dog waste carries parasites and bacteria that could survive composting, and septic or sewer treatment.
  2. Keep dogs on-leash in sensitive areas such as streams, riparian areas and wetlands.   Minimize contact with streams and wildlife. Dogs can leave scents that deter wildlife from using riparian areas, which are critical habitats for most animals.
  3. Spread the message to other dog owners! Share what you’ve learned with other dog owners.  Bring extra bags when you’re out for a walk so you can help others who forgot their bags or confront people in a friendly way.


An average horse produces 50 pounds of manure a day. Left unmanaged, horse manure contributes to mud and hoof problems, transmits parasites and bacteria, and provides a breeding ground for pests.  

On the flip side, managing manure properly and composting can yield a valuable soil amendment and slow release fertilizer to improve pastures.  Follow these quick manure management tips to keep your animals healthy, your farm looking good, and clean water clean.  For detailed information on manure management contact WSU Clark County Extension or the Clark Conservation District.  

  1. Collect – regularly collect manure every one to three days from turnouts, stalls and confinement areas. This prevents reinfestation from parasites, reduces mud and other pests and reduces nutrients (nitrogen and phosphorous) and sediment picked up by stormwater. Store the manure on a level, dry location with easy access to reduce mud, minimize runoff and make chores easier.
  2. Cover – use tarp to keep rain off the manure pile or store under a covered area.  A tarp will help to regulate moisture in wet and dry months, optimizing composting conditions.  It will also help to prevent clean rainwater from becoming polluted.
  3. Compost – composting require three conditions 1) oxygen 2) approximately 25:1 carbon: nitrogen ratio and 3) a moisture level about as wet as a wrung out sponge.  Incorporate oxygen by turning or other passive methods.  Consider your bedding practices to achieve the correct C:N ratio and keep it covered to regulate moisture.  Composting can reduce a pile by 50%, kill weed seeds, and provide a slow-release fertilizer so it’s worth the extra effort. 


Collecting cat waste outdoors is much more difficult than with dogs, so it’s best to keep them indoors.  Just like with dogs, bagging waste from a litter box and throwing it away is better than flushing it.  The harmful organism, toxoplasma gondii, found in cat waste and potentially dangerous to children, elderly, and pregnant women, may be able to survive the municipal waste treatment process.

Keeping cats indoors is also better for encouraging urban wildlife.

Everyday home maintenance and improvement projects require special care to prevent water pollution.  Sources of pollution include:

  • household hazardous waste (i.e. paint thinners, oil-based paints/stains, cleaning products, fuels, pesticides, nail polish remover etc.)  
  • septic systems
  • dirt and sediment from construction or bare soil
  • pools and spas
  • project waste (paint chips, roofing material, sawdust, etc.)

As you undertake these projects follow best practices to make sure you’re not harming our streams, rivers, lakes or ground water, and the people and wildlife that use them.   


When hazardous materials spill on the ground or into a storm drain, they can go directly into streams, lakes, or wetlands harming humans, fish and wildlife. They can also infiltrate into the ground and contaminate drinking water supplies.

Due to the toxicity of household hazardous waste, contamination occurs even from pouring hazardous products into a sink, toilet, or septic system, or piping them to a municipal sewer system. Many compounds will pass through the wastewater treatment plant and may contaminate receiving waters or harm the biological process used at the treatment plant, which reduces overall treatment efficiency.

Learn more about household hazardous waste at Clark Green Neighbors and follow these tips to prevent pollution.

  • Use less toxic products whenever possible.  
  • Dispose of hazardous materials and their containers properly. Never dump products labeled with poisonous, caustic, flammable, inflammable, volatile, explosive, danger, warning, caution, or dangerous outdoors, into a storm drain, or in sinks, toilets, or other drains.  Visit  or Clark Green Neighbors for disposal information.
  • Store hazardous material containers under cover and off the ground. Keep them out of the weather to avoid rusting, freezing, and cracking.  Store out of children’s reach in clearly labeled, unbreakable containers.
  • Prevent spills with ground cloths and drip pans when outdoors.  
  • Keep spill cleanup materials on hand. Apply kitty litter or sawdust to absorb the liquid before sweeping into a bag and disposing properly.  NEVER wash spills with a hose.
  • Follow manufacturers’ directions when using all materials. Over-applying can allow chemicals to wash into nearby water bodies. Never apply pesticides when rain is expected.


Many yard maintenance or small outdoor projects remove vegetation and expose bare soil to erosion. Preventing erosion is essential to protecting waterways and maintaining the quality and productivity of soil.  

The “mud” in muddy water is sediment, a mixture of soil components and particles of sand, silt, and clay that can cover the bottom of streams and lakes, smothering bottom-dwelling plants and animals and covering essential fish spawning areas. Sediment can block sunlight for aquatic plants, clog the gills of fish, reduce the amount of dissolved oxygen in the water, and contain nutrients that cause excessive plant and algae growth.

When a project exposes bare soil, help prevent erosion by following these practices.

  • Cover small mounds of dirt with a tarp or other cover so that wind and rain don’t carry the sediments to nearby water bodies.
  • Mulch with straw, wood chips, or shredded bark.  A two or three-inch layer placed directly on top of the soil will control erosion by covering soil. 
  • Temporary seed with rapid-growing annual grasses or small grains to stabilize disturbed soils until the project is completed or there are permanent plantings.
  • Sod cover will permanently stabilize an area. Sod is especially useful for immediate cover on steep, critical areas and in areas unsuitable for seed.
  • Compost barrier berms are mounds of material used to trap a pollutant or sediment. On steep slopes, compost berms at the top or bottom of slopes will slow the velocity of water and filter out some of the sediment.
  • Use a silt fence made of filter fabric as a temporary sediment barrier. The fabric is placed around the lower part of the bare soil to trap sand and silt but allow water through. The fabric is stretched and staked around the edge of the disturbed area. Burying the base of the silt fence keeps sediment from washing under it.


Even though we swim in it, pool water can still be harmful to streams and must be kept out of storm drains. Pool water is treated to kill microbes that can make us sick, but the nutrients, pH, and chlorine in these treatments can adversely affect fish and aquatic wildlife.

Follow these tips to ensure your pool maintenance isn’t polluting our streams and lakes.

  • Pool and spa water must be dechlorinated before emptying into a ditch, on the ground, or into the storm drainage system. Contact your pool chemical supplier for the neutralizing chemicals you’ll need.
  • If the pool or spa water cannot be dechlorinated, it must be discharged to the sanitary sewer. Your local sewer agency must be notified prior to draining so it is aware of the volume of discharge and the potential effects of chlorine level.
  • When discharging, ensure the rate of flow into does not cause erosion, surcharging, or flooding. It’s best to discharge into a vegetated area so the water does not cross property lines or produce runoff. 
  • Enzyme-based maintenance and cleaning products that have less impact on the environment are available at many pool and spa product retailers – ask your supplier about environmentally friendly products.

Keeping your vehicle maintained isn’t just about safety and convenience, it can also keep pollution out of our streams, rivers and lakes.  When working with oil and toxic chemicals, even small drips and spills have big impacts when storm runoff carries it to storm drains. 

Washing cars on driveways, parking lots or in the street can also send harmful soaps and grime to our waterways.


The fluids used to keep our vehicles operating are highly toxic to humans and wildlife.  With so many vehicles on the road, even small drips can add up to big problems.  A study in Puget Sound found that over 66% of oil and grease pollution came from vehicle’s small drips and leaks.

Keep your vehicle running smoothly and our streams clean by following regular maintenance and fixing leaks when you find them. 


When cars are washed in driveways and streets, the water used typically flows into a storm drain or ditch, leading directly to the nearest stream, lake, or groundwater supply. Soaps and detergents (even biodegradable ones) along with the oil and grime being washed off of the car, can have harmful effects on fish and other aquatic wildlife.  Here are some ways to keep your car washing from sending pollution to our streams:

  • Go to a commercial car wash.  Water from commercial car washes is collected and treated to remove pollutants.
  • Wash on the lawn.  The next best option is to wash your car on the lawn so that the soap and grime can be soaked up and treated by the soil.
  • Use an old towel to divert wash water. Putting an old rolled up towel at the end of the driveway can divert the wash water on to a landscaped or grassy area. 
  • Try waterless washing products. Waterless options can keep suds and oil out of the water, but make sure you dispose of the rags and products properly. 


Changing your own oil or antifreeze, topping off the battery with water, and keeping your vehicle maintained can save money, ensure your vehicle runs efficiently and reduce environmental impacts.  But whenever you’re working with highly toxic materials, it’s critical to prevent spills and be prepared when the do happen.  Here are a few tips will help you prevent pollution.

  • Use pans, cardboard or a plastic tarp to catch spills.  Spilled antifreeze and oil can be deadly to children, pets, and wildlife. Use care when draining and refilling to prevent accidental spills.
  • Keep a bag of kitty litter on hand to absorb spills. Sprinkle a thick layer on the spill to absorb it, then sweep the used litter in a plastic bag and dispose of it in your garbage.  NEVER wash with a hose.
  • NEVER dump automotive fluids or solvents on the ground or in a storm drain, street gutter, or water body.
  • Recycle all oils, antifreeze, solvents, and batteries. Many local car parts dealers and gas stations accept used oil. Used oil can be recycled with your curbside recycling. 

Contact Information

Public Works Department
510 Pioneer St., Suite B
Ridgefield, WA 98642
Phone: (360) 887-8251
Fax: (360) 887-2507

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