Concrete washout

Keep concrete waste out of storm drains

Concrete SpillWhen concrete waste and washout gets into our storm drains and travels to local streams, it causes a number of problems. Once in the water, it kills fish by clogging their gills and causing asphyxiation. From an infrastructure standpoint, the waste builds up in the storm drainage system and reduces capacity for rainwater to move freely through the system. With our rainy Pacific Northwest weather, overburdened storm systems can lead to localized flooding. From a cost perspective, concrete waste is very hard - if not impossible - to remove from parts of the storm drainage system. Home and landowners are invested in the infrastructure around them, and repairs can be costly. You can protect the environment, your neighborhood, and your wallet by helping to keep the storm drainage system functioning as designed.

What to do if you see concrete washout on the street or near a storm drain

Please call our 24/7 Spill Hotline right away. Our staff will respond quickly to help mitigate any potential damage caused by the concrete waste, and we will follow up with the responsible party if known.

Spill Hotline: 425-806-6750

What the law says

Here's what Bothell Municipal Code 18.04.260 says about concrete washout going down our storm drains:

"It shall be prohibited and in violation of this chapter for any person or entity to: 

A. Throw, drain, or otherwise discharge, cause or allow others under its control to throw, drain or otherwise discharge into the municipal storm drain system and/or surface and ground waters any materials other than storm water. Examples of prohibited contaminants include but are not limited to the following:

...2. Construction materials.
 26. Silt, sediment, concrete, cement or gravel."

So what does that mean? 

It means that whether you're a contractor or construction company hired to do a project, or if you're a homeowner doing a small project at your home, you should prevent concrete waste from entering into a storm drain.

How to safely work with concrete

Locate a washout area at least 50 feet from any storm drain, open ditch, or water body. Prevent runoff from this area by constructing a temporary lined pit or a bermed area large enough for liquid and solid waste. Wash waste into the temporary pit, allow the concrete to set, break it up, and then use proper disposal sitConcrete BMPs Opens in new windowes to get rid of it.

How to store and dispose of concrete products

Exposed aggregate concrete washouts must be collected and disposed of properly, just like all other concrete products. Store dry and wet material under cover away from drainage areas. Train employees and subcontractors to dispose of concrete properly. Do not allow excess concrete to be dumped on site, except in designated areas.

Learn more about concrete washout safety

Review EPA's Stormwater Best Management Practice for Concrete Washout (PDF) to learn more about concrete washout, including.

  • Explanation of what concrete washout is
  • Environmental and human health impacts
  • Recycling options for concrete
  • Different types of washout containers
  • Safe locations and procedures for washout facilities
  • Educating concrete subcontractors