Concrete washout contains chemicals harmful to aquatic animals, can pollute groundwater, and can cause flooding when it clogs stormdrains. Follow the link to learn tips for washing concrete off tools safely...
Small concrete patch jobs can lead to big problems. Namely, how do you wash your tools safely? Concrete washoff does not belong on the ground or in the stormwater system (stormdrains or curb and gutter). The washwater is highly toxic to aquatic animals and can clog stormwater pipes, causing flooding. The key is to keep the washwater and extra concrete from touching the ground.
Good news, there are simple solutions available. For small jobs, layer several sturdy garbage bags inside each other in a garbage can. Wash tools off into your new cheep containment device. Allow the washwater to evaporate (this may take several days so protect from overflows due to rain) and the concrete to harden. Dispose of the hardened concrete in the trash or at the dump. For medium sized projects, you can practice the same principal and use several sheets of sturdy poly within a frame created out of hay bales. For large projects, make sure contractors are aware that you expect proper disposal and have them haul it away.
Remember, it is illegal to wash concrete or other substances into the stormdrain system no matter what size the project is. Help keep our City clean and practice good habits at home.