Materials and excess concrete or mortar can be blown or washed into the storm drains that flow to the ocean. Unlike water in sanitary sewers (from sinks and toilets), water in storm drains is not treated before entering our waterways.

You would never throw building materials into the ocean, so don’t let them enter the storm drains. Follow these easy tips to help prevent water pollution.

• Schedule projects for dry weather
• Store materials under cover, with temporary roofs or plastic sheets, to eliminate or reduce the possibility that the materials can be carried from the project site to streets, storm drains or adjacent properties via rainfall, runoff or wind.
• Minimize waste by ordering only the amount of materials needed to complete the job.
• Take measures to block nearby storm drain inlets.

• Set up and operate small mixers on tarps or heavy drop cloths.
• Do not mix more fresh concrete or cement than is needed for the job.
• When breaking up pavement, pick up all chunks and pieces and recycle them at a local construction and demolition recycling company.
• When making saw cuts in pavement, protect nearby storm drain inlets during the saw-cutting operation and contain the slurry. Collect the slurry residue from the pavement or gutter and remove from the site.

• Dispose of small amounts of dry concrete, grout or mortar in the trash.
• Never hose materials from exposed aggregate concrete, asphalt or similar treatments into a street, gutter, parking lot, or storm drain.

• Never hose down pavement or impermeable surfaces where fluids have spilled. Use an absorbent material such as cat litter to soak up a spill, then sweep and dispose in the trash.
• Clean spills on dirt areas by digging up and properly disposing of contaminated dry soil in trash.
• Immediately report significant spills to 1-(888)-CLEAN LA

To Report Illegal Dumping into the County's Storm Drain System, Call:
1(888)CLEAN LA, 24 Hours per Day

The tips contained in this brochure provide useful information to help prevent water pollution. If you have other suggestions, please contact your city’s stormwater representatives or call the Los Angeles County Stormwater Program.