Cement and Masonry

Stormwater Related Information for the Cement & Masonry Industry

Preventing runoff from cement and masonry activities from entering our streets and storm drains helps protect our waterways from pollution!  All sources of pollution, including runoff from cement and masonry activities, are prohibited from leaving your property and entering streets or storm drains. Only rainwater is allowed in the streets and storm drains.

Did you know…

  • Masonry and cement work generate pollutants such as toxic chemicals, dust, debris and aggregate. These pollutants can be easily washed off work sites and flow untreated into our storm drains and waterways where they degrade our water quality and harm aquatic life.  

  • Cement and aggregate can cause blockages in our storm drain systems resulting in flooding.  

  • Releasing pollutants directly or indirectly into the storm drain system is a violation of the County’s Watershed Protection Ordinance (WPO).  


What can I do?

  • Dispose of waste thoughtfully: Liquid wastes may be disposed of by drying out material onto a 10-millimenter layer of plastic.  Once dry, waste material may be disposed of to a dumpster. 

  • Use Best Management Practices (BMPs) for your business: BMPs are techniques or controls used to prevent or reduce the discharge of pollutants, such as cement rinse water, into the storm drain system. BMPs for a cement and masonry business include keeping materials covered and off the ground, using a ‘wet-vac’ to vacuum water used to wash equipment and sweeping rather than hosing. 


Want to learn more?

The resources below provide suggested BMPs and further information on how to protect our waterways. Click the buttons to view available languages:

Masonry and Cement
Green Business Program
General Pollution
Inspect Your Business
Materials Management Spill Response
Train Your Employees

Know before you go… 

A designated concrete wash out area must be used for washing of tools, mixer chutes or emptying liquid concrete waste. 


Contact Us

If you would like to report a cement or masonry discharge concern, have questions about our program, or would like additional information call the County Storm Drain Pollution hotline at: 1(888) 846-0800 or e-mail us at watersheds@sdcounty.ca.gov 


Thank you for doing your part to protect our waterways!