Clean Water Program

Storm Drain Systems

What is the difference between a storm drain and a sanitary sewer?

The water that goes down a sink or toilet in your home or business flows to a wastewater treatment plant where it is treated and filtered as part of a sanitary sewer.

Water that flows down driveways and streets and into a gutter goes into a storm drain, which flows directly to a lake, river or the ocean is a storm drain. This water may pick up pollutants along the way, which are never treated. It is important to not put anything other than water down the storm drain.

What can I do to help reduce Nonpoint pollution?

• Urban Stormwater Runoff
• Keep litter, pet wastes, leaves and debris out of street gutters and storm drains–these outlets drain directly to streams and wetlands.
• Apply lawn and garden chemicals sparingly and according to directions.
• Dispose of used antifreeze, paints and other household chemicals properly, not in storm sewers or drains. Most vehicle fluids can be recycled. Check for your nearest oil recycler.
• Use a dry clean up method to clean up spilled brake fluid, oil, grease and antifreeze. Do not hose them into the street where they can eventually reach local streams and the bay.
• Control soil erosion on your property by planting ground cover and stabilizing erosion-prone areas.
• Have your septic system inspected and pumped, at a minimum, every 3-5 years so that it operates properly.
• Purchase household detergents and cleaners that are low in phosphorus to reduce the amount of nutrients discharged into our streams and coastal waters.
• Limit the amount of impenetrable surfaces in your landscape. Use permeable paving surfaces such as wood decks, bricks and concrete lattice to let water soak into the ground.
• Allow thick vegetation or buffer strips to grow along waterways to slow runoff and soak up pollutants. Plant trees, shrubs and ground cover. They will absorb up to 14 times more rainwater than a grass lawn and don’t require fertilizer.
• Use natural alternatives to chemical fertilizers and pesticides. If you must use chemicals, test your soil to determine the right amount.
• Don’t hose down driveways or sidewalks. Dry sweeping paved areas, along with careful trash disposal, are simple, effective pollution reducers.
• Gutters and downspouts should drain onto vegetated or gravel- filled seepage areas – not directly onto paved surfaces. Splash blocks also help reduce erosion.
• Divert runoff from pavement to grassy, planted or wooded areas of your property, so stormwater can seep slowly into the ground.
• Compost grass clippings and leaves. Never allow them to wash into roadways where they will reach storm drains.
• Get involved in the planning and zoning process in your community. That’s where the decisions are made that shape the course of development and the future quality of our environment.
• Place litter, including cigarette butts, in trash receptacles. Never throw litter in streets or down storm drains.
• Properly dispose of household hazardous wastes.
• Recycle all used motor oil by taking it to a service station or local recycling center.
• Animal wastes contain bacteria and viruses that contaminate shellfish and cause the closing of bathing areas. Pet owners should pick up after their pets and dispose of the wastes in the garbage or toilet.
• Wash your car on the grass so soapy water soaks into the ground. Use a hose nozzle to prevent water from running when not in use.

What are the consequences of car washing or charity car washing?

Most soap contains phosphates and other chemicals that harm fish and water quality. The soap, together with the dirt and oil, brake dust washed from cars, flows into nearby storm drains which run directly into lakes, rivers or marine waters. The phosphates from the soap cause excess algae to grow and harm water quality. As algae decay, the process uses up oxygen in the water that fish need.

Pursuant to our National Pollution Discharge Elimination System permit, fleet or mass car washing, or commercial vehicular waste water may not enter the storm drainage system. Charity car washes fall into this category due to the car volume.

Can I drain my pool to the street?

Did you know that draining pool or spa water into the street is prohibited because of the chlorine and chemical content? Find out how to dechlorinate pool water before discharging.

Disposing of pool, spa and fountain water:
Disposing of pool, spa and fountain water to the sanitary sewer system is the only disposal method allowed.

Disposing of filter rinse water: 
If you have a cartridge type filter these should be cleaned in a sink or on a landscaped area where the water will not run into the street.

Diatomaceous earth (DE) filters: ensure that the DE is captured prior to discharge. The DE should never enter the storm drain system as it is hazardous to the beneficial waterborne insects.