DID YOU KNOW?
by Shawna Anderson

URBAN STORMWATER

Did you know that urban stormwater is one of the most significant sources of pollution affecting our nation’s rivers, lakes, and estuaries?   If fact, according to the U.S. Environmental Protection Agency, urban stormwater represents the single most significant source of water pollution within our coastal wetlands.    We must keep this in the forefront of our minds as we continue the very positive trend of reclaiming and restoring our precious coastal lagoons and estuaries.   In order to ensure long term productivity and species diversity within these restored areas, considerable strides must be made toward reducing these damaging water pollutants, referred to as nonpoint source pollutants.

Nonpoint source pollution is water pollution that consists of contaminated runoff associated with agriculture, urban activities and other sources.   Every time it rains, pollutants, such as dirt, nutrients, bacteria, oils and heavy metals, are swept off the land surfaces and carried by runoff water into our storm drains and ultimately into our surface and groundwater.   During drier months, irrigation runoff also carries these pollutants down storm drains and into our natural drainages.   Unlike the sewer system, which carries water from indoor drains to water treatment plants, the storm drain system releases water into various bodies of water including the ocean, untreated. This means that any trash or hazardous chemicals which are dumped into the storm drain system can pollute our important water resources.

The origins of nonpoint sources are diverse and can include fuel leaked from cars, used motor oil illegally dumped, pesticide runoff from yards, pet wastes, detergents that wash down driveways and spilled paint products. Some of contaminants commonly found in stormwater discharge include heavy metals, such as copper, zinc and lead, and oxygen-robbing nutrients such as phosphorus and nitrogen.   Stormwater is also a major source of bacterial contamination in the coastal zone, leading to beach closures and contaminated shellfish populations.   Another aspect of stormwater damage stems from increases in the quantity and velocity of the stormwater flowing through our stream and rivers.   When natural vegetation is removed from the landscape and replaced by pavement, buildings, or cleared open areas, the volume and speed of the stormwater runoff increases significantly.   This in turn increases soil erosion and scouring of streams and river banks.   The final result is increased siltation within our lakes, rivers, and coastal wetlands.   

Each of us is a part of the problem, but we can also be a big part of the solution.   The Resource Conservation District of Greater San Diego County, outlined in a recent edition of their newsletter, Resource Conservation Points, a number of measures that we can implement to reduce our effect on water quality.   These include:

• Watching for soil erosion around our homes and installing landscaping as need to hold the soil in place.
• Only fertilizing lawns and gardens according to needs as shown by soil tests.   Avoiding the use of fertilizers when it might be washed away by rains.   Recycling grass clippings and leaves by mulching or composting and keeping the gutters free of grass clippings, leaves and other vegetation.
• Using non-toxic gardening products and methods.   When pesticide or herbicide use is indicated, apply according to the directions on the product label.   Avoid applying these products when it might be washed away by rains.
• Picking up litter and animal wastes before they wash into the stormdrain.   Sweeping paved surfaces and disposing of the debris properly.   Never dump anything into the street or stormdrain.
• Keeping cars tuned-up and leak free.
• When changing the oil, transmission fluid, or radiator fluid, always dispose of these fluids at a recycling depository.   Check with the local service station or auto parts store.   DO NOT dump oil or other automotive fluids into a stormdrain.

Other measures to consider:

• While working on vehicles, keep absorbent materials nearby to allow prompt cleanup of all spills.   Do not hose down any spills.
• Do not over water lawns or gardens.   Irrigation water that runs down the street carries with it any fertilizer or pesticide that may have recently applied to the yard, and it also carries pollutants from the street, such as oils and heavy metals, as it travels from the yard to the nearest storm drain.
• Wash vehicles with biodegradable, phosphate-free detergents and use a bucket (not a running hose) to wash and rinse car to conserve water.
• Make an effort to purchase those products that are water based, less hazardous, and non-toxic.
• Use organic or non-toxic fertilizers. Don’t over fertilize and don’t fertilize near ditches, streams, or other water bodies.
• Use pesticide alternatives when possible.
• Store pesticides, fertilizers, and other chemicals in a covered area.
• Don’t mix more fresh concrete or cement than you will use and store bags of cement and plaster as well as paints and solvents in a covered area.
• Never clean paintbrushes or rinse paint containers into a street, gutter, or storm drain.

Remember - storm drains lead straight to the ocean.   None of us would want household chemicals, oils, and fertilizers to drain into our swimming pool right, well the fish, birds, and other organisms swimming down stream of our stormdrains don’t want these pollutants draining into their waterways either.    Please do you part. The quality of our beaches and coastal wetlands depends upon it.

The Resource Conservation District of Greater San Diego County offers a watershed education program for K-12 classes.   For information about the program or for more information about water quality and stormwater runoff, contact the Resource Conservation District at 760-745-2061.  

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