We all play a part in preventing stormwater pollution

Published Jan 16, 2024

Any amount of precipitation is appreciated when you live in the desert. And when it does rain in Arizona, it often comes down quickly and causes flooding that sweeps over driveways and sidewalks, through streets and parking lots. These forceful water flows can also carry pollutants such as trash, oil, pet waste, and pesticides into our storm drains, contaminating water that eventually flows into our local washes, parks, streams, and wetlands.

Stormwater runoff is one of the leading causes of water pollution in the United States. As it flows, it picks up dirt, trash, oil, grease, chemicals, and other pollutants. Seeing stormwater runoff is not treated, those pollutants are then carried into waterways, canals, parks, community lakes, retention basins, and dry wells. Polluted stormwater runoff can also negatively impact aquatic ecosystems, the environment, and our drinking water sources.

It’s also important to note that not all water is treated equally. Cities have two separate water collection systems. The sanitary sewer system collects wastewater from sinks, toilets, showers, and washing machines that is transported through pipes and flows to treatment plants. Storm drains carry untreated water directly into washes, parks, and riverbeds, which can then seep into our aquifers. While both systems have extensive infrastructure, the stormwater system that includes - ditches and culverts, ponds and lakes, curbs, and gutters is not part of a treatment process before the stormwater can find its way into our groundwater. This is why we must all do our part to protect our water and environment by remembering “only rain in the storm drain.”

Basic stormwater runoff facts  can help us better understand the impact of contaminated rainwater on our environment. Here are some valuable tips to help us all better understand the role we can play in keeping our stormwater free of contaminants, including the following:

Pet waste
Collect pet waste in a plastic bag and throw it away in a garbage can. Pet waste contains bacteria and other pathogens that are not healthy additives to our water.

Automobile Maintenance
One quart of motor oil can contaminate over 250,000 gallons of water. That is why it is vital to maintain vehicles to prevent fluid leaks. Use drip pans to catch leaks. Clean up leaks and spills using an absorbent such as kitty litter or sand. Just remember to sweep it up immediately and properly dispose of it.

Vehicle Washing
Use a commercial or self-service car wash when possible because it is more water-efficient. If you wash your vehicle at home, use a bucket and phosphate-free, biodegradable detergent and direct wash water to landscaping when possible. Make sure you dispose of wash water in a sink or toilet.

Lawn Care
Overwatering can carry pollutants to rivers and washes. So, use pesticides, fertilizers, and other lawn care products sparingly and follow label instructions. Do not sweep or wash yard debris into the street because it can clog storm drain inlets, causing flooding.

Household Chemicals
Keep chemicals in labeled, closed containers. Unused household chemicals, including paint, used oil, cleaners, and yard chemicals, should be appropriately disposed of or recycled. Take these items to your city's Household Hazardous Waste site or collection event.

Pools and Spas
Backwash or drain your pool, spa, or water feature to the sanitary sewer using your home’s cleanout. Discharging pool water to the street can contaminate water with chemicals, bacteria, and other pollutants.

Trash & Recycling
Bag and tie up loose trash. Also, make sure you keep trash and recycling bins closed.

These healthy household habits can keep common pollutants off the ground and out of our stormwater. Protecting our water sources is a community effort that begins long before it rains.

During Stormwater Awareness Week, Phoenix Water is hosting a virtual workshop at noon on Wednesday, January 24, 2024, to discuss the City’s Stormwater Management Program and its efforts to reduce stormwater pollution. Please register here  to participate. 

To print or save this week's blog, a PDF version is available HERE .

For 55 years, the Arizona Municipal Water Users Association has worked to protect our member cities' ability to provide assured, safe, and sustainable water supplies to their communities. For more water information, visit .