Prevent Stormwater Pollution: Only Rain Should Go in the Storm Drain

Though it's been far too long since we've experienced a good rainstorm, we must remember that when it does rain in Arizona, it often falls rapidly, which can lead to unexpected flooding. This water can rush over driveways, sidewalks, streets, and parking lots. These strong water flows can carry pollutants such as trash, oil, pet waste, and pesticides into our storm drains, contaminating the water that ultimately reaches our local washes, parks, streams, and wetlands.

Stormwater runoff is a major cause of water pollution in the United States. As it flows, it collects dirt, trash, oil, grease, chemicals, and other pollutants. Since stormwater runoff is not treated, these pollutants are carried into waterways, canals, parks, community lakes, retention basins, and dry wells. Polluted stormwater can also harm 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, which are transported through pipes to treatment plants. Storm drains carry untreated water directly into washes, parks, and riverbeds, where it can seep into our aquifers. While both systems have extensive infrastructure, the stormwater system—which includes ditches, culverts, ponds, lakes, curbs, and gutters—does not undergo treatment before the stormwater enters 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
Choose a commercial or self-service car wash whenever you can, as they are more water-efficient. If you wash your vehicle at home, use a bucket with phosphate-free, biodegradable detergent and redirect the wash water to your landscaping whenever possible. Additionally, ensure you dispose of wash water in a sink or toilet.

Lawn Care
Overwatering can carry pollutants to rivers and washes. So, sparingly use pesticides, fertilizers, and other lawn care products 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.

Adopting healthy household habits plays a crucial role in preventing common pollutants from gathering on surfaces and eventually entering our stormwater systems. These simple actions can greatly reduce pollution levels. Protecting our water sources requires a community-wide effort that begins long before it rains. Together, we can effectively protect our local waterways and ensure a healthier environment for future generations.

During Stormwater Awareness Week,  Phoenix Water is hosting a virtual ​workshop at noon on Wednesday, January 22, 2025, to discuss the City’s Stormwater Management Program and its efforts to reduce stormwater pollution. Please register here​  to participate. ​