Storm Drain Pollution Prevention

Storm and Sewer Drains

In the City of Rosemead, there are two different water drainage systems: sewers and storm drains. Sewers carry wastewater from our homes and businesses to a wastewater control facility or sewer treatment plant where the water is cleaned and discharged into the San Gabriel River. The storm drain system collects rainwater, runoff from our yards and anything else dumped into our gutters and catch basins. That storm drainage water goes directly to our local waterways with no treatment.

Sewer Vs. Storm Drain

Storm Drain - Flooding or Illegal Dumping

The storm drain system is for the sole purpose of collecting rainwater overflow. Storm drains divert the water and debris after a storm or shower away from road surfaces, public access areas, or low basins, where water collection could be unhealthy and dangerous.

Dumping trash, pollutants and debris in the catch basins is illegal and is a federal violation of the Clean Water Act of 1972, as well as the City of Rosemead's Municipal Code. Pollutants may require an immediate clean up to prevent them from getting into our local waterways.

To report illegal dumping (Municpal code 9.12.020 Illegal dumping) or a storm drain that is backed up or flooding, please call (626) 569-2262.  If a person is illegally dumping into a storm drain, please try to provide a license number or physical description of the person if possible.  Some people may not understand the catch basin's direct connection to the San Gabriel River and other waterways. It may be just a matter of making them aware of its environmental impact. City staff would be more than happy to provide them with information.

For the latest information and tips, please visit the following sites:
California Department of Water Resources
Water for LA
Los Angeles County Waterworks District
SoCal WaterSmart

Storm Water FAQs

Rosemead has two drainage systems - the sewers and the storm drains. The storm drain system was designed to prevent flooding by carrying excess rainwater away from the city streets out to the ocean. Because the system contains no filters, it now serves the unintended function of carrying urban pollution straight to the ocean.

Rain, industrial and household water mixed with urban pollutants creates storm water pollution. The pollutants include oil and other automotive fluids, paint and construction debris, yard and pet wastes, pesticides and litter.

Urban runoff flows to the ocean through the storm drain - a system of pipes, channels and reservoirs that take water and debris straight from Rosemead streets to the ocean. Each day 100 million gallons of polluted urban runoff enter the ocean untreated leaving toxic chemicals in our surf and over 4,300 tons of trash on our beaches.

Urban runoff pollution contaminates the ocean, closes beaches, harms aquatic life and increases the risk of inland flooding by clogging gutters and catch basins.

These Best Management Practices will ensure a cleaner ocean and city.

Facts About Storm Drains

The Clean Water Act of 1977 (CWA) established criteria for the cleanup of water, regulated the discharge of pollutants and toxic chemicals, fostered the protection of wildlife, and promoted intergovernmental cooperation. In 1987 the CWA was amended and provisions regarding the water quality of discharges from major storm drain systems were added. Counties and local cities are required to develop and carry out programs to enhance the quality of runoff discharging into our storm drain system. These programs are aimed at reducing the flow of storm water urban runoff that may be contaminated by oil, grease, toxic metals, solvents, pesticides, and litter from city streets into oceans, bays, lakes and other waterways.

Q: What are Storm Drains?

A:  The storm drain system was designed to prevent flooding by carrying rainwater from the streets out to the ocean. Curbs and gutters, catch basins (curbside openings), drain pipes, and open flood control channels make up the storm drain system. Eventually the water flows all the way from your property, along curbside gutters, to a storm drain outlet emptying directly into the ocean.

Q: Isn't the Storm Drain System like a Sewer System?

A:  The storm drain systems collects rain and urban runoff and dumps it directly into the ocean completely untreated, while the sewer system carries wastes to a treatment plant and discharges them only after treatment. Storm drains are meant to carry only rainwater. Unfortunately, flowing water is already conduit for pollutants found on city streets.

Q: What are the Impacts of Storm Water Pollution?

A:  Chemicals, hazardous materials, and trash are being carried directly to our beaches, rivers, and lakes. Such substances pollute water resources. Urban runoff pollution can harm both marine wildlife and plant life. It also destroys the natural beauty of our beaches and waterways. At times, it can also be responsible for unsafe swimming conditions in our beaches and lakes.

Most of the pollution can be controlled by each one of us. The major pollutants are often contributed through negligence. By taking a few moments, we can take responsible actions that will prevent this pollution.

Q: What are the Major Pollutants?

  • Oil and automotive fluids from leaks, spills, and dumping
  • Paint and paint thinners through improper disposal
  • Pesticides, herbicides, and fertilizers - over watering causes these pollutants to flow to storm drains.
  • Lawn clippings, other green waste, and animal droppings
  • Paper, plastic, and other trash items such as cups, wrappers, and packaging

Q: Can I really Make a Difference?

A:  YES YOU CAN!! The City of Rosemead is counting on our citizens to work jointly toward reducing the pollution of storm water and urban runoff. Read ahead for more valuable ways that your can help to reduce storm drain runoff.

Q: How Can You Help Reduce Storm Drain Pollution?

  • Take household hazardous waste materials such as oil, automotive fluids, paints and paint thinners to a hazardous materials collection center or round-up event.
  • Use pesticides, herbicides, and fertilizers in accordance with label instructions. Do not apply before rain and avoid over watering.
  • Use a broom rather than a hose to clean garden clippings. Put leaves or clippings in a trashcan or compost pile.
  • Do not let the hose run unattended while washing the car. Conserve water and use biodegradable soap.
  • Call the City of Rosemead Public Works Department at 626-569-2150 or the Los Angeles County Department of Public Works at 1-888-CLEANLA for more information to report illegal dumping.
  • Also, visit

Public Information and Outreach
For additional resources, please visit the LA County website at
For school district resources, please visit