Water Pollution

Shows the path of water from our homes and storm drains to the Bay

Your Home's Water Flows to the Bay

Water from tubs, toilets, and taps inside homes travels through pipes to the Union Sanitary District’s Wastewater Facility where it is treated and then discharged into East San Francisco Bay.

Common Indoor Pollutants

Common Outdoor Pollutants

Water that enters Fremont’s storm drain system flows untreated into the nearest creek or channel and ultimately to the Bay. Stormwater runoff – rain or irrigation water flowing over sidewalks, driveways, and landscaping – can carry pollutants into storm drains.

Cleaning Spray Bottle

Household Cleaners

Make your own cleaner from common household items It's effective, economical, and less toxic.
See recipes.

Why? Cleaning products can contain harsh chemicals, which when washed down the drain, can mix with other chemicals and negatively impact the Union Sanitary District’s Wastewater Facility treatment process and the Bay.

Dog getting flea treatment

Pet Flea Treatment

Talk to your vet about using oral medications to control fleas and ticks.

Why? When you apply a “spot-on” flea and tick product to your pet, it doesn’t just stay there! See the pictures.

Spot-on treatments are applied by pouring liquid onto the back of your pet, between the shoulders. Even though they may seem dry after a few minutes, these products can easily spread around your home and even wind up in our waterways.

Spot-on treatments and other products such as flea collars, sprays, and foggers, contain toxic pesticides. These toxins can also end up in our local waterways when you wash your pet, its bedding, or clothing, or carpets.

Fipronil and imidacloprid are chemicals commonly found in flea and tick treatments. The California Department of Pesticide Regulation is currently reviewing the use of these chemicals because of potential human health risks. These chemicals cannot be completely removed at wastewater treatment facilities. and are discharged into our creeks, channels, and the Bay. These pesticides can accumulate at concentrations that are toxic to sensitive aquatic species.

More information about pets and toxins.

Paints and glues are considered hazardous waste

Household Hazardous Waste

Drop-off your Household Hazardous Waste at the Fremont Facility  Never pour leftover materials down the sink, toilet, or storm drain.

Items include:

  • paint
  • batteries
  • needles
  • medications
  • pesticides
  • propane tanks
  • Mercury thermometers
  • thermostats
  • electronic waste
  • other corrosive, flammable, and toxic materials

Why? Household hazardous wastes can accumulate in your garage or shed and endanger your family and the environment. 

See a full list of hazardous materials.

Pharmacy Pill Bottle


Drop off medications instead of flushing unwanted prescriptions or putting them in the garbage.

Drop off Fremont's Household Hazardous Waste Facility or find a local pharmacy.

Why? Flushed medicine flows through the sanitary sewer system which was not designed to remove all pharmaceutical compounds. Small amounts may pass through and be released into the Bay, impacting wildlife.

Fats, Oils, and Grease

After cooking, let fats, oil, and grease cool down and solidify, then transfer to a container such as a soup can. Cover the can and throw it into the trash (up to one quart).

To get rid of more than one quart of fats, oil, and grease, drop off at the Hazardous Waste Facility in Fremont.

Overflowed Sewer

  • If you have a sanitary sewer overflow in your home, please call a plumber. 
  • Overflow in the street and sidewalks should be reported to Union Sanitary District at 510-477-7500  (24 hours a day, 7 days a week)

Antibacterial Soaps

Use plain soap and warm water instead of using antibacterial soap. Scrub for 15-20 seconds, to fight germs on hands. 

Why? Triclosan is toxic and is a common chemical in antibacterial soaps and other products. A registered pesticide and endocrine disrupter, it can be toxic to you and to fish in the Bay.

Disposable Wipes

Throw disposable wipes (even those labeled as disposable) in the trash instead of flushing them.

Why? Disposable wipes can clog your sewer line or the public sewer system, leading to sewage overflows that can endanger public health, the environment, and your property.

Owner carries bag with dog poop

Pet Waste

Carry disposable bags when you walk your pet. Pick up and throw pet waste in a garbage can. Pet waste from your yard can be thrown in the garbage or toilet (without the bag). Keep pet waste out of compost piles and garden soil.

Why? Pet waste left on sidewalks, streets, yards, or other open areas can be washed away by rain or irrigation water into storm drains. Pet waste contains harmful bacteria and parasites that can cause disease as well as nutrients that encourage algae growth in waterways.

Swimming Pool Water


  • Drain your pool to a sanitary sewer cleanout instead of the storm drain. Call Union Sanitary District for approval first: 510-477-7500
  • Minimize algae buildup to prevent the need for toxic algaecides, which contain copper.

Why? Draining pools, spas, and fountains with copper, chlorine, sediments, and other contaminants to storm drains can pollute creeks.

Garden chemicals are hazardous waste, pesticides, herbicides, etc.

Garden and Yard Chemicals

Use integrated pest management (IPM) methods to reduce the need for pesticides.

Create healthy soil by following these tips, reducing the need for fertilizers.

Why? Pesticides, fertilizers, and other chemicals can wash off during rain or irrigation into storm drains that flow directly into creeks, channels, and the Bay, affecting the health of humans and wildlife.

Used Oil Set Out at Curb

Car Maintenance

Use drip pans or tarps to catch car leaks and spills. You can drop off your used motor oil and filters or request jugs to use which can be set out with your trash bins on collection day. 

Why? Leaks and drips wash off streets into storm drains that flow into creeks, rivers and, ultimately, the Bay.


Always throw trash in the proper can. If you see litter in the street in front of your home or business, pick it up and throw it away.

Volunteer in your community. Coastal Cleanup Day happens once a year. 

Why? Litter can collect in urban creeks, like Alameda Creek, impacting water quality, hampering recreational use, and potentially hindering flood control protection.

Visit Alameda County’s Online Guide for Reuse, Repair, and Recycling to find out what to do with just about everything.