Bay Crossings Article

Holiday Kitchen Tips for Preventing Bay Pollution

Deb Self
From the December 2011 edition of Bay Crossings

Ah, the holidays. Gathering with friends and family—turkey, roasts, gravy, buttery homemade desserts, sewage . .


Yes, unfortunately. For San Francisco Bay, the holiday season comes with a surge of pollution from sewage. A major reason is the cooking and cleanup of rich holiday meals. Fortunately, there are ways we can all make sure our kitchens don’t pollute the Bay by accident.

Cooking rich foods like turkey and gravy creates fats, oil and grease—cleverly referred to as FOG—that get washed down the drain during cleanup of pots, pans and fryers.  The fats and greasy scraps harden and clump together, especially in cold weather. Fats stick to the inside of sewer lines and build up over time, causing clogs and overflows.

Even the occasional tablespoon of bacon fat down the drain can lead to sewage backing up in your home or apartment sewer line, sending untreated sewage into your home or yard.

When small amounts of fat from your kitchen join small amounts from your neighbors, it can add up to a clogged street sewer line. Sewage can then back up in multiple driveways and yards. From there it can be washed into storm drains, where it flows directly into local creeks and the Bay. Sewage pollution causes problems that range from skin infections in swimmers to disease in sea lions to algae blooms that choke off the oxygen supply of fish and aquatic plants.

We can all keep our kitchens from polluting the Bay—and avoid sewage backups in our homes and neighborhoods. Here are the foods not to wash down the drain: cooking oil, meat fat, lard, shortening, butter, dairy products, margarine, fatty food scraps, sauces, gravy, and salad dressing. 

Here are tips for Bay-friendly fat cleanup:

  • Pour cooled fats and oils into a can with a lid and dispose of in the garbage.
  • Wipe down greasy pots, pans and dishes with a paper towel before washing them.
  • Dispose of the paper towel in your kitchen scrap recycling or in the garbage.
  • Don’t use hot water or the garbage disposal to wash fats down the drain. Water cools through the pipes, causing fats to harden into clogs further along in the sewer system.
  • Drop off large amounts of cooking oil—like used oil from a turkey fryer—at recycling locations in Marin, San Francisco and the East Bay (see list below). 

Cooking fats are just one cause of winter sewage pollution in San Francisco Bay. During the rainy season, large amounts of rainwater seep into the Bay Area’s aging sewer systems through crumbling pipes. When local sewage treatment plants can’t handle the increased water, hundreds of millions of gallons of undertreated and untreated sewage spill into the Bay and local creeks—as is often the case in the East Bay and Marin County

Last year, a quarter billion gallons of undertreated sewage spilled into the Bay (not counting San Francisco, which has a different kind of system and doesn’t report its overflows). Most of that sewage was spilled in Marin County or through East Bay Municipal Utility District’s plants in Oakland and Richmond. To stem the flow, Baykeeper recently won agreements to compel 11 East Bay cities to upgrade their sewage collection systems. Over the next several years, we’ll see major reductions in sewage spills, but you can help spur more progress. To learn more about how, please visit or call (415) 856-0444.

Used Cooking Oil Collection Sites

Marin Household Hazardous Waste Facility
565 Jacoby St., San Rafael
8 a.m. to 4 p.m. Tues-Sat
(415) 485-6806

East Bay
Whole Foods Oakland
230 Bay Place
(510) 834-9800
8 a.m. to 10 p.m. daily

EBMUD Wastewater Treatment Plant
2020 Wake Avenue, Oakland
Self-service receptacle
(510) 287-1651

West Contra Costa County Integrated Waste Management Authority
101 Pittsburg Avenue, Richmond
9 a.m. to 4 p.m. Thurs and Fri, plus first Saturday each month
(888) 412-9277

Central Contra Costa County Household Hazardous Waste Collection Program
4797 Imhoff Place, Martinez
9 a.m. to 4 p.m. Mon-Sat
(800) 646-1431

Baykeeper Executive Director Deb Self is a member of the California Office of Spill Response Technical Advisory Committee, the San Francisco Harbor Safety Committee, the Coast Guard’s Area Committee and an advisor on oil spill response technologies to the Gulf of the Farallons National Marine Sanctuary.  Baykeeper uses on-the-water patrols of San Francisco Bay, science, advocacy and the courts to stop Bay pollution.