Active Alerts

Flood and high wind watch for San Francisco. 

For your safety, avoid driving or walking through standing water at all cost.
Please be cautious of manhole covers that may have been dislodged. Report dislodged manhole covers to @SF311. 

Emergency Operations Center (EOC) Activated

The City has activated the Emergency Operations Center (EOC) to coordinate citywide operations, such as clearing storm drains, responding to hill slides, distributing sandbags, and ensuring residents are informed.
Report non-life-threating storm issues to 311, such as:

  • Clogged catch basins
  • Non-life-threatening street and residential flooding
  • Sewer backups or wastewater odors
  • Downed trees

Read more about what to do before and during the storm.

Stay safe and avoid unnecessary travel.

message View Details

Sewer System

You can rely on our high-tech wastewater treatment systems, which handle wastewater for thousands of San Francisco residents every day and help keep pollutants out of our beautiful bay and ocean. Learn how we treat wastewater safely and responsibly.

Sections of uninstalled sewer pipes

Where Does Wastewater Go?

Every time you flush the toilet, take a shower, brush your teeth, do your laundry, or wash the dishes, the resulting wastewater is collected and treated by the City's sewer system. Learn how San Francisco collects and treats sewage from homes and businesses, stormwater (rainwater), and street runoff into the drains.

SFPUC employee inside sewer during construction

Our Combined Sewer

San Francisco is the only coastal city in California with a combined sewer system that collects and treats both wastewater and stormwater in the same network of pipes. Learn more about our combined sewer system.

Drain inside rain garden

Wastewater Collection System

San Francisco's combined sewer system includes a network of pipes, treatment plants, catch basins, storm drains, and storage/transport boxes. Learn how all these parts work together in our combined sewer system.

Secondary sedimentation tank

Treating the Liquid Flows

We separate liquids from solids in several phases during our processing, and we treat each separately. Learn more about the different wastewater treatment processes for liquids.

Anaerobic digesters at Oceanside Wastewater Treatment Plant

Treating the Solids

We separate liquids from solids in several phases during our processing, and we treat each separately. Learn more about our different wastewater treatment processes for solids--from sludge into biosolids, a recycled product that can be used as a fertilizer replacement.