If a drain or toilet is backing up, stop using all water right away, shut off the toilet's water valve if it is overflowing, and keep people and pets away from any dirty water. Do not pour chemical drain cleaner into a backed-up drain. Then work out whether one fixture or several are affected, and call for help.
Step 1: Stop the water
- Toilet overflowing: turn the valve behind the toilet clockwise to close it. If you cannot, lift the tank lid and raise the float to stop the fill.
- Sink or tub backing up: turn off the faucet and stop running water anywhere else in the house.
- Washer causing backups: stop the cycle.
Step 2: Protect people and property
- Keep children and pets away from dirty water.
- Move rugs, towels and valuables away from the area.
- Wear gloves when handling anything touched by sewage water.
Step 3: Work out what is affected
One fixture backing up usually means a local clog. Water appearing in a different fixture, such as the tub when you flush, points to the main line. Read signs your main sewer line is clogged.
Step 4: Check with neighbors if it is a main line
If neighbors are also backing up, the public sewer main may be blocked. Contact City of Whittier Public Works if you are inside city limits, or Los Angeles County Public Works at (800) 675-HELP in unincorporated areas. See our sewer lateral guide.
What not to do
- Do not keep flushing a toilet that is not draining.
- Do not pour chemical drain cleaner into standing water; it can splash and makes the job hazardous for whoever clears the drain.
- Do not use water elsewhere in the house until the line is clear.
- Do not try to open a cleanout that is under pressure without protection; sewage can spray out.
Step 5: Call for help
Call to describe what is happening, which fixtures are affected and what you have tried. Relevant services: clogged toilet repair, main sewer line cleaning and floor drain cleaning.
Not sure which drain service you need? Describe the problem and we'll point you in the right direction.
Call (562) 245-5818Frequently asked questions
Is a sewage backup dangerous?
Sewage can carry bacteria and other contaminants. Avoid contact, keep children and pets away and clean affected areas thoroughly.
Should I call my insurance company?
If sewage has damaged floors or belongings, contact your insurer to ask about coverage. Policies vary, and some require a specific sewer backup endorsement.
Related services
Clogged Toilet Repair
Help for toilets that clog, overflow or drain weakly, including main line warning signs.
Learn MoreMain Sewer Line Cleaning
Clear main drain and sewer lateral blockages that back up several fixtures at once.
Learn MoreMore drain guides
- Whittier Sewer Lateral Guide: Who Is Responsible for Your Sewer Line?
- 7 Signs Your Main Sewer Line Is Clogged, Not Just One Drain
- Why Does My Drain Keep Clogging? 8 Common Causes and Fixes
- Hydro Jetting vs. Drain Snaking: Which One Does Your Drain Need?
This guide is general information, not legal or engineering advice. Rules and agency contacts can change; confirm details with the City of Whittier or Los Angeles County Public Works.