Sewage backup cleanup in Boise
Stop running water and flushing, keep everyone out of the contaminated area, and do not touch sewage without protective gear. Call a plumber to clear the line and a restoration company for Category 3 cleanup; porous materials that sewage touched usually need to be removed, not just dried.
Water Damage Boise is an independent guide, not a restoration company. Requests go to a local restoration partner. Last reviewed 2026-11-09.
What happens next, step by step
- 1
Stop using water
Stop flushing, running faucets, and running the washer or dishwasher. Every gallon you send down the drain can come back up the lowest fixture.
- 2
Keep people and pets out
Close off the area. Do not walk through sewage, and keep children and pets away. Turn off HVAC that pulls air from the affected space if you can do it without entering it.
- 3
Watch out for electricity
If sewage has reached outlets, cords, or the panel area, stay out and shut off power from a dry location, or call for help.
- 4
Find out if it is your line or the public main
If only your house is affected, the blockage is likely in your private service line. If neighbors are also backing up, contact your sewer provider. In Boise, the owner is responsible for the private line under City Code 10-2-5-2.
- 5
Call a plumber to clear the line
A plumber can snake or jet the line and often camera-inspect it to find roots, a collapse, or a belly. Get the camera findings in writing.
- 6
Professional Category 3 cleanup
Crews wearing protective equipment remove sewage, discard porous materials it touched (carpet, pad, drywall, insulation), clean and disinfect hard surfaces, and dry the area. EPA guidance says not to run fans before confirming water is clean, since air movers can spread contaminants.
- 7
Verify, then rebuild
After drying and sanitizing, the space is rebuilt. Some households ask for post-cleanup testing for peace of mind; ask what is included.
What causes sewage backups in Boise-area homes
Roots in older clay and cast-iron lines
Older neighborhoods like the North End and East End combine mature trees with decades-old sewer laterals. Roots find joints in clay and cast-iron pipe, catch debris, and eventually block the line. Boise code makes the owner responsible for clearing roots from private property even when they settle in the public part of the line.
Basements and low fixtures
Sewage comes out at the lowest drain first, which is why basement floor drains, basement showers, and lower-level toilets are where most backups appear. Homes with finished basements carry the most risk of costly damage.
Grease, wipes, and the wrong things down the drain
Cooking grease and “flushable” wipes are common culprits in any city. A line that is already partly restricted by roots or a sag fails faster when these are added.
Storm surges and system issues
Less often, a problem in the public main or a heavy storm affects several homes at once. If neighbors have the same problem, call your sewer provider before paying for private line work.
Septic systems outside city sewer
Some rural properties in Ada and Canyon counties are on septic systems. A full tank or failed drain field can push wastewater back into the house; that needs a septic contractor as well as cleanup.
Warning signs
- Gurgling from toilets or drains when another fixture runs
- Several slow drains at once, especially on the lowest floor
- Water in the basement floor drain or shower when the washer drains
- Sewer odor in the basement or yard
Sewage cleanup cost factors
Published national figures only; we have not verified Boise-specific sewage cleanup pricing.
- HomeGuide: about $7 to $15+ per square foot; roughly $2,000 to $3,000 for a small single-room spill, $3,000 to $7,000 for a multi-room backup, $7,000 to $15,000 for large contamination, and $15,000 to $50,000+ when extensive repairs are needed.
- Angi (water damage guide): black water mitigation averages about $7.50 per square foot nationally.
- Angi (flooded basement guide): black water basement cleanup $7,000 to $15,000.
- Line repair is separate: HomeGuide lists sewer camera inspection at $125 to $500 and full sewer line replacement at $2,000 to $10,000 on average.
What changes the total
- Square footage and number of rooms contaminated
- How long sewage sat before cleanup
- Finished basement materials that must be discarded
- Crawl-space access
- Whether the private sewer line also needs repair or replacement
Insurance often excludes sewer backup unless you bought an endorsement; see the Idaho insurance guide.
Frequently asked questions
Can I clean up a sewage backup myself?
For anything beyond a small, contained toilet overflow on a hard floor, professional cleanup is the safer choice. Sewage is Category 3 water under the IICRC standard and can carry bacteria and viruses. The EPA says that if water or mold damage was caused by sewage or other contaminated water, you should call in a professional experienced with contaminated water.
Who is responsible for a sewer backup in Boise?
Under Boise City Code 10-2-5-2, the property owner is responsible for cleaning, unstopping, maintaining, and repairing the private sewer service line, and for clearing roots or debris from private property that settle in the public portion. The City is responsible for repairing the public service line. If you are outside Boise city sewer, check with your own sewer district.
Does homeowners insurance cover sewer backup?
Usually not under a standard policy. The Insurance Information Institute says sewer backup is not covered by a typical homeowners policy or by flood insurance, and is usually added as a separate endorsement. Check whether your policy has a water backup or sewer backup endorsement and its limit.
What is the difference between gray water and black water?
Gray water (Category 2) is significantly contaminated, such as washer or dishwasher discharge. Black water (Category 3) is grossly contaminated and includes sewage. Gray water left to sit can become Category 3, so speed matters.
How much does sewage cleanup cost?
HomeGuide lists sewage cleanup at roughly $7 to $15 or more per square foot, or $2,000 to $15,000 or more in total, depending on area and how long it sat. Angi’s national black water average is about $7.50 per square foot for mitigation. We have no verified Boise-specific figure.
Related guides
- Basement floodingWater in basements and crawl spaces from inside or outside the house.
- Mold remediationWhen mold follows a leak, what is DIY-sized, and when to call a pro.
- Insurance claims in IdahoHow homeowners policies typically treat water damage.
- Water damage in Boise: start hereThe overview of every guide on this site.
Talk to a local restoration partner
When you are ready, you can ask a local restoration partner to look at the damage and explain your options. There is no obligation, and you can still get other quotes.