Sewage Cleanup Cost

Sewage is classified as category 3 blackwater, the most contaminated class of water damage, and it is priced accordingly: $6.50 to $9.50 per square foot for extraction and sanitizing alone. A typical single-bathroom backup, around 300 square feet, runs $1,950 to $2,850 before any porous material removal.

The short answer

Sewage cleanup cost by affected area

Affected areaWhat it typically meansCost
150 sq ftA small bathroom or single fixture area$975 to $1,425
300 sq ftA larger bathroom or small room$1,950 to $2,850
600 sq ftA basement or multiple affected rooms$3,900 to $5,700
$6.50 to $9.50/sq ft
Category 3 blackwater extraction and sanitizing
IICRC Category 3
The industry classification for sewage, the most contaminated water class
+$1.50 to $3.50/sq ft
Removing and disposing of contaminated carpet, drywall, or insulation
+15%
Main sewer line or septic backups over a single fixture overflow
Cost factors

What changes the price

Affected square footage
The main driver, priced per square foot of contaminated area.
Source of the backup
A single toilet or appliance overflow is more contained. A main sewer line or septic backup usually means more volume and complexity, adding about 15%.
How much of the space is affected
Multiple rooms or a full basement cost about 30% more than damage confined to one room, since containment gets harder to maintain across a larger area.
Porous material removal
Carpet, drywall, and insulation that absorbed contaminated water usually cannot be sanitized and has to be removed and disposed of, priced per square foot on top of extraction.
Fogging and testing
Antimicrobial fogging after extraction and post-cleanup air quality testing are both common, optional add-ons rather than automatic parts of the base job.
Act quickly

Why this is not a wait-and-see job

Sewage contamination is a health hazard from the moment it happens, not something that gets worse gradually the way a slow leak does. The area needs to be avoided and ventilated immediately, and a licensed restoration company called for anything beyond a small, contained spill. See our water damage restoration cost guide for the broader category system sewage sits inside.

Frequently asked

Questions people ask before booking

How much does sewage cleanup cost?

Sewage cleanup runs $6.50 to $9.50 per square foot for category 3 extraction and sanitizing. A small bathroom backup, around 150 square feet, runs $975 to $1,425. A larger event affecting a basement, around 600 square feet, runs $3,900 to $5,700.

What makes sewage different from regular water damage?

Classification. The IICRC, the restoration industry's standards body, classifies sewage as category 3, or blackwater, the most contaminated class of water damage. It requires biohazard PPE, specialized extraction equipment, and disposal of porous materials that cannot be safely sanitized, all of which cost more than a clean or gray water job.

Can I clean up a sewage backup myself?

Only if it is genuinely small and contained, like a toilet overflow with no contact with people or pets. Anything beyond that carries real health risk, and a licensed restoration company has the PPE, extraction equipment, and disposal process that a DIY cleanup cannot safely replicate.

Does sewage cleanup include repairing the underlying plumbing issue?

No. This covers extraction, sanitizing, and disposal of contaminated materials, not fixing the clogged or damaged line that caused the backup in the first place. That is a separate plumbing repair, usually handled by a different contractor.

Is contaminated carpet or drywall always removed?

Usually, yes, if it made direct contact with the sewage. Porous materials like carpet, padding, drywall, and insulation absorb contamination in a way that cannot be fully sanitized, so removal and disposal is standard practice rather than an unusual add-on.

Get the affected square footage as accurately as you can, even a rough walkthrough estimate, and run it through the calculator above. Then call a licensed restoration company immediately, this is not a category of job worth shopping around slowly on.

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