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Emergency · Sewage Backup Emergency

Sewage in Your Home — Category 3 Biohazard Response

Sewage backup is Category 3 black water — a biohazard. Evacuate affected areas, do not attempt DIY cleanup, and call IICRC-certified decontamination specialists immediately.

(888) 840-6512Mold window: 24 hours

Emergency checklist

  1. Evacuate all people and pets from affected areas immediately — sewage contains pathogens and bacteria

    ⚠ Do NOT walk through sewage without full PPE (Category 3 biohazard)

  2. Open windows in unaffected areas for ventilation — do NOT use fans in the contaminated zone (aerosolizes bacteria)

    ⚠ Fans spread contamination to clean areas of the home

  3. Photograph the backup source, affected rooms, and water line marks from a safe distance

    ⚠ Do not touch contaminated items before documentation

  4. Do NOT attempt to clean sewage yourself — Category 3 water requires professional decontamination per IICRC S500

    ⚠ Bleach does not properly decontaminate porous materials like carpet and drywall

  5. Call an IICRC-certified restoration company with Category 3 experience — 24/7 emergency dispatch

    ⚠ Verify they follow IICRC S500 decontamination protocols

  6. Call your insurer — ask specifically about sewer backup coverage (often requires a separate rider)

    ⚠ Standard policies often exclude sewer backup without an endorsement

Typical cost range

$3,000 – $20,000

Full cost breakdown

Mold growth timeline

Mold Growth Clock

What happens hour by hour after water damage

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Water Intrusion

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Water enters the structure. Clock starts NOW.

Recommended Action

Shut off water source, move valuables off floor, begin documentation with photos/video.

Next milestone: Absorption Begins at 1 Hour

All Milestones

Sewage Backup Emergency FAQ

Is sewage backup covered by homeowners insurance?
Often NO — unless you have a sewer backup endorsement (typically $50–$250/year). Standard policies exclude sewer and drain backup. Check your declarations page for 'Water Backup' or 'Sewer Backup' coverage.
Can I clean sewage backup myself?
No. Category 3 water contains bacteria, viruses, and parasites. IICRC S500 requires professional extraction, antimicrobial treatment, and removal of porous materials that cannot be decontaminated. DIY cleanup creates serious health risks.
How much does sewage cleanup cost?
Sewage backup cleanup typically costs $3,000–$20,000 depending on affected area, materials involved, and whether structural demolition is required. Category 3 water costs $7–$7.50/sq ft for extraction alone, plus decontamination and material replacement.
How to Replace a Main Shutoff Valve | Ask This Old House — This Old House walks through locating, operating and replacing the main water shutoff valve — the most important emergency skill for limiting water damage. Read the full guide →

Read the full guide: sewage backup cleanup guide

(888) 840-6512