Sewage Backup in Your Home — Health Risks and What the Cleanup Involves

Why Sewage Backup Is Different from Other Water Damage

Most water damage events involve clean or gray water that, while damaging to structure and materials, doesn't create immediate pathogen exposure risk. Sewage backup is different. Raw sewage contains a complex biological load: fecal coliform bacteria including E. coli, Salmonella, and Campylobacter; enteric viruses including Hepatitis A and norovirus; and parasites including Cryptosporidium and Giardia.

These pathogens enter the body through ingestion of contaminated material, direct skin contact with open wounds, or inhalation of aerosols created when sewage water is disturbed. Standard household cleaning products are not sufficient to address the pathogen load on porous materials — which is why material removal, not cleaning, is the standard protocol.

Health Risks from Sewage Exposure

Health effects vary by pathogen, exposure route, and individual immune status:

• Gastrointestinal illness — Nausea, vomiting, diarrhea, and abdominal cramping from bacterial or viral pathogens. Can be severe in elderly individuals, young children, and immunocompromised persons.
• Hepatitis A — Viral liver infection transmitted through fecal-oral route. Vaccine-preventable but potentially serious for unvaccinated individuals with sewage exposure.
• Leptospirosis — Bacterial infection spread through water contaminated by animal urine — common in floodwater events with sewage overflow. Can cause kidney and liver damage.
• Respiratory symptoms — Inhalation of sewage aerosols or mold spores in a contaminated space causes respiratory irritation, particularly in individuals with asthma or compromised lung function.
• Skin and wound infections — Direct contact between sewage water and broken skin creates infection risk. Any cuts or abrasions should be covered with waterproof dressings before any proximity to contaminated areas.

What You Should and Should Not Do

Immediate actions before professionals arrive:

• Do: Evacuate children, elderly, and immunocompromised individuals from the affected area immediately.
• Do: Shut off water at the main if sewage is backing up through fixtures.
• Do: Open windows if safe to improve ventilation and reduce aerosol concentration.
• Do: Document everything with photographs before any cleanup.
• Do not: Attempt cleanup without full PPE — N95 respirator, chemical-resistant gloves, protective eyewear, disposable coverall.
• Do not: Use household fans in the affected area — they spread contaminated aerosols to adjacent spaces.
• Do not: Run the dishwasher, washing machine, or flush toilets until the sewer line blockage is cleared.

What Professional Sewage Cleanup Involves

Licensed biohazard restoration contractors follow IICRC S500 Category 3 protocols. The process begins with containment barriers to prevent contamination spread, followed by extraction of standing sewage using equipment rated for Category 3 use.

All porous materials in contact with sewage — carpet, drywall, insulation, wood flooring — are removed and disposed of. Non-porous surfaces are cleaned with EPA-registered hospital-grade disinfectants. HEPA air scrubbers run throughout. After demolition and disinfection, the space is dried and tested if required before reconstruction begins.