The Real Health Risks of a Sewage Backup
Sewage is classified as Category 3 water, the most contaminated class under the IICRC S500 standard used by the restoration industry. It is not just unpleasant. It carries germs that can make people sick through skin contact, splashes, and hand-to-mouth contact.
What is in raw sewage
| Type | Examples | Common effects |
|---|---|---|
| Bacteria | E. coli, Salmonella, Shigella | Diarrhea, stomach cramps, fever |
| Viruses | Norovirus, hepatitis A | Vomiting, diarrhea; liver infection with hepatitis A |
| Parasites | Giardia, Cryptosporidium | Long-lasting diarrhea and stomach upset |
| Gases | Hydrogen sulfide | Rotten-egg smell, headache, nausea in closed spaces |
How people get exposed
- Touching sewage or contaminated surfaces, then touching the mouth or eyes
- Splashes while trying to clean up
- Cuts or scrapes that come in contact with sewage
- Breathing air in a closed room with sewage, especially while scrubbing or vacuuming
Who is most at risk
Babies and young children, adults over 65, pregnant women, and anyone with a weakened immune system, such as people receiving chemotherapy, should stay out of the area entirely until it has been cleaned and disinfected. Pets should be kept out too, since they walk through the water and then lick their paws.
Protecting yourself
- Wear waterproof gloves, rubber boots, and eye protection if you must be near the water.
- Wash hands with soap and clean water after any contact, and before eating.
- Keep open cuts covered and away from contaminated water.
- Wash clothes worn near sewage separately in hot water.
- Throw away food, medicine, and baby items that sewage touched.
When to see a doctor
Call a doctor if anyone develops diarrhea, vomiting, fever, or stomach cramps after exposure, or if a cut that touched sewage becomes red, swollen, or painful. Ask about a tetanus shot if you were cut and are not up to date. This article is general information, not medical advice.
Why porous materials usually go
Carpet, pad, drywall, and insulation soak up sewage deep into the material, where disinfectant cannot reach. That is why a proper Category 3 black water cleanup removes them instead of cleaning the surface. For first steps and local contacts, see sewage cleanup in Garland.
