Contaminated water is not a wet-carpet problem.
The categories
Category 1 is clean water from a supply line. Category 2 is used water — dishwasher, washing machine. Category 3 is grossly contaminated: sewage, backups, floodwater from outside. The category sets the scope, and it can escalate: clean water sitting for days becomes Category 2, then 3.
Why it comes out
Category 3 water carries bacteria and pathogens into porous materials — carpet, pad, drywall, insulation — where cleaning cannot reliably reach. The standard is removal and disposal, then cleaning and verifying the structure underneath. Anyone offering to “sanitize and dry” your sewage-soaked carpet is selling you a problem.
Insurance
Sewer backup usually requires a specific endorsement, separate from standard water coverage. Check your policy — a lot of Atlanta homeowners find out they don’t have it at the worst possible moment.