The single word that moves a water bill the most is the category. It sounds technical, but it just describes how clean or contaminated the water is — and that decides whether soaked materials can be dried and saved or have to be torn out and thrown away. The category is set by where the water came from, not by how it looks after a few days.
Category 1 — clean water
Water from a sanitary source: a broken supply line, a tub or sink overflow with no contaminants, rainwater. It poses no immediate health risk. On a Category 1 loss, most materials can often be dried in place rather than removed — which keeps the cost down. Left too long, though, Category 1 water can degrade to Category 2.
Category 2 — gray water
Water with some contamination that could cause discomfort or illness: washing-machine or dishwasher discharge, a toilet overflow of urine but no solids, a sump-pump failure. Some porous materials (carpet pad, saturated drywall) are typically removed; others may be cleaned and dried.
Category 3 — black water
Grossly contaminated water: sewage, a toilet backup with solids, ground or flood water, or any water carrying harmful bacteria. This is the highest risk. Porous materials the water touched — carpet, pad, drywall, insulation — are normally removed and disposed of, and the area is cleaned and disinfected before drying. That tear-out and disposal is why Category 3 losses cost the most.
What the category means for your bill
Because the category decides how much gets removed versus dried in place, it's the biggest single swing in a mitigation cost. A red flag works both ways: heavy tear-out on a clean Category 1 job deserves a question, and no removal at all on a sewage loss deserves a bigger one.
Not sure which category you had?
BidsScores' Emergency Service Projector determines the category from a simple question about the water's source, then explains the class, a fair-cost and drying-days range, and what should have been removed — all in plain English. You get the definition and the number in one place.