Reviewed by Tyler Bennett, Restoration Project Manager, IICRC WRT/ASD #291438, October 2026.
Short answer: Category 1, 2 and 3 water damage describes how dirty the water is. Category 1 is clean water from a supply line, Category 2 is gray water with some contamination, and Category 3 is black water such as sewage or outside floodwater. The higher the category, the more material has to be removed and the more protection the crew needs.
If water is in your home right now, our Spanish Fork water damage restoration crew can test it, sort out the category and start drying the same day.
Why the category matters
The IICRC S500 standard sorts water into three categories. The category tells a crew what is safe to dry in place and what has to go.
It also tells them what gear to wear and how to set up the work area. Insurance adjusters use the same terms when they review a claim.
Getting the category right at the start saves money. Getting it wrong can leave germs or odor behind your walls.
The three categories side by side
| Category | Common sources | What usually happens |
|---|---|---|
| 1 – clean | Burst supply line, sink overflow with clean water, broken ice maker line | Most materials can be dried in place if work starts fast |
| 2 – gray | Washing machine or dishwasher discharge, toilet overflow with urine but no feces, aquarium leaks | Carpet pad is usually replaced; surfaces get cleaned and treated |
| 3 – black | Sewer backup, toilet overflow with feces, outside floodwater | Porous materials that got wet are removed; PPE and containment required |
Category 1: clean water
This water comes from a clean source, like a pressurized pipe. It is not a health risk at first.
If drying starts quickly, carpet, pad and drywall can often be saved. A burst pipe in the house is the classic example.
Category 2: gray water
Gray water has enough contamination to make people sick if they touch or swallow it. Appliance drain water is the most common source.
Most crews replace wet carpet pad after Category 2 water. The carpet itself can sometimes be cleaned and saved. Hard surfaces get cleaned and treated with an EPA-registered antimicrobial.
Category 3: black water
Black water carries bacteria, viruses and other harmful material. Sewage and outside floodwater are always Category 3.
Porous items that got wet, like carpet, pad and the lower part of drywall, are usually removed. The crew wears PPE and seals off the area so dust and germs don’t spread. Our Utah County sewage cleanup service follows this process.
Water does not stay in one category
Clean water does not stay clean. Once it sits, it picks up dirt from floors and walls and starts to grow bacteria.
Category 1 water left for a day or two can become Category 2. Gray water left too long can become Category 3. That is one big reason speed matters.
Mold can also start in 24–48 hours on wet materials. So a small, clean leak that sits over a weekend can turn into a much larger job.
What you can do before the crew arrives
- Stop the water if you can. Shut off the main valve or the valve at the fixture.
- Keep kids and pets away, and assume dirty water is Category 3 until someone checks it.
- Turn off power to wet rooms at the breaker if you can reach it safely.
- Take photos and video of the water and the source for your insurance claim.
- Do not run a household vacuum on standing water, and do not try to bleach sewage yourself.
How we handle each category in Spanish Fork
Our crew checks the source and tests materials with pin and pinless moisture meters. A FLIR thermal camera helps us find wet areas you cannot see.
For Category 1 and 2 jobs we extract water, then set air movers and LGR dehumidifiers. For Category 3 we add containment, PPE and HEPA air scrubbers before any demolition.
We scope every job in Xactimate and bill your insurance directly. Mitigation usually runs $3,500–$8,500, and our water damage cost breakdown explains what drives the number.
Not sure if the leak hit your insulation or framing too? Read signs of water behind your walls.
Common questions
How can I tell which category my water is?
Start with the source. A supply line is usually Category 1, an appliance drain is Category 2, and sewage or outside floodwater is Category 3. Time matters too, so older water may be dirtier than its source.
Can I clean up Category 1 water myself?
Small, fresh spills on hard floors are often fine to clean up yourself. If water soaked into carpet, drywall or a subfloor, it needs moisture readings and real drying equipment.
Is a toilet overflow always Category 3?
No. A clean-tank overflow can be Category 1 or 2. If the bowl had feces, or the water came up from the sewer line, treat it as Category 3. See our toilet overflow cleanup page.
Does insurance care about the category?
The adjuster will note it, because it affects what gets replaced. Coverage depends on your policy and the cause of loss, so check your policy and call your carrier.
Why do you remove carpet pad after gray water?
Pad soaks up water like a sponge and is hard to clean all the way through. Replacing it is the standard step after Category 2 or 3 water.
Related reading
Call (385) 247-9387. Answered live 24/7 by our own crew. 45-minute arrival inside Spanish Fork city limits.
A real local job: in Centennial, Spanish Fork (February 2026), a pipe burst inside an exterior wall. See that job and how we handle it.