Before you book

Where carpet cleaning water is allowed to go

A carpet cleaning machine pulls gallons of dirty water out of your floors. Washington's guidance is plain about one place that water may not go: the storm drain.

The storm drain is off limits

Storm drains carry water to streams and the Sound without treatment. Ecology calls dumping carpet cleaning wash water into them dangerous and illegal. (Ecology)

Seattle's stormwater manual covers mobile carpet cleaning and says discharging washwater to the drainage system or local waters is illegal. (Seattle)

King County's manual covers carpet cleaners too. It bars wash water on pavement, on the ground or in the storm drain system, and says a soap sold as nontoxic or biodegradable does not make a storm drain acceptable. (King County)

Where the water can go

Homes on sewer: with your permission, the cleaner can empty the water into your toilet or utility sink. Ecology says to filter it first. (Ecology)
No sink or toilet available: the cleaner hauls the water away and empties it at an authorized sewage discharge point. (Ecology)
Homes on septic: Ecology's plan is a collection tank on the truck and a trip to an authorized discharge point. (Ecology)
Lacey, Olympia and Tumwater: the LOTT dump station takes loads from mobile carpet cleaners that apply and are approved. (LOTT)

Ecology also tells cleaners to ask the local sewer authority about its own requirements. (Ecology)

What a crew should have on the truck

In King County, a spill kit is required for mobile businesses doing this kind of cleaning. (King County)
In Seattle, mobile cleaning equipment must carry a label telling the crew to dispose of all wastewater and not to discharge it to a catch basin, ditch, stream or the ground. (Seattle)
Seattle also requires the company to document its employee training. (Seattle)

What we did not find

We found no Washington state rule written for truck-mount units or for carpet cleaning chemicals. The rules on this page are about where the water goes.

Questions for the cleaner

Where will the dirty water go when you finish?
If you use my toilet or sink, do you filter the water first?
If you haul it away, where do you empty it?
Do you carry a spill kit?

Read how to hire a house cleaner or what bonded and insured means for a cleaner.

Sources

We read each source on October 18, 2026. Rules and prices change, so check the linked page before you rely on a number.

Written by the Puget Sound Residential Cleaners team. We list businesses; we do not employ, bond or insure them. Spot a mistake? Use the claim page to tell us.