The state of Montana has enacted a new regulatory change concerning hot tub maintenance for short-term rentals that is expected to save the state millions of gallons of water every year.
It is no longer required to drain hot tubs at tourist homes or hotel rooms between individual rental use.
The Montana Department of Public Health and Human Services (DPHHS) has issued a clarification memorandum for the maintenance requirements of hot tubs in individual hotel rooms and short-term rentals. The new policy now states that such hot tubs must be cleaned and serviced between individual rental use, and that such service must include, at a minimum:
• Cleaning, sanitizing, and rinsing filters.
• Maintaining appropr iate chemistry levels consistent with manufacturer guidelines.
• Displaying documentation of cleaning and maintenance performed.
Such maintenance and cleaning protocols no longer requires draining the hot tubs between renters, which has been the practical reality for most spa operators until now, in an effort to avoid being classified as a “public spa.”
It is interesting to note that draining spas was never actually mandated in the first place. However, prior to the regulatory change, most people did it to avoid regulatory oversight, That’s because, according to Montana law, the definition of “spa” included a crucial phrase: “an artificial pool that is designed for recreational bathing or therapeutic use that is not drained, cleaned, or refilled for individual use.”
This definition essentially implies that if a hot tub wasn't drained and refilled for individual use (i.e., between guests), it could fall under the “spa” definition, which then typically leads to being treated as a “public swimming pool” if it's accessible to multiple, transient users.
And if it were treated as a public swimming pool, it would require a public pool license and be subject to all public pool regulations (such as requiring a certified pool operator on-site, daily chemical logs, more frequent inspections, etc.) that applied to true “public spas.”
For many operators, therefore, the safest and clearest way to ensure their hot tub was not considered one “that is not drained… for individual use” was to literally drain it between guests. This practice removed any doubt about its classification.
The recent change in Montana’s law was spearheaded by Big Skybased organizations, including Big Sky Resort, Big Sky Sustainability Network Organization (SNO), and the Gallatin River Task Force. The change went into effect mid-January, 2025, with broader implementation beginning at the end of March.
Big Sky is a large resort area in Montana, about an hour outside of Bozeman, encompassing the Big Sky Resort, as well as numerous additional hotels, condos, vacation rentals, and private homes.
As such, it has thousands of rentals, many of which have private hot tubs, and until now, all of them had to be drained every time a guest checked out.
“Draining the hot tubs every time allowed operators to avoid the stricter regulations, but it wasted a significant amount of water,” said, Milosz Shipman, Big Sky SNO Sustainability Coordinator.
And the ambiguity in the law had been creating issues within the community, pitting environmentalists and conservationists against shortterm rental owners.
Within the Big Sky Community alone, the new clarification is expected to save between seven and eight million gallons of water per year, and it is also expected to have significant additional environmental benefits.
“All that drained water goes somewhere, and typically, it’s full of chemicals harmful to local waterways and wildlife,” Shipman said.
The clarification in the law will also save time, chemicals, labor, and energy costs, when you consider what it takes to properly treat and heat all of that water.
It looks like a rare case of good news all around, both for the capitalists and the conservationists.
