Administrative Rules of the State of Montana

(1) Pools, spas, and other water features constructed or modified after March 1, 2010 must have a circulation system capable of producing a turnover rate for the entire volume of water within the time period specified in Table 5.

(2) Existing pools, spas, or other water features that have not lost their grandfather status under ARM 37.115.1905 must continue to meet the minimum turnover rates approved at the time of initial licensing.

(3) Table 5.

Pool or Other Water Feature Type	Required Minimum turnover Rate (Hours)
Wave Pool	2
Activity Pool -less than 24 inches in depth	1
Activity Pool -24 inches or greater in depth	2
Catch Pool (for slides and flumes)	1
Lazy River	2
Vortex Pool	1
Interactive Play Attractions	1
Pools	6
Wading Pool	1
Flow through Hot Springs	8
Spa	30 minutes
Hydrotherapy Pool	1 hour or less if pool is less than 1,000 gallons or 2 hours or less if pool is 1,000 gallons or more
Spray pools, splash decks (no standing water)	1

(4) The system shall be designed to meet the required turnover rate when operated in accordance with the manufacturer's recommended maximum pressure and flow with the filter in a clean media condition.