(1) Any hot springs pool other than a flow-through hot springs pool must comply with all other provisions of this subchapter, with the exception that the pH of pool water must be maintained at no less than 7.2 and no greater than 8.5.

(2) In addition to the requirements of (1) above, any hot springs pool, whether or not it is a flow-through pool, must meet the following requirements:

(a) The pool must be equipped with an accurate flow indicator to measure the turnover in the pool, except that the department may allow a deviation from the use of an accurate flow indicator by an applicant who demonstrates in a written application to the department that the water volume exchange turn-over rate from the pool can be accurately measured by an alternative method and that the deviation does not have the potential to cause adverse public health effects. To be eligible for a deviation from the accurate flow indicator requirement, the applicant must submit to the department as part of its application a plan that describes the alternative method that accurately measures the water volume exchange turn-over rate.

(b) Each pool must have an inline thermometer installed to monitor the temperature of the pool. The department may allow a deviation from the use of an inline thermometer by an applicant who can demonstrate in a written application to the department that the water temperature can be accurately measured by an alternative method in lieu of an inline thermometer and that the deviation does not have the potential to cause adverse public health effects. To be eligible for a deviation from the inline thermometer requirement, the applicant must submit to the department as part of its application a plan that describes the alternative method that accurately measures the water temperature.

(c) Upon request by the department, the pool operator must collect water samples for bacteriological or other testing for public health investigations or when the turnover rate is greater than 8 hours, the provisions of (3) (c) (i) below are not met, or the pool is a flow-through hot springs pool that does not utilize the alternative of chemical disinfection but has not been drained, cleaned, and sanitized every 72 hours.

(d) Each pool must be maintained to prevent corrosion, algae growth and other mineral accumulation on the pool walls, floor and equipment. Hot water mineral pools are particularly subject to such conditions.

(3) Every flow-through hot springs pool must comply with the following:

(a) Each such pool must comply with the provisions of ARM 37.111.1105, 37.111.1112 through 37.111.1115; 37.111.1132 and 37.111.1133; 37.111.1141; 37.111.1143(1) and (3) ; 37.111.1147(1) ; 37.111.1148 and 37.111.1149; 37.111.1150(2) ; 37.111.1151(1) , (2) , (6) , (7) , and (9) ; 37.111.1152 through 37.111.1155; and 37.111.1158 through 37.111.1161.

(b) The temperature of a pool or spa used primarily for soaking may not exceed 106 E F, and the temperature of a pool used primarily for swimming may not exceed 100 E F. Water temperature must be monitored and recorded in accordance with ARM 37.111.1152.

(c) As required by 50-53-115 , MCA, each flow-through hot springs pool must either be drained, cleaned, and sanitized every 72 hours, along with all surfaces that flow into the pool, or the pool must be disinfected with a chlorine or bromine residual. The following requirements apply to each alternative:

(i) If the pool and the surfaces flowing into it are drained, cleaned, and sanitized every 72 hours, records of the cleanings must be maintained in accordance with ARM 37.111.1151; or

(ii) If the pool is disinfected, a chlorine residual of 1 to 5 ppm (3-5 ppm is recommended) or a bromine residual of 3 to 6 ppm must be maintained in the pool at all times. In addition, the pool must comply with the provisions of ARM 37.111.1139, 37.111.1140, and 37.111.1147.

(d) If, as allowed by 50-53-115 , MCA, the pool is not chemically disinfected, a sign must be conspicuously posted at poolside that states the following in the same words or words of substantially the same meaning: "State law does not require chemical disinfection of this pool (or spa) if it is completely drained and sanitized every 72 hours. No one with disease communicable by water is allowed in the pool".

(e) The pH of the pool water must be maintained at no less than 7.2 and no greater than 8.5.

(f) A flow-through hot springs pool may submit to the department in writing a standard operating plan which proposes how that operation plans to meet the standards of ARM 37.111.1156(3) using an alternative method or methods. The applicant must demonstrate in the standard operating plan that the standards can be achieved and that the plan does not have the potential to cause adverse public health effects. The standard operating plan is not effective until the department approves the written standard operating plan in writing. A copy of the approved standard operating plan must be kept on the pool premises and be available for review and verification during pool or spa inspections.

(4) Discharge of pool waste water may be subject to the provisions of the Montana Pollutant Discharge Elimination System (MPDES) , ARM Title 17, chapter 30, subchapter 12. Persons whose discharges of pool waste water are subject to MPDES shall comply with ARM 16.20.901, et seq.