(1) A circulation system must include one or more outlets, or suction outlets to conduct water to a recirculation pump and to serve as a drain when needed.
(2) All pools, spas, and other water features must have main drain outlets at the deepest point to permit the water to be completely and easily removed unless the department has approved a complete shutoff of the main drain and allows alternative use of skimmers or 100 percent flow through as a way for the pool, spa, or other water feature to comply with the VGBPSSA.
(3) The grated areas of any outlet shall be of sufficient size to decrease the possibility of clogging or creating suction hazards dangerous to the safety of the bathers and must meet the VGBPSSA.
(4) On or before March 1, 2011, the licensee shall provide the department with certification by an engineer licensed in Montana which documents that the main drain velocity of the pool, spa, or other water feature complies with the requirements of the VGBPSSA. The velocity may not exceed a flow of 1.5 feet per second. The pool, spa, or other water feature may not operate after that date until the certificate of compliance is provided to the department.
(5) A minimum of two hydraulically balanced suction outlets per pump suction line are required except as described in (6) and must meet the following criteria:
(a) the outlets shall be spaced not more than 20 feet apart, not less than three feet apart, and not more than 15 feet from side walls;
(b) when dual suction outlets are used, no piping or valve arrangement is permitted that will isolate one suction fitting as the sole source of fluid to the pump. However, once the water from multiple outlets flows into a single pipe that loads to a pump suction inlet, the single pipe may be valved off to shut off the flow to the pump;
(c) each suction outlet shall be capable of handling 100 percent of the flow without creating a suction hazard;
(d) each suction outlet, other than skimmers, that measures less than 18 inches by 23 inches or a diagonal of less than 29 inches shall be provided with a cover that has been tested by a nationally recognized testing laboratory and complies with the VGBPSSA; and
(e) the maximum openings of the main drain cover must not exceed one-half inch.
(6) A single outlet shall be permitted only where the outlet's dimensions are at least 18 inches by 23 inches or a diagonal of at least 29 inches or it otherwise meet the requirement of the VGBPSSA.