ARM 17.56.205
ARM 17.56.205. ANTI-SIPHON REQUIREMENTS
Cite as Mont. Admin. R. 17.56.205
(1) The owner or operator of an UST system that is located at an elevation that produces a gravity head on an underground piping system shall ensure that the product pipe is equipped with one of the following devices:
(a) a department-approved anti-siphon valve;
(b) a department-approved normally closed solenoid valve; or
(c) any other department-approved device designed to prevent siphoning.