2023 Montana Code Annotated › Title 80. Agriculture › Chapter 15. Montana Agricultural Chemical Ground Water Protection Act › Part 2. Control › 80-15-201. Ground water standards

80-15-201. Ground water standards.
(1) The department of environmental quality shall adopt standards and, as applicable, interim numerical standards for agricultural chemicals in ground water. The standards must be the same as any promulgated or nonpromulgated federal standard established by EPA, although the department of environmental quality may determine, pursuant to the requirements of subsection (4), that an interim numerical standard different from either a promulgated or nonpromulgated federal standard is justified. Promulgated federal standards must receive preference. Except as provided in subsections (3) and (4), if more than one nonpromulgated federal standard exists for an agricultural chemical, the department of environmental quality must adopt the most recently established nonpromulgated federal standard.
(2) The department of environmental quality is not required to adopt a standard or interim numerical standard for each agricultural chemical registered in the state. The only standards and interim numerical standards required are for those agricultural chemicals:
(a) that are addressed by promulgated and nonpromulgated federal standards;
(b) the presence of which has been verified in ground water as provided in 80-15-202; or
(c) that the department and the department of environmental quality predict may appear in ground water, in accordance with the procedures and determinations specified in 80-15-202 and 80-15-203.
(3) If a promulgated federal standard has not been adopted or a nonpromulgated federal standard has not been published for an agricultural chemical for which the department of environmental quality is required to establish a standard or interim numerical standard as specified in subsections (2)(b) and (2)(c), the department of environmental quality shall request EPA to establish a promulgated or nonpromulgated federal standard. If the department of environmental quality determines that EPA cannot comply with the request within 15 days, the department of environmental quality shall adopt an interim numerical standard, provided that the department of environmental quality shall review the interim numerical standard whenever EPA adopts a promulgated federal standard or publishes a nonpromulgated federal standard for the agricultural chemical in question.
(4) The department of environmental quality may adopt an interim numerical standard that is different from either a promulgated or nonpromulgated federal standard if there is significant new and relevant technical information available that is scientifically valid. The department of environmental quality shall review the interim numerical standard when EPA establishes or revises the promulgated or nonpromulgated federal standard for the agricultural chemical in question.
(5) The department of environmental quality shall consider the following in adopting any interim numerical standard under either subsection (3) or (4):
(a) effects on a person weighing 70 kilograms and drinking 2 liters of water per day over a lifetime; and
(b) EPA's conclusions regarding the no observable effect level, including the margin of safety identified by EPA, when scientific data indicates oncogenic potential for the agricultural chemical and EPA has determined that a numerical risk assessment is not justified, is inappropriate, or does not serve as the primary toxicological basis for regulation.
(6) Nothing in this section may interfere with the department of environmental quality's responsibility to adopt rules and standards under Title 75, chapter 6.
History: En. Sec. 9, Ch. 668, L. 1989; amd. Sec. 336, Ch. 418, L. 1995; amd. Sec. 81, Ch. 324, L. 2021.