2023 Montana Code Annotated › Title 75. Environmental Protection › Chapter 5. Water Quality › Part 3. Classification and Standards › 75-5-317. Nonsignificant activities

75-5-317. Nonsignificant activities.
(1) The categories or classes of activities identified in subsection (2) cause changes in water quality that are nonsignificant because of their low potential for harm to human health or the environment and their conformance with the guidance found in 75-5-301(5)(c).
(2) The following categories or classes of activities are not subject to the provisions of 75-5-303:
(a) existing activities that are nonpoint sources of pollution as of April 29, 1993;
(b) activities that are nonpoint sources of pollution initiated after April 29, 1993, when reasonable land, soil, and water conservation practices are applied and existing and anticipated beneficial uses will be fully protected;
(c) use of agricultural chemicals in accordance with a specific agricultural chemical ground water management plan promulgated under 80-15-212, if applicable, or in accordance with an environmental protection agency-approved label and when existing and anticipated uses will be fully protected;
(d) changes in existing water quality resulting from an emergency or remedial activity that is designed to protect public health or the environment and is approved, authorized, or required by the department;
(e) changes in existing ground water quality resulting from treatment of a public water supply system, as defined in 75-6-102, or a public sewage system, as defined in 75-6-102, by chlorination or other similar means that is designed to protect the public health or the environment and that is approved, authorized, or required by the department;
(f) the use of drilling fluids, sealants, additives, disinfectants, and rehabilitation chemicals in water well or monitoring well drilling, development, or abandonment, if used according to department-approved water quality protection practices and if no discharge to surface water will occur;
(g) short-term changes in existing water quality resulting from activities authorized by the department pursuant to 75-5-308;
(h) land application of animal waste, domestic septage, or waste from public sewage treatment systems containing nutrients when the wastes are applied to the land in a beneficial manner, application rates are based on agronomic uptake of applied nutrients, and other parameters will not cause degradation;
(i) use of gray water, as defined in 75-5-325, from nonpublic gray water reuse systems for irrigation during the growing season in accordance with gray water reuse rules adopted pursuant to 75-5-305;
(j) incidental leakage of water from a public water supply system, as defined in 75-6-102, or from a public sewage system, as defined in 75-6-102, utilizing best practicable control technology designed and constructed in accordance with Title 75, chapter 6;
(k) discharges of water to ground water from water well or monitoring well tests, hydrostatic pressure and leakage tests, or wastewater from the disinfection or flushing of water mains and storage reservoirs, conducted in accordance with department-approved water quality protection practices;
(l) oil and gas drilling, production, abandonment, plugging, and restoration activities that do not result in discharges to surface water and that are performed in accordance with Title 82, chapter 10, or Title 82, chapter 11;
(m) short-term changes in existing water quality resulting from ordinary and everyday activities of humans or domesticated animals, including but not limited to:
(i) such recreational activities as boating, hiking, hunting, fishing, wading, swimming, and camping;
(ii) fording of streams or other bodies of water by vehicular or other means; and
(iii) drinking from or fording of streams or other bodies of water by livestock and other domesticated animals;
(n) coal and uranium prospecting that does not result in a discharge to surface water, that does not involve a test pit located in surface water or that may affect surface water, and that is performed in accordance with Title 82, chapter 4;
(o) solid waste management systems, motor vehicle wrecking facilities, and county motor vehicle graveyards licensed and operating in accordance with Title 75, chapter 10, part 2, or Title 75, chapter 10, part 5;
(p) hazardous waste management facilities permitted and operated in accordance with Title 75, chapter 10, part 4;
(q) metallic and nonmetallic mineral exploration that does not result in a discharge to surface water and that is permitted under and performed in accordance with Title 82, chapter 4, parts 3 and 4;
(r) stream-related construction projects or stream enhancement projects that result in temporary changes to water quality but do not result in long-term detrimental effects and that have been authorized pursuant to 75-5-318;
(s) diversions or withdrawals of water established and recognized under Title 85, chapter 2;
(t) the maintenance, repair, or replacement of dams, diversions, weirs, or other constructed works that are related to existing water rights and that are within wilderness areas so long as existing and anticipated beneficial uses are protected and as long as the changes in existing water quality relative to the project are short term;
(u) discharges of total phosphorus or total nitrogen that do not:
(i) create conditions that are toxic or harmful to human, animal, plant, and aquatic life;
(ii) create conditions that produce undesirable aquatic life; or
(iii) cause measurable changes in aquatic life; and
(v) any other activity that is nonsignficant because of its low potential for harm to human health or to the environment and its conformance with the guidance found in 75-5-301(5)(c).
History: En. Sec. 6, Ch. 501, L. 1995; amd. Sec. 4, Ch. 588, L. 1999; amd. Sec. 2, Ch. 73, L. 2009; amd. Sec. 7, Ch. 342, L. 2021.