Lawsuit filed over repeal of numeric water quality standards – Bitterroot Star

Report on Legal Challenge to Montana’s Repeal of Numeric Water Quality Standards

Introduction

In January 2026, the Upper Missouri Waterkeeper, Flathead Lakers, and the Confederated Salish and Kootenai Tribes filed a lawsuit challenging the Environmental Protection Agency’s (EPA) approval of Montana’s repeal of science-based, numeric water quality standards for nitrogen and phosphorus. This legal action emphasizes the critical importance of maintaining sustainable water quality in alignment with the United Nations Sustainable Development Goals (SDGs), particularly SDG 6 (Clean Water and Sanitation), SDG 14 (Life Below Water), and SDG 15 (Life on Land).

Background and Legal Context

1. Montana Department of Environmental Quality (MDEQ) submitted HB664 revising nutrient criteria to EPA on May 6, 2025, one day before adopting the changes.
2. HB664 replaced numeric nutrient standards with vague, unenforceable narrative standards, which the plaintiffs argue violates the Clean Water Act (CWA).
3. Upper Missouri Waterkeeper petitioned EPA on June 4, 2025, to disapprove HB664 and impose science-based nutrient standards; however, EPA approved HB664 on October 3, 2025.

Significance of Numeric Nutrient Standards

• Numeric standards provide precise, science-based criteria to identify water impairment due to nitrogen and phosphorus pollution.
• Montana was among the first states to adopt such standards in 2014, enabling timely corrective actions to prevent harmful algal blooms and fisheries degradation.
• According to MDEQ’s latest Water Quality Integrated Report, significant portions of Montana’s lakes and streams are impaired for nitrogen and phosphorus:
• 13% of assessed lake acres and 22% of streams impaired for nitrogen.
• 14% of lake acres and 23% of streams impaired for phosphorus.

Stakeholder Perspectives and Environmental Implications

Upper Missouri Waterkeeper: Guy Alsentzer emphasized the federal government’s role as a scientific backstop to protect water quality, criticizing EPA’s approval as a failure to uphold this responsibility. He highlighted that this rollback is unprecedented in the 53-year history of the Clean Water Act and poses risks to fisheries, public health, and endangered species.

Flathead Lakers: Executive Director Coby Gierke stressed that clean water sustains the local economy, communities, and cultural heritage. The organization opposes the rollback, citing decades of scientific evidence linking nutrient pollution to environmental degradation.

MDEQ: Director Sonja Nowakowski described HB664 as a legislative “time travel” returning to 2013 processes that emphasize flexibility over numeric criteria, despite previous EPA rejection of similar attempts due to insufficient protection assurances.

Legal and Regulatory Challenges

• The lawsuit contends EPA’s approval of HB664 is arbitrary, capricious, and violates the Clean Water Act and Endangered Species Act.
• Plaintiffs argue that EPA failed to complete required consultations with the U.S. Fish and Wildlife Service regarding impacts on threatened and endangered species.
• The nutrient monitoring group initiated by MDEQ to implement narrative standards was ineffective and eventually disbanded.

Requested Court Actions

1. Declare EPA’s approval of Montana’s repeal of numeric nutrient standards unlawful.
2. Vacate and set aside EPA’s October 3, 2025 approval of HB664.
3. Order EPA to complete consultations with the U.S. Fish and Wildlife Service.
4. Direct EPA to finalize federally enforceable nutrient water quality standards in compliance with the Clean Water Act within a reasonable timeframe.

Conclusion and SDG Implications

This case underscores the vital role of science-based environmental regulations in achieving Sustainable Development Goals, particularly:

• SDG 6: Ensuring availability and sustainable management of water and sanitation for all by maintaining water quality standards.
• SDG 14: Conserving and sustainably using aquatic ecosystems by preventing nutrient pollution and protecting fisheries.
• SDG 15: Protecting terrestrial ecosystems and endangered species through rigorous environmental oversight.

The outcome of this lawsuit will have significant implications for environmental governance, public health, and the preservation of Montana’s natural water resources.

1. Sustainable Development Goals (SDGs) Addressed or Connected

1. SDG 6: Clean Water and Sanitation
   • The article focuses on water quality standards, nutrient pollution, and the protection of water bodies, which directly relate to ensuring availability and sustainable management of water and sanitation for all.
2. SDG 14: Life Below Water
   • The protection of fisheries and aquatic ecosystems mentioned in the article connects to conserving and sustainably using the oceans, seas, and marine resources.
3. SDG 15: Life on Land
   • The article references threatened and endangered species and critical habitats, linking to the goal of protecting, restoring, and promoting sustainable use of terrestrial ecosystems.
4. SDG 3: Good Health and Well-being
   • Public health concerns due to unsafe drinking water and pollution are highlighted, connecting to ensuring healthy lives and promoting well-being.

2. Specific Targets Under Those SDGs Identified

1. SDG 6: Clean Water and Sanitation
   • Target 6.3: Improve water quality by reducing pollution, minimizing release of hazardous chemicals and materials, and substantially increasing water recycling and safe reuse.
   • Target 6.6: Protect and restore water-related ecosystems, including mountains, forests, wetlands, rivers, aquifers, and lakes.
2. SDG 14: Life Below Water
   • Target 14.1: Reduce marine pollution of all kinds, particularly from land-based activities, including nutrient pollution causing harmful algal blooms.
3. SDG 15: Life on Land
   • Target 15.1: Ensure conservation, restoration and sustainable use of terrestrial and inland freshwater ecosystems and their services.
   • Target 15.5: Take urgent action to reduce the degradation of natural habitats and halt the loss of biodiversity, including threatened and endangered species.
4. SDG 3: Good Health and Well-being
   • Target 3.9: Reduce the number of deaths and illnesses from hazardous chemicals and air, water and soil pollution and contamination.

3. Indicators Mentioned or Implied to Measure Progress

1. Water Quality Indicators:
   • Percentage of lakes and rivers impaired for nitrogen and phosphorus (e.g., 13%-14% of lakes and 22%-23% of rivers impaired).
   • Presence and extent of harmful algal blooms and degraded fisheries as measures of water body health.
2. Regulatory Compliance Indicators:
   • Existence and enforcement of numeric nutrient water quality standards versus narrative standards.
   • Completion of consultations with U.S. Fish and Wildlife Service regarding endangered species and critical habitats.
3. Legal and Policy Indicators:
   • Approval or disapproval of water quality standards by EPA in accordance with the Clean Water Act.
   • Number of lawsuits or legal challenges related to water quality standards enforcement.

4. Table of SDGs, Targets, and Indicators

Source: bitterrootstar.com