The vast majority of the most impactful environmental laws and programs, such as the Clean Air Act and Clean Water Act, are enacted at the federal level. However, state agencies are the primary implementers and enforcers of these laws. States are closest to the issues, industries, and environmental challenges on the ground, giving them direct insight into how federal policies function in real world conditions.
As such, it is critical that states leverage their technical expertise, operational experience, and on the ground knowledge to play an active role in the development of federal environmental rules and standards. Meaningful state involvement helps prevent undue burdens and strengthens federal policies to achieve real improvements in environmental quality.
Recognizing that Hoosiers deserve a voice in the federal policymaking process, the Indiana Department of Environmental Management actively engages with federal agencies to provide clear, practical, and data driven feedback on proposed actions. Since 2025, IDEM has filed more comments on federal environmental matters than any other state environmental agency, reflecting the department’s commitment to ensuring that national policies consider Indiana’s perspective and implementation experience.
Below is an active list of recent comments filed on proposed federal regulations:
- 10.15.2026 - Updated Definition of "Waters of the United States"
- 09.18.2026 - National Pollutant Discharge Elimination System (NPDES) 2027 Issuance of General Permit for Stormwater Discharges from Construction Activities
- 09.01.2026 - Revisions to Establish the Sixth Unregulated Contaminant Monitoring Rule (UCMR 6) for Public Water Systems
- 08.25.2026 - Minor New Source Review Program Air Permitting Public Participation Requirements for State Implementation Plans
- 07.22.2026 - Rescission of Regulatory Determinations and Removal of Related Provisions for Four PFAS Substances (PFHxS, PFNA, HFPO–DA (GenX), and the Mixture of These Three PFAS Plus PFBS)
- 07.22.2026 - Extending the Compliance Deadline for the PFOA and PFOS Maximum Contaminant Levels; Notice of Public Hearing
- 07.15.2026 - Ozone Reclassification State Implementation Plan Rule
- 06.30.2026 - Begin Actual Construction in the New Source Review Preconstruction Permitting Program
- 06.30.2026 - Hazardous and Solid Waste Management System: Disposal of Coal Combustion Residuals from Electric Utilities; Legacy/CCRMU Amendments
- 06.18.2026 - Effluent Limitations Guidelines and Standards for the Steam Electric Power Generating Point Source Category: Unmanaged Combustion Residual Leachate
- 06.11.2026 - Drinking Water Contaminant List 6-Draft
- 06.28.2026 - Guidance: Clean Water Act Financial Capability Assessment
- 05.15.2026 - Solicitation of Input on Potential Future Changes to Nationwide Permits
- 05.07.2026 - Paper Manifest Sunset Rule: Modification of the Hazardous Waste Manifest Regulations
- 03.10.2026 - National Primary Drinking Water Regulation for Perchlorate
- 02.18.2026 - Updating the Water Quality Certification Regulations
- 02.09.2026 - Hazardous and Solid Waste Management System: Disposal of Coal Combustion Residuals from Electric Utilities; Extension of an Alternative Closure Requirement Deadline
- 01.08.2026 - Updated Definition of "Waters of the United States"
- 12.18.2025 - Air Quality State Implementation Plans; Approvals and Promulgations: Indiana; Regional Haze Plan for the Second Implementation Period; Extension of Comment Period
- 12.02.2025 - Visibility Protection: Regional Haze State Plan Requirements Rule Revision
- 11.14.2025 - Procedures for Chemical Risk Evaluation Under the Toxic Substances Control Act (TSCA)
- 11.04.2025 - Effluent Limitations Guidelines and Standards for the Steam Electric Power Generating Point Source Category—Deadline Extensions
- 10.28.2025 - Proposed approval of the Huntington County Indiana 2010 SO2 Redesignation and Maintenance Plan
- 10.23.2025 - Reconsideration of 2009 Endangerment Finding and Greenhouse Gas Vehicle Standards
- 08.23.2025 - Repeal of Greenhouse Gas Emissions Standards for Fossil Fuel-Fired Electric Generating Units
- 08.07.2025 - Hearings, Meetings, Proceedings, etc.: Implementation Challenges Associated with Clean Water Act Section 401
- 08.01.2025 - National Emission Standards for Hazardous Air Pollutants: Coal- and Oil-Fired Electric Utility Steam Generating Units
- 07.30.2025 - Proposed approval of the Indiana 2010 SO2 Huntington Attainment Plan
- 06.26.2025 - Emissions Budget and Allowance Allocations for Indiana Under the Revised Cross-State Air Pollution Rule Update
- 01.31.2025 - Regional Haze Third Implementation Period: Extension of the State Implementation Plan Due Date