U.S. Environmental Protection Agency Administrator Lee Zeldin announced Sunday that the agency is processing updates to Iowa’s impaired waterways list while expanding certification authority for aftermarket vehicle products.
Zeldin made the remarks during a tour of Summit Products in Altoona, marking his first stop in Iowa before scheduled events in Iowa City and Dyersville on Monday. The visit highlighted two distinct regulatory shifts: the agency’s approach to state water quality data and new rules governing automotive aftermarket compliance under the Clean Air Act.
Waterway Listing Dispute
The EPA is currently adjudicating Iowa’s 2024 impaired waterways list and processing a new submission for 2026. The agency’s actions follow a contentious period regarding nitrate levels in state waterways.
In late 2024, the EPA attempted to add seven segments to Iowa’s Impaired Waterways list due to nitrate impairment. Listing a waterway on this roster determines whether a segment meets criteria for fishing, recreation, and drinking water using retroactive data. Once listed, restoration efforts are triggered under the Clean Water Act.
The Iowa Department of Natural Resources challenged the EPA’s seven additions. Consequently, the federal agency removed those segments from the 2024 list. The EPA finalized its decision to delist the waterways in late September.
Environmental groups have contested the removal. Food & Water Watch, the Iowa Environmental Council, and the Environmental Law & Policy Center filed a lawsuit in May challenging the delisting. The suit seeks an order to relist the segments.
The litigation remains ongoing. On Thursday, the Environmental Law & Policy Center issued a news release criticizing the delisting for failing to address high nitrate levels.
Zeldin stated that the EPA is partnering with local businesses, farmers, and state government to address water quality concerns. He specifically mentioned nitrate levels and potential links to rising cancer rates as areas of focus. Zeldin emphasized that the agency respects that state and local communities know their water better than federal officials.
The administrator noted that the EPA sets new maximum contaminant levels for nitrate when necessary. He described the agency’s approach as focused on cooperative federalism and working with the Iowa state government on water quality.
Aftermarket Vehicle Certification
Zeldin also addressed changes to automotive regulations. The EPA allowed the Specialty Equipment Market Association (SEMA) to certify aftermarket vehicle products for Clean Air Act compliance.
Before President Donald Trump signed a memorandum in July, only the California Air Resources Board (CARB) could perform this certification. Zeldin stated that the previous CARB-only process was backlogged, expensive, and took a year or more to complete.
Zeldin said hundreds of SEMA members in Iowa will benefit from Trump’s memorandum. Albert Marasco, CEO of Summit Products, stated that EPA steps to help certify aftermarket products have been helpful as the business expands. Summit Products is adding 30,000 square feet of new space this year.
Zeldin referenced guidance announced at the 2025 Iowa State Fair regarding diesel exhaust fluid (DEF) systems. The guidance aims to prevent sudden shutdowns and power losses in vehicles. In February, the EPA issued a clarification letter related to “right to repair” efforts.
Regulatory Timeline
The EPA’s current work on Iowa’s water data follows a rapid sequence of regulatory actions. The agency attempted to add seven segments in late 2024. The state challenged the move, leading to removals from the 2024 list. Environmental groups sued in May. The EPA finalized the delisting in late September.
Zeldin stated that updates regarding impaired waterways have occurred in the last couple of weeks. The agency is now processing the 2026 submission while the lawsuit challenging the 2024 delisting remains active.
The shift in automotive certification authority represents a broader change in how the EPA delegates compliance verification. By allowing SEMA to certify products, the agency aims to reduce delays associated with the previous single-state model. Zeldin indicated that this change would benefit Iowa-based businesses involved in aftermarket vehicle parts.