When former President Donald Trump last held office, he rolled back more than 100 environmental rules that regulated air and water pollution, greenhouse gas emissions and toxic chemicals — and as he prepares to re-enter the White House, experts anticipate he’ll draw from the same playbook.

That could have ripple effects in Wisconsin, which in recent years has received close to a billion dollars from a landmark climate law Trump seeks to unwind. Experts worry some of those effects could be on the safety of drinking water.

Like other states, Wisconsin has used the U.S. Environmental Protection Agency to “police” environmental problems, said Sara Walling, water and agriculture program director at Clean Wisconsin. She pointed to an August proposal to bring the state drinking water standard for PFAS in line with more stringent federal regulations, and also to the EPA’s updated lead and copper rule, which pushes communities to replace all lead pipes by 2037.

“I’m extremely concerned that really well thought-out, science-based standards … are going to be pretty quickly pulled back,” Walling said.

Wisconsin, and Milwaukee in particular, has thousands of lead pipes yet to replace and has received millions of federal dollars to expedite the process. If the mandate is rescinded, Walling said, that pressure is off.

Shead added that pulling funding back would only slow the process down, “pushing it off to the next generation.”

Under President Joe Biden, the EPA also restarted a human health assessment of nitrate, which had been suspended in 2018 after the Trump administration deemed it no longer a priority for evaluation. Nitrate is Wisconsin’s most widespread contaminant of groundwater, the source of the majority of residents’ drinking water.

“We were really hoping to use the health assessment as another strong human health pillar to underpin additional nitrate regulation,” Walling said.

More: Great Lakes, PFAS, lead pipes: How Trump’s policies could impact Wisconsin’s environment

Here are other environmental issues that could be affected by the Trump administration:

Sustainable, climate-smart agriculture

Wisconsin farmers are feeling the effects of climate change, and at the same time, agriculture accounts for about 10% of U.S. greenhouse gas emissions. The Inflation Reduction Act dedicated nearly $20 billion to U.S. Department of Agriculture programs that help farmers protect their operation and reduce its environmental impact.

In Wisconsin, that investment is set to nearly double funding for popular farm conservation programs through 2026. Although Trump has declared his intention to claw back unspent Inflation Reduction Act funds, experts say rescinding farm conservation money could irritate the agriculture industry.

“One of the biggest truths about those dollars is they’ve served so many farmers who were having such a hard time getting (conservation program) contracts,” said Margaret Krome, policy director for the Michael Fields Agricultural Institute. “You don’t have to be a climate believer, don’t have to be a scientist … farmers of all stripes have said, ‘Oh good, here’s my chance to finally get funding.’”

Sara Walling, water and agriculture program director at Clean Wisconsin, said its broad benefits may make it hard to dismantle the funding entirely, especially because these practices often make farms more resilient and productive in addition to mitigating climate change.

Krome pointed to a number of other sustainable agriculture developments that she hopes will be protected, including money for beginning farmers and programs that support managed grazing of livestock.

She also pointed out that during Trump’s previous term, what she called “one of the most innovative programs to support sustainable agriculture in years” came into being — the Sustainable Agricultural Systems grant program, which has funded projects in Wisconsin to support transformation in agriculture.

“Sometimes, new innovations can come from administrations that you would not have expected to support those innovations,” Krome said. “It’s important not to assume that we cannot find that practical common ground.”

Enbridge’s Line 5 oil pipeline

Enbridge’s Line 5 oil pipeline has been a contentious issue in the Great Lakes for years, as it is locked in legal battles in Wisconsin and Michigan. The Canadian company’s 645-mile pipeline carries oil products from across northern Wisconsin through Michigan’s Upper and Lower peninsulas to Sarnia, Ontario. 

In 2019, northern Wisconsin’s Bad River Band of Lake Superior Chippewa sued the Canadian company to get the pipeline off its land as the right-of-way easement expired more than a decade ago. Tribal officials have long feared the consequences of an oil spill to its land, water and way of life.

A federal judge found the company had been illegally operating on the tribe’s land, and ordered the pipeline be removed or rerouted by June 2026. That decision was appealed and both parties are awaiting a decision from a federal appeals court. 

The Biden administration largely remained silent on the issue, until it submitted a long-awaited brief that pushed multiple deadlines. The brief was mixed, providing support for both parties. 

The Bad River Band, along with environmental groups and other Great Lakes tribes, are trying to stop a 41-mile reroute project around the Band’s land, hoping the pipeline is removed from its watershed entirely. 

While the president-elect has not made public statements about the Canadian-owned pipeline, the Republican 2024 platform championed lifting restrictions on oil, natural gas and coal as Trump has repeatedly vowed to “drill, baby, drill” during the campaign. 

Whether the new administration will speak up on the issue is unclear, but environmental groups say they are committed to making newly elected leaders in Wisconsin and Michigan aware of the pipeline’s environmental dangers. 

For now, the issue will remain in the courts.

Environmental justice

During Biden’s presidency, he launched the Justice40 Initiative, which requires 40% of the overall benefits of certain federal climate and clean energy investments to reach communities that have been disproportionately affected by environmental harms.

Trump has promised to reverse Biden’s equity measures, which experts say puts Justice40 at risk.

Language around diversity, equity and inclusion has been demonized by the far right, Shead said, which is especially troublesome for Milwaukee, where a lot of work is centered around environmental justice.

Great Lakes cleanup efforts

Federal funding through the Great Lakes Restoration Initiative has been key to cleaning up legacy pollution, restoring habitat and updating unsafe drinking water infrastructure throughout the Great Lakes. Since 2010, the landmark program has funded more than $4.1 billion across roughly 8,100 projects.

Milwaukee’s waterways are designated as an “area of concern,” or one of the most degraded places in the Great Lakes region. 

Milwaukee received $450 million from a boost through the Bipartisan Infrastructure Law, which is helping to rid toxic contamination from the city’s three rivers and Lake Michigan. It’s also advanced projects that restore habitat and recreational access, like the new fish passage around Kletzsch Dam and the project to relocate South Shore Beach. 

The Lower Fox River and bay of Green Bay; Sheboygan River; and St. Louis River are three other sites in Wisconsin benefiting from this program. 

While Trump attempted to gut the program during his presidency, Vice President-Elect JD Vance, of Ohio, co-sponsored a bill to reauthorize and increase funding to the program in February. The bill has stalled in committee. 

Kirsten Shead, a co-executive director of Milwaukee Water Commons, said she wouldn’t be surprised if the new administration puts pressure on environmental issues. 

But “I’m hopeful that with advocacy and continued work, we can keep the area of concern program prioritized under the new administration,” Shead said. 

Madeline Heim and Caitlin Looby are Report for America corps reporters who write about environmental challenges in the Mississippi River Basin and the Great Lakes, respectively. Contact them at mheim@gannett.com and clooby@gannett.com.