Adrees Latif/Reuters A corn field is seen in DeWitt, Iowa in this July 12, 2012 file photo. The state's agriculture lobby is fighting a lawsuit that could set a new national precedent for farming-related water pollution.

Earlier this month, the Iowa Soybean Association had a big announcement to make.

The group, which represents some 11,000 growers of the state’s second-most-lucrative crop, pledged $150,000 in support for three highly agricultural counties — Buena Vista, Calhoun and Sac — named in a controversial lawsuit brought by the Des Moines Water Works.

The lawsuit, which was filed in 2015, claims that nitrogen-rich water flowing off the area’s farms pollutes the Raccoon River, which, along with the Des Moines River, provides drinking water for half a million people. The water authority wants the counties to pick up the dramatically higher treatment costs for the water. The counties, who want the case dismissed, counter that there’s no proof that agriculture is directly responsible for the nitrates.

The case has thus far been upheld, though it won’t be brought to trial until next June. Meanwhile, both sides are digging in for a pivotal Iowa Supreme Court hearing on the matter set for September.

If the water utility wins the suit, it would mark the first time in the U.S. that agribusiness is forced to pay for water pollution, potentially setting a precedent with nationwide ramifications.

The ISA, which previously contributed $65,000 for the counties’ legal expenses, considers the case a “must win.” Meanwhile, it says, the lawsuit is an “unfortunate distraction” from the voluntary approaches to solving the state’s nutrient runoff issues that it has been touting.

ISA CEO Kirk Leeds said the suit is affecting the progress the state has made over the past 15 years in encouraging farmers to implement practices to mitigate runoff, like putting cover crops and conservation tillage in their fields.

“The lawsuit does not identify one tangible tactic or strategy that would actually improve water quality,” Leeds told The Huffington Post in a statement. “Without the lawsuit, labor and financial resources could be focused on deploying more practices across the state to improve soil and water resources.”

The ISA pointed to the over 970,000 acres Iowa farmers have enrolled in the federal conservation reserve program — more than any other state — as further signs the state’s industry is on the right track toward addressing the problem. (The program removes environmentally sensitive lands from agricultural production, which helps improve water quality and wildlife habitat.)

But the ISA’s efforts are “nothing more than greenwash” to Des Moines Water Works CEO Bill Stowe.

“They’re sprinkling money and acting like they have some kind of environmental awareness when, in fact, they’re undermining public health and environmental protections,” Stowe told HuffPost.

The ISA isn’t the only group supporting the defending counties in the lawsuit, but it’s hard to know who’s been paying the rest of the bill. As the Des Moines Register has reported, the donors picking up 90 percent of the counties’ $1.1 million legal tab are anonymous and likely to remain that way, thanks to a state law regulating private foundation contributions to government groups.

Stowe’s utility has been spending a lot of money, too — seven figures’ worth of extra treatment costs to ensure the drinking water he delivers to their customers is safe, he said.

The DMWW is home to what he calls the “world’s largest” nitrate removal facility. The plant is in need of repairs and expansion, he said, thanks to the historically high amount of nitrates they’ve had to remove from the drinking water they provide to their customers.

In 2013, when nitrate levels in the source water reached a record high, the utility’s tab for additional treatment costs and lost revenue totaled $900,000, DMWW said. Last year, it spent $1.5 million on denitrification efforts.

Stowe argues that tile drainage systems used by the upstream farms to reduce crop flooding should be identified as “point sources” of pollution under the federal Clean Water Act, from which they traditionally have been exempt.

The Iowa lawsuit could drastically change how the Clean Water Act can be used to remedy nutrient pollution, which is having a severe impact on communities throughout the U.S.

For this reason, the suit carries national significance. John Rumpler, senior attorney at Environment America, a Boston-based nonprofit, called it a “huge, precedent-setting” matter.

Rumpler authored a report last month linking nutrient runoff from agribusiness to the growth of algal blooms and dead zones that have devastated ecosystems and damaged local economies in places like Lake Erie, the Chesapeake Bay and the Gulf of Mexico. The EPA has also linked nutrient runoff to acid rain and air pollution.

He sees what is happening in Iowa as one example of runoff issues bubbling up nationwide, like South Florida’s “guacamole-thick” algal blooms that prompted Gov. Rick Scott (R) to declare a state of emergency earlier this summer. Environmentalists have largely blamed agriculture, and particularly the powerful sugar industry, for the pollution.

“The overriding story here is that the corporations that are producing our food in an industrializing fashion are now threatening our water,” Rumpler said. “America should not have to choose between healthy food and safe water.”

Some Iowa farmers have already changed their ways ― before the lawsuit was even filed.

One of them is 62-year-old Tim Smith. Smith has been farming his whole life and currently grows 800 acres of corn and soybeans in Eagle Grove, Iowa, not far from the three counties named in the suit.

Five years ago, Smith signed up through a USDA program to start planting cover crops on some of his fields, as well as installing a woodchip bioreactor with the aim of reducing the nitrogen runoff from his farm.

It wasn’t long before he observed, through sampling, that the amount of nitrates flowing off his farm had been cut in half. Seeing the results made him acknowledge he’d had a runoff problem he wasn’t aware of.

“I thought I was doing everything right on my farm prior to this,” Smith told HuffPost.

Still, Iowa’s estimated 470,000 acres of cover crops planted as of 2015 pale in comparison to the 26 million acres of statewide cropland. Though the Iowa Farm Bureau notes, accurately, that this is a 35 percent increase over the previous year, that number still represents less than 2 percent of the state’s overall cropland.

This is evidence, Smith believes, that many farmers in the state don’t realize they are contributing to the problem. He anticipates that, with time, more of his colleagues will come around to the idea of conservation and see that the practices accomplish what they are designed to do.

But the lawsuit, he says, could hinder that progress.

“It’s kind of a slap in the face to agriculture. It does throw a little insult,” Smith said. “If they lose or the case is thrown out, farmers are going to say, well, you’ve already sued me, so what’s the big deal? I’m going to keep doing things the way I used to do them. There’s a danger in that.”

For his part, Stowe is confident the utility will win, but he’s not limiting that to mean a win in the courtroom. He believes the suit, regardless of its outcome, challenges the state’s political status quo, which he says has favored agricultural interests for too long.

“If we were to lose and continue to pass on this cost to our consumers, there will be a political impact,” Stowe said. “Our customer base will more clearly understand why they are paying more, so we think we win anyway. We will be the long-term winners no matter what happens in our legal case.”