Oregon’s Nitrate Reduction Plan is supposed to provide a road map toward meaningfully reducing nitrates in the drinking water found in Eastern Oregon’s Lower Umatilla Basin. It’s also providing something else: a legal defense.

In February, several basin residents sued some of the biggest players in the local agriculture industry, accusing the businesses of putting their health at risk by polluting the region’s groundwater with excessive amounts of nitrates applied to fields and left to seep into the ground. The defendants responded by clinging tightly to state regulators, arguing that the state is already working on the nitrate issue and intervention from the federal court system is unnecessary.

The defendants used the release of the Oregon Nitrate Reduction Plan in September as further evidence that a federal judge should dismiss the lawsuit, submitting a flurry of filings the same day the plan was unveiled.

“If, as Plaintiffs would like, this Court were to shoulder the efforts of that massive collaboration — which contemplates remedial action as far as ten years into the future — it would pose ‘a serious drain of judicial resources,’” attorneys for food processor Lamb Weston wrote in a filing.

Multiple defendants argued that the state was best equipped to deal with the issue because it was “technical” and “complex.” Although studies have shown that irrigated agriculture and confined animal feeding operations are the two top sources of nitrates in the basin, attorneys for cattle farm Beef Northwest Feeders said that a court could not compel the agriculture industry to prevent nitrate pollution from a “whole host of other potential sources.”

Beef Northwest referred to an interview Portland television station KGW did with Oregon Department of Environmental Quality director Leah Feldon, who talked about wanting to balance regulating the Port of Morrow with the potential economic impacts to the region.

“By asking this Court to impose an immediate order requiring remediation on a regional scale (but directed at only five entities), Plaintiffs are asking the Court to jump directly into the lose-lose scenario DEQ is working to avoid,” the lawyers wrote.

Outside of court filings, the agriculture industry has been generally supportive of the Nitrate Reduction Plan. Water for Eastern Oregon, a nonprofit industry group formed to respond to the issue, praised the plan while waiting to see what rules it would impose. The group, which includes lawsuit defendants in its membership, declined to respond to questions about the lawsuit.

While the basin residents who brought the lawsuit have not publicly commented on the nitrate reduction plan, they have been skeptical of the industry’s arguments. In an early August filing, the group’s attorneys said the state has largely been “ineffective” in regulating groundwater pollution in the basin, evidenced by more than three decades of elevated nitrate levels.

“Since gaining control over the Umatilla (groundwater management area), DEQ has been largely incapable of addressing the nitrate problem it has been tasked with remedying,” they wrote. “DEQ has mostly asked Defendants to take certain remedial or preventative measures on a voluntary basis, requests they have largely ignored. And in the few instances where DEQ has issued mandatory orders—including issuing permits to limit dumping of nitrogen—Defendants have routinely flouted them.”

All of these arguments will come to a head Oct. 29, when a federal judge in Pendleton will hold a hearing on the defendants’ motion to dismiss. The plaintiffs are not only aiming to have their case proceed, but also have the judge declare it a class action case, which would add thousands of basin residents in Umatilla and Morrow counties to the lawsuit.