A pair of American Indian tribes in Maine aired in court Tuesday their concern that the Environmental Protection Agency will change water quality standards on rivers where members maintain fishing rights.

The Penobscot Nation and Houlton Band of Maliseet Indians are involved in a legal struggle over water quality on Maine rivers that also involves the EPA and the Maine Department of Environmental Protection. The EPA imposed stricter criteria for a pair of Maine rivers at the end of former President Obama’s administration, but court documents filed this month show the EPA wants to revisit those standards.

The EPA’s court filings say that federal agencies are allowed to “reconsider the wisdom of their policies in response to a change in administrations,” and that is what it’s doing.

But the tribes fear that could mean weaker protections for the Penobscot and the Meduxnekeag rivers, and members and their lawyers are pushing back at the possibility of a standards rollback.

“Our only goal and objective is to make sure we have a water system that’s conducive to fish consumption rates,” said Penobscot Nation Chief Kirk Francis, who noted the Penobscots have harvested herring and salmon from their namesake river for generations.

Judge Jon Levy held a hearing on an EPA motion related to the case Tuesday at U.S. District Court in Portland. The agency has moved for a voluntary remand because it has “decided to reconsider and change the decisions challenged in this case,” court papers state.

The state of Maine supports the motion, but the tribes do not, according to court filings. Levy did not make a decision on Tuesday.

The state previously argued in court the EPA is unfairly imposing heightened water quality standards in tribal areas. The EPA has previously made the case that water standards in the state are not strong enough because Maine’s tribal sustenance fishers eat more fish than the population at large.

David Carson, an attorney for the U.S. government, said in court Tuesday the EPA would like four months to come up with a proposed set of decisions. Scott Boak, an assistant attorney general for Maine, said the state’s priorities are to “maintain status quo” and protect the “interests of the tribes and the environment.”

Carson and Boak both declined to comment after the hearing ended.