PORTLAND — A Passamaquoddy Tribe reservation in Maine has been granted authority to regulate its drinking water, opening the door to greater sovereignty.

Gov. Janet Mills signed a bill into law on Thursday that gives the Passamaquoddy Tribe at Pleasant Point the right to secure clean drinking water by drilling wells on tribe-owned land and working with the U.S. Environmental Protection Agency instead of state agencies.

The tribe has long been frustrated by poor water quality that sometimes caused brown liquid to flow from faucets at Pleasant Point, also called Sipayik.

“Members of the Passamaquoddy Tribe at Sipayik, like all people in Maine, deserve access to clean, safe drinking water. This legislation will build on our efforts to ensure that they get it,” the Democratic governor said Thursday.

The bill is one of three dealing with Native Americans and sovereignty during the current legislative session in Augusta. The two other bills are awaiting a final vote.

The most far-reaching proposal would amend the Maine Indian Land Claims Settlement Act of 1980 to give tribes in the state the same rights as other tribes across the nation. Another bill would funnel mobile sports gambling revenue to three tribes in Maine.

Tribal reservations in Maine are currently treated like municipalities, making them subject to state laws, under the land claims settlement.

Hundreds of people rallied earlier this month on behalf of the water bill and full sovereignty for the state’s federally recognized tribes, the Passamaquoddy, Penobscot, Maliseet and Mi’kmaq.

One of the speakers, 19-year-old Passamaquoddy Noela Altvater, spoke of the irony that Maine is known for its pristine water and that clean water was available virtually everywhere except on the Pleasant Point reservation where she’s grown up.

Maggie Dana, chief of the Passamaquoddy at Pleasant Point, who previously described the water as poison, said Thursday evening she was grateful that the governor signed the water bill.

“We can now access solutions to our public health crisis. For a long time, we’ve been feeling powerless. There was no solution. You could see them on the horizon. Now it’s real,” Dana said.

But she’s also still hopeful that the larger sovereignty bill will be passed and signed by the governor.

Mills, who has vowed to improve tribal relations, has expressed reservations about going too far in amending the land claims act. But she said the water bill has demonstrated that state government and tribes can work together and build on previous success on installing filters this summer for the water system that serves both Pleasant Point and in the town of Eastport.

At the governor's request, the bill was recalled and tweaked to make explicit that it applies to specific parcels where wells could be drilled, and not other tribal land across the state.

“I thank the Passamaquoddy people for their collaboration on this law, which demonstrates that we can make progress for all when we work together,” Mills said in a statement.

It was a victory for tribes in the state after the U.S. Supreme Court earlier this week declined to hear a Penobscot Indian Nation appeal over ownership and regulation of the tribe’s namesake river in Maine.