North Dakota's Devils Lake outlet may begin pumping greater amounts of saltier water into the Sheyenne River after the state Health Department concluded the water channel no longer needs a permit.

The agency no longer has authority to require the state Water Commission to obtain a discharge permit for the outlet's operations, said David Glatt, chief of the Health Department's environmental health section.

Glatt's decision was influenced by a federal appeals court ruling in Atlanta earlier this month that upheld an Environmental Protection Agency rule on transfers of untreated water.

The EPA rule, which took effect in August, says discharge permits are not needed to regulate transfers from one body of water to another, as long as the transferred water is not changed.

The 14-mile outlet is a series of open channels, pipes and pumping stations that funnels water from Devils Lake's west bay into the Sheyenne River in an attempt to slow the lake's rising waters.

The lake has been expanding since the early 1990s because of plentiful rain and snow runoff, along with farmland drainage. Its rise has flooded thousands of acres of farmland and forced the raising of roads and dikes.

Devils Lake stood at 1,450.4 feet above sea level Friday, an increase of 28 feet since October 1992, when the waters began rising.

The Sheyenne is a tributary to the Red River, which forms most of North Dakota's border with Minnesota and flows north into Manitoba's Lake Winnipeg.

Canadian and Minnesota officials, as well as North Dakotans concerned about the Sheyenne's water quality, opposed the outlet's construction - it was completed in August 2005 - and recent attempts to increase its water-pumping capacity.

They fear river degradation and the possible transfer of invasive species into the Red River and Lake Winnipeg. The outlet's supporters say the concerns are unfounded.

Christine Melnick, Manitoba's minister for water stewardship, said Friday the province was exploring ways to respond to the North Dakota Health Department's move.

"Our concerns about interbasin transfer (of foreign aquatic life) are not concerns just held in Manitoba," Melnick said. "This is a universally accepted concern right now. When we look at the Great Lakes, all you have to say is 'zebra mussels' to understand concerns around invasive species."

The zebra mussel, a type of mollusk that feeds on algae and is normally about an inch long, multiplies rapidly and can clog water intakes, block pipes and cover boat hulls.

The Devils Lake outlet's existing permit, which took effect last July and was to expire in June 2013, limited its flow to 100 cubic feet per second of water. In most cases, it restricted the outlet from raising the river's natural sulfate content by more than 15 percent.

With the permit rescinded, the Water Commission, which operates the outlet, eventually intends to pump up to 250 cubic feet per second of water. It may continue doing so as long as it does not push the Sheyenne's sulfate levels over 450 milligrams per liter. The permit had mostly limited sulfate levels to the mid-300s.

Water high in sulfates, including salts, can taste bitter and act as a laxative. The EPA has recommended limiting sulfates to 250 milligrams per liter for drinking water.

Dale Frink, the Water Commission's chief engineer, said the outlet's existing pumps can't move more than 100 cubic feet of water per second. New pumps will be needed to increase the outlet's capacity, and those will not be operating until next year, he said.

However, the new, higher sulfate limit will allow the outlet to pump at maximum capacity more often, Frink said. Until now, the outlet's operators often had to reduce its water flow or risk exceeding the sulfate limit.

Minnesota and eight other states filed a lawsuit challenging the EPA water transfer rule last October in federal court in New York. It was consolidated with a separate lawsuit filed by environmental groups and outdoors organizations.

U.S. District Judge Kenneth Karas in White Plains, N.Y., put the cases on hold last April at the EPA's request to wait for the 11th U.S. Circuit Court of Appeals in Atlanta to rule in a Florida case on the water transfer rule.

On June 4, a three-judge appeals panel upheld the rule. North Dakota Attorney General Wayne Stenehjem was one of a group of state attorneys general who filed a friend-of-the-court brief supporting the EPA.