NEWPORT – In its 20th year of a major quality restoration program, Sebasticook Lake is in fair condition, David Courtemanch of the Maine Department of Environmental Protection said Wednesday.

Aside from keeping tabs on contaminants slowly leaching from the Corinna Superfund site upstream on the East Branch of the Sebasticook River, Courtemanch said regular testing of the fish and water keep track of phosphorus, the component that so severely threatened the lake two decades ago.

A crew took samples of lake water in March and Courtemanch said another crew was on the lake Thursday. Courtemanch is the director of environmental assessment for the DEP and has been personally involved in its restoration since the inception of the program in 1982.

“We have continuously been carefully tracking the Corinna contamination,” said Courtemanch. “The toxic analysis has been OK,” he said. “We have had a mercury advisory, but there is a mercury advisory all across the state.”

“We think the toxins [from Corinna] have been diluted enough not to cause a concern,” said Courtemanch.

The lake experienced an algal bloom last summer that was heavier than in several recent years, he said, but Courtemanch assessed the lake’s overall health as fair. “The tests put phosphorus at a range a little higher than we would have liked,” he said, “and the oxygen level was only fair.”

Sebasticook Lake has been the object of a 20-year restoration program to remove and diminish phosphorus, which causes an overabundance of algae. “The program is working, but it is slow,” Courtemanch admitted.

When the program first began, lakeside residents sarcastically joked that you could walk from one side of the lake to the other across the pea-green algal bloom that coated the lake by July 4.

By draining the lake through the North Street Dam each Labor Day, the algae is flushed downstream and will not feed the next year’s crop of algae. An aggressive program of managing manure on farms within the lake’s watershed also has helped.

Although last year’s lake bloom was heavy, most recent summers have seen minimal blooms very late in the season.

“It is internal phosphorus that is driving this lake now,” said Courtemanch. “Once the Corinna Sewer District goes offline within the next two years things are going to improve quickly.” Courtemanch said the Corinna facility has been discharging into the East Branch of the Sebasticook for years. The town is installing a closed system.

“We are getting close to hitting some real good water conditions,” said Courtemanch.

“The future consists not so much of us forcing the lake to turn a corner, but allowing the lake to fix itself. We’ve patched the wound, given the antibiotics and now the lake must heal itself,” he said.

Courtemanch said, however, that DEP officials never will back off monitoring the lake. “It is still a marginal lake and we will always want to make sure we do not disrupt what gains have been made. But the overall program will change from restoration to protection.”