AUBURN — Water District officials will set aside $50,000 to handle water quality testing, mitigation, planning and public relations to deal with a lake trout-killing algae bloom this summer.

“We can’t just Band-Aid this for the short term,” John Storer, superintendent of the Auburn Water District, said. “It has to be a widespread fix that’s going to cure the problem. Since 1875, Auburn has been taking out water (from the lake). We have a legacy to keep the lake going for an indefinite time period. There is no other source on the horizon, so we have to get this under control.”

Water district trustees approved the spending, which amounts to Auburn’s share of the costs for studies and mitigation. Lewiston and Auburn share responsibility for the lake.

Storer said the bloom is not a threat to the quality of Auburn and Lewiston’s drinking water today. It could become a problem later on, however, by clouding the lake’s water and making the current treatment efforts less effective. Lake Auburn’s water is currently run through an ultraviolet light system, then treated with chlorine and ammonia.

It could hurt Auburn’s status as a lake trout habitat, however.

“Right now, if we can’t show we’ve identified the problem and can get phosphorous loads down, the state Department of Wildlife won’t stock the lake next year,” he said. “They’ve been stocking annually, with 1,000 or 2,000 fish. But they won’t stock it unless we can get this controlled.”

The money will help pay for more tests by water district officials and by the Maine Volunteer Lake Monitoring program. Storer said the district plans to install meters at the Basin and at Thompson Brook, northern inlets that feed the lake.

“During a rain event, we’ll be able to monitor how much flow is going through and how many pounds of phosphorous reach the lake,” Storer said.

The water district also plans to work with consultants to study the lake’s water and shoreline.

Storer said the $50,000 should pay for Auburn’s share of the studies through Oct. 17, the next meeting for the water district’s Board of Trustees.

Dave Jones, Lewiston’s director of Public Works, said he would make a similar report to Lewiston city councilors when the final costs for studies and mitigation are known.

Water officials said that warm temperatures this spring and summer are behind the algae bloom. Warm early spring temperatures extended the algae growing season and hot summer temperatures supercharged it. Combined with heavy June rainstorms, which eroded soil around the lake and brought phosphorus rich runoff into the water, the algae had an optimum growing environment. The algae grows and dies, sinking to the lowest, coldest parts of the lake as it decays, using up oxygen in the process.

That layer of the lake, where the lake trout live, is already low in oxygen later in the summer. The decaying algae use up available oxygen, suffocating the lake trout.

Water Quality Manager Mary Jane Dillingham said at least 50 fish were killed and washed up on shore. The largest discovered was a 36-inch trout weighing between 15 and 20 pounds. The other fish averaged around 22 inches long, Dillingham said.

Officials say the lake’s water temperatures have already started to drop, which slows the growth of algae and mixes the bottom layers of water with the oxygen-rich upper layers.

Storer said water engineers have discussed stirring up water to increase oxygen and adding chemicals to bind the phosphorous. But much of the change has to come around the lake, keeping soil and phosphorous out.

“We need a balanced approach,” he said. “We don’t want to mechanically fix the problem for one year and let the conditions get worse. Once that treatment wears off, we’re back at square one.”

staylor@sunjournal.com