ILION — Keeping and maintaining Ilion’s Reservoir 3 would be far less expensive than removing it, engineers from Barton & Loguidice told the Ilion village board.

The board had asked the firm to look into the matter after the state Department of Environmental Conservation advised the village to make the reservoir operational or shut it down.

Reservoir 3 currently is not in use.

Eric Schuler and Wendell R. Buckman, of Barton & Loguidice, said the engineers had reviewed an earlier report by McDonald Engineering but also did their own inspection and brought in one of the firm’s senior environmental scientists to take a look at the reservoir.

The engineers presented three alternatives:

* Keep and maintain the reservoir.

* Partially breach the reservoir to reduce the amount of water it could hold.

* Completely remove the reservoir.

If the village decides to keep the reservoir, trees and brush on the face of the dam would have to be removed, and the concrete spillway repaired along with the walls, Buckman said. He said the DEC requires an operational low level drain. While there is a drain, the engineers likely would recommend installing a new valve.

The engineers did not recommend the partial breach option which would lower the water level and the capacity of the reservoir.

“If you’re going to spend the money, you might as well keep the asset,” said Buckman.

The third option — removal — is very expensive he said. Compared with a cost of about $600,000 to keep and maintain the reservoir, removal would cost more than $2 million. Valves would have to be removed and terminated, the site no longer could hold any water and a stream would have to be established.

“It’s quite substantial,” said Buckman.

Maintenance of the reservoir would include regular inspections, as well as mowing and updating an emergency action plan with key personnel listed.

Schuler said there are some problems with organic matter in the reservoir. While the village would not be using Reservoir 3 as its primary water source, he recommended the water department take samples every month or even every three weeks to evaluate what is in the water and measure the level of organic material.

Bruce Morgan, Ilion water treatment plant supervisor, said the department has taken some samples from that reservoir. The department currently is taking weekly samples from the reservoirs to test for algae due to a high level of algae right now.

Schuler recommended he take samples to put together data that could be used to craft a treatment plan for Reservoir 3. He added that the $660,000 estimated cost to keep and maintain the reservoir does not take into account the treatment upgrades that would be necessary.

Morgan said the reservoir had been used in the winter and spring, but not in the summer due to problems with Eurasian Milfoil. The reservoir was treated, but the invasive plant grew back.

“It’s been 10 years since we used it,” he said.