SKANEATELES - Part of determining a lake's purity is finding the ratio between the size of its watershed and the volume of water it contains.

Because Skaneateles Lake's watershed-to-volume ratio is the smallest of the Finger Lakes, it is therefore the cleanest.

But part of that cleanliness is also due to the dedicated efforts of local advocacy and action groups such as the Tri-County Skaneateles Lake Pure Water Association and its Skaneateles Lake Milfoil Eradication Project. Members of the SLMEP presented a program this week at the monthly Skaneateles Area Chamber of Commerce luncheon, which took place at Skaneateles Country Club.

Dr. Robert Werner, chairman of the Town of Skaneateles Lake Monitoring Committee, and Syracuse University science professor Dr. Christopher Scholz presented recent updates on the ongoing milfoil eradication project, which will soon begin the last of a three-year initial cleanup that started in 2007.

“We're about two-thirds of the way to being finished,” Werner said.

The project, which has been in the planning stages for about the last decade, began the actual milfoil removal two years ago and has so far removed about 20 acres of the evasive plant species, with approximately 11 acres remaining.

The project has relied mostly on private donations for its funding, he continued, and needs a little more than $300,000 to be completed.

After the active eradication is finished, the lake will need to be monitored annually to see if more patches of milfoil appear.

“We're in the process of talking to the city of Syracuse and Onondaga County to see if they'll be willing to take over that maintenance,” Werner added.

Scholz began the presentation using slides to help him explain exactly what milfoil is and how the eradication project is being executed.

After migrating to the United States, the plant began to spread during the 1950s and 1960s as personal watercraft gained popularity.

“Milfoil is spread from lake to lake because it attaches to boat engine propellers,” he said.

As part of the eradication, teams of divers have gone to the lake floor and “vacuumed” the plant into air tubes that pile the milfoil onto a boat.

“We have several points near Lourde's Camp, Spafford and other places where we pile the vacuumed milfoil. People can come pick some up to use as garden mulch, and what's left we take to the transfer and recycling station,” he added.

After Scholz finished, Werner moderated a question-and-answer session with the audience.

One question concerned how the divers can see the difference between milfoil and native plant species.

“Those guys are really good at visually identifying milfoil. It's a very unique-looking plant, so they're able to just get milfoil and leave the other plants alone,” he answered.