Swimming won't be allowed for 24 hours in Lake Potanipo after herbicide is applied this morning.
Experts also recommend that boaters stay off the lake for two or three days to allow the treatment to take hold, although boating isn't prohibited.
The procedure, being conducted from a boat, is similar to fertilizing a lawn: Technicians drop pellets that sink and dissolve, getting into the root system of the invasive weeds known as variable milfoil.
Variable milfoil, a scrubby-looking plant that resembles a bottle brush, grows on lake and pond bottoms, typically in the more shallow water near shore.
Uncontrolled, it can choke out aquatic life, eventually clogging a water body with a dense tangle of thick material that can be removed with chemical treatments, by hydroraking or by hand.
There is also a native milfoil found in the state's lakes and ponds that scientists describe as "well-behaved," saying it creates a healthy habitat.
On Sunday, Buddy Dougherty, chairman of the Conservation Commission, hosted a fact-finding tour on Lake Potanipo for a group of state lawmakers who represent area towns, enlisting Bob Bramley, who lives on the lake, to ferry the group in his pontoon boat.
Dougherty's aim was to promote awareness of variable milfoil. But he also wanted to urge lawmakers to sponsor legislation that would fund milfoil removal and continued monitoring.
"You need someone to carry the banner," he said, lamenting a shortage of volunteers and attention on the issue.
In some ways, it's a tough sell.
For one thing, the invasive milfoil isn't obvious until you get up close, whether swimming, fishing or riding in a boat.
For another, it's hard to believe that lurking under a lake that looks as perfect as a scenic postcard, is something so terrible.
"You have to see, touch and feel to understand," Bramley told the lawmakers riding in his boat.
Bramley and his wife, Kathleen, are unofficial Potanipo Lake stewards. Recently, they collected water samples for testing, and they spent summer evenings fishing near the shoreline and keeping an eye on the weeds.
Twice, Kathleen lost two bass that got tangled in milfoil, and she said that every time she goes out on the water, she checks to see if more fish are getting snagged by the weeds.
On Sunday, Dougherty predicted that prospects this week for a successful treatment were high, given the low level of the lake and the continuing drought.
Read more at http://www.nashuatelegraph.com/news/854324-196/lake-being-treated-for-invasive-weed.html