Lake weeds spur chemical reaction
What to do about those weeds?
It's a question that an increasing number of communities are asking as they monitor lakes and ponds choked by creeping invasive plants and algae. And over the past decade, according to information from the state's Executive Office of Environmental Affairs, it's a question that many apparently are answering with herbicides.
In 1996, the state issued 91 permits for herbicide use on lakes and ponds. By last year , the number had risen to 239.
State officials say it is unclear whether aquatic weeds have run more rampant over the past decade, or their presence has simply become more noticeable, prompting more communities to look for ways to eliminate them.
Mike Gildesgame , director of the Office of Water Resources for the state Department of Conservation and Recreation, said he believes the weed problem has grown, but noted that the potential use of herbicides has led to some high-profile public policy debates that have drawn attention to invasive plants.
``I think we can say that . . . more people are aware of it," he said.
Despite assurances that herbicides are safe when properly used, many have said they do not want to take a chance on chemicals, especially when the lakes or ponds in question are near drinking-water supplies.
The most prominent debate over herbicide use has centered on Lake Cochituate, which touches shorelines in Natick, Wayland, and Framingham. In the latest chapter, the Natick Conservation Commission voted against a plan by the state Department of Conservation and Recreation to use chemicals on the lake, citing safety concerns. The vote prompted a group of residents who want the weeds cleared to appeal the board's decision. The state has moved forward with other removal methods, such as pulling weeds by hand, while it awaits a ruling on the appeal, Gildesgame said.
This year, the state Department of Environmental Protection has issued permits for chemical use on more than 230 lakes and ponds. Several communities in Boston's western suburbs have the go-ahead to use chemicals on at least one body of water, according to the state.
Some communities -- including Berlin, Holliston, Hopkinton, Hudson, Maynard, Millis, Northborough, Sherborn, Southborough, Stow, Sudbury, and Wayland -- have no permits issued this year.
In Natick, permits have been issued to use chemicals on Dug Pond and Nonesuch Pond. The Conservation Commission was willing to allow chemical use on those ponds because, unlike Lake Cochituate, they are f arther from the town's drinking water supply, said Bob Bois , Natick's conservation agent.
Similarly, in Norfolk, the Conservation Commission approved the use of chemicals on some private fishing ponds, but refused to allow them on a lake that was near the public water supply. ``The Conservation Commission was not willing to take the chance on herbicides," said Marie Simpson , the board's administrative assistant.
Wellesley, which has permits to use chemicals on Sabrina Lake and Morses Pond, emphasizes non chemical weed-removal methods such as harvesting, and will use herbicides only as a last resort.
Janet Bowser , director of Wellesley's Natural Resources Commission, called weeds a symptom of a larger problem, namely storm-water runoff that carries lawn fertilizers and other weed-enhancing nutrients into ponds.
She believes pond and lake management has to involve educating nearby homeowners about how their practices can affect the larger environment.
`` Education is a huge piece of this," Bowser said.
Jackson Madnick , who chairs Wayland's Surface Water Quality Committee, said his group is trying to track failing septic systems, which can leak into ponds, and to teach residents about alternative lawn-care methods.
Wayland also has been testing non chemical weed-removal methods, such as harvesting, hand-pulling, and introducing weed-eating weevils into the water.
While he would consider herbicides as a last-ditch solution, Madnick said, many people still are concerned about their potential health effects. He also doesn't believe they are effective over the long term.
``They don't get rid of the plant," Madnick said. ``They just knock it back two or three years."
In Framingham, chemicals have been used to clear weeds from recreational ponds for several years, said Michele Grzenda , the town's conservation agent. Non chemical methods are more expensive, she said, and given the extent of the weed problem how effective they would be is unclear.
``It's sort of become a common practice," she said of herbicides.
Gildesgame said that while he understands ``there are some folks who say 'no herbicides, no way, no how, never,' " chemicals are sometimes simply the best option.
``It's one of those tools in our tool chest."