Pittsfield, Lake Onota Association Partner for Herbicide Treatment
PITTSFIELD, Mass. — The city and Lake Onota Preservation Association are working together to treat the lake from invasive plants.
Last week, the City Council voted to use $210,000 in free cash for the herbicide treatment of Onota Lake and accepted more than $46,000 from LOPA for the effort. City officials and LOPA members regard the lake as one of Pittsfield's gems and spoke to the importance of maintaining it, even at this cost.
Eurasian milfoil is currently invading the lake, and aquatic herbicide ProcellaCOR will be used to treat it.
"Onota Lake is a treasured asset for the city of Pittsfield and Berkshire County, and is home to a wide variety of fish, wildlife, invertebrates, and aquatic plants. The lake also provides a wide variety of recreational activities for residents and visitors," LOPA President Dave Reinhart said.
"Onota Lake has a very healthy and diverse population of native aquatic plants, with over 24 species represented. These plants occupy different heights and spaces in the water column, which provides a very beneficial habitat for fish and other species. Unfortunately, we also have several invasive aquatic plants, with Eurasian milfoil creating the most significant issues at this time."
The Eurasian milfoil is a very aggressive plant that spreads quickly and smothers many of our native plants, he said, reducing biodiversity and negatively affecting recreational activities such as boating and swimming.
Pittsfield did a control treatment with an herbicide that specifically targets the milfoil in 2021, which was effective, and another was expected in about five years. Reinhart said a lack of funding in 2025 prevented an effective control strategy, and the invasive plant spread through the lake.
Recognizing the challenges Pittsfield faces with finances, LOPA, earlier this year, fundraised to help support the treatment. The board of directors approved a $46,150 to the city, contingent on the City Council allocating the $210,000 in free cash.
Parks, Open Space, and Natural Resources Manager James McGrath reported that 218 acres have been identified as a priority for treatment. The project has gone out to bid, and a vendor has been selected, though a contract had not been signed because money was not in place.
The treatment will ideally happen in the second or third week of June.
McGrath said Onota Lake has a "very abundant" assemblage of native plants that they want to encourage, and "We feel really confident that this is the right approach." Addressing this issue is paramount to the Lake Onota Management Plan that has been in progress for the past year or so.
ProcellaCOR is a systemic herbicide that specifically targets Eurasian milfoil and is said to require an extremely low dose compared to other herbicides.
The Environmental Protection Agency categorizes the herbicide as "reduced risk," meaning there are no restrictions for swimming, fishing, or other uses even on the day of treatment, McGrath said, but the city would likely not allow swimming on the same day. This method was approved by the Environmental Protection Agency, Conservation Commission, and the Natural Heritage and Endangered Species Program.
There will be public notification before the treatment, and when all boats are off the lake, the herbicide will be applied from an air boat based on GPS coordinates. The lake will be closed for the duration of the day, and the efficacy will be monitored; bid documents require an 80% success rate.
"This is important stuff. I don't want to minimize lake management of this really critical resource, and not only from an ecological perspective, but a recreational perspective," McGrath said.
"Onota Lake is absolutely to be valued, and I know this is a lot of money. It is not taken lightly, but we feel, again, this is the best approach to keep the lake healthy. We spent a lot of time thinking about this."
Ward 7 Councilor Katherine Moody, who grew up on the lake, thanked the city and LOPA for being such a good friend of "my lake and my home and my woods and my park."
Ward 4 Councilor James Conant, who has been on the Conservation Commission for 25 years, said ProcellaCOR represents the best scientific active ingredient that is environmentally sensitive and environmentally responsible for this body of water.
"We've used it before with great success and with no fish killed, no amphibian killed, no animal killed," he reported.
"This is held in the highest regard. This represents the safest, and what I feel is the material that is needed for Eurasian milfoil, which has just taken over the lake in a big way."
LOPA raised close to $100,000 from about 98 donors who live on the lake.
On Monday, the Ordinances and Rules subcommittee voted to create a Lake Management Commission for Pittsfield's waterbodies. They will be expected to produce a three to five-year lake management plan based on water quality tests and plant surveys to locate areas for aquatic plant control and applications for possible zebra mussel control applications.
McGrath said the proposed commission would be a great vehicle for studying the true costs of lake management for Pittsfield, as there were questions about using free cash.
Tags: herbicide, invasive species, onota,
