ENFIELD — On a clear, if slightly chilly July morning, a small coalition of volunteers bobbed in a red pontoon boat off the shore of Mascoma Lake, lowering various tools, tubes, buckets and strings down into the depths to test the water where many people swim, sail, kayak and boat all summer long.
Jim Martel, chairman of the Mascoma Lake Association’s water quality committee, was at the helm of the little boat.
For 22 years, Martel, a retired scientist, has been part of the crew testing the lake’s water each summer for New Hampshire’s Volunteer Lake Assessment Program, or VLAP.
For him, the work is second nature. The data the group collects is important both locally and at the state level to help keep the lake that also supplies drinking water to Lebanon clean and healthy.
The New Hampshire Department of Environmental Services oversees about 175 lake-specific VLAP programs across New Hampshire, Chief Aquatic Biologist Amy Smagula said.
The program began in the 1980s at the request of volunteers “who were concerned about water quality and wanted to become active in monitoring their lakes,” Smagula said.
DES currently has just eight staff biologists. “There’s no way that we could get out to all those spots,” she said.
Instead, DES trains volunteer groups on proper sampling protocols including what, where and how to test the water. State training and oversight ensures that the groups collect water samples that align with state and federal standards.
While volunteers learn how to sample the water and conduct basic tests, scientists analyze the water samples and DES staff compile the results into written reports. Scientists at the Colby-Sawyer College water quality lab analyze most of the samples in the Upper Valley.
“Data help inform our decisions to list water bodies as impaired or not impaired for uses like recreation, drinking water, aquatic life use, fisheries; all kinds of things like that. And those are our volunteers doing that,” Smagula said.
The data establishes a healthy baseline for New Hampshire’s lakes and ponds and can be used to identify specific problems to be solved. DES shares results and future recommendations with the lake associations, and uses the information gathered by volunteers to write reports that are submitted to Congress to help inform legislation and funding, Smagula said.
“Having volunteers and a program like this is important because if they do have water quality issues, it allows us to find funding to help them mitigate those issues,” she said.
‘A constant battle’
The Mascoma Lake Association, a group dedicated to protecting the lake and surrounding environment, has run a VLAP program since 1991. In addition to tracking water quality, testing the lake helps the group to see the results of other conservation work it is doing and inform future projects.
Mascoma Lake has reached its “highest level of purification” since he started with the VLAP 10 years ago, volunteer Mark Manikian said.
The lake is now classified as oligotrophic, he said, which means that it is relatively clear and low in nutrients. Lake clarity improved in 2024, according to a DES report.
“Most lakes are moving in the other direction, they’re getting worse and worse,” Manikian said. “A geologist will tell you millions of years from now every lake that exists is going to be first a swamp and then dry land because the stuff around washes it in. It’s a constant battle.”
Over the years, most of the water quality indicators on Mascoma have remained stable with the exception of worsening conductivity, or measure of salts in the water, which Smagula said has been trending down statewide because of increased use of road salts in wintertime.
The success at Mascoma Lake is due to a combination of factors, including the 2018 extension of a sewer line along Route 4A,where Manikian said most of the homes had “primitive septic systems that were damaging the lake.”
The effects of cleanup efforts in the Mascoma River in the 1970s through the 1990s “are showing up now” as well, he added.
Mainly, these amounted to infrastructure changes, according to a history compiled by the town of Enfield.
For years, mills, factories and private homeowners dumped raw sewage, chemicals and production waste into the river and the lake, leading to a major pollution problem. In the late 1960s, state and federal intervention and a massive algal bloom captured public interest and forced Enfield and Lebanon to work on solutions to clean up the river and Mascoma Lake.
The years of effort included an unsuccessful attempt to build a joint wastewater treatment plant for the two municipalities. A 1971 study of the watershed identified key pollution sources and possible solutions. In the late 1980s Enfield completed a municipal sewer system that cut off a major source of pollution to the lake. The town has since expanded the system multiple times.
More recently, the Mascoma Lake Association pushed for a new set of rules in Enfield that require homeowners to regularly inspect and pump their septic systems. The ordinance is aimed at reducing the risk of septic system failures that can spread harmful bacteria and nutrients into the lake and contribute to cyanobacteria blooms. Towns around Lake Sunapee have adopted similar rules.
Last summer, DES issued one cyanobacteria warning and one cyanobacteria watch on Mascoma Lake. Warnings are the more severe of the two notifications, issued when there is enough cyanobacteria to threaten public health. During a warning, lake users and animals are directed to avoid contact with water near the bloom. A watch is issued when there is an unconfirmed report, like a photo submitted to DES, or if there was a recent bloom.
There has been one watch issued so far this summer for Mascoma Lake.
Statewide, 60 cyanobacteria blooms have been reported to DES this year, Smagula said. Last year, there were 66 cyanobacteria warnings from May through September.
Water quality data can help to establish a baseline of what a lake such as Mascoma looks like when it’s healthy and allow DES to easily identify changes or problems, Smagula said. Several of the indicators, such as the phosphorus count, chlorophyll count and plankton analysis, can be used to track the presence of cyanobacteria or how likely blooms are to occur.
Water clarity
For this July’s testing session — the second of three the group will do this year — Martel was joined by Manikian and Patty Murra. Two more Lake Association volunteers headed out to test six tributaries around the lake.
The group gathered at Martel’s lakeside home at 9 a.m. and quickly split off to their different assignments, with the boat crew hauling a wagon of supplies out to the dock.
The wagon held a collection of tools to test the lake’s conductivity, phosphorus levels, plankton, pH, temperature, dissolved oxygen, turbidity and transparency.
“This is a beautiful day, the sun is out and everything. Sometimes we go out and it’s raining and windy,” Martel said as he navigated his pontoon boat out to the deepest point in the lake.
Per VLAP guidelines, water is sampled at the “deep spot,” which on Mascoma sits not in the middle of the lake, but close to shore on the Route 4A side, near the Enfield Shaker Museum.
The first thing the crew tested was water clarity, something that they can do themselves out on the water. For most other metrics, they collected water samples to be tested at the Colby-Sawyer water quality lab later in the day.
While laying face down on the deck of the boat, Manikian lowered an 8-inch plastic disk with two black and two white sections, called a Secchi disk, into the lake calling out the depth meter by meter until he could no longer see the disk in the water.
Both Manikian and Murray, who took her own chance at watching the disk drop, could see down about 12 feet. The relatively clear water is a good sign of a healthy lake.
“It’s also a test of our eyesight,” Murray, a recently retired high school biology teacher, joked. For years, Murray taught at Woodstock Union High School before ending her career in Bellows Falls, Vt.
After retrieving the disk, Manikian and Murray still weren’t done. They used a viewing scope aimed above the Secchi disk to check the clarity again. The tool typically increases visibility and with it both volunteers could see about 16 feet down in the 70-foot-deep lake.
“Today you could actually see the particulate matter in the lake with the scope,” Manikian noted in describing the water’s clarity.
Manikian, of Lebanon, is a retired dentist and chemical engineer. When he moved to Lebanon from Massachusetts 10 years ago, helping out with the VLAP “fit into my skillset,” he said.
‘A good sign’
Throughout the testing process, Manikian worked closely with Murray to navigate the testing tools to the appropriate depths and ensure that nothing got lost or went awry. Meanwhile, Martel recorded the data and weather observations on a tracking sheet, frequently chiming in with advice.
After checking the water clarity, Manikian and Murray moved on to taking samples of the water at three different depths using a tool called a kemmerer bottle. The clear acrylic tube features caps on both ends that can be locked open while the bottle is lowered into the lake.
To use the bottle, the two had to work together to lower it and send down a small metal weight called a “messenger” that triggered the ends of the tube to close and collect water at specific depths. After a couple of tries, they got into a rhythm.
“There, now we’re in sync!” Murray declared after successfully filling the bottle a second time.
The pair took one sample each near the bottom, middle and top of the lake.
Murray, who lives in Plainfield, has had a family cottage on Mascoma Lake for three generations. A water skier, Murray grew up using the lake and groundwater for drinking and showering during her summers at the lake. Between her family ties and her professional background, joining the volunteer crew five or six years ago was “an easy jump,” she said.
The group collected samples from the kemmerer bottle in smaller containers, labeled them and stored them away in the cooler to be tested for their phosphorus content, conductivity, pH and turbidity (or haziness of the water.) Phosphorus feeds algae and bacteria, including cyanobacteria, and a small shift in levels can be an early sign that a bloom is coming.
After finishing with the bottle, the group conducted the shortest and longest collections of the day.
First, Murray lowered down a long plastic tube to collect a sample of the entire water column, a process that only took a few minutes. The water column sample is tested for chlorophyll, another indicator of algae and cyanobacteria growth.
The longest test of the day was using a small scanner to collect dissolved oxygen and temperature readings at every meter down to the bottom of the lake.
At the bottom of the lake, the scanner read 25% oxygen saturation, which Manikian said indicates “really healthy water.”
“That’s what the fish like,” he said.
Living on the Lebanon side of the lake, Manikian pointed out the importance of keeping Mascoma clean and healthy as the source of the city’s drinking supply.
The last sample of the day was what Martel called: “Patty’s specialty.”
As a long-time biology teacher, Murray is in charge of sampling the water for phytoplankton, which she analyzes using a home microscope.
Before packing away her bottle of plankton-rich water, Murray held the sample up to the light and lit up.
She had identified her favorite phytoplankton; pollution-sensitive copepods that looked like tiny black specks bouncing in the bottle.
“It’s a good sign,” Murray said. “It’s an indicator, not proof” of healthy water.
In addition to the bouncy plankton, Murray later analyzed the water for other organisms, including cyanobacteria, which she noted “should be in there,” but in low quantities. As a naturally occurring bacteria, cyanobacteria is only harmful at high levels.
With Murray’s phytoplankton sample secured, testing was done for the day.
About two hours after setting off from the dock, Manikian hauled up the anchor and Martel navigated the boat back home, ready to transfer the sample-filled cooler to his car and drive it over to the lab for testing.
