What we do can make a big difference in the health and welfare of our lake. Eutrophication is the natural aging of lakes from the addition of nutrients such as phosphorus and nitrogen. They stimulate algae and aquatic plant growth. In modern times a large percentage of these nutrients enter the lake from the development of its watershed. The watershed area of Lake Wononscopomuc is the total area from which water drains into the lake. Anyone who lives within this area has an effect on the quantity of nutrients entering the lake. The rate at which eutrophication advances is determined by the rate at which the lake is fertilized by its watershed.
Like many lakes in North America Lake Wononscopomuc has a problem with Eurasian Water Milfoil. Experts believe it was brought into our area in an aquatic garden that someone threw away. It is an invasive weed that has no natural enemy. Even a tiny particle can establish itself in the lake bed and start to grow as quickly as several inches per week. It quickly takes over large areas of the shallower portions of the lake in depths from 3 feet to 18 feet or more depending on the clarity of the water. It displaces native weeds that are essential to maintaining a healthy ecosystem and makes swimming or boating almost impossible.
The Key is to limit the amount of phosphorus, nitrogen and sedimentation entering the lake.
One of the major contributors to the eutrophication of the lake is overburdened septic systems. The problem of phosphorus loading from septic systems has been documented in studies done on Lake Wononscopomuc as early as 1975 by Richard L. Miller, Ph.D. for The Salisbury Association. Dr. Miller found that only 4 other highly eutrophic lakes in Connecticut had higher concentrations of phosphorus than Lake Wononscopomuc in the spring of 1976.
In 1990 Dr. Nina Caraco of the Institute for Ecosystem Studies in Millbrook, New York, presented a report to the town on Management of Lake Wononscopomuc. In that report she cited “phosphorus loading” as the main cause of lake eutrophication “which is associated with decreased clarity of waters, extensive weed growth and depletion of oxygen in cold bottom waters.”
Dr. Caraco concluded that most of the phosphorus input from the watershed comes from the urbanized areas. “The phosphorus is delivered to the lake in sub-surface water (groundwater), but the ultimate source of this phosphorus is likely detergents, human waste and fertilizers,” she wrote. “The phosphorus from the watershed can be reduced,” she said, “by limiting fertilizer use, using low phosphorus detergents and frequently pumping septic systems which lie in the watershed.”
“As for nutrient loads each person eats and excretes approximately 0.6 kg phosphorus per year. Added to this is phosphorus in detergents (particularly dishwasher detergents) that can add an additional 0.2 kg phosphorus per person. Twenty non sewered homes can potentially add, therefore, about 60 kg of P to the watershed in sewage,” she said.
However, we already knew that poorly managed septic systems present a particular problem. In a 1975 report to the town sewer commission Minges Associates, Inc. pointed out that lake area “sub-surface sewage disposal systems are hampered from operating properly by high ground water and poor soil percolation.” The report said many homes have been built close to the lake. “Sub-surface disposal systems at these locations actually cease to operate because during the wet season the system is actually flooded. In many other systems, the sewage frequently overflows on the ground surface and into the lake,” the report said.
So it is the responsibility of all homeowners with septic systems in the watershed to follow these rules:
- Have your septic system pumped out at least every 2 years.
- Do not dispose of grease, fats, solvents chemicals or medicines into the system.
- Do not use in-sink garbage disposal systems
Landscaping is another major factor in limiting the leaching of fertilizers into the lake. Plan landscaping with erosion control in mind. Use buffer strips of trees, shrubs, grasses and ground cover to stabilize the lake shoreline and stream banks and to prevent nutrient run-off. Our local county agricultural extension service is a good source of information on environmentally correct plantings. (860-626-6240) Another good source is The Housatonic Valley Association hvatoday.org.
Dispose of all animal waste, vegetation materials such as leaves, grass clippings, weeds and harvested aquatic weeds away from the lake and the streams that flow into it. Milfoil raked out of the lake dries quickly so you can scoop it all up and take it away.
Do not use fertilizers or pesticides on lawns and gardens. Even organic fertilizers are injurious when they seep into the lake where they stimulate noxious weeds such as Eurasian milfoil.
Dr. Nina Caraco estimated that 22% of phosphorus loading in the lake comes from stream runoff. That is from Belgo Hill and Sucker Brooks. 62% comes from groundwater. It is because such a large proportion of the phosphorus comes from the watershed either down the two streams or directly from the land around the lake that the Lake Wononscopomuc Association has tried to educate the public about the dangers of fertilizers and overflowing septic systems.
Our lake is a fragile environment. The major danger to the lake is Phosphorus Runoff. “Phosphorus is a naturally occurring nutrient contained in lawn and garden fertilizers; it is deposited on impervious surfaces with dust and is attached to moist soil particles. Phosphorus and other nutrients fertilize the small almost invisible algae in the lake and help them multiply rapidly. The growth of excessive algae can decrease water clarity, turn the lake green and deplete the oxygen fish need to thrive.”1
There are three major categories of lake quality; Oligotrophic, well supplied with dissolved oxygen and clear, Mesotrophic, depleted oxygen levels, increased algae formations and lower water clarity and Eutrophic, prolific weed growth, nuisance algae blooms, sedimentation and deteriorated fisheries. Lake Wononscopomuc, the deepest lake in Connecticut, was already categorized as mesotrophic in 1940. “It is a hard water lake and supports an extensive crop of aquatic vegetation. The waters are poor in nutrients.” 2
By the mid-1960s the lake was being described as depleted of oxygen during the summer months and the cold water fishery had declined significantly. The lake was classified as a problem lake, i.e. on the edge of advanced eutrophication by Ketelle and Uttormark (1971)3 The lake suffered serious algae problems in the 1980s.
Fortunately, the lake has stabilized so that by the early 1990s it was still classified as mesotrophic.4 Phosphorus readings taken by Ted Davis at Hotchkiss during the 90s and, as recently as August 2004, by Dr. George Knoecklein, former president of The Connecticut Federation of Lakes indicate total phosphorus loading has not worsened.
It is a majestic site during the annual migration of Canada Geese to see hundreds of these large birds circling the lake and then swooping down as a flock to land on the water. Thousands of geese may visit for a few hours or a day during the migration months.
However, they can be a major problem as well. Their incessant honking all night is the least of it. Dr. Caraco estimates that 8% of the phosphorus loading in the lake comes from the geese. They can ruin a lawn in an hour and their waste is a major problem in the children’s play areas.
Never feed the waterfowl on the lake. Many of them like it so much here they refuse to leave. The lake association organizes a hunt each spring to find their nests and addle the eggs so they do not produce too many goslings.
It is possible to keep them off your lawn with a low fence along the shore. It works because they are creatures of habit. In the spring the adult geese will not go anywhere their goslings can not go. Since the goslings can not fly they can’t go over the fence. In late June and early July the geese molt and without all their feathers they can not fly very well. So they get in the habit of going up on grass that s easy to reach.
Unfortunately, if you leave a fence open, the geese will find it quickly and you will be faced with a messy clean up job.
- Androscoggin Valley council of Governments under grant from the U.S. Environmental Protection agency ↩
- Edward S. Deevey, Jr. Limnological Studies in Connecticut: VI. The Quantity and Composition of the Bottom Fauna of Thirty-Six Connecticut and New York Lakes 1939-1940 ↩
- Richard L. Miller Ph.D. Hydrologic/Nutrient Budget Study of Lake Wononscopomuc, March 1977 ↩
- Nina Caraco, Ph.D. Management of Lake Wononscopomuc, March 30, 1990 ↩