Editor’s Note: This is a revised version of the document we published yesterday. A member of the Old Lyme Conservation Commission (OLCC) sent us this version when it was realized that we had inadvertently been sent a version, which did not contain the final edits. We have not edited this document ourselves other than to remove the underlines. This version was approved by the OLCC for publication.

The fundamental purpose of the Old Lyme Conservation Commission is to protect the natural resources of the Town of Old Lyme. We believe that Rogers Lake is one of the most important natural resources we have and that it deserves the attention of not just those taxpayers who live around the lake, but the attention of the entire town. Clean water is a precious resource that should be preserved. Rogers Lake is the next best thing we have to a reservoir.  Because deep deposits of porous sand and gravel underly much of Rogers Lake,  lake water supplies many of the shallow wells not only in the Rogers Lake area but also in the Lieutenant and Blackhall River watersheds to the south. The Commission opposes the use of pesticides in Rogers Lake.

The situation:

The Selectmen of the Towns of Lyme and Old Lyme favor applying pesticides to kill vegetation in the lake, as does the majority of the Rogers Lake Authority and a number of lakeside homeowners.  It may appear to be an expedient way to answer the complaints of swimmers and boaters, who are bothered by the burgeoning growth of both 27 natural species of plants as well as by two new invasive plants.

 First time for pesticides

This will be the very first time that a pesticide is applied to the lake.  Forty-three acres have been identified for treatment or about 17 percent of the lake.

The history of this problem:

Over the last twenty years, the Old Lyme Conservation Commission has  supported the Rogers Lake Authority (RLA) for their efforts to improve conditions in and around the lake. These efforts have included an aggressive program to reduce the number of water fowl that yearly account for a rather startling amount of raw sewage.  RLA has used minor drawdowns, raking, harvesting, even scuba divers in attempts to control weeds.  One of their most successful methods has been the use of benthic mats which block the sunlight so that the invasive plants die out.  All of the techniques did what they were advertised to do, but the weeds returned, and now we have two new invasive weeds to deal with.

So, after various efforts over twenty years at a cost of about $400,000, Rogers Lake appears to be worse off than before.

Addressing the problem:

To face the new challenge, the Towns of Lyme and Old Lyme in 2014 formed a committee which included a professional ecologist.  They  then hired a Massachusetts environmental firm (NEE) that has recommended using the pesticide Clipper (flumioxazin) as the most effective approach to killing the weeds. The stated cost is $405. per acre.

The problems with this approach are:

• This chemical quickly disperses, forming two metabolites (by-products) APF and THPA. These byproducts “tend to leach into the soil and may become persistent over time.”
• While Clipper is not supposed to be very toxic to humans and “moderately to highly” toxic to fish, there have been no comprehensive tests for toxicity or bioaccumulation on the two metabolites (as of 2012).
• Rogers Lake is considered a trophy trout lake. The DEEP has recently stocked the lake with unusually large trout attracting fishermen from near and far. In the past their boats probably brought the two invasive species of weeds to the lake in spite of a RLA boat inspection program.
• In addition, the DEEP has a salmon egg project at the Lower Mill Pond. The newly hatched fish are then placed  in cold water streams like Roaring Brook in the hope of creating a future salmon run.
• The DEEP has fish ladders at both the lower and upper mill ponds as well as at the Rogers Lake dam. Clipper is “moderately to highly “ toxic to fish. No one can predict with certainty that Clipper will not impact these valuable programs.
• Killing 17 % of the lake’s vegetation can have a negative impact on the whole ecosystem essential to a healthy lake which normally requires 20 to 40% vegetation. NEE representatives admitted that treatment with pesticides would probably have to be repeated for the foreseeable future. It is not a solution.

In addition to the unresolved long term effects of using pesticides to kill weeds, there remain other major concerns, especially the source of the yearly contribution of nutrients that make lake vegetation thrive:

• There are a large number of houses on very small building lots around Rogers Lake. Almost all of these started out as  summer cottages. Now it is estimated that more than half of these cottages are being used year round, putting additional loading on septic systems that were marginal even during two months of use.
• To try to head off pollution from these marginal systems, the Old Lyme Health Department has maintained an active program that requires residents to adhere to a schedule of septic system pump-outs, inspections, and repairs. Thirty or so homes are due for pump-out this year. Three septic system failures at the lake were recently reported. Because the Town of Lyme does not have a comparable program, there is no way of knowing whether or not homes around the north end of the lake are adding pollutants.
• Every year, five streams that flow into Rogers Lake flood the lake with fresh nutrients during major rain events, contributing lawn fertilizer and soil nutrients to assure a new healthy crop of weeds. Silt ponds need to be constructed and maintained to reduce nutrient levels in the lake from this source.
• There has been a gradual increase in year round waterfowl around the lake. Currently, forty to fifty Canada geese average three pounds of feces per day! Do the math and be shocked at the amount of raw sewage that enters the lake from just this one source! Swans and ducks add to this input of nutrients.

Conclusion

The members of the Old Lyme Conservation Commission side with the ecologist on the Rogers Lake Committee who voted against applying Clipper to 43 acres of the lake. It is a stop-gap measure that solves none of the long term problems facing the lake. We seek a comprehensive long term management program for this extremely valuable natural resource.