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| The Duane Lake watershed, more or less |
It was and still is a useful test for protecting public health. But it tells us nothing useful about where these bacteria come from since all mammals excrete coliform bacteria. Are they from cows? Deer? Geese? Chipmunks? Or humans? Coliform analysis doesn’t differentiate.
So then, where do you go to block such bacteria from entering the water if you don’t even know where it comes from?
Now, the same technology that gives us crime-scene DNA testing can identify the species that put poop into water. And it’s an affordable test. Added to that is the new ability to find caffeine in a lake or stream. That, too, is an affordable test.
For the past few years the Duane Lake Association has been investing your dues dollars in these tests.
What have we learned?
In-lake findings
DNA unique to the gut of geese has been found in Duane Lake. No surprise there, of course. But the same samples failed to detect human source gut bacteria. Before you jump to any conclusion about the implications of that finding, consider the uniformly positive findings of caffeine in about a dozen water samples from scattered locations in Duane Lake. We have no record of cows drinking coffee.
Dr. Sebastien Sauve, director of the caffeine testing laboratory at the University of Montreal, tells us there is a typical correlation between caffeine concentration and coliform bacteria concentration — seeing as how they come from the same source — and they use this correlation to recommend when a beach in a Canadian lake ought to be closed. Caffeine concentrations in Duane Lake were well below the level of concentration that would compel a beach closure, he says. He did not yet say if there is a similar standard for drinking water.
We’ll do more searching of lake waters this summer to search for DNA evidence of excreted human-gut bacteria. It will be far more difficult to identify a specific source-location of either DNA or caffeine because of the diffuse nature of lake water, compared to, say, a small stream such as the two tributaries that join to fill up Duane Lake.
Tributary findings
Analyses of water flowing down the two small tributaries, flowing westward parallel to Schoharie Turnpike, that connect just before entering Duane Lake can be much more accurate in narrowing-down the range of possible sources; they are all lined up quite nicely along the streams. If you find evidence slightly downstream from a suspected source but not slightly upstream from it, you can pretty reliably say it is a source of the contaminant. Or the opposite.
For example, our DLA sampling has found irrefutable evidence that the upstream cattle farm discharges excreted cow-gut bacteria into the stream. However, as that same water flows out of a relatively large swamp half-way to Duane Lake, it no longer shows evidence of cow poop. Swamps are reputed to be effective filters and that appears to be confirmed by our testing.
The other branch of our tributary flows westward from a golf course, through two horse farms, and closely past four or five residences. Samples drawn from that branch tributary in early spring 2025 did contain low levels of DNA of excreted horse-gut bacteria. More concerning was the finding of rather significant levels of human-gut bacteria that could only have come from one or more of three specific homes—and probably just one or both of two specific ones.
More sampling will be done this summer, searching for human-source contamination in the branch tributary as it flows out of the swamp mentioned above.
All of this, of course, suggests the question of “So what? Can (or should) anything be done about upstream contamination and/or shoreline-source contamination?”
Please bear in mind that while these excreted animal and human-source contaminants do contain phosphorus and nitrogen, both of which fuel algae, research tells us that accumulation of these nutrients in our lake-bottom mud – arriving with storm runoff and silt over almost 100 years -- is the leading cause of our algae blooms.
Nonetheless, blocking or at least minimizing the deposition of both pathogens and nutrients from storm runoff, septic systems, and animals – four-legged and two-legged – is important to the health of both the lake and those who depend on it. – A.K.
DLA gains ground on funding for septic system replacement
In the face of determined opposition by the NY State Department of Environmental Conversation (DEC), our State Senator Patricia Fahy and Assemblyman Angelo Santabarbara have jointly filed legislation that would direct that department and the Environmental Facilities Corporation to admit the Duane Lake watershed into the NY State Septic Replacement Program.
The program provides up to $10,000 reimbursement to homeowners in selected watersheds to repair or replace their septic systems.
This proposed legislation comes after years of persistent pleas from the DLA to Assemblyman Santabarbara and now-retired State Senator Neil Breslin to argue our case to DEC, which has inexplicably listed a half dozen reasons why Duane Lake is ineligible for the program – reasons that are demonstrably false, invented, and easily and accurately refuted.
It was newly-elected Senator Fahy who finally got DEC staff to a meeting to discuss the Duane Lake application. The submitting of special legislation pretty much describes Fahy’s and Santabarbara’s dissatisfaction with DEC’s resulting comment that they would study the matter.
Meanwhile, discussions with several Capital Region banks about offering low-interest loans for septic system repairs or replacement in the Duane Lake watershed – similar to a program offered by banks serving the Lake George area – has reached success with home-town bank NBT. It would be an excellent complementary bit of assistance for the Septic Replacement Program when and if it ever comes to Duane Lake, or even own its own.
If interested, stop in at any branch of NBT. There is one right in “downtown” Duanesburg.
- Alan Knight