Peering deep into the brown waters of Lens Lake, I squint to keep track of the black and white Secchi disk as it sinks. There! A cloud of organic debris temporarily obscures the disk as it settles on the mucky substrate. Even though the waters are naturally dark from dissolved tannins, the lake is clear enough to see all the way to the bottom, seven and a half feet at the deepest point.
My husband and I are taking a water sample for the Adirondack Lake Assessment Program (ALAP), as we have done five times a summer for the past ten years. We have really enjoyed being part of this program; it’s a great reminder to get out on the water, and we’ve learned a lot about the lake we love. The best part is the report we receive in the Spring describing our sample results and adding them to the previous years’ findings. Ten years seems like enough time for a trend in water quality to emerge, but yearly fluctuations add a lot of “noise” to the data, and skewed readings can take years to normalize again. A few years ago a very rainy summer spiked the data for that year, and it took two years after that for levels to slowly return to “normal”.
In general however, Lens Lake appears to be “mesotrophic”, and slowly acidifying. We kind of knew this already, since it is very shallow and muddy and contains a very large floating bog. These factors, plus its location in the southeastern Adirondacks, makes us think the acidification is natural, not caused by acid rain. But we will continue to take our samples and study the results!
Collecting the sample takes less than ten minutes. When we get back to our camp we run a portion of it through a filter using the provided vacuum pump. Then we fold up the filter paper and seal it in a Ziploc baggie along with the 8 oz. sample bottle and the info sheet and freeze it. It goes to a temporary freezer in North Creek or gets mailed to the Adirondack Watershed Institute (AWI) at Paul Smiths College where the laboratory work is done.
Researchers at the Institute test the samples for calcium, chloride, phosphorus, aluminum, nitrate, pH and conductivity, and extract chlorophyll from the filter papers. These elements are markers for various aspects of water quality, and can indicate sources and causes of water quality problems. Concentrations of these elements seem to vary with each sample during the season. The amount of chlorophyll (in the form of algae and phytoplankton) increases as the summer wears on, which is why the filter time increases with each successive sample. In May the water just drains through the filter paper, but by August it quickly clogs up the filter and takes longer to pass through.
Participating in the ALAP program has been a fun, educational and rewarding experience. Even though the sample collection process is pretty simple, we still feel like Jacques Cousteau out there in our canoe, with our box of tubing, rope, sample bottles and Secchi disk. We have learned about the chemistry of our lake, and factors that affect it, and we are proud to contribute to the greater purpose of establishing baseline data for lakes throughout the Adirondack Park. We encourage you to do it for your lake too! If your lake is already in the program, consider sending a donation to Protect the Adirondacks to support their sponsorship of this worthy project.
Margaret Kinosian spends as much time as she can traipsing through the woods at her camp in Stony Creek. She has a BS in Geology from Skidmore College and an MS from Rensselaer Polytechnic Institute in Urban and Environmental Studies. She worked for the USDA Soil Conservation Service in the 1980’s and for the Town of Clifton Park as an Environmental Specialist. She lives with her husband and two daughters in Ballston Lake , and has been a member of Protect the Adirondacks for twenty years.