Ross S. Whaley
Upper Saranac Lake is amongst those few lakes In the Adirondack Park that have over twenty years of continuous measurements of some attributes of water quality. Measures of pH (acidity of the lake), phosphorus, transparency and conductivity go back as far as 1989. The advantage of these time series data is that we can see trends that indicate improvement or decline in water quality, and implications for steps needed to maintain water quality.
The Adirondack Watershed Institute (AWI) at Paul Smiths College will soon be completing a comprehensive review of the past 22 years of data for Upper Saranac Lake. This article is only a a sneak preview of lake water quality. It will look at only three attributes of water quality: phosphorus concentrations, acidity (you all have heard of the impacts of acid rain on lakes in the Park) and chloride concentrations (possibly resulting from use of road salt on highways during the winter). The base year for water quality data is 1989. As many remember, an algae bloom in the lake during the late 80’s made it clear to anyone who simply looked over the side of their boat or out from their dock that something dramatic was happening to water quality. The Upper Saranac Lake Association took immediate action to determine the underlying cause and source of the bloom. The expected cause was an increase in phosphorus concentration in the lake, and an expected source was input from the DEC fish hatchery. Water testing showed that, indeed, the suspicions were correct. Good information followed by cooperation from DEC in adjusting hatchery practices resulted in significant reductions in phosphorus concentrations and improvement in water clarity the following year.
If one compares water samples from the period 1989 to1992 to the period of 2007 to 2010, the average phosphorus concentration dropped 50% from 24 ppb (parts per billion) to 12 ppb. Even more revealing, the highest concentration measured during the early period was almost six times higher (167 ppb compared to 29 ppb). Measurements since 1992 indicate that phosphorus levels have remained quite stable. In spite of this success in reducing phosphorus concentrations, water clarity has declined slightly if you compare the earlier and later periods. This makes a good case for vigilant water monitoring of the lake.
Measurements of acidity of lakes across the Adirondacks during the early 1980s along with other measures of the impacts of acid rain generated by midwest coal burning power plants encouraged the State of New York to bring suit to decrease sulfate emissions from mid west power plants. The success of that suit and associated legislation has reduced the acidity of the atmospheric deposition and the lakes which received it. Fortunately, Upper Saranac Lake showed considerably less impact from acid rain than lakes in the southwest part of the Adirondack park. Nonetheless, we have been a beneficiary of that legislation. The average pH (measure of acidity) has increased from 6.9 to 7.4 from the 1989-1992 period to the current period. An increase in pH indicates a decrease in acidity.
A more recent concern about water quality has been chloride concentrations caused from run off from adjacent roads that are heavily salted during the winter. A recent study by the Adirondack Watershed Institute sponsored by AdkAction identified run-off from heavily salted state highways as a potential source of increased chloride concentrations in Adirondack lakes. Here, USL time series data are not as complete as for other variables, in that calcium concentrations were measured for only four years. These few measurements, however, did indicate a fourfold increase in chloride concentrations. However, there may be a close relationship between calcium concentrations and conductivity for which we have longer term measures. Average (mean) conductivity has increased by eight percent since the 1989-92 period. It is important to point out that while the increase in chloride concentrations is of concern, they are still at a level well below those at which there are human, fish or invertebrate health concerns. Recently the Adirondack Watershed institute also has been monitoring chloride concentrations in six feeder streams to Upper Saranac Lake. Late summer chloride concentrations in three of these are quite high. The plans for next summer is to have the AWI continue to monitor phosphorus, cation concentrations (calcium, magnesium, potassium and sodium), anion concentrations (chloride, sulfate and nitrate) pH and conductivity in the feeder streams and the same measures plus transparency in the north and south basins of the lake.
The purpose of this brief summary of water quality trends in Upper Saranac Lake is to not only inform our residents and visitors as to the state of water quality (actually quite good), but to thank those who had the foresight to launch the water quality monitoring program and make the case for the importance of continuing monitoring intomthe future.