The chemical response following base application to Little Simon Pond, New York State

Little Simon Pond, a moderately acidic lake located in the Adirondack region of New york State, was treated during August 1986 by application of three particle sizes of limestone (CaCO₃), ranging from finely ground (14 μm) to coarsely ground (40 μm). Immediately after base addition, there was a marked increase in pH, acid neutralizing capacity (ANC), and Ca²⁺ associated with the dissolution of CaCO₃. Water quality targets (pH greater than 6.5, ANC greater than 100 μeq/L) were immediately met in the epilimnion, and approximately 2 months after treatment were attained in the hypolimnion. This delayed response in the lower waters was due, in part, to restricted water-column mixing as a result of thermal stratification both prior to and following the treatment. Short-term reacidification occurred during the snowmelt period and was limited to the upper waters after 1 year of treatment. Results show that application of multiple limestone particle sizes may be a useful method for mitigating acidification in thermally stratified lakes like Little Simon Pond.