Water concerns prompt lake drawdown

KEUKA LAKE--The Finger Lakes region of New York is known for the 11 lakes that span across the western and central part of the state. Water quality and clarity are often features that describe the region as well. However, as harmful algal blooms (HABs) have increased in quantity and duration they are beginning to impact the use of the lakes.
This year there were multiple beach closures on Keuka Lake due to blooms and local water monitoring groups found countless suspected or confirmed HABs in Seneca, Keuka and Canandaigua Lakes.
The Keuka Lake Outlet Compact, the group charged with managing the level of Keuka Lake, recently held a special meeting at the request of the Penn Yan Department of Public Works and the New York State Department of Health. Because of algal blooms potential to contain cyanobacteria and its ability to produce the liver toxin microcystin, they are referred to as harmful. Monitoring of public water sources has been underway at the Penn Yan village water treatment plant with raw water samples showing levels of the toxin from 0.4 ug/l (parts per billion) to 2.34 ug/l (ppb). No microcystin toxin has been detected in the village's finished (treated) water.
While a number of additional measures have been taken such as increasing the level of disinfectant (chlorine residual), reducing the plant production rate and adjusting the flow out of the lake to move water past the water plant intake, a modified down-draw will be used this fall to help control contaminates seen at the water plant.
KLOC Chairman Mark Illig (town supervisor of Pulteney) summarized the actions taken by the outlet compact: "The board of the compact has authorized a modified downdraw of the lake beginning in early October to support the efforts of the Penn Yan water plant to address the cyanotoxin in the lake." Illig explained that under normal conditions the drawdown of the lake to its winter level begins Nov. 1 and that level is about 12 inches lower than the normal summer level.
The KLOC manages the level of Keuka Lake with six flood control gates at the Main Street bridge in the village of Penn Yan. The group noted this early drawdown is a temporary action to support water quality.