Cyanos Activity July 11
Reconsider activities and limit exposure to the water.
Disclaimer: The information presented below reflects conditions throughout the lake and may differ from conditions on specific shorelines. For information regarding beach closings please contact the Torrington Area Health District or local town officials.
Water clarity continued to decline with a loss of 0.5 meters at Center station and 0.65 meters at North Bay station. Secchi disk depth at North Bay and 7 other sites around the lake (13 sites visited) had clarity readings of less than the 2m. Best recorded clarity of the day was 2.1m, worst was 1.8m. Cyanobacteria cell numbers increased dramatically since last visit, with cell numbers now between 60K and 76K, with North Bay showing higher cyanobacteria numbers and poorest clarity. Percent saturation of dissolved oxygen in top 2 meters of the lake exceeded 115% at all stations indicating that phytoplankton are actively growing suggesting the Lake is entering cyanobacteria bloom season with strong likelihood that clarity will continue to decline in the days and weeks ahead to reach poorest seasonal clarity of about 1.0 meter in early August. Cyanobacteria cell numbers could easily increase to values exceeding 100K if sunny-warm-calm conditions persist. There is a significant potential for formation of surface scums in the days and weeks ahead.
The surface water temperatures decreased by about 1oC since last week. Surface cooling indicates lack of sunshine due to overcast weather and heavy rain events during the past week. This cooling is uncommon, further indication that this season has been unusually dark with regard to rainy, cloudy days slowing lake warming. Bottom waters at and below 5.5 meters was anoxic at all stations with that depth (4). Water at 5 meters was anoxic at half the stations with that depth (4 of 8). Water at 4 meters was between 60% and 119% saturation at all stations (13).
|Bantam Lake, CT 2017 Cyanobacteria Cell Count and CT DPH 2017 Recreational Waters Category Guidelines (Green = Safe, Yellow = Caution, Red = Posted Advisory)|
|Bantam Lake, CT 2017 Secchi Depth|