Cyanos Activity July 18
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 remained the same at Center station holding at 2 meters. Clarity at North Bay increased slightly to
2.15 meters. Changes in water clarity
were mixed throughout the lake with 7 stations showing a slight increase of
about 0.2 meters, 3 stations showed slight decreases of about 0.1 meters and 3
stations remained the same. Changes in
clarity don’t appear to reflect actual trends but instead inherent variation
due to the high number of cyanobacteria cells in the water. Further decreases in water clarity are
expected with poorest clarity of 1.0 meters usually occurring in early August.
Cyanobacteria counts show that Anabaena continued to increase at North Bay to
reach a new high of 86K cells/ml. Cell
counts and water clarity are not tightly connected probably due to clumping and
buoyance of cells in the water column.
Percent saturation of dissolved oxygen increased in top couple of feet
of the water column with all stations having values over 120% and 5 station
having saturation values over 125% indicating high rates of
photosynthesis. Cyanobacteria cell
numbers could easily increase to values exceeding 100K if sunny-hot-calm
conditions persist. There is a significant potential for formation of surface scums in the
days and weeks ahead. Predominantly
southern winds will push algae into northern water of the lake expect scums
along the north shore especially in, Keeler Cove, Point Folly Cove, and the
Litchfield Beach.
The surface water temperatures increased by
about 1oC since last week to reach warmer surface water temperatures
than last year. Surface heating
indicates that the last week was marked by warmer air temperatures with more
sunshine. Lake water is warmer deeper
than last year indicating that stratification is and probably will continue to
be weaker and focused to a narrow band between 5 and 6 meters. Dissolved oxygen loss was similar to last
time.
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| Bantam Lake, CT 2017 Cyanobacteria Cell Count and CT DPH 2017 Recreational Waters Category Guidelines (Green = Safe, Yellow = Caution, Red = Posted Advisory) |
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| Bantam Lake, CT 2017 Secchi Depth |
Selected areas of Bantam Lake will be
chemically treated with Reward (diquat) & Aquathol-K (endothall) herbicides
for control of nuisance aquatic vegetation. Additionally, the lake will be
treated with copper sulfate to manage nuisance blue-green algae. The treatment is scheduled for Monday, July
24th. Use of the lake water within and
for a distance of 500-feet beyond the treatment areas (shown below) will be
restricted for swimming on the day of treatment, livestock watering &
drinking/domestic purposes for 7 days following treatment or until August 1st,
and irrigation for 5-days following treatment or until July 30th.
There are no restrictions on boating or fishing and the CT DEEP & Town boat
ramps will remain open. Prior to
treatment, the lake shoreline will be posted with signs showing the treatment
areas and applicable water use restrictions in accordance with DEEP
requirements. This chemical treatment at Bantam Lake is being performed, pursuant
to a permit from CT DEEP. The chemical
treatment is but one part of a comprehensive watershed assessment and in-lake
management program that is well underway.
The projects organizers and proponents include the Bantam Lake
Protective Association, the Bantam Lake Authority, the Towns of Morris and
Litchfield, and the White Memorial Foundation.
SOLitude Lake Management of Shrewsbury, MA, is the CT licensed company
performing the chemical treatment and is a consultant to the Bantam Lake
Protective Association.
Data is collected and analyzed by Northeast Aquatic Research, who is contracted by Bantam Lake Protective Association.
