Large portions of both Lake Seneca and Lake Cayuga are classified by New York State as Class A. As such, the best usages of these waters are as “a source of water supply for drinking, culinary or food processing purposes; primary and secondary contact recreation; and fishing.....
Watershed Management
Seneca Lake is considered a highly-valued water resource due to its designation of a Class AA(TS) drinking water
supply, such that the water can be used as a potable source with limited treatment. The (TS) subdesignation refers
to the lake support of trout spawning. The inclusion of this waterbody on the DEC/DOW Priority Waterbodies
List as a Threatened water is a reflection of the particular resource value reflected in this designation and the need
to provide additional protection, rather than any specifically identified threats.
Seneca Lake is not included on the current (2016) NYS Section 303(d) List of Impaired/TMDL Waters. There
are no impacts/impairments that would justify the listing of this waterbody.
https://www.dec.ny.gov/docs/water_pdf/fl17senecal.pdfend of story