Lake Water Quality PLA Meeting August 17, 2019

Piseco lake Environment Characteristics Lake Area: 1,066 ha (2,634 acres or 10.2 m²) Max Depth: 38 m (125 feet) Shoreline: 25 km (15.5 miles) Water Retention Time: 1.5 years Watershed Area: 14,490 ha (56 m²) Forested Area (%) 83 Surface Water Area (%) 11 Wetland Area (%) 5 Developed Area (%) 1

Piseco Lake Physical Data Transparency Secchi disk measurement 3.5 m or 11.5 feet (range 2.5-4.3 m) Decreasing trend

Piseco Lake Physical Data Temperature Isothermal Epilimnion Hypolimnion Thermocline

Piseco Lake Physical Data Dissolved Oxygen Adequate at all depths

Piseco Lake Physical Data pH Average 7.0 (range 6.7 – 7.4) No trends observed No impact range is 6.5 - 7.5

Physical measurements Milligrams per Liter (mg/L) 1 inch in 16 miles 1 second in 11.5 days 1 minute in 2 years Micrograms per Liter (µg/L) 1 second in 32 year One sheet in a roll of toilet paper stretching from NYC to London

Piseco Lake Chemical Data Alkalinity (Calcium carbonate) Average 7 mg/L (5 – 8 mg/L) Moderate acid neutralizing ability Increasing trend

Piseco Lake Chemical Data Phosphorous Average 6.7 µg/L (4.9 – 10 µg/L) Low productivity lakes < 10 µg/L High productivity lakes >20 µg/L Decreasing trend

Piseco Lake Chemical Data Nitrates Average 8 µg/L (BD – 30 µg/L) Decreasing trend

Piseco Lake Chemical Data Chlorophyll a Average 4.1 µg/L (0.9 – 7.5 µg/L) Low algae production <2 µg/L High algae production >8 µg/L No trends observed

Piseco Lake Chemical Data Calcium Average 2.4 mg/L (2.0 – 2.8 mg/L) Increasing trend Zebra muscles require 12 – 20 mg/L

Piseco Lake Chemical Data Aluminum Average 27 µg/L (BD – 47 µg/L) No trends observed

Piseco Lake Chemical Data Chloride Average 5.6 mg/L (5 – 8 mg/L) Oxbow 20.3 mg/L Spy 15.2 mg/L No trends observed High road salt influence > 20 mg/L NH exposure value of 230 mg/L over 4 days may cause harm to aquatic organisms

Piseco Lake Chemical Data Specific Conductivity (2009 – 2018) Piseco average 33 – 41 µS/cm Eat shore near NYDOT salt storage: 356 – 493 µS/cm Undeveloped lakes range from 10 – 20 µS/cm Road salt presence directly related to conductivity values

Trophic State Eutrophic Excess nutrients Elevated biological activity Depressed transparency Anoxic bottom water

Trophic State Oligotrophic Deep lakes Low nutrients Low biological productivity High transparency Adequate oxygen at bottom

Trophic State Mesotrophic Intermediate between oligotrophic and eutrophic Chlorophyll-a concentration between 2.1 and 8.0 µg/L Just over 70 % of the 100+ Adirondack Lakes samples by AWI were mesotrophic

Harmful algae Blooms (HABs) Characteristic green color

HABs Blue-green algae (cyanobacteria) Contain cytotoxins Confirmed HABs have Chlorophyll-a levels >25 µg/L Lakes with zebra muscles and quagga mussels Low N:P ratio (Piseco ration 1.1)

HABs NYSDEC has a web site with daily updates of affected lakes