1. Lake Water Quality
PLA Meeting
August 17, 2019

2. 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

3. Piseco Lake Physical Data Transparency
Secchi disk measurement
3.5 m or 11.5 feet (range m)
Decreasing trend

4. Piseco Lake Physical Data Temperature
Isothermal
Epilimnion
Hypolimnion
Thermocline

5. Piseco Lake Physical Data Dissolved Oxygen
Adequate at all depths

6. Piseco Lake Physical Data pH
Average 7.0 (range 6.7 – 7.4)
No trends observed
No impact range is

7. 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

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

9. 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

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

11. 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

12. 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

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

14. 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

15. 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

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

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

18. 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

19. Harmful algae Blooms (HABs)
Characteristic green color

20. 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)

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