Status of Water Quality of Ballston Lake 1990-2017

By Dave Pierce – Lake Management

• Water clarity varies from day to day as well as year to year. This is due to conditions such as wind speed, water temperature, precipitation, algae activity, and abundance of zebra mussels.
• The yearly average range from 2.5 meters to 1.25 meters. The 2017 average was 2.00 meters.
• Surface phosphorus levels have risen from 20 ug/L in 1990 to 42 ug/L in 2012. In 2017 the phosphorus levels averaged 32 ug/L for the 8 samples submitted to CSLAP.
• pH or acidity of the water ranged from 8.4 in 1990 to 7.7 in 2017. The lake is becoming more acidic. However this 7.7 value has remained constant since 2007.
• The average lake surface water temperature for the 8 samples has slightly warmed from 1990 to 2017 from 69.8 F to 75.2 F. At times the lake water can reach above 80 degrees.
• Algae thrives in Ballston Lake. The water temp, and abundance of phosphorus are ideal for its growth. A bloom of blue green algae happens on warm days, with little wind to mix the water, and it is most dense in areas downwind where the algae congregate especially near the shoreline.
• Zebra mussels do filter the water and take algae out of the water column, However they prefer green algae thus leaving the blue green algae behind.The result is a higher concentration of blue green algae in a bloom. A bloom may happen in the morning and disappear as the day goes on since algae prefer low sunlight.
• Blue green algae can contain toxins. The presence of a bloom does not mean that toxins are present.
• In 2017 Ballston Lake had blue green algae blooms with very low concentrations of toxins. However a bloom may contain toxins so BLIA does sample algae blooms and sends the sample to DEC for testing. Be alert to notices on the web site and on the town website for information when you see a bloom.
• A measure of algae in the lake is chlorophyll A concentration. The lake had the highest values for this from July 15th to August 15th.

In light of the above information every homeowner in the watershed can do their part to reduce the phosphorus that enters the lake. Less phosphorus=less algae= clearer lake.

1. If you need lawn fertilizer use phosphorus free brands. NYS law
2. Pump septic tanks at least every 3 years.
3. Remove leaves and organic debris from the shoreline.
4. Pick up pet wastes and flush it down the toilet.
5. Direct house rain gutters away from asphalt driveways.
6. Do not power wash deck, dock, or boat with phosphorus containing detergents.

Now you can say “I am doing all I can to make Ballston Lake clearer and cleaner?”