Summary of the 2014 DEC CSLAP Report:
Since 1990 BLIA members have been taking water samples of the lake and sending them to NYDEC for evaluation. In addition, this year water samples were sent to NYS College of Environmental Science for algae determination. This is a report of the status of Ballston Lake as stated in the 2014 DEC report and an evaluation of the long term trends. The biggest problem for Ballston Lake is the increasing Total Phosphorous levels in the lake. Prior to 2000 this value remained around 20-22 ppB. Since 2000 it has risen to 42 ppB.
DEC states that the cause of this increase is:
- Poorly functioning or failing septic systems
- Erosion of the shoreline.
- Increased stormwater run off due to urbanization in the watershed.
- Inability of the lake ecosystem to use or dilute all the phosphorous entering the surface water from the bottom of
the lake. As a result of the increasing phosphorous concentrations Ballston Lake experiences periods of increased
algae production that is driven by high water temperature. When algae increases chlorophyll increases and clarity
The following trophic measurements that CSLAP tracks are variable during a summer but the long term trend since
1990 is relatively unchanged:
- Ammonia level
- Total nitrogen
- Water clarity
- Aquatic plant coverage.
In addition to the CSLAP water quality sampling, BLIA has also sampled the lake for fecal coliform and total coliform bacteria. These bacteria enter the lake from problematic septic systems in the watershed and from animal droppings that wash into the lake.
During the summer 8 water samples were taken and analyzed by Darrin Lab at Lake George. The average for total coliform was 54 colonies/100 ml and fecal coliform 13 colonies/100 ml. These values are relatively low compared to the standards for contact recreation of 2400 colonies for total coliform and 200 colonies for fecal coliform. However the fecal coliform level of 13 colonies is above the standard for drinking water.
The final issue with Ballston Lake is that the pH has decreased from 8.3 to 7.5 since 1990. This means the lake is more acidic than it was in 1990. This present level of 7.5 has been maintained since 2000. DEC states that Ballston Lake is stressed for contact recreation and threatened for drinking water. Care must be taken when using the lake. Drinking water should be purified to remove bacteria, sediment, and algae. Intake pipes should be at least 10 feet deep and not more than 30 feet deep. Recreation use of the lake is OK. I would recommend rinsing with fresh water after swimming to remove algae and debris from your skin.