The Club received notice on Wednesday, July 13th that a sample taken near the beach on Lake 4 (Beach 5) yielded a cyanobacteria cell count of more than 20,000 cells per milliliter (cells/mL), which is the “Watch” level established by the New Jersey Department of Environmental Protection (NJDEP). While this level of cyanobacteria (blue-green algae) has the potential to produce the cyanotoxin microcystin, there was no microcystin present in the sample.
The WATCH NOTICE recommended by the NJDEP has been posted at the beach. Under a Watch notice, recreational activities may continue with caution including swimming, fishing, and boating. DO NOT DRINK THE WATER OR EAT FISH FROM THE LAKE.
Following is a summary of common questions and answers about harmful algae blooms.
Q: What causes “bad” lake conditions such as algae and green water?
A: The leading causes are excess nutrients in the water, higher than normal temperatures and bright sunny days. Excess nutrients occur naturally and because of human activity. For example, rainwater runoff washes organic compounds and minerals into the lakes and streams from the surrounding lands. But this same runoff also carries with it your grass clippings, lawn and garden fertilizers, detergents, and seepage from poorly operating septic systems. When excess nutrients combine with warm sunny weather algae blooms often occur.
Q: Will Beach 5 need to be closed and if so, when will it reopen?
A: It is not necessary to close the beach under “Watch” level conditions. The beach will need to be closed if cyanobacteria cell counts exceed 80,000 cells/mL, which is the NJDEP’s “Advisory” level. Boating and fishing may continue under Advisory conditions, but not swimming. We will continue to monitor the situation. If it becomes necessary to close Beach 5, it will be reopened only after 2 successive samples indicate that the cell counts are below the Advisory level and no cyanotoxins are detected.
Q: Should I be concerned about all the algae I see in/on the lakes? Is it all harmful?
A: No. In fact, most algae are harmless and amount to nothing more than an unsightly and sometime smelly nuisance. However, cyanobacteria, also known as blue-green algae, are naturally present in lakes and streams and can form both toxic (harmful) and non-toxic blooms. Cyanobacteria are responsible for the majority of freshwater HAB occurrences. Microscopic and chemical analysis are required to positively confirm the existence of a HAB.
Q: What is the Club doing to treat and control algae and the health of our lakes?
A: First, there is no foolproof method to prevent HABs short of sterilizing the entire lake with chlorine or similar compounds, effectively killing all aquatic life, and turning it into a swimming pool. The Club employs two well-qualified firms; Princeton Hydro, which performs inspections, water quality monitoring and analysis, and Solitude Lake Management, which also performs inspections and is responsible for application of appropriate chemical and organic compounds for lake treatment when needed. From Spring to Fall, both Princeton Hydro and Solitude visit each lake two or more times each month to inspect and sample the waters, provide narrative reports, and update lab test results
The information above should answer the most common questions and concerns regarding the health and overall condition of our lakes and our lake management efforts. If you would like more information on HABs, please visit the NJDEP website at https://www.nj.gov/dep/hab/.
