Highland Lakes

Country Club and Community Association

About Algae Blooms, Cyanobacteria, and News Reports of Closures at Lake Hopatcong and Greenwood Lake

Publiished July 2019
Many Highland Lakes Country Club and Community Association (the “Club”) members know of the recent closures of both Lake Hopatcong and Greenwood Lake. These closures in lakes owned and managed by the State of New Jersey have been due to Harmful Algal Blooms (HABs). What follows is a brief discussion of this phenomena and the Club’s continuing efforts to manage its lakes.

Algae occurs naturally in all fresh and marine water environments. According to the New Jersey Department of Environmental Protection’s (NJDEP) HAB webpage (https://www.state.nj.us/dep/hab/):

“A bloom is a rapid increase or accumulation in the population of algae and algae-like bacteria in a waterbody. These “blooms” often result in a thick coating or mat on the surface of the water, which can also result in lowering the dissolved oxygen in the water column.  In turn, low dissolved oxygen can be detrimental to aquatic organisms, particularly fish. Certain environmental conditions, such as sunlight, high nutrient concentrations, warm temperatures and calm water can favor the development of a bloom.

A harmful algal bloom (HAB) is an algal bloom that can be dangerous to people, animals or the ecology. Some, but not all, HABs produce chemicals that can be toxic to humans and animals if ingested, inhaled, or if contacted by skin or mucous membranes. These toxins can also accumulate in fish and shellfish which can cause illness when either are consumed. Cyanobacteria, also known as blue-green algae, are responsible for the majority of freshwater HAB occurrences. These are called CyanoHABs. Cyanobacteria are naturally present in lakes and streams and, can form both toxic (harmful) and non-toxic blooms. The toxic blooms can cause health effects when people and animals come in contact with them.

However, not all algal blooms are harmful. Some are merely called “nuisance blooms” because they result in discolored water and/or offensive odors. While they are not dangerous, they can result in people choosing not to swim or recreate in water that is experiencing the bloom.”

The Club takes multiple measures in an effort to prevent such beach and lake closures from happening in our community. A brief description of these measures is as follows:

  • Our water and wetland resources consultant, Princeton Hydro, conducts our water quality monitoring program under the direction of a Certified Lake Manager. This program brings its staff to our lakes from early May through late September. During the warmer months of June, July and August, Princeton Hydro staff are on our lakes twice a month. During this monitoring program they collect the physical, chemical and biological data that allows us to predict water quality as best we can, including algal blooms. More specifically, Princeton Hydro collects samples of algae during each visit, as well as conducts testing for the aforementioned toxins at a swim beach on each of our five (5) Lakes. Princeton Hydro then sends us a service report after each visit, as well as authors a comprehensive annual report, with future recommendations included, in the fall.
  • Princeton Hydro has also assisted over the years to help find ways to reduce runoff and non-point source from our community. Several projects have been investigated recently to assist in reducing runoff, and the nutrients associated with it, from entering our lakes. Additionally, Princeton Hydro monitored field conditions several years back during the Tennessee Gas pipeline construction to ensure soil migration from the pipeline construction project did not damage our lakes.
  • Additionally, the Club’s lake treatment contractor, Solitude Lake Management (Solitude), also conducts an independent water monitoring program aimed specifically at the careful control and natural balance of both aquatic plants and algae. Solitude’s personnel are at Highland Lakes two-three times a month during the warmer months of the summer season collecting algae samples and performing an inventory of submerged vegetation. Solitude’s algae samples are used in an effort to predict a bloom before it occurs so that a plan of action can be formulated and instituted prior to bloom conditions. Treatments with algaecides (usually copper sulfate) are authorized when it is determined that a bloom is likely. Throughout the warmer months, the Club, Princeton Hydro and Solitude confer on a regular basis with regards to the water quality of our lakes, and specifically the algal concentrations. Solitude submits a service report after each visit.

The Club tests its beaches (as required under NJ Department of Health (NJDOH) regulations) and adjoining streams from before Memorial Day through Labor Day. Under NJDOH regulations beach closures must take place when two consecutive tests for E. coli result in measurements greater than 320. Beaches may close for other factors including the accumulation of droppings from geese or a significant algae presence. It must be noted that there has been no instance of a whole lake closure in Highland Lakes due to an algae bloom. At Lake Hopatcong and Greenwood Lake, the beaches were closed not by NJDEP but by the local health authorities based upon guidance from NJDEP.

According to the Director of the lab performing the weekly tests of the Club’s beaches, there does not exist any objective cyanobacteria advisory thresholds based on cell counts, and there are no certified laboratory methods to analyze water samples for the various toxins potentially generated by cyanobacteria. The Director stated that while New Jersey’s guidance level is 20,000 cyanobacteria cells per milliliter in another state the guidance level is 100,000. Operators of recreational bathing areas like the Club rely upon NJDEP and guidance from the local health authority in determining whether to close or not.

Monitoring algae blooms which may be potentially harmful, first undertaken by NJDEP in 2014, is a developing science with no clear understanding of when an advisory should be issued or a closure ordered. NJDEP currently offers guidance while it continues to analyze samples from approximately 40 of New Jersey’s 400 lakes yearly to develop a more precise understanding of potential algae blooms which may be harmful. What is learned from this sampling may lead to firm guidance and established laboratory methods, and potentially the addition of specific testing for cyanobacteria at bathing beaches. This additional testing is anticipated to be exceptionally expensive depending upon its frequency.

While there are no fool-proof methods to prevent HABs, Highland Lakes and its consultants are proactive in predicting and reacting to these potential situations. As always, the office of the General Manager is open for your questions and concerns regarding the overall water quality of the lakes of our community. The Club’s Ecology Committee welcomes all members to its meetings on the third Thursday of each month. Thank you.

Jack McLaughlin                        Christopher L. Mikolajczyk, CLM
General Manager                      Senior Aquatic Project Manager
Highland Lakes                          Princeton Hydro, LLC


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