Last summer, 39 of New Jersey’s lakes were plagued with toxic algae outbreaks, also known as harmful algae blooms or HABs, causing major water quality degradation, beach closures and health advisories. In response, the NJDEP implemented a unified statewide approach to addressing HABs in freshwater recreational waters and sources of drinking water, and protecting the public from risks associated with exposure to cyanobacteria.
Last week, NJDEP announced a new component to its statewide Cyanobacterial HAB Response Strategy: a color-coded health alert index that provides precise recreational use recommendations for impacted waterbodies based on levels of cyanobacteria and/or cyanotoxins present. The index has six tiers – NONE, WATCH, ALERT, ADVISORY, WARNING, and DANGER – each providing recommendations on the specific activities that should or should not be pursued based on water monitoring results.
“Princeton Hydro is proud to be one of the contributing factors in the development of the Updated Guidance for HABs,” said said Dr. Fred Lubnow, Director of Aquatic Resources for Princeton Hydro. “We feel this updated protocol will provide the necessary and objective information for State and local organizations to make informed and rational decisions, based on sound and scientifically-based data, on how to deal with HABs in a recreational setting.“
Princeton Hydro and Clean Water Consulting are the technical advisers for the New Jersey Lake Group, who have met a number of times over the last 8 to 9 months to discuss the State’s guidance on dealing with HABs. In late 2019, on behalf of the New Jersey Lake Group, Princeton Hydro and Clean Water Consulting developed a White Paper providing recommended changes for consideration to NJDEP’s Recreational Response Strategy to HABs.
“I’m proud to say that many of the provided recommendations were integrated into NJDEP’s Updated Guidance for HABs,” explained Dr. Lubnow.
(Suspected or confirmed HAB with potential for allergenic and irritative health effects)
This warning will be posted when HAB cell counts exceed 20,000. In this scenario, public beaches remain open, but the index instructs the public to use caution, provides information on the potential less serious health effects, and allows for more informed decision-making.
(Confirmed HAB that requires greater observation due to increasing potential for toxin production)
This warning indicates a public bathing beach closure only and is posted when a HAB has been confirmed with cell counts between 40,000 and 80,000 and no known toxins above the public threshold. Beaches remain open (dependent upon local health authority) and monitoring for future toxin production should be increased.
(Confirmed HAB with moderate risk of adverse health effects and increased potential for toxins above public health thresholds)
Signs will be posted for this warning level when cell counts exceed 80,000 or when toxin levels exceed 3 micrograms per milliliter of microcystins. Public bathing beaches will be closed, but the waterbody will remain accessible to some “secondary contact” activities, like boating.
WARNING and DANGER
(Confirmed HAB with high risk of adverse health effects due to high toxin levels) and (Confirmed HAB with very high risk of adverse health effects due to high toxin levels)
These tiers are designed to alert the public to the presence of HABs that are producing very high levels of toxins which justify additional caution. In some instances, the entire waterbody may be closed for all public use. New Jersey has experienced approximately 12 “warning level” HAB events over the last 3 years; monitoring has never indicated a “danger level” HAB event.
According to their press release, NJDEP is committed to working with local officials to implement the index and get signage posted at lakes throughout the state as soon as possible.
In order to create the health index, NJDEP scientists carefully reviewed HABs data collected over the last three years by Lake Hopatcong Commission, Lake Hopatcong Foundation, Princeton Hydro, and other sources. The tiered warning system will enable lake communities, residents and visitors to make more individualized decisions about what risks they are willing to take and what activities they feel comfortable engaging in at the various levels of HABs.
In the coming days, the NJDEP’s Harmful Algal Bloom website will be updated to include the new health index and accompanying signage, relevant monitoring data, and other information for each of the impacted bodies of water, as well as an updated HAB Monitoring and Response Strategy. For now, you can read the full press release and additional information here: https://www.nj.gov/dep/newsrel/2020/20_0023.htm.
To learn more about HABs, check out our recent blog: