Mitigating Harmful Algal Blooms at Lake Hopatcong: Largest Application of Phoslock in Northeast

To prevent harmful algal blooms (HABs) in New Jersey’s largest lake, a clay-based nutrient inactivating technology called Phoslock, is being applied in Lake Hopatcong this week. This is the largest Phoslock treatment to occur in the Northeastern U.S. The Phoslock treatment, which is happening in the southern end of the lake called Landing Channel, is expected to take approximately one week depending on the weather conditions.

Over the course of the 2019 summer season, Lake Hopatcong suffered from large-scale and persistent HABs causing local and county health agencies to close off all beaches and issue advisories over large sections of the lake. These unprecedented conditions had significant negative impacts on the ecological, recreational, and economic resources of the lake and region. In order to combat HABs in this upcoming 2020 summer season, the Lake Hopatcong Commission has partnered with the Lake Hopatcong Foundation, four municipalities (Jefferson, Hopatcong, Mt. Arlington, and Roxbury), two counties (Morris and Sussex), and their environmental consultant, Princeton Hydro, to develop both short- and long-term lake management strategies.

“The negative effects of HABs in our lake last year were numerous, widespread, and in some cases devastating,” recalled Donna Macalle-Holly of Lake Hopatcong Foundation. “It is imperative for every stakeholder to pool our resources to keep it from happening again. Collaboration is the only way to protect public health, as well as the health of New Jersey’s largest lake.”

In an effort to evaluate a variety of innovative in-lake and watershed-based measures to prevent, mitigate, and/or control harmful algal blooms in Lake Hopatcong, the Lake Hopatcong Commission was awarded a $500k grant as part of New Jersey Department of Environmental Protection’s (NJDEP) new $13.5M initiative to reduce and prevent future harmful algal blooms in New Jersey. In addition to the $500k grant, the aforementioned local government and nonprofit stakeholders provided $330k in matching funds to implement and evaluate a variety of ways to address HABs in Lake Hopatcong.

“Our lake community cannot sustain another year like 2019,” said Lake Hopatcong Commission Chairman Ron Smith. “Since the news of our grant award in early March, we have been working with our partners to make sure the projects are implemented in time for the 2020 season.”

This week, the water resource engineering and natural resource management firm, Princeton Hydro—a lake management consultant to Lake Hopatcong for over two decades—is implementing the first and largest innovative measure as part of the NJDEP HABs grant-funded project. This involves treating 50 acres of the southern end of the lake with Phoslock, a clay-based product that inactivates phosphorus in both the water column and the sediments, making this critical nutrient unavailable for algal growth. The Phoslock treatment, which requires proper permitting by NJDEP, is applied as a slurry and will be distributed from a boat. The slurry will temporarily make the water appear turbid, but should disperse approximately two to six hours after each treatment.

“We are expecting the Phoslock treatment to limit the growth of algae and therefore reduce the occurrence of harmful algal blooms in the lake this summer, keeping it open for recreation and business,” said Dr. Fred Lubnow, Director of Aquatic Resources at Princeton Hydro and leading HABs expert. “If this technology is deemed successful and cost-effective in Lake Hopatcong, we could set the precedent for large-scale HABs prevention in other lakes throughout New Jersey, and even across the nation.”

Developed by the Australian national science agency CSIRO, Phoslock is frequently used to strip the water column of dissolved phosphorus, as well as to inactivate phosphorus generated from deep, anoxic sediments. Recently, at a smaller scale, it has been shown to inactivate the mobilization of phosphorus from shallow sediments where there is a mobilization of phosphorus from both chemical and biological processes.

Algae uses phosphate, the biologically available form of phosphorus, as a food source to grow. When there is an excessive amount of phosphorus in a lake, algal growth can be dense and can negatively affect water quality. This excessive plant growth, caused by eutrophication, can both cause a lack of oxygen available, leading to fish kills, as well as produce harmful algal blooms with cyanotoxins, which are harmful to humans and pets.

Photo credit: SePRO Corporation

After Phoslock is applied, it sinks through the water column, binding phosphate as it moves towards the sediment. Once settled at the bottom of the lake, it forms a very thin layer and continues to bind phosphate released from the sediment, thus controlling the release of phosphorus into the lake. One pound of phosphorus has the potential to generate up to 1,100 lbs of wet algae biomass. However, 1.1 tons of Phoslock is capable of removing 24 pounds of phosphorus — that’s over 26,000 lbs of wet algae biomass not growing in the lake for every 1.1 ton of Phoslock applied. In turn, Phoslock’s ability to suspend biologically available phosphorus is therefore a major step towards improving a lake’s water quality.

As part of the NJDEP HABs grant funding, the stakeholder group will be evaluating the relative effectiveness of this treatment strategy. Because of its shallow depth and separation from the main lake, the Landing Channel area was a good candidate for evaluation of this technology. Princeton Hydro will conduct pre- and post-treatment monitoring of the Phoslock treatment area in order to conduct an objective evaluation of the cost effectiveness of the treatment as a means of preventing the development and/or mitigation of HABs. If the study indicates that Phoslock is a cost-effective treatment, the Lake Hopatcong Commission may consider additional trials in other sections of the lake, if funding is available.

To learn more about HABs, check out our recent blog:

Identifying, Understanding and Addressing Harmful Algae Blooms

Washington Post’s Climate Story Features Princeton Hydro

Photo credit: The Washington Post

Did you know that New Jersey is one of the fastest-warming states in the nation? Not only that, did you know the average temperature increase in the state is double the average of the rest of the Lower 48 states?

In a recent article, the Washington Post uncovers quite startling findings from analysis of more than a century of National Oceanic and Atmospheric Administration temperature data across the Lower 48 states and 3,107 counties. The article takes a specific look at the impacts climate change has had on Lake Hopatcong.

Princeton Hydro has been working with Lake Hopatcong for 30+ years, restoring the lake, managing the watershed, reducing pollutant loading, and addressing invasive aquatic plants and nuisance algae bloomsLake Hopatcong has one of the longest, continuous, long-term ecological databases in New Jersey; 30+ years of consistently collected water quality data.

Dr. Fred Lubnow, Director of Aquatic Programs, and Katie Walston, Senior Scientist, are featured in the Washington Post article. Here’s an excerpt:

On a cool but sunny day in May, Fred Lubnow, director of aquatic programs at Princeton Hydro, and Katie Walston, a senior scientist there, pulled up their anchor in Lake Hopatcong to find it covered with aquatic weeds. The culprit? Fertilizer runoff combined with winters too warm to kill them off.

“The plants start growing earlier and linger around longer, as well,” Lubnow said. The thick ice blocked sunlight from nurturing the weeds. But “in some of these shallow areas, as early as February, we’re looking through the ice seeing the plants growing.”

By summer, the weeds become a nuisance, forcing the state government to “harvest” them with large paddles and toss them onto a conveyor belt, then onto barges. Some years, funding has been hard to get, delaying harvesting and angering homeowners.

“If this area is not harvested, you can’t get a boat through it,” Lubnow says. Swimming isn’t possible, either. Fishing becomes difficult.

Get the full Washington Post story here!

If you’d like to read more about climate change, check out our recent blog:

Four Ways Climate Change Can Affect Your Lake

 

 

 

*FREE DOWNLOADS* 2019 NJ Land Rally Presentations

The New Jersey Conservation Foundation held its 23rd Annual NJ Land Conservation Rally, a one-day educational conference focused on “Conservation Innovations in a Changing World.” The day included networking activities, workshops, and a keynote address given by the First Lady of New Jersey Tammy Snyder Murphy.

During the conference, Princeton Hydro, a proud sponsor of the event, lead three workshops on a variety of topics. Below, we provide a synopsis and free download of each presentation:

 

Fundraising & Marketing Strategy:
“Nonprofit Storytelling A-Z: How to Transform Passive Clickers into Action Takers”

Our Communication Strategist, Dana Patterson, along with Lindsay McNamara of the National Audubon Society lead a workshop that taught participants how to use values-driven and science-congruent narratives to reach key stakeholders and supporters in the New Jersey conservation community and beyond. Dana and Lindsay demonstrated how to implement humanistic storytelling strategies and translate technical stats and science findings into interesting, relatable stories that will resonate with and activate valuable target audiences.

Download the full presentation

 

Community Education & Outreach:
“Floating Classroom: Successful Citizen Science on New Jersey’s Largest Lake”

Chris Mikolajczyk, CLM, our Senior Aquatic Scientist, and Donna Macalle-Holly, Grant and Program Director for Lake Hopatcong Foundation, discussed how to start an innovative citizen science project in the community. For the presentation, they showcased a recently launched and highly successful citizen-science initiative: the “Floating Classroom.” Together, the Lake Hopatcong Foundation and Princeton Hydro conceptualized, funded, and launched a custom-built 40-foot education vessel that provides community members and students an interactive, hands-on education experience to explore Lake Hopatcong while learning about freshwater ecology. This initiative has helped to engage the community in stewardship while continuing to closely monitor the lake’s water quality.

Download the full presentation

 

Ecology & Stewardship:
“From Scum to Fish – A Journey Through the Aquatic Food Web and its Management”

Our Director of Aquatic Programs, Dr. Fred Lubnow, and our Senior Aquatic Ecologist, Dr. Jack Szczepanski, lead a workshop on the many facets that make-up a healthy freshwater ecosystem. They explored the various types of life that inhabit the aquatic environment: from algae and cyanobacteria to submerged aquatic vegetation and fish. And, they delved into each one’s place in the food web, how they interact with each other, their effects on the health of the water they live in, and management techniques to tackle water quality issues associated with each.

Download the full presentation

 

The NJ Land Conservation Rally conference also included presentations on topics ranging from environmental advocacy to land acquisition to urban conservation to non-profit organizational management. To view presentation hand-outs and learn more about the conference, go here.

Princeton Hydro is a proud supporter of the New Jersey Conservation Foundation, a private, nonprofit organization that relies on philanthropic support and grants from a variety of public and private organizations and individual donors. Through acquisition and stewardship, they protect strategic lands, promote strong land use policies, and forge partnerships through education and assistance programs. Since 1960, New Jersey Conservation Foundation has protected over 120,000 acres of natural areas and farmland in New Jersey – from the Highlands to the Pine Barrens to the Delaware Bay, from farms to forests to urban and suburban parks. For more information, or to become a member, go here.