Dredging Children’s Pond to Restore Water Quality in Strawbridge Lake

Sedimentation in Children’s Pond, which is located in Strawbridge Lake park, was negatively impacting the water quality Strawbridge Lake. In order to restore the pond and reduce impacts to Strawbridge Lake, the Moorestown Township Council awarded contracts to Princeton Hydro for the dredging and cleanup of the Children's Pond.

Strawbridge Lake is located in Moorestown Township in Burlington County, New Jersey with portions of the watershed also extending into Mount Laurel and Evesham Townships. This 33-acre, tri-basin lake is a result of the impoundment of the confluence of Hooten Creek and the North Branch of the Pennsauken Creek that dates back to the 1920s.

Image by NJ.govThe lake receives surface runoff through Hooten Creek to the Upper and Middle Basins and the Lower Basin receives runoff from the headwaters of the North Branch of Pennsauken Creek. The lake then discharges back into another section of the North Branch Pennsauken Creek, which then flows into the Delaware River.

The watershed area that drains into the Strawbridge Lake is made up of an intricate mix of land uses: agriculture, new and mature residential subdivisions, office parks, major highways, retail stores, and large industrial complexes. The lake and the park area that surrounds it are heavily used for a variety of recreational activities.

Children’s Pond, which is located in Strawbridge Lake Park, is a popular fishing spot in the community. The pond initially functions as a wetland and drains from the northern portion of the watershed. Sedimentation—the naturally occurring process of the deposition and accumulation of both organic and inorganic matter in the bottom and/or banks of waterbodies—had significantly reduced the mean pond depth, thereby reducing the pond’s aesthetic appeal, impairing the fishery, contributing to eutrophication, and impacting the water quality of Strawbridge Lake. Sedimentation can also lead to contamination that poses a threat to aquatic plant and wildlife.

The dredging of Children’s Pond was identified by Princeton Hydro’s Lake and Watershed Management Plan and presented to the Moorestown Township Council’s environmental committee as one of a number of immediate actions needed in order to restore the pond, preserve the health of the watershed, and reduce impacts to Strawbridge Lake. Dredging, often used as an efficient solution for sediment removal, can expeditiously restore the waterway to its original depth and condition while also removing dead vegetation, pollutants, excess nutrients, and trash that may have accumulated.

Moorestown Township Council awarded contracts to Princeton Hydro for the dredging and cleanup of the Children’s Pond, which was an important part of the previously mentioned Watershed Management Plan for Strawbridge Lake.

Before the dredging could begin, a variety of surveys, field investigations, and data collection activities took place at the project site. A bathymetric survey is a critical component of any dredging project because it measures the depth of a waterbody, as well as maps the underwater features of a waterbody.

Due to the small area and shallow depths of Children’s Pond, the survey was conducted using a calibrated sounding rod and a Trimble GPS unit. The calibrated sounding rod was lowered into the water until it reached the top of the accumulated sediment. The location of the sample point and the water depth was then recorded with the GPS unit. Next, the pole was pushed down into the sediment until the point of refusal, and the bottom of sediment elevation was also recorded with the GPS unit. Data was collected from shoreline to shoreline at 25-foot transect intervals.

The data collected via the bathymetric survey, as well as the site survey, field investigations, and soil analysis, was used to shape the project’s engineering design and construction plans.

Before the dredging commenced, Princeton Hydro conducted a bathymetric survey to understand the depth and underwater features of a water body.

With the data collection process complete, Princeton Hydro was able to finalize the engineering plans and obtain all necessary permits for the project. Once the project commenced, Princeton Hydro oversaw the construction process and documented the project’s progress through Daily Field Reports (DFRs).

DFRs act as a living record of the project and provide the project’s key stakeholders with full details of the team’s daily performance and productivity, including arrival and departure times, the weather and temperature, equipment utilized on-site that day, a description of the work completed, and photographs of the work in progress.

This photo from the DFR on March 2, 2020 documents the beginning of excavation work in Children’s Pond:

This photo from the DFR on April 16, 2020 shows grading being completed on the west side of Children’s Pond: 

This photo from the DFR on April 20, 2020 documents the continuation (and near completion) of the excavation and grading work:

Princeton Hydro provides construction oversight services to private, public, and nonprofit clients for a variety of ecosystem restoration, water resource, and geotechnical projects across the Northeast. For more information, go here. And, to get an inside look at all that construction oversight entails, check out our blog:

A Day in the Life of a Construction Oversight Engineer

WATCH: NYSFOLA Hosts Free Lake Management Webinar Series

The New York State Federation of Lake Associations (NYSFOLA), in collaboration with Syracuse University Environmental Finance Center, hosted a four-part, educational webinar series on a variety of topics related to lake management. The goal of the webinar series was to bring together people involved with New York’s lake associations, as well as local government leaders to discuss management tips, understand more about their lakes and watersheds, and explore strategies around improving and protecting New York lakes.

The series concluded on July 23, 2020 with a webinar lead by Chris L. Mikolajczyk, CLM, Senior Project Manager, Aquatics of Princeton Hydro, and Jim Cunningham, NYSFOLA Board Member and the Town of Nelson, NY Supervisor.

In the webinar, titled, “Working with Local Government to Improve Lakes and Communities,” Chris presents a unique initiative lead by the Borough of Ringwood, which became the first municipality in the state of New Jersey to take a regional approach to private lake management through a public-private partnership (PPP) with four lake associations.

Chris provides an overview of The Borough of Ringwood, home to several public and private lakes, which took an active role in the management of its natural resources within multiple watersheds. He explains how the project came together and illustrates why a comprehensive, integrated approach to watershed and lake management is an incredibly important strategy to improve water quality for millions of people and reduce potential future incidents of aquatic invasive species and harmful algal blooms.

During Jim’s portion of the presentation, he discusses the role of local government in lake management and provides examples from projects and initiatives in Madison County, New York. To watch the recording of this webinar, click here.

The webinar series also included presentations about choosing the right liability insurance for a nonprofit organization; turning resource management-related conflicts into opportunities; and understanding lake science and water quality management. To access all of the webinars in the series, go here.

The New York State Federation of Lake Associations, Inc. was founded in 1983 by a coalition of lake associations concerned about water quality, invasive species, and other issues facing New York’s lakes. Today, more than 200 lake associations across the state are members of the only statewide voice for lakes and lake associations. NYSFOLA also has corporate members and individual members who support our efforts.

Princeton Hydro is the industry leader in lake restoration and watershed management. We have conducted diagnostic studies and have developed management and restoration plans for over 300 lakes and watersheds throughout the country. This has included work for public and private recreational lakes, major water supply reservoirs, and watershed management initiatives conducted as part of USEPA and/or state-funded programs. For more information about our lake management services, click here.

Client Spotlight: Lake Hopatcong Foundation

This month we are launching the first blog in our Client Spotlight Blog Series! Each spotlight will feature one of our important client relationships in order to give you an inside look at our collaboration. We pride ourselves on forming strong ties with organizations that share our values of creating a better future for people and our planet. So we are excited to be able to share snippets of the incredible teamwork we’ve been able to accomplish over the years!

At Princeton Hydro, we value our client relationships, as the collaborative work we are able to complete with organizations like the Lake Hopatcong Foundation (LHF) reaches exponentially further than anything we could complete alone. One of the reasons our organizations have such strong symmetry is that our values align and complement each other.

As their mission states,”Lake Hopatcong Foundation dedicates itself to protecting the lake environment and enhancing the lake experience, bringing together public and private resources to encourage a culture of sustainability and stewardship on and around New Jersey’s largest lake, for this and future generations.” We are so proud to help protect New Jersey’s largest lake with LHF.

We have been working with LHF since its inception in 2012, which is why we are excited to feature them in our first client spotlight blog. We spoke with Jessica Murphy, President/Executive Director of the Foundation, and Donna Macalle-Holly, Grants and Program Director, to give you an insider look at the organization:

Q: What makes the Lake Hopatcong Foundation unique?

A: The Lake Hopatcong Foundation is unique in that our mission spans a wide spectrum of activities. In addition to projects that focus on the lake environment, we also take on initiatives that support education, safety, community-building, recreation, and even arts and culture. The lake is split between two counties and four towns, so bringing the community together for all these things is very important to us, in addition to making sure the lake itself is healthy.

Q: What does the Lake Hopatcong Foundation value?

A: During our strategic planning process, the board and staff developed a list of values that we go back to when operating and making decisions. They are:

  • Collaboration – We operate in a way that brings people together throughout the community.
  • Action – We are committed to our mission, moving quickly to take on projects that have an impact on and around the lake.
  • Sustainability – We are forward-thinking when making decisions, taking future generations into account when considering projects and initiatives.
  • Warmth – We are a friendly face to the community, showing the best of ourselves and bringing out the best in the people of Lake Hopatcong.

Q: How long have you been working with Princeton Hydro?

The Lake Hopatcong Floating Classroom ready for take off!

When we first started the Lake Hopatcong Foundation in 2012, Dr. Fred Lubnow was kind enough to do a water quality presentation as one of our very first events as an organization! In the years since, we’ve worked closely with Princeton Hydro, particularly in a support role as they conduct business with the Lake Hopatcong Commission. The Lake Hopatcong Commission is a state entity created in 2001 through the Lake Hopatcong Protection Act dedicated to protecting the water quality of Lake Hopatcong and to preserve the natural, scenic, historical and recreational resources of the lake. LHF funded Princeton Hydro’s water quality monitoring during the years that the Commission ran out of money

Q: What types of services has Princeton Hydro provided to your organization?

A: In addition to water quality monitoring on the lake, Princeton Hydro has led volunteer training for us in our efforts to prevent the spread of invasive species and to teach local students in our spring field trip program. Dr. Lubnow has also worked alongside us in applying for grants and in providing insight and expertise for other environmental projects at the lake, including helping guide the installation of floating wetland islands, and helping our NJ Lakes Group to work with NJDEP on Harmful Algal Bloom (HAB) policies. He even did a quick fact check on our children’s book, Lake Hopatcong Speaks Out, before we published it!

Q: Do you have a favorite or most memorable project we’ve worked on together?

Princeton Hydro’s Senior Project Manager, Christopher Mikolajczyk, CLM, presenting during a Water Scout training held by the Lake Hopatcong Foundation.

A: The days that Chris Mikolajczyk spent teaching our volunteers about how to find and remove water chestnuts from the lake were a lot of fun, particularly because we were kayaking on the lake for it! And, also because the kayak we provided Chris was too small for him, and he had to scrunch in to fit, but he was a trouper and paddled on.

Q: What are some exciting things your organization is working on right now?

A: We are working closely with Princeton Hydro and LHC on a series of projects, funded through NJDEP grants, LHC, LHF, and local governments, that we hope will prevent and mitigate HABs on the lake. Those projects include aeration systems, phosphorus-locking technologies, and stormwater infrastructure upgrades. We’re excited to see how effective each can be. Also, on August 7 at 12:30, Dr. Lubnow will be presenting the Lake Hopatcong water quality monitoring project results at LHF’s “Thirst for Knowledge” lunch-and-learn webinar series, which was created to share information and discuss topics of interest to our lake community. To register for the free webinar, visit lakehopatcongfoundation.org.

Photo by: Colleen Lyons of the Lake Hopatcong Commission

Photo by: Colleen Lyons of the Lake Hopatcong Commission

Q: What drives you to want to go to work every day?

A: All of us at Lake Hopatcong Foundation have a passion for this lake and want to see it protected; we have a love for the community that surrounds it, too. Jessica Murphy grew up on the lake, met her husband here, and now is raising her four children to love the lake, too. Donna Macalle-Holly also met her husband on Lake Hopatcong, lives on the lake, and has worked professionally to take care of it for nearly two decades. Everyone in our office has made memories on Lake Hopatcong and developed friendships with those who live and work here. Those personal connections fuel our passion for what we do.

Q: How can Princeton Hydro support you/your organization in the future?

A: Continue to be the incredible resource you are! We are so fortunate to have the deep knowledge and expertise that Fred and your entire team provide, and we look forward to continuing to work together in the years ahead.

Water Scouts paddling on Lake Hopatcong.


Some recent projects we are/have been working on with LHF include installing biochar bags to help control phosphorus levels and applying Phoslock to help mitigate harmful algal blooms! Because of our history working on Lake Hopatcong, we too have gained a passion for protecting and maintaining this lake. This incredibly important work could not be done without the genuine devotion and dedication from the Lake Hopatcong Foundation. We look forward to continuing great work with this incredible group!

Princeton Hydro’s Chris Mikolajczyk Featured in LakeLine Magazine

The latest issue of LakeLine Magazine, a quarterly e-magazine published by the North American Lake Management Society (NALMS), features an article written by Chris L. Mikolajczyk, CLM, Senior Project Manager and Senior Aquatic Ecologist with Princeton Hydro. Chris also contributed the beautiful photo that appears on the magazine’s cover.

In his article, titled, “A Regional Approach to Land Use Planning,” Chris discusses a unique project in Ringwood, New Jersey. The Borough of Ringwood is home to several public and private lakes. In order to take an active role in the management of these natural resources within multiple watersheds, the Borough of Ringwood was the first municipality in the state of New Jersey to take a regional approach to private lake management through a public-private partnership (PPP) with four lake associations.

Chris’ article provides an in-depth look at how the project came together; details the ongoing assessment and planning activities taking place; and displays why a comprehensive, integrated approach to watershed and lake management is an incredibly important strategy to improve water quality for millions of people and reduce potential future incidents of aquatic invasive species and harmful algal blooms.

“A regional approach to lake and watershed management is a normal approach from a scientific, technical, and community point of view,” writes Chris. “However, historically, state and municipal governments and private lake associations have rarely partnered to take such an approach in New Jersey.”

As the article states, funding for the Watershed-based Assessment for the Lakes of the Borough of Ringwood is being provided by the New Jersey Highlands Council through a grant reimbursement to the Borough of Ringwood. The Borough of Ringwood will review and, where feasible, implement any suggested actions surrounding the lakes, while the lake communities themselves will be responsible for any recommended in-lake actions, such as aeration, mixing, nutrient inactivation, etc., should they choose to implement them.

At the conclusion of the study, the final report provided to the Borough will identify and prioritize watershed management techniques and measures that are best suited for immediate and long-term implementation, as well as provide cost projections for implementation and maintenance in both the short-term and long-term.

To learn more, click here for the complete article and check out our recent blog:

BOROUGH OF RINGWOOD INITIATES FIRST-IN-STATE REGIONAL APPROACH TO LAKE MANAGEMENT THROUGH PUBLIC-PRIVATE PARTNERSHIP

The Summer 2020 issue of LakeLine, which was published as “open source” and is available as a free download on the NALMS website, is intended to serve as a general primer on lakes and empower environmental stewards in their efforts to safeguard the integrity of our surface waters.

NALMS was founded in 1980 as an organization with membership open to both professionals and citizens interested in applied lake management, while other organizations focused on either one or the other. From the beginning, NALMS has published LakeLine.

Princeton Hydro is the industry leader in lake restoration and watershed management. We have conducted diagnostic studies and have developed management and restoration plans for over 300 lakes and watersheds throughout the country. This has included work for public and private recreational lakes, major water supply reservoirs, and watershed management initiatives conducted as part of USEPA and/or state funded programs. For more information about our lake management services, click here.

Using Triploid Grass Carp to Control Aquatic Vegetation

Invasive aquatic weeds can create major impacts on freshwater ecosystems. One of the primary reasons invasives are able to thrive, spread rapidly, and outcompete native species is that the environmental checks and predators that control these species in their natural settings are lacking in the ecosystems and habitat in which they become introduced.

The subsequent damages they cause occur on many ecological levels including competition for food or habitat (feeding, refuge, and/or spawning), direct predation and consumption of native species, introduction of disease or parasites, and other forms of disruption that lead to the replacement of the native species with the invasive species. As a result, invasives often cause serious harm to the environment, the economy, and even human health.

Some of the more commonly occurring non-native aquatic plant species that impact East Coast lakes, ponds, and reservoirs include curly-leaf pondweed, eurasian watermilfoil, hydrilla, and water chestnut.

The introduction of triploid grass carp to freshwater lakes and ponds can be an effective solution and natural alternative to managing and mitigating aquatic weed growth. When stocked at a proper rate, at correct sizes, targeting proper plant species, and the right time, triploid grass carp can reduce or eliminate the need for chemical treatment of the water to control aquatic vegetation.

Originally from Asia, grass carp have been imported to the United States since the 1960s to intentionally release into controlled freshwater environments for aquatic plant control. Grass carp, which rely almost entirely on aquatic plants for their diet, prefer to eat many of the non-native aquatic plant species that negatively impact freshwater environments, including the aforementioned pondweed species and watermilfoil.

Triploid Grass Carp in Woodridge Lake

Woodridge Lake is a beautiful 385-acre freshwater lake tucked away in the hills of Litchfield County, Connecticut. The lake, which is fed by the Marshepaug River, is a man-made resource, with a dam at one end that allows the level of the lake to be controlled.

Woodridge Lake Property Owners’ Association (WLPOA) closely monitors the lake, conducting water sample testing on a weekly basis. As with all waterbodies, the lake experiences aquatic weed growth, some years worse than others due to a variety of factors including climate change.

As a method to naturally mitigate aquatic weed growth, WLPOA plans to introduce triploid grass carp to the waterbody. A study by the Connecticut Agricultural Experiment Station states that grass carp is “the only biological control used successfully in Connecticut.”

Since the grass carp are an introduced species, only triploid grass carp, which are sterile, can be used. This eliminates the possibility that the stocked fish can reproduce and overpopulate the lake, or if any were to escape the lake they could not affect other waterbodies. As an additional measure of protection, to ensure that the carp remain in the lake, a screen, or emigration control device, is required. Princeton Hydro, in partnership with WLPOA, Rowledge Pond Aquaculture, and CTDEEP recently completed the installation of a carp screen.

The screen, which was custom designed by Princeton Hydro, is located in the outlet structure of the Woodridge Lake Dam, downstream of the spillway crest and within the concrete stilling basin of the spillway structure. Subsequently, the installation and operation of the carp screen will have no impact on spillway capacity or water surface elevations at the spillway crest. In addition, there will be no impact on the flow capacity or the water surface elevations of the Marshepuag River downstream of the dam outlet structure.

The emigration control device is a modular, vertical-bar screen composed of eight sections. A modular screen design was chosen to facilitate off-site fabrication and easier installation, as well as repair of an individual section, if necessary. Installed, all eight sections transect the entire 40-foot width of the spillway structure.

WOODRIDGE LAKE CARP EXCLUSION DEVICE DESIGN by Princeton Hydro

The carp screen was specifically designed to be easy to operate and maintain, minimizing clogging and facilitating easy cleaning from the downstream side of the screen during a range of flows. The operation and maintenance plan also consists of inspections every three months and precipitation-based inspections conducted by the WLPOA staff.

Overall, the use of grass carp will help Woodridge Lake manage aquatic weed growth in a natural way and maintain a healthy and vibrant lake environment for years to come.

To learn more about Rowledge Pond Aquaculture, the oldest private fish hatchery in Connecticut, go here: rowledgepond.com. For more information about Princeton Hydro’s lake management services, go here: bit.ly/pondlake.

Using an Ancient Technology in a New Way: Preventing Algal Growth with Biochar

Photo by: Colleen Lyons of the Lake Hopatcong Commission

Photo by: Colleen Lyons of the Lake Hopatcong Commission

The use of biochar, a pure carbon, charcoal-like substance made from organic material, to enhance soil fertility is thought to have originated over 2,000 years ago in the Brazilian Amazon. Archeological studies indicate populations of native Amazonians used biochar to amend nutrient-poor soils to increase agricultural productivity.

Biochar is generally produced through a process called pyrolysis. Pyrolysis is the decomposition of organic matter brought about by high temperatures (typically 800°F) in an environment with limited oxygen. The word pyrolysis is coined from the Greek-derived elements pyro “fire” and lysis “separating.”

Recently, biochar has received tremendous attention and its usage has moved beyond traditional agricultural and landscaping soil amendment applications. It is being championed as a useful technique for soil restoration, carbon sequestration, and – the one we’re most excited about – water quality management.

Photo by: Colleen Lyons of the Lake Hopatcong Commission

Photo by: Colleen Lyons of the Lake Hopatcong Commission

That’s right! Biochar has been shown to improve water quality by removing dissolved phosphorus from fresh waterbodies limiting algal growth and reducing the likelihood of harmful algae blooms (HABs).

Biochar can be placed in floatation balls, cages, or sacks, which are then tethered along the shoreline and in critical locations throughout the waterbody, like where an inlet enters a lake.

The benefits of biochar far outweigh the relatively low-cost investment. In addition to phosphorus removal and algal growth prevention, once the biochar’s capacity to absorb phosphorus has been exhausted, it can be re-purposed as compost for soil enrichment.

Photo by: Colleen Lyons of the Lake Hopatcong Commission

Photo by: Colleen Lyons of the Lake Hopatcong Commission

Princeton Hydro recently installed biochar flotation bags in various locations throughout Lake Hopatcong, including the Lake Winona outlet, the Lake Forest Yacht Club inlet, Lakeside Avenue and Holiday Avenue inlet in Hopatcong, and the Edith Decker School outlet in Mount Arlington.

The biochar bag installation, which was funded by the NJDEP Freshwater HABs Prevention & Management Grant provided to the Lake Hopatcong Commission (LHC) and its project partner the Lake Hopatcong Foundation (LHF), is one part of a multi-pronged lake management plan that aims to prevent the development of HABs and protect the overall water quality of Lake Hopatcong. Last summer, Lake Hopatcong – along with freshwater lakes throughout the country – was hit hard by a HAB outbreak that caused beach closures, health advisories, and water quality degradation.

Princeton Hyrdo has been working with the LHC, LHF, Morris & Sussex Countys, and local municipalities to implement a number of lake management strategies, including the recent dispersal of Phoslock, a different type of HAB-battling material, in Landing Cove, which was the largest application of Phoslock ever completed in the Northeast. Read more about it in our recent blog:

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

The team also installed Floating Wetland Islands, which use a mix of microbes and native plants to remove excess algae-causing nutrients from the water, in different areas of Lake Hopatcong.

Over the coming weeks, our team is installing more biochar bags in Roxbury, NJ at Duck Pond and in Mount Arlington, NJ at Memorial Pond. Stay tuned for more info! To learn more about our water quality management services, go here: bit.ly/pondlake.

Floating Wetland Islands: A Sustainable Solution for Lake Management

Nick Decker, PA State Parks Resource Manager, and Cory Speroff and Katie Walston of Princeton Hydro position a floating island of native plants in the lake at Frances Slocum State Park

Looking for a unique and creative way to manage nutrient runoff in freshwater lakes? Installing Floating Wetland Islands (FWI) is a low-cost, effective green infrastructure solution used to mitigate phosporus and nitrogen stormwater pollution often emanating from highly developed communities and/or argricultural lands.

FWIs are designed to mimic natural wetlands in a sustainable, efficient, and powerful way. They improve water quality by assimilating and removing excess nutrients that could fuel algae growth; provide valuable ecological habitat for a variety of beneficial species; help mitigate wave and wind erosion impacts; provide an aesthetic element; and add significant biodiversity enhancement within open freshwater environments.

“A pound of phosphorus can produce 1,100 lbs of algae each year. And, each 250-square foot island can remove 10 lbs of phosphorus annually.” explains Princeton Hydro Staff Scientist Katie Walston. “So, that’s 11,000 lbs of algae that is mitigated each year from each 250 square foot of FWI installed!”

This illustration, created by Staff Scientist Ivy Babson, conveys the functionality of a Floating Wetland Island

This illustration, created by Staff Scientist Ivy Babson, conveys the functionality of a Floating Wetland Island

Typically, FWIs consist of a constructed floating mat with vegetation planted directly into the material. Once the islands are anchored in the lake, the plants thrive and grow, extending their root systems through the mat and absorbing and removing excess nutrients from the water column such as phosphorus and nitrogen.

Native plants on the floating island designed by Princeton Hydro that will help reduce the phosphers and algae in the lake at Frances Slocum State ParkThe plants uptake a lot of nutrients, but the workhorse of the FWIs is the microbial community. The matrix used within the islands has a very high surface area and it promotes microbial growth, which performs the majority of the nutrient uptake. Additionally, the root growth from the plants continues to increase the surface area for the microbial biofilm to grow on. Both the plants and microbes acting together help optimize nutrient removal.

Princeton Hydro has designed and installed numerous FWIs in waterbodies large and small for the purpose of harmful algal bloom control, fisheries enhancement, stormwater management, shoreline preservation, wastewater treatment, and more. FWIs are also highly adaptable and can be sized, configured, and planted to fit the needs of nearly any lake, pond, or reservoir.

Greenwood Lake

Recently, the Princeton Hydro team completed a FWI installation in Belcher’s Creek, the main tributary of Greenwood Lake. The lake, a 1,920-acre waterbody located in  both Passaic County, New Jersey and Orange County, New York, is a highly valued ecological and recreational resource for both states and has a substantial impact on the local economies. In addition, the lake serves as a headwater supply of potable water that flows to the Monksville Reservoir and eventually into the Wanaque Reservoir, where it supplies over 3 million people and thousands of businesses with drinking water. 

Since the lake was negatively impacted by HABs during the 2019 summer season, Greenwood Lake Commission (GWLC) has made a stronger effort to eliminate HABs and any factors that contribute to cyanobacteria blooms for 2020 and into the future. Factors being addressed include pollutant loading in the watershed, especially that of Belcher’s Creek. The installation of FWIs in Belcher’s Creek will immediately address nutrients in the water before it enters Greenwood Lake and help decrease total phosphorus loading. In turn this will help reduce HABs, improve water quality throughout the Greenwood Lake watershed, and create important habitat for beneficial aquatic, insect, bird and wildlife species.

“In addition to the direct environmental benefits of FWIs, the planting events themselves, which involve individuals from the local lake communities, have long-lasting positive impacts,” said Dr. Jack Szczepanski, Princeton Hydro Senior Project Manager, Aquatics Resources. “When community members come together to help plant FWIs, it gives them a deepened sense of ownership and strengthens their connection to the lake. This, in turn, encourages continued stewardship of the watershed and creates a broader awareness of how human behaviors impact the lake and its water quality. And, real water quality improvements begin at the watershed level with how people treat their land.”

The project was partially funded by the New Jersey Department of Environmental Protection’s (NJDEP) Water Quality Restoration Grants for Nonpoint Source Pollution Program under Section 319(h) of the federal Clean Water Act. As part of the statewide HAB response strategy, the NJDEP made $13.5 million in funding available for local projects that improve water quality and help prevent, mitigate and manage HABs in the state’s lakes and ponds. The GWLC was awarded one of the NJDEPs matching grants, which provided $2 in funding for every $1 invested by the grant applicant. For this project, the GWLC purchased the FWIs and NJDEP provided the 2:1 cash match in order for the GWLC to implement additional HAB prevention and mitigation strategies in critical locations throughout the watershed.

Check out the photos from last month’s installation:

Here are a few more examples of FWI design and installation projects we’ve completed:

Frances Slocum Lake

Officials with the state Department of Conservation and Natural Resources, Luzerne Conservation District, Nanticoke Conservation Club, and students at Rock Solid Academy in Shavertown teamed up with Princeton Hydro to install two floating islands on the lake. They were planted natives to the area, including Green Bulrush, Broadleaf Arrowhead, Blue Flag Iris, Shallow Sedge, and Spotted Joe-Pye.

Princeton Hydro also installed solar-powered aeration systems in the middle of the FWIs. Aeration systems provide additional water quality improvements, help prevent water around the islands from stratifying, promotes “through-column” mixing, and helps to minimize the occurrence of phytoplankton blooms. The use of solar-powered aeration, whether installed on a FWI or along the shoreline, creates a sustainable, cost-effective, zero-energy water treatment solution, and eliminates the need to run direct-wired electrical lines to remote locations. Learn more.

Princeton Hydro also installs solar-powered aeration systems on FWIs, creating a sustainable, cost-effective, holistic water treatment solution.
Harveys Lake

Princeton Hydro, along with project partners, installed five floating wetland islands in Harveys Lake in order to assimilate and reduce nutrients already in the lake. The islands were placed in areas with high concentrations of nutrients, placed 50 feet from the shoreline and tethered in place with steel cables and anchored. A 250-square-foot FWI is estimated to remove up to 10 pounds of nutrients per year, which is significant when it comes to algae. Learn more.

Volunteers install native plants in one of the FWIs installed in Harveys Lake. Photo by: Mark Moran, The Citizen’s Voice.
lake hopatcong

Through a nonpoint source pollution grant awarded by NJDEP to the Lake Hopatcong Commission, Jefferson Township was able to install FWIs in order to deliver better water quality to Ashley Cove and Lake Hopatcong. The primary goal of the project was to reduce high levels of algae-causing phosphorus present in the lake. In each FWI, indigenous plants, Milkweed and Hibiscus, among other vegetation, were planted along with peat and mulch. Learn more.

Casey Hurt, right, and Richard Ampomah maneuver one of two floating wetland islands in Ashley Cove.
Lake Holiday

Two interconnected sets of FWIs were installed in Lake Holiday in the tributary coves of Isaac’s and Yeider’s Creeks. The strategic placement of the islands eliminates interference with normal boat traffic. In order to minimize movement, the FWIs were secured to trees along the bank with coated cable and protective bands and anchored to the lake bottom with submerged concrete blocks. Learn more.

Senior Scientist Katie Walston installs goose netting around the vegetation in order to prevent geese and other unwanted species from feeding on the plants.

Over the coming weeks, our team will be in Asbury Park, New Jersey installing FWIs in Sunset Lake. Stay tuned for more! For additional information about floating wetland islands and water quality management, go here: bit.ly/pondlake.

6 Ways to Celebrate Lakes Appreciation Month

July is Lakes Appreciation Month – a great time of year to enjoy your community lakes and help protect them.

Lakes Appreciation Month was started by North American Lake Management Society (NALMS) to help bring attention to the countless benefits that lakes provide, to raise awareness of the many challenges facing our waterways, and to encourage people to get involved in protecting these precious resources.

“You work and play on them. You drink from them. But do you really appreciate them? Growing population, development, and invasive species stress your local lakes, ponds, and reservoirs. All life needs water; let’s not take it for granted!” – NALMS

Chemical pollutants, stormwater runoff, hydrocarbons, invasive aquatic species, and climate change are just a few of the the serious threats facing lakes and other freshwater habitats. So what can you do to to help?


We’ve put together six tips to help you celebrate Lakes Appreciation Month and get involved in protecting your favorite lakes:

1. Join the “Secchi Dip-In” contest

The “Secchi Dip-In” is an annual citizen science event where lake-goers and associations across North America use a simple Secchi disk to monitor the transparency or turbidity of their local waterway. Created and managed by NALMS, volunteers have been submitting information during the annual Dip-In since 1994. Get all the Dip-In details here.

2. Monitor and report algae blooms

With the BloomWatch App, you can help the U.S. Environmental Protection Agency understand where and when potential harmful algae blooms (HABs) occur. HABs have the potential to produce toxins that can have serious negative impacts on the health of humans, pets, and our ecosystems. Click here to learn more and download the app here. For more information on HABs, check out our recent blog.

3. Commit to keeping your lake clean

Commit to keeping your lake clean: Volunteers play a major role in maintaining the health and safety of community waterways. If you’re interested in helping to conserve and protect your water resources, you can start by cleaning up trash. Choose a waterbody in your community; determine a regular clean-up schedule; and stick to it! Cleaning your neighborhood storm drains really helps too; click here to find out how.

Photo: Santiago Mejia, The Chronicle
4. support your local lake

You can help support your favorite lake by joining or donating to a lake or watershed association. As an organized, collective group, lake associations work toward identifying and implementing strategies to protect water quality and ecological integrity. Lake associations monitor the condition of the lake, develop lake management plans, provide education about how to protect the lake, work with the government entities to improve fish habitat, and much more.

5. Get outside and enjoy (safely)

There are countless ways to enjoy and appreciate your community lakes. During Lakes Appreciation month, take photos that illustrate how you appreciate your community lakes, share them on social media using the hashtag: #LakesAppreciation, and hopefully you’ll inspire others to show their Lake Appreciation too.

6. ENTER the Lakes Appreciation Challenge

NALMS invites you to participate in its social media photo contest, titled “Show Your Lakes Appreciation Challenge.” To participate: Take a picture of yourself or someone you know enjoying or working on a lake or reservoir during July. And, upload the photo to Facebook, Instagram and/or Twitter using a descriptive caption and the #LakesAppreciation hashtag. Three winners will be determined via a raffle and announced via social media on Monday, August 3rd. Learn more.

fishing on lake

To ensure you’re staying safe while participating in Lakes Appreciation Month and all outdoor activities, please be sure to follow local regulations and the CDC’s recommended COVID-19 guidelines.

To learn more about NALMS and get more ideas on how to celebrate your local lakes, go here: https://www.nalms.org. If you’re interested in learning more about Princeton Hydro’s broad range of award-winning lake management services, go here: http://bit.ly/pondlake.

 

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

NJDEP Releases Updated Guidance for Harmful Algal Blooms

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.

WATCH
(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.

ALERT
(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.

ADVISORY
(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:

Identifying, Understanding and Addressing Harmful Algae Blooms