Ecological Uplift in an Urban Setting

The City of Elizabeth, the fourth most populous in New Jersey, is not exactly the first place that comes to mind when envisioning a wild landscape. This bustling urban area is well known for its Port Newark-Elizabeth Marine Terminal and the Philips 66 Bayway Refinery, and sits at the intersection of several major roadways like the NJ Turnpike and the Goethals Bridge. The landscape, which was once teeming with dense wetlands and associated habitats, is now heavily urbanized with a vast mix of residential, commercial, and industrial properties. The largely channelized Elizabeth River courses through the city for 4.2 miles before draining into the Arthur Kill waterway. However, in this 14-square mile city, native flora and fauna are taking root again thanks to ecological restoration and mitigation efforts.

Urban landscapes like Elizabeth can pose significant challenges for restoration efforts, but they also provide an array of opportunity for significant ecological uplift.

In 2004, Princeton Hydro was retained to restore an 18-acre site adjacent to the Elizabeth Seaport Business Park, which is located in an area that was once part of a large contiguous wetland system abutting Newark Bay. The site was comprised of a significantly disturbed mosaic of wetland and upland areas and a monoculture of Phragmites australis, also known as Common Reed, on historic fill. Historic fill consists of non-native material, historically placed to raise grades, and typically contains contaminated material not associated with the operations of the site on which it was placed.

The highly invasive Phragmites australis had overtaken most of the wetland areas, and the upland woodland areas only contained four tree species, mostly Eastern Cottonwood, with very low wildlife value. The 18-acre site had huge potential but was significantly degraded and was being vastly underutilized. Overall, the mitigation plan focused on the enhancement of existing wetland and transition areas to increase the area’s wildlife value through the establishment of a more desirable, diverse assemblage of native species subsequent to eradication of non-native-invasive species.

2005 (Before Plantings)
2019
In 2004, Prologis hired Princeton Hydro to restore an 18-acre area adjacent to the Elizabeth Seaport Business Park, which a significantly disturbed and degraded mosaic of wetland and upland areas. This project serves as an example of how degraded urban areas can be successfully rehabilitated and the land’s natural function restored and enhanced.

The freshwater wetland aspect of the mitigation plan, which included inundated emergent, emergent, and forested habitat, was designed to be a combination of wetland creation (2.40 acres) and enhancement (8.79 acres), emphasizing the establishment of more species rich wetlands in order to increase biodiversity and improve the site’s wildlife food value.

The upland forest aspect of the mitigation plan involved the enhancement of 5.40 acres and creation of 1.45 acres of upland forest to foster the development of a species rich and structurally complex upland forest. The upland areas targeted for enhancement/creation consisted of areas where woody vegetation was lacking or forested areas that were dominated by eastern cottonwood.

2008
2019
The 18-acre site in Elizabeth, NJ had huge potential but was significantly degraded and was being vastly underutilized. The mitigation plan emphasized the establishment of more species rich wetlands in order to increase biodiversity and improve the site’s wildlife habitat value.

The project team worked to remove Phragmites australis from the site utilizing a combination of herbicide and mechanical removal techniques. Once the Phragmites australis was cleared, the team installed 27,000 two-inch native herbaceous plant plugs in the wetland portions of the mitigation site, and 2,705 native trees/shrubs throughout the site.

In order to ensure the continued success of the mitigation project, monitoring is regularly conducted at the site. A monitoring report conducted at the end of 2019 revealed a plethora of well-established habitat areas, a diverse community of plant and tree species, and a thriving, highly-functional landscape.

2004 (Before Plantings)
september 2019
In 2004, before the restoration work began, the site consisted of degraded Phragmites australis dominated wetlands and an urban woodland area dominated by Eastern cottonwood. The planting component of the mitigation project commenced in 2015, and the installation of all woody plant material began Fall 2015 and was completed in Fall 2016. The 2019 Monitoring Report revealed the plantings are well-established and the area is thriving.

Presently, the Elizabeth Seaport Business Park Mitigation Site boasts a variety of productive wildlife habitats that are rare in a highly urbanized setting and provides valuable ecosystem services, including sediment retention and roosting, foraging, and nesting opportunities for both resident and migratory bird species with over 150 bird species identified within the mitigation site.

2008
2019
The Elizabeth Seaport Business Park site was comprised of a monoculture of Phragmites australis, also known as Common Reed. The mitigation plan focused on enhancing the existing wetland by eradicating non-native-invasive plant species, like Phragmites, and establishing more diverse population of productive, native species with high ecological value.

This project serves as an example of how degraded urban areas can be successfully rehabilitated and the land’s natural function restored and enhanced.  If you’d like to learn more about this project from our Natural Resources Senior Project Manager Michael Rehman, check out the video of his presentation at the 2020 Delaware Wetlands Conference below.

We’re at the Delaware Wetlands Conference and our Senior Project Manager, Michael Rehman, is presenting on a successful urban wetland restoration in Elizabeth, NJ.

Posted by Princeton Hydro on Thursday, January 30, 2020

 

If you’re interested in learning more about our wetland restoration and mitigation services, go here!

Managing Invasive Phragmites and Restoring Natural Wetland Habitat

Non-native Phragmites australis, also known as Common Reed, is a species of perennial grass found across North America, especially along the Atlantic coast, in wetlands, riparian areas, shorelines, and other wet areas like roadside ditches and drainage basins. This aggressively invasive grass can grow up to 20 feet tall, in dense groupings, and tends to spread rapidly, quickly colonizing disturbed wetlands.

Once established, the invasive plant forms a monoculture with a dense mat, outcompeting native vegetation, lowering the local plant biodiversity, and displacing native animals. These landscape changes impair the natural function of the marsh ecosystem by altering its elevations and tidal reach. A higher, drier marsh leads to less vigorous growth of native salt marsh vegetation, allowing Phragmites australis to gain a stronger foothold and continue to take over.

USDA NRCS Plants Database phragmites illustrationPhragmites australis can also eliminate small, intertidal channels and obliterate pool habitat that offers natural refuge and feeding grounds for invertebrates, fish, and birds. The spread of invasive Phragmites australis also has negative impacts on land aesthetics and outdoor recreation by obscuring views and restricting access. And, each Fall, when Phragmites australis die off, the large concentrations of dry vegetation increase the risk of fast-spreading fires near highly populated residential and commercial areas.

Over the last century, there has been a dramatic increase in the spread of Phragmites australis, partly due to an increase in residential and commercial development that resulted in disturbances to wetlands. According to the U.S. Fish and Wildlife Service, the rapid spread of Phragmites australis in the 20th century can also be attributed to the construction of railroads and major roadways, habitat disturbance, shoreline development, pollution, and eutrophication.

Princeton Hydro has worked in areas throughout the East Coast to address and properly manage Phragmites australis in order to restore natural habitats and enhance plant diversity, wildlife habitat, and water quality. Two recent projects include the restoration of John A. Roebling Memorial Park in Hamilton and Pin Oak Forest Conservation Area in Woodbridge, New Jersey.

John A. Roebling Memorial Park

Mercer County’s John A. Roebling Memorial Park is home to the northernmost freshwater tidal marsh on the Delaware River, the Abbott Marshlands, an area containing valuable habitat for many rare species. Unfortunately, the area experienced a significant amount of loss and degradation, partially due to the introduction of the invasive Phragmites australis.

For Mercer County Park Commission, Princeton Hydro put together a plan to reduce and control the Phragmites australis, in order to increase biodiversity, improve recreational opportunities, and enhance visitor experience at the park. This stewardship project replaced the Phragmites australis with native species in order to reduce its ability to recolonize the marsh.

By Spring of this year, the team expects to see native species dominating the landscape from the newly exposed native seed bank with minimal Phragmites australis growth.

Pin Oak Forest Conservation Area

The Pin Oak Forest Conservation Area is a 97-acre tract of open space that contains an extremely valuable wetland complex at the headwaters of Woodbridge Creek. The site is located in a heavily developed landscape of northern New Jersey. As such, the area suffered from wetland and stream channel degradation, habitat fragmentation, ecological impairment, and decreased biodiversity due to invasive species, including Phragmites australis.

The site was viewed as one of only a few large-scale freshwater wetland restoration opportunities remaining in this highly developed region of New Jersey. A dynamic partnership between government agencies, NGOs, and private industry, was formed to restore the natural function of the wetlands complex, transform the Pin Oak Forest site into thriving habitat teeming with wildlife, and steward this property back to life.

This award-winning restoration project converted over 30 acres of degraded freshwater wetlands, streams and disturbed uplands dominated by invasive species into a species-rich and highly functional headwater wetland complex. The resulting ecosystem provides valuable habitat for wildlife including the state-threatened Black-crowned Night-heron and Red-headed Woodpecker. Biodiversity was also increased through invasive species management, which allowed establishment of native plants such as pin oak, swamp white oak, marsh hibiscus, and swamp rose. The restored headwater wetland system provides stormwater management, floodplain storage, enhanced groundwater recharge onsite, and surface water flows to Woodbridge Creek, as well as public hiking trails, all benefiting the town of Woodbridge.

Managing and Monitoring Phragmites

Scientific field research continues to be conducted in order to identify the best way(s) to manage and control the spread of Phragmites australis. Depending on the landscape and how established the Phragmites australis population is, there are several different methods that can be effective in reducing Phragmites australis infestations in order to allow for the regeneration of native wetland plant communities and protect fish and wildlife habitat.

Recently, a group of more than 280 scientists, resource managers and policy professionals gathered together at the Hudson River Estuary Program’s (HEP) annual conference to explore how natural and nature-based solutions (i.e. building living shorelines, enhancing tidal wetlands and stream corridors, and conserving vulnerable floodplains) can be used as critical tools for addressing the impacts of climate change while also protecting and enhancing critical habitat.

The conference included six interactive workshops and dynamic panel discussions. Christiana Pollack, GISP, CFM of Princeton Hydro, Terry Doss of New Jersey Sports and Exposition Authority, Kip Stein from New York City Parks, and Judith Weis of Rutgers lead a panel discussion, moderated by Lisa Baron from U.S. Army Corps Engineers, on “The Yin and Yang of Estuarine Phragmites Management” to share lessons learned over many years of combating invasive species, including how sea level rise is changing minds and techniques.

Together, representing decades of experience in Phragmites australis management and research, these experts presented the evolving nature of restoration for this habitat type, common control/management methodologies, and longterm management and monitoring strategies for this reed and other invasive species. During the panel discussion, Christiana made specific mention of the Roebling Park project as one example of successful strategies in action.

If you’re interested in learning more and seeing photos from a few recent Phragmites australis management projects, click below for a free download of Christiana’s full presentation.

Through a combination of prevention, early detection, eradication, restoration, research and outreach, we can protect our native landscapes and reduce the spread of invasive species. Learn more about our invasive species removal and restoration services.

 

NJ Takes Serious Steps to Prevent Harmful Algal Blooms

Photo by: Lake Hopatcong Commission

Last year, there were more than 70 suspected and 39 confirmed Harmful Algal Blooms (HABs) in New Jersey, which is significantly higher than the previous two years. New Jersey wasn’t the only state impacted by HABs. The increase caused severe impacts on lakes throughout the country, resulting in beach closures, restricting access to lake usage, and prompting wide-ranging health advisories.

In November, New Jersey Governor Phil Murphy and officials from the New Jersey Department of Environmental Protection (NJDEP) announced a three-pronged, $13 million initiative to reduce and prevent future HABs in the state. As part of the initiative, NJDEP hosted its first regional HABs Summit with the goal of prevention by improving communication throughout lake communities and sharing information ahead of the warmer months when HABs begin to appear.

The summit, which was held on January 28, 2020 at NJDEP’s Pequest Trout Hatchery and Natural Resource Education Center in Warren County included a Q&A panel discussion, information resource tables for one-on-one discussions, and presentations from a variety of NJDEP representatives and environmental experts. Princeton Hydro’s  Director of Aquatics and regional HABs expert Dr. Fred Lubnow’s presentation focused on how to properly and effectively manage HABs.

According to Dr. Lubnow, “Managing loads of phosphorous in watersheds is even more important as the East Coast becomes increasingly warmer and wetter thanks to climate change. Climate change will likely need to be dealt with on a national and international scale. But local communities, groups, and individuals can have a real impact in reducing phosphorous levels in local waters.”

In a recent press release from Governor Murphy’s office, the NJDEP Chief of Staff Shawn LaTourette said, “We will reduce HABs by working closely with our local partners on prevention and treatment techniques, while relying on the best available science to clearly communicate risk to the public. Our new HABs initiative will enhance the Department’s ability to evaluate statewide strategies and increase the capacity of lake communities to reduce future blooms.”

New Jersey’s new HABs initiative is comprised of three main components:

Providing Funding:

More than $13 million in funding will be available to local communities to assist in preventing HABs, including:

  • $2.5 million will be available as matching funds for lakes and HABs management grants, including treatment and prevention demonstration projects.

  • Up to $1 million in Watershed Grant funding will be made available for planning and projects that reduce the nonpoint source pollution, including nutrients, that contribute to HABs in surface waters of the State.

  • $10 million in principal forgiveness grants will be offered through the Clean Water State Revolving Fund for half of the cost, capped at $2 million, of sewer and stormwater upgrades to reduce the flow of nutrients to affected waterbodies.

Increasing Expertise & Implementing Prevention Tactics:

Per the Governor’s press release, “the second element of the initiative is to build upon the state’s scientific expertise and enhance its capacity to respond to HAB events. This includes establishing a team of experts from across various sectors to evaluate the state’s strategies to prevent HABs and pursuing additional monitoring, testing and data management capacity.”

Connecting with Communities:

The third component is focused on increasing NJDEP’s ability to communicate with affected communities. The regional HABs Summit held on January 28 was one of two Summits that will occur in early 2020 (the date of the next Summit has not yet been announced). NJDEP has also developed new web tools to provide HABs education, offer a forum to discuss and report potential HAB sightings, and better communicate HAB incidents.

To learn more about New Jersey’s new HABs Initiative, click here. To learn more about HABs, check out our recent blog:

Identifying, Understanding and Addressing Harmful Algae Blooms

Setting the Precedent: Blue Acres Floodplain Restoration in Linden

The City of Linden, located 13 miles southwest of Manhattan in Union County, New Jersey, is a highly urbanized area with a complex mix of residential, commercial, and industrial land uses. Originally settled as farmland on broad marshes, the City has deep roots in industrial production that emerged in the 19th century, and its easily accessible location on the Arthur Kill tidal straight helped fuel this industrial development.

Now, the City of Linden, which is home to more than 40,000 people, is considered a transportation hub: it has three major highways running through it (the New Jersey Turnpike, Route 1, and Route 27); its rail station provides critical commuter and industry access; the Linden Municipal Airport is a gateway to the NY/NJ metropolitan area; and its access point on the Arthur Kill is used by shipping traffic to the Port Authority of NY and NJ.

Unfortunately, the industrial boom left a legacy of pollution in the city, so much, that the Tremley Point Alliance submited an official Envionmental Justice Petition to the state. In 2005, the New Jersey Environmental Task Force selected the community for the development of an Environmental Justice Action Plan and listed it as one of six environmental justice communites in New Jersey.

As do many urban municipalities, Linden suffers severe flooding from heavy rains and storms. One of the significant sources of flood water threatening the City comes from stormwater runoff.

Like other communities in the Arthur Kill Watershed, Linden also suffers severe flooding from heavy rains and storms with one of the significant sources of flood water coming from stormwater runoff. Due to a high percentage of impervious cover from houses, roadways, and sidewalks, even small rain events generate a significant amount of stormwater runoff. Over time, these conditions have been exacerbated by the historic loss of coastal wetlands and outdated infrastructure. Nuisance flooding is especially problematic as runoff cannot drain from the area at a sufficient rate to prevent flooding during normal or elevated tidal conditions. Very simply, heavy rainfall is one factor contributing to recurring flooding.

In 2012, Hurricane Sandy caused wide-spread destruction throughout New Jersey and the entire eastern seaboard. The City of Linden was hard hit, and the City’s Tremley Point neighborhood was especially storm-ravaged. Tremley Point, a low-lying community of about 275 homes located at the headwaters of Marshes Creek and in the 100-year floodplain of the Rahway River, is regularly flooded during normal rain events. During Hurricane Sandy, local news outlets reported that a 15-foot tidal surge overtook Tremley Point homes, destroyed roads, and washed up hazardous material such as a 150-gallon diesel tank.

To help communities like Tremley Point recover, the New Jersey Department of Environmental Protection (NJDEP) launched the Blue Acres program under which NJDEP purchases homes from willing sellers at pre-Sandy market values, so residents in areas of repetitive and catastrophic flooding can rebuild their lives outside flood-prone areas. Structures are demolished and the properties are permanently preserved as open space for recreation or conservation purposes. The program began in 1995 and expanded with federal funding after Sandy. The goal of the Blue Acres Program is to dramatically reduce the risk of future catastrophic flood damage and to help families to move out of harm’s way.

As part of the NJDEP Blue Acres Program, Princeton Hydro, in collaboration with the City of Linden, Rutgers University, NJDEP, Phillips 66, National Fish and Wildlife Foundation, New Jersey Corporate Wetlands Restoration Partnership, and Enviroscapes, has undertaken one of the first ecological restoration projects within Blue Acres-acquired properties, which are located in the Tremley Point neighborhood. This project increases storm resiliency by reducing flooding and stormwater runoff by improving the ecological and floodplain function within the former residential properties acquired by the NJDEP Blue Acres Program.

The City of Linden Blue Acres restoration project increases storm resiliency by reducing flooding and stormwater runoff by improving the ecological and floodplain function within the former residential properties acquired by the NJDEP Blue Acres Program.

The project includes the development and implementation of an on-the-ground green infrastructure-focused floodplain enhancement design involving the restoration of native coastal floodplain forest and meadow, as well as floodplain wetlands. The restored area provides natural buffering to storm surge and enhances floodplain functions to capture, infiltrate, store, and slow excess stormwater to reduce the risk of future flood damage. In addition, it restores natural habitat and provides public recreation access on NJDEP Blue Acres property.

The design includes re-planting the parcels and the installation of a walking path through part of the area. It also includes the creation of a floodplain bench for the adjacent drainage ditch, an unnamed tributary to Marshes Creek. A floodplain bench is a low-lying area adjacent to a stream or river constructed to allow for regular flooding in these areas. Site improvements include grading of the floodplain bench and minor depressional area; 6-12-inches of tilling, soil amendment, and planting within the planting area; and construction of the gravel pathway.

The project will result in valuable environmental and community benefits to the area, including an annual reduction in stormwater runoff of 4.1 million gallons. This represents a 45% reduction in stormwater runoff. Restoration of the floodplain will also help reduce community vulnerability to storms. The hope is that this project will be a model that fosters more floodplain restoration projects in the future.

For more information on the Blue Acres Program, please visit the DEP website.

Regional Watershed Planning: A Critical Strategy to Prevent HABs

Photo by @likethedeaadsea, submitted during our 2019 #LAKESAPPRECIATION Instagram Photo Contest.

Harmful Algae Blooms (HABs) were in the spotlight last summer due to the severe impacts they had on lakes throughout the country. Nation-wide, HABs caused beach closures, restricted lake usage, and led to wide-ranging health advisories. There were 39 confirmed harmful algal bloom (HAB) outbreaks in New Jersey alone.

As a reminder, HABs are rapid, large overgrowths of cyanobacteria. These microorganisms are a natural part of aquatic ecosystems, but, under the right conditions (primarily heavy rains, followed by hot, sunny days), these organisms can rapidly increase to form cyanobacteria blooms, also known as HABs. HABs can cause significant water quality issues; produce toxins that are incredibly harmful (even deadly) to humans, animals, and aquatic organisms; and negatively impact economic health, especially for communities dependent on the income of jobs and tourism generated through their local lakes.

“A property’s value near an infested lake can drop by up to $85,000, and waterside communities can lose millions of dollars in revenue from tourism, boating, fishing and other sectors,” reports Princeton Hydro President Geoff Goll, P.E.

Generally, the health of a private lake is funded and managed in isolation by the governing private lake association group. But, in order to mitigate HABs and protect the overall health of our local waterbodies, it’s important that we look beyond just the lake itself. Implementing regional/watershed-based planning is a critical step in preventing the spread of HABs and maintaining the overall health of our natural resources.

At the end of 2019, the Borough of Ringwood became the first municipality in New Jersey to take a regional approach to private lake management through a public-private partnership with four lake associations.

The Borough of Ringwood is situated in the heart of the New Jersey Highlands, is home to several public and private lakes, and provides drinking water to millions of New Jersey residents. In order to take an active role in the management of these natural resources, Ringwood hired Princeton Hydro, a leader in ecological and engineering consulting, to design a municipal-wide holistic watershed management plan that identifies and prioritizes watershed management techniques and measures that are best suited for immediate and long-term implementation.

Map showing the four private lakes involved in the Borough of Ringwood's regional holistic watershed management plan.

Funding for Ringwood’s Watershed-based Assessment is being provided by the New Jersey Highlands Council through a grant reimbursement to the Borough of Ringwood. The Highlands Council offers grant funding and assistance to support the development and implementation of a wide range of planning initiatives. Examples of the types of efforts that can be funded for municipalities and counties include:

  • Land Use and Development projects like sustainable economic development planning and green building and environmental sustainability planning;
  • Infrastructure projects like stormwater management and water use/conservation management;
  • Resource Management projects like habitat conservation, lake management and water quality monitoring; and
  • Recreation and Preservation projects like land preservation and stewardship, farmland preservation and agriculture retention, and historic preservation.

Chris Mikolajczyk, CLM, Princeton Hydro’s Aquatics Senior Project Manager and the Ringwood project’s lead designer, presented with Keri Green of the NJ Highlands Council, at a recent New Jersey Coalition of Lake Associations meeting. The duo showcased Ringwood’s unique approach, spread the word about available funding through the NJ Highlands Council, and encourage other municipalities to follow Ringwood’s lead in taking a regional approach to lake and watershed management.

Mikolajczyk said, “This regional approach to lake and watershed management is a no-brainer from a scientific, technical, and community point of view. Historically, however, municipal governments and private lake associations have rarely partnered to take such an approach. The hope is that the Borough of Ringwood efforts, funded by the New Jersey Highlands Council, will set a precedent for this logical watershed management strategy and open the door for future public-private partnerships.”

This integrated approach to watershed and lake management is an important preventative measure to improve water quality for millions of people and reduce potential future incidents of aquatic invasive species and harmful algal blooms throughout the region.

To learn more about NJ Highlands Council and available grant funding, go here.
To download a complete copy of the presentations given by Mikolajczyk and Green at the recent NJCOLA meeting, go here.
To learn more about Princeton Hydro’s pond, lake and watershed management services, go here.

 

Identifying, Understanding and Addressing Harmful Algae Blooms

Harmful Algae Bloom Visible in Owasco Lake. Photo by: Tim Schneider

Harmful Algae Blooms (HABs) were in the spotlight this summer due to the severe impacts they had on lakes throughout the country. The nation-wide HABs outbreak caused beach closures, restricted access to lake usage, and wide-ranging health advisories.

What exactly are HABs? Why were they so severe this summer? Will this trend continue? Can anything be done to prevent the occurrence or mitigate the impacts?

In this blog, we provide answers to all of those questions, exploring what HABs are, why they occur, why they were particularly prevalent this summer, and what we can do to combat them.

What are HABs?

Simply put, HABs are rapid, large overgrowths of cyanobacteria. Cyanobacteria, also known as blue-green algae, aren’t actually algae, they are prokaryotes, single-celled aquatic organisms that are closely related to bacteria and can photosynthesize like algae. These microorganisms are a natural part of aquatic ecosystems, but, under the right conditions (primarily heavy rains, followed by hot, sunny days), these organisms can rapidly increase to form cyanobacteria blooms, also known as HABs.

HABs can cause significant water quality issues in lakes and ponds, often forming a visible and sometimes odorous scum on the surface of the water. They can produce toxins that are incredibly harmful (even deadly) to humans, animals, and aquatic organisms. HABs also negatively impact economic health, especially for communities dependent on the income of jobs and tourism generated through their local lakes and waterways.

What causes HABs?

HABs are caused by a complex set of conditions, and many questions remain about exactly why they occur and how to predict their timing, duration, and toxicity. Primarily, HABs are caused by warmer temperatures and stormwater run-off pollutants, including fertilizers with phosphates.

NY Times article, featuring Princeton Hydro, looks at how climate change affects lakes nationwide, using NJ as an example. Photo by: Rick Loomis, NY Times.HABs are induced by an overabundance of nutrients in the water. The two most common nutrients are fixed nitrogen (nitrates and ammonia) and phosphorus. Discharges from wastewater treatment plants, runoff from agricultural operations, excessive fertilizer use in urban/suburban areas, and stormwater runoff can carry nitrogen and phosphorus into waterways and promote the growth of cyanobacteria.

Climate change is also a factor in HAB outbreaks, which typically occur when there are heavy rains followed by high temperatures and sunshine. Climate change is leading to more frequent, more intense rainstorms that drive run-off pollutants into waterways, coupled with more hot days to warm the water. These are the ideal conditions for HABs, which in recent years have appeared in more places, earlier in the summer.

With climate change and increasing nutrient pollution causing HABs to occur more often and in locations not previously affected, it’s important for us to learn as much as we can about HABs so that we can reduce their harmful effects.

What Can I Do to Prevent HABs?

Signs on the closed beach at Hopatcong State Park warn residents of the Harmful Algae Bloom at Lake Hopatcong on July 2019, in Landing, NJ. (Photo by: Danielle Parhizkaran of NorthJersey.comThe number one thing individuals can do to protect their waterbodies and prevent HABs is to reduce phosphorous use and reduce nutrient loads to waters.

According to Dr. Fred Lubnow, Director of Aquatic Programs for Princeton Hydro, “Managing loads of phosphorous in watersheds is even more important as the East Coast becomes increasingly warmer and wetter thanks to climate change. Climate change will likely need to be dealt with on a national and international scale. But local communities, groups, and individuals can have a real impact in reducing phosphorous levels in local waters.”

Here are a few steps you can take to improve water quality in your community lakes:

Controlling stormwater runoff is another critical factor in improving water quality and reducing HABs. There are a number of low-cost green infrastructure techniques that can be implemented on an individual and community-wide scale. You can read more about green infrastructure stormwater management techniques in our recent blog.

In a recent Op/Ed published on NJ.com, Princeton Hydro President Geoff Goll lists four things that residents, businesses, and local governments should do to prevent another HABs outbreak next summer:

  1. Improve aging “gray” infrastructure
  2. Invest in “green” stormwater infrastructure
  3. Implement regional/watershed-based planning
  4. Pass the Water Quality Protection and Jobs Creation Act

“By making the necessary investments, we can simultaneously create jobs, reduce flood impacts, improve fisheries, maintain or increase lakefront property values, improve water quality and preserve our water-based tourism. The time to act is literally now,” said Geoff. Go here, to read the full article.

HABs Management in Action through Floating Wetland Islands:

Nitrogen and phosphorus are utilized by plants, which means they uptake these nutrients to sustain growth. We see this naturally occurring in wetland ecosystems where wetlands act as a natural water filtration system and can actually thrive from nutrients flowing in from external sources.

This process is replicated in floating wetland islands (FWIs), where you typically have a constructed floating mat with vegetation planted directly into the material. The plants then grow on the island, rooting through the floating mat.

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

Not only do FWIs assimilate and remove excess nitrogen and phosphorus out of the water, they also provide habitat for fish and other aquatic organisms; help mitigate wave and wind erosion impacts; provide an aesthetic element; and can be part of a holistic lake/pond management strategy. Because of this, FWIs are being utilized to improve water quality and control HABs in lakes and ponds throughout the country. Princeton Hydro has designed and implemented numerous FWIs in waterbodies large and small. Go here to learn how they’re being used in Harveys Lake.

 

Recognizing and monitoring the changes that are taking place in our local waterways brings the problems of climate change, stormwater pollution and the resulting water quality issues closer to home, which can help raise awareness, inspire environmentally-minded action and promote positive, noticeable change.

If you spot what you believe to be a harmful algae bloom in your community lake, contact your local lake association right away. They, along with their lake management team, can assess the situation and determine what further actions need to be taken.

For more information about harmful algae blooms and water quality management, go here: http://bit.ly/pondlake.

Special thanks to Princeton Hydro Staff Scientist Ivy Babson for her contributions to this blog.

Don’t Get Sunk: Everything You Need to Know About Sinkholes (Part Two)

Sinkhole in Frederick, Maryland. Credit: Randall Orndorff, U.S. Geological Survey. Public domain.

Sinkholes can be quite terrifying. We see them on the news, on television and in movies seemingly appearing out of nowhere, swallowing up cars and creating calamity in towns across the world. In this two-part blog series, our experts uncover the mystery around sinkholes and arm you with the facts you need to make them less scary.

In part one of the blog series, we discuss what a sinkhole is, three different types of sinkholes, and what causes them to form. In this second part, we explore how to detect sinkholes, what to do if you detect a sinkhole, and the steps taken to repair them.

WELCOME TO PART TWO: DON’T GET SUNK: EVERYTHING YOU NEED TO KNOW ABOUT SINKHOLES
How to Detect a Sinkhole:

Cover-collapse sinkholes (outlined in red) in eastern Bullitt County Kentucky. Photo by Bart Davidson, Kentucky Geological Survey.Not all sinkholes are Hollywood-style monstrosities capable of swallowing your whole house. But even a much smaller, less noticeable sinkhole can do its fair share of harm, compromising your foundation and damaging utilities.

Although sinkholes can be scary to think about, you can take comfort in knowing there are ways to detect them, both visually and experimentally. Often, you can spot the effects of a developing sinkhole before you can spot the hole itself. If you live in an area with characteristics common to sinkhole formation (i.e. “karst terrain,” or types of rocks that can easily be dissolved by groundwater), there are some things you can do to check your property for signs of potential sinkhole formation.

According to the American Society of Home Inspectors, there are key signs you should be on the lookout for in and around your home:

Inside:

  • structural cracks in walls and floors;
  • muddy or cloudy well water;
  • interrupted plumbing or electrical service to a building or neighborhood due to damaged utility lines; and
  • doors and windows that don’t close properly, which may be the result of movement of the building’s foundation.

Outside:

  • previously buried items, such as foundations, fence posts, and trees becoming exposed as the ground sinks;
  • localized subsidence or depression anywhere on the property; in other words, an area that has dropped down relative to the surrounding land;
  • gullies and areas of bare soil, which are formed as soil is carried towards the sinkhole;
  • a circular pattern of ground cracks around the sinking area;
  • localized, gradual ground settling;
  • formation of small ponds, as rainfall accumulates in new areas;
  • slumping or falling trees or fence posts; and
  • sudden ground openings or ground settlement, keeping in mind that sudden earth cracking should be interpreted as a very serious risk of sinkhole or earth collapse.
Actions to Take if You Believe You’ve Detected a Sinkhole:

If you spot any of the signs listed above, or you suspect that you have a sinkhole on or near your property, you should contact your township, public works, or the local engineering firm that represents your municipality right away. If you have discovered a sinkhole that is threatening your house or another structure, be sure to get out immediately to avoid a potentially dangerous situation.

Also, it is highly recommended that:

  • Credit: USGSIf a sinkhole expert can’t get to the area relatively quickly, you ensure that kids and animals keep away, fence/rope-off the area while maintaining a far distance away from the actual sinkhole, keeping in mind that doing so requires extreme caution and is always best left to the experts when possible;
  • Notify your neighbors, local Water Management District, and HOA;
  • Take photos to document the site;
  • Remove trash and debris from around the suspected area in order; and
  • Keep detailed records of all the actions you took.

If you’re trying to determine whether or not you have a sinkhole on your property, there are a few physical tests that can be conducted to determine the best course of action.

In Australia, a courtyard formed a sinkhole. Credit: Earth-Chronicles.comElectro-resistivity testing: This extremely technical test can best be summed up by saying it uses electrodes to determine the conductivity of the soil. Since electricity can’t pass through air, this test shows any pockets where the current didn’t pass through. This is a fairly accurate way to determine if there is a sinkhole and where it is.

Micro-gravity testing: Another incredibly technical method, this test uses sensors that detect the measure of gravity. Since the gravitational pull in a given area should be the same, you can see if there are minute differences in the measurement. If there is a difference, then it’s likely that you have a sinkhole in that area.

If you are still unsure whether or not you live in a sinkhole risk area, you can check with your local, territorial, or national government offices; review geological surveys such as the United States Geological Survey (USGS); and contact an expert.

How a Sinkhole is Repaired?

There are three main techniques experts utilize to repair sinkholes. The type of sinkhole and landowner’s aesthetic preferences determine the methodology used to repair the sinkhole.

The three common methods are:

  1. Inject grout with a drill rig: This uses a piece of large drilling equipment that pierces the ground and goes down into the sinkhole, injecting it with grout/concrete. This method stops the filling of the carbonate crack with sediment since concrete and grout do not break down into such small particles (no piping).
  2. Inverted cone: With this method, the construction crew digs down and finds the bowl-shaped opening. They then open up the surface so that the entire sinkhole area is exposed. To stop the draining of sediment into the crack in the carbonate rock, they fill the hole with bigger rocks first, then gradually fill in the seams with smaller rocks until the sinkhole is plugged.
  3. Filling it with concrete/grout from the surface: This is a combination of the prior two methods. The construction crew opens the surface all the way up so the entire hole is exposed. Then, they bring in a big concrete pourer and fill the sinkhole with concrete.

Missouri Dept of Natural Resources, Inverted cone repair sinkhole mitigation diagram

Our engineers regularly go out in the field to oversee and inspect sinkhole repairs. If you detect a sinkhole, or what might be a sinkhole, on your property, our experts strongly advise immediate actions be taken. Ignoring a sinkhole will only cause it to get larger and more dangerous as time passes, and putting topsoil over a sinkhole will only exacerbate the symptoms.

What Can You Do to Prepare for a Sinkhole?

While there’s really no way to prevent a sinkhole, you can never be too prepared! Here are three easy steps you can take to determine if you live in or around a sinkhole-prone area and what to do in the event of a surprise sinkhole:

  1. Find out whether or not you’re living in one of the sinkhole-prone states, which includes Pennsylvania, Texas, Florida, Alabama, Tennessee, and Missouri. You can do so by visiting USGS.com and searching for Bedrock Geology maps of your area. If your town is underlain by carbonate rocks, you are likely in a sink-hole prone area.
  2. Contact an engineer who’s certified to deal with sinkholes to determine if your property is at-risk.
  3. Develop a plan for what to do in the event of a sinkhole. Do you grab your family, pets, and leave immediately? Do you have a safe zone somewhere near (but not too near) your property? Do you have the appropriate emergency contact numbers in your phone? Does your car have a safety kit? These are some of the things to consider when making your emergency plan.
  4. Speak with your insurance company to see if they have sinkhole coverage, especially if you live in an area where they’re known to occur.

Although scary, sinkholes are a manageable threat if you’re informed and prepared. After all, it is possible to do something about sinkholes – if they can be detected in time.

Special thanks to Princeton Hydro Staff Engineer Stephen Duda, Geologist Marshall Thomas, and Communications Intern Rebecca Burrell for their assistance in developing this blog series.

Revisit Part One of this blog series in which we provide a detailed look at what a sinkhole is, three different types of sinkholes, and what causes them to form:

Don’t Get Sunk: Everything You Need to Know About Sinkholes (Part One)

Don’t Get Sunk: Everything You Need to Know About Sinkholes (Part One)

Photo by Steven Reilly/New Jersey Herald

Sinkholes are a phenomenon that tend to baffle and frighten most people. How is it possible that the ground beneath our feet could just drop? How do we know if we’re nearby a sinkhole? What should we do if we see one? How are sinkholes fixed? The mystery of the unknown around sinkholes can be quite unnerving.

Have no fear, we’ve got answers to all of those questions and more! In this two-part blog series, our experts share their knowledge and provide important information about this scary occurrence. In part one, we provide a detailed look at what a sinkhole is, three different types of sinkholes, and what causes them to form. In part two, we explore how to detect sinkholes and the steps taken to repair them.

What is a Sinkhole?

Sinkholes are a common phenomenon around the world. They result from both man-made and natural causes. Marshall Thomas, a Princeton Hydro geologist, describes sinkholes as “depressions observed from the surface, caused by dissolution of carbonate rocks.” In other words, sinkholes form when the rock below the land surface gets dissolved by water that penetrates the surface and continues to move downward, further into the subsurface.

Most common in areas with “karst terrain,” or types of rocks that can easily be dissolved by groundwater, sinkholes can go undetected for years until the space underneath the surface gets too big or enough of the surface soil is washed away. Sometimes the holes are small, measuring a few feet wide and ten feet deep. Sometimes the holes are hundreds of miles wide and deep. However, all of them can be dangerous.

Sinkholes are found throughout the world. States like Pennsylvania, Texas, Florida, Alabama, Tennessee, and Missouri are at higher risk for sinkholes because they tend to have more soluble rocks like salt beds and domes, gypsum, limestone, and other carbonate rocks. People living in these states are recommended to have professionals look at any property they intend to buy to make sure it isn’t in an area above soluble rock.

Types of Sinkholes

Not all sinkholes are the scary, earth-falling-out-from-underneath-your-feet events. Some occur slowly over time and are very evident from the surface. Geologists classify sinkholes in three major types. Their formation is determined by the same geological processes, barring a few differences. Let’s dive in!

1. Dissolution Sinkholes

Illustration by USGSDissolution sinkholes start to form when limestone or dolomite is very close to the soil surface, usually covered by a thin layer of soil and permeable sand which washes away or is eroded. Rain and stormwater runoff gradually percolate through crevices in the rock, dissolving it. Consequently, a bowl-shaped depression slowly forms.

Sometimes, dissolution sinkholes become ponds when the depression gets lined with debris, which traps water inside. Dissolution sinkholes develop gradually and are normally not dangerous. However, the ones that become ponds can drain abruptly if water breaks through the protective bottom layer.

Fun fact: Most of Florida’s lakes are actually just large sinkholes that filled up with water!

2. Cover-Subsidence Sinkholes

Illustration by USGSThis type of sinkhole, which starts with the dissolution of the underlying carbonate bedrock, occurs where the covering sediment is permeable (water can pass through it) and contains sand. First, small pieces of sediment split into smaller pieces and fall into openings in the carbonate rock underneath the surface. With time, in a process called piping, the small particles settle into the open spaces. This continues, eventually forming a dip in the surface ranging from one inch to several feet in depth and diameter. Again, these aren’t the sinkholes movies are made about.

3. Cover-Collapse Sinkholes

Illustration by USGSThis type of sinkhole is the one making headlines and causing fear. In order for cover-collapse sinkholes to happen, the covering soil has to be cohesive, contain a lot of clay and the bedrock has to be carbonate. Similar to the cover-subsidence sinkholes, the cohesive soil erodes into a cavity in the bedrock. The difference with this is that the clay-filled top surface appears to remain intact from above. However, underneath, a hollowed out, upside down bowl shape forms. That hollowing gets bigger and bigger over time until eventually, the cavity reaches the ground surface, causing the sudden and dramatic collapse of the ground. Just like that, poof, we have a sinkhole that appears to be surprising and abrupt but really has been brewing for many years.

What Causes a Sinkhole?

Sinkholes can be natural or man-made. The most common causes of a sinkhole are changes in groundwater levels or a sudden increase in surface water.

Intensive rain events can increase the likelihood of a sinkhole collapse. Alternatively, drought, which  causes groundwater levels to significantly decrease, can also lead to a greater risk of collapse of the ground above. In a world with a greater variability in rainfall and drought events due to climate change, sinkholes may become a more common occurrence around the world.

Humans are also responsible for the formation of sinkholes. Activities like drilling, mining, construction, broken water or drain pipes, improperly compacted soil after excavation work, or even significantly heavy traffic (heavy weight on soft soil) can result in small to large sinkholes. Water from broken pipes can penetrate through mud and rocks and erode the ground underneath and cause sinkholes.

Most commonly, human-caused sinkholes are the result of:

  • Land-use practices like groundwater pumping, construction, and development
  • Changing of natural water-drainage patterns
  • Development of new water-diversion systems
  • Major land surface changes, causing substantial weight changes

In some cases, human-induced sinkholes occur when an already forming sinkhole is encountered during construction processes such as excavation for stormwater basins and foundations. Dissolution of bedrock generally occurs in geologic time-frames (thousands of years). In these cases, the excavation process has removed the covering soils, decreasing the distance between the top of the void and the ground surface.  

In other cases, voids in the bedrock are generated due to rock removal processes such as hammering and blasting. Hammering and blasting can generate fractures or cracks in the bedrock that soil can then erode into. A void in the bedrock may already exist, however, the process of removing the bedrock by hammering and/or blasting can speed up the meeting of the upside-down bowl and the surface that much quicker. One site where this happened has experienced over 35 sinkholes in 4 years.

Overall, it’s generally not a good idea to pump groundwater or do major excavation in areas that are prone to sinkholes. According to the USGS, over the last 15 years sinkhole damages have cost on average at least $300 million per year. Because there is no national tracking of sinkhole damage costs, this estimate is probably much lower than the actual cost. Being more mindful about the subsurface around us and our actions could help lower the average yearly cost in damages and even save lives.

Photo by Barbara Miller PennLive Patriot News

Stay tuned for Part Two of this blog series in which we explore we explore how to detect sinkholes and the steps taken to repair them! For more information about Princeton Hydro’s Geotechnical Engineering services, go here: http://bit.ly/PHGeotech

Special thanks to Princeton Hydro Staff Engineer Stephen Duda, Geologist Marshall Thomas, and Communications Intern Rebecca Burrell for their assistance in developing this blog series.

Sources:

DIY: Protecting Water Quality in Your Community

There are lots of things we can do to preserve our precious water resources. Reducing stormwater pollution in our neighborhoods is something everyone can take part in. Storm drain cleaning is a great place to start!

DIY Storm Drain Cleaning

Urbanization has fundamentally altered the way that water moves through the landscape. Stormwater that doesn’t soak into the ground runs along streets and parking lots and picks up pollutants. Much of the pollution in our nation’s waterways comes from everyday materials like fertilizers, pesticides, motor oil, and household chemicals. Rainwater washes these substances from streets, yards and driveways into storm drains.

It’s a common misconception that storm drains lead to wastewater treatment plants. In actuality, storm drains rarely lead to treatment plants and instead stormwater systems carry untreated water directly to the nearest waterway. This polluted runoff can have negative impacts on water quality, overstimulate algal growth (both toxic and non-toxic), harm aquatic species and wildlife, and cause trash and debris to enter our lakes, streams, rivers and oceans.

https://www.middlesexcentre.on.ca/Public/Stormwater

We can all do our part to improve and preserve water resources in our community and beyond!

Keeping neighborhood storm drains cleaned is one simple step. Removing debris that collects in nearby stormwater catch basins, storm drains and along curbs promotes cleaner runoff, reduces the potential for flooding, and decreases the amount of pollution and trash entering our waterways.

Follow these simple steps for DIY storm drain cleaning:

  1. Photo: Santiago Mejia, The ChronicleRake/sweep and discard debris that has collected on top of the storm grate and in curbside rain gutters. Please note: If you notice a major blockage or issue with a storm drain, contact your local municipality immediately.
  2. Use a scrub brush or toilet bowl scrubber to remove debris that may be stuck to the storm grate.
  3. Adopt a storm drain(s) and maintain a regular cleaning schedule: Make a note on your calendar each quarter to clean and clear debris from storm drains nearby your home or workplace. And, make a habit of checking your storm drains after rainstorms when clogging is most common.
  4. Host a community clean-up day that includes trash pick-up, storm drain cleaning, and disseminating information on the impacts of stormwater runoff and what we can do to help.
  5. Consider contacting your local watershed association or municipality about getting drain markers installed on storm drains throughout the community. The markers act as a continued public reminder that anything dumped into a storm drain eventually ends up in our precious waterways downstream.

Remember: Small actions lead to big achievements in protecting water quality. 

Dr. Fred Lubnow of Princeton Hydro Featured in Magazine Article on Chautauqua Lake

The U.S. is home to thousands of lakes both natural and manmade. Lakes are incredibly important features in the landscape that provide numerous beneficial services, including domestic water supply, hydro-electric power, agricultural water supply, recreation, and tourism. They also provide essential habitat for fish, wildlife and aquatic organisms.

Lakes are complex and dynamic systems, each situated in a unique landscape context. Maintaining the ecological health of a lake is no easy feat. A lot goes on behind the scenes to maintain water quality and a balanced lake ecosystem. Successful, long-term lake management requires a proactive approach that addresses the causes of its water quality problems rather than simply reacting to weed and algae growth and other symptoms of eutrophication.

Chautauqua Magazine recently published an article about the science behind the management of Chautauqua Lake, which features our Director of Aquatic Programs Dr. Fred Lubnow. We’ve included an excerpt below. Click here to view the full article and photos:

Dr. Fred Lubnow is a scientist and director of aquatic programs at Princeton Hydro, a consulting organization based in Exton, Pennsylvania, that is often called on to support lake and watershed regions that want to develop a long-term plan for lake conservation.

He says that while his firm focuses on the development of data and intelligence to inform decision making in regard to freshwater ecosystems, his work is really about coalition building.

“As a scientist and a consultant, you learn over time that you are building a coalition stakeholders and determining what we can agree on to help everyone in the community,” Lubnow said.

Ten years ago, Princeton Hydro was hired to do some stream and inlet monitoring for various stakeholders at Chautauqua Lake. More recently, they’ve been contracted to conduct third-party monitoring of the impacts of the Spring 2019 herbicide applications in the south basin of Chautauqua Lake…

Continue reading!

 

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 reservoir, and watershed management initiatives conducted as part of USEPA and/or state funded programs. For more information about our lake management services, go here: http://bit.ly/pondlake.