We’re committed to improving our ecosystems, quality of life, and communities for the better.
Our passion and commitment to the integration of innovative science and engineering drive us to exceed on behalf of every client.
WP_Query Object ( [query] => Array ( [tag] => engineering ) [query_vars] => Array ( [tag] => engineering [error] => [m] => [p] => 0 [post_parent] => [subpost] => [subpost_id] => [attachment] => [attachment_id] => 0 [name] => [pagename] => [page_id] => 0 [second] => [minute] => [hour] => [day] => 0 [monthnum] => 0 [year] => 0 [w] => 0 [category_name] => environmental-services [cat] => 34 [tag_id] => 369 [author] => [author_name] => [feed] => [tb] => [paged] => 1 [meta_key] => [meta_value] => [preview] => [s] => [sentence] => [title] => [fields] => all [menu_order] => [embed] => [category__in] => Array ( [0] => 34 ) [category__not_in] => Array ( ) [category__and] => Array ( ) [post__in] => Array ( ) [post__not_in] => Array ( ) [post_name__in] => Array ( ) [tag__in] => Array ( ) [tag__not_in] => Array ( ) [tag__and] => Array ( ) [tag_slug__in] => Array ( [0] => engineering ) [tag_slug__and] => Array ( ) [post_parent__in] => Array ( ) [post_parent__not_in] => Array ( ) [author__in] => Array ( ) [author__not_in] => Array ( ) [search_columns] => Array ( ) [ignore_sticky_posts] => [suppress_filters] => [cache_results] => 1 [update_post_term_cache] => 1 [update_menu_item_cache] => [lazy_load_term_meta] => 1 [update_post_meta_cache] => 1 [post_type] => [posts_per_page] => 10 [nopaging] => [comments_per_page] => 5 [no_found_rows] => [order] => DESC ) [tax_query] => WP_Tax_Query Object ( [queries] => Array ( [0] => Array ( [taxonomy] => category [terms] => Array ( [0] => 34 ) [field] => term_id [operator] => IN [include_children] => ) [1] => Array ( [taxonomy] => post_tag [terms] => Array ( [0] => engineering ) [field] => slug [operator] => IN [include_children] => 1 ) ) [relation] => AND [table_aliases:protected] => Array ( [0] => ph_term_relationships [1] => tt1 ) [queried_terms] => Array ( [category] => Array ( [terms] => Array ( [0] => 34 ) [field] => term_id ) [post_tag] => Array ( [terms] => Array ( [0] => engineering ) [field] => slug ) ) [primary_table] => ph_posts [primary_id_column] => ID ) [meta_query] => WP_Meta_Query Object ( [queries] => Array ( ) [relation] => [meta_table] => [meta_id_column] => [primary_table] => [primary_id_column] => [table_aliases:protected] => Array ( ) [clauses:protected] => Array ( ) [has_or_relation:protected] => ) [date_query] => [queried_object] => WP_Term Object ( [term_id] => 369 [name] => engineering [slug] => engineering [term_group] => 0 [term_taxonomy_id] => 369 [taxonomy] => post_tag [description] => [parent] => 0 [count] => 79 [filter] => raw [term_order] => 0 ) [queried_object_id] => 369 [request] => SELECT SQL_CALC_FOUND_ROWS ph_posts.ID FROM ph_posts LEFT JOIN ph_term_relationships ON (ph_posts.ID = ph_term_relationships.object_id) LEFT JOIN ph_term_relationships AS tt1 ON (ph_posts.ID = tt1.object_id) WHERE 1=1 AND ( ph_term_relationships.term_taxonomy_id IN (34) AND tt1.term_taxonomy_id IN (369) ) AND ((ph_posts.post_type = 'post' AND (ph_posts.post_status = 'publish' OR ph_posts.post_status = 'acf-disabled'))) GROUP BY ph_posts.ID ORDER BY ph_posts.menu_order, ph_posts.post_date DESC LIMIT 0, 10 [posts] => Array ( [0] => WP_Post Object ( [ID] => 18379 [post_author] => 1 [post_date] => 2025-10-14 17:37:53 [post_date_gmt] => 2025-10-14 17:37:53 [post_content] => When most people think of engineering, they picture bridges, buildings, and dams rising above the landscape. Yet the performance and longevity of these structures depend just as much on the subsurface conditions beneath them. Geotechnical engineering is the discipline dedicated to investigating, analyzing, and characterizing soil, rock, landscape, and groundwater conditions, and applying that data to the design and construction of safe, resilient, and sustainable infrastructure and restoration projects. At Princeton Hydro, our geotechnical and soils engineers design and execute customized, cost-effective investigations that provide the parameters needed for successful design. Because geotechnical services touch every stage of a project, our integrated approach of investigation, including soils laboratory testing, analysis, and design, all done in-house, ensures streamlined communication, efficiency, and technical excellence. This blog offers a closer look at what geotechnical engineering entails, the specialized capabilities Princeton Hydro provides, and real-world examples of how our work supports resilient, sustainable design. Princeton Hydro’s Geotechnical Capabilities Geotechnical Investigations: Our engineers can perform subsurface investigation, identification, and assessment of accumulated sediment, subsurface soils, and rock, as well as slope stability and stabilization modeling. Our work ranges from foundation type and bearing capacity assessments to mitigation strategies for unsuitable materials. We also regularly conduct forensic geotechnical investigations, which focus on investigating soil-interaction-related failures of engineered infrastructure. Laboratory Testing: We operate an American Association of State Highway and Transportation Officials (AASHTO) Accredited laboratory in Sicklerville, NJ. This allows us to complete 100% of geotechnical investigation planning and oversight, laboratory testing, analysis, design, and reporting in-house. Our geotechnical laboratory performs a full suite of soils and materials testing, including grain size analysis, plasticity index, organic content, moisture content, compaction characteristics of soil (Standard and Modified Proctor), California bearing ratio (CBR), one dimensional consolidation, and flexible and rigid wall permeability testing under constant or falling head conditions. With this capability, we can rapidly deliver high-quality data to inform project design and construction. Our laboratory is also a U.S. Army Corps of Engineers (USACE) Validated Laboratory. Click here to view Princeton Hydro’s complete accreditation listing and certificate. And, click here to learn more about the USACE Materials Testing Laboratories and Validation. Field & Construction Services: Our engineers are experienced in construction requirements, design, and methodology for various structures, as well as field inspections and special testing. We have a Certified Construction Specifier (CCS) on staff and ACI-certified concrete field-testing technicians. Our team performs compaction testing of soil and asphalt using a nuclear density gauge, reinforcing steel inspections, and 2006 International Building Code (IBC) special inspections. We help determine foundation type, site improvements, and optimal construction techniques. Dredging & Sediment Investigations: Over our 25-year history, we’ve managed more than 100 dredging projects across freshwater and estuarine systems. We specialize in beneficial reuse of dredged material for ecological restoration, including wetland creation, thin-layer placement, and living shorelines. Our team provides sediment characterization, slope stability modeling, and contaminant analysis in complex, developed watersheds. Princeton Hydro’s Geotechnical Work in Action To bring this work to life, we’ve chosen a few Princeton Hydro projects that showcase where our geotechnical expertise helped solve unique challenges: Geotechnical Design & Subsurface Investigations for Coastal Wetland Restoration – New York At Spring Creek Park North in Jamaica Bay, New York, decades of urbanization and dredged material placement had degraded more than 40 acres of tidal marsh and uplands. To address this, Princeton Hydro provided subsurface investigations and design services for a large-scale ecosystem restoration led by the USACE New York District, in partnership with NYC Parks. A key design assumption was the reuse of excavated material: soils removed from wetland areas were repurposed to construct upland hills, supporting both ecological function and cost-effective implementation. Our work included geotechnical borings, slope stability analyses, and hydraulic modeling, as well as the collection of topographic and bathymetric survey data, wetland delineations, vegetation assessments, and hydrodynamic measurements. This data informed the development of slope stability and hydraulic models and guided the restoration design. The project advanced through a structured engineering design process — with 30%, 60%, 90%, and 100% design submissions — along with preparation of technical specifications, permit applications, and a detailed construction cost estimate. When complete, the project will restore more than 43 acres of marsh and upland habitat, improving water quality, enhancing biodiversity, and strengthening climate resilience in one of New York City’s most ecologically significant coastal systems. [gallery size="medium" link="none" columns="2" ids="18187,18188"] Offshore Subsurface Investigation for Jetty Reconstruction – Delaware Princeton Hydro was contracted by USACE Philadelphia District to perform offshore subsurface geotechnical investigations in support of reconstructing the Indian River Inlet jetty at Delaware Seashore State Park. Working under challenging marine conditions, our team successfully advanced deep geotechnical borings (to depths of 100 feet) from a lift boat platform, collected soil samples, performed laboratory testing including triaxial strength, consolidation, and direct shear tests; and delivered detailed soil data. Despite difficult sea states, we maintained close communication with USACE to ensure safety and project continuity. The resulting data provided USACE with critical insight into subsurface conditions, helping inform design alternatives for the new jetty structure. [gallery size="medium" columns="2" link="none" ids="18185,18184"] Subsurface Investigations for Dike Raising – New Jersey At the Killcohook Confined Disposal Facility (CDF), Princeton Hydro carried out a large-scale subsurface investigation to support USACE Philadelphia District’s plans for raising the site’s perimeter dikes. The project site, formerly a National Wildlife Refuge, is located in Pennsville, New Jersey, on the eastern bank of the Delaware River, to the north of Fort Mott State Park and adjacent to the Supawna Meadows Wildlife Refuge. Each cell of the CDF receives dredge material from the Delaware River. The subsurface explorations performed by Princeton Hydro were conducted along the existing dike comprising the border of Cell 1 of the CDF. Cell 1 consists of an area of approximately 710 acres with the entire CDF covering 1,200 acres. For this exploration project, Princeton Hydro was tasked with the performance of thirty-one (31) geotechnical borings as well as sixty-five (65) cone penetrometer tests with porewater measurements (CPTu) soundings. Princeton Hydro also provided site safety oversight in accordance with USACE standards. Soil samples were logged and collected by Princeton Hydro and tested at their Sicklerville, New Jersey geotechnical laboratory, which is accredited under the AASHTO Accreditation Program and validated by USACE for soils testing. The data collected is now being used by USACE to design the upgraded dike system, ensuring safe, resilient operation of the facility for future dredged material management. [gallery link="none" columns="2" size="medium" ids="18181,18183"] Comprehensive Geotechnical Investigation and Reporting – New Jersey At the 545-acre Pedricktown North Confined Disposal Facility in Oldmans Township, New Jersey, located on the Delaware River west of Route 130 between Porcupine Road and Pennsgrove-Pedricktown Road, Princeton Hydro conducted a comprehensive subsurface investigation in support of a dike raising project led by the USACE Philadelphia District. As part of this field exploration, our team performed eight geotechnical borings, thirty-eight cone penetrometer tests with porewater measurement (CPTu) soundings, and collected five grab samples. These efforts provided critical soil strength and settlement data to inform USACE’s design of the upgraded dike system. In addition to managing subcontractors and ensuring compliance with USACE safety protocols, Princeton Hydro oversaw the field program, coordinated directly with the Project Manager, and delivered the final geotechnical report. This investigation is supplying USACE with essential geotechnical data to guide the design and construction of the improved dike infrastructure. [gallery link="none" size="medium" ids="18190,18193,18192"] This blog only scratches the surface of what geotechnical engineering entails. To dive deeper, we invite you to read “A Day in the Life: Princeton Hydro’s Geotechnical Laboratory,” where you’ll step into our laboratory and shadow Marissa Ciocco, P.E. as she turns soil samples into the data that drives resilient design. [post_title] => Beneath the Surface: Exploring the World of Geotechnical Engineering [post_excerpt] => [post_status] => publish [comment_status] => open [ping_status] => open [post_password] => [post_name] => beneath-the-surface-exploring-the-world-of-geotechnical-engineering [to_ping] => [pinged] => [post_modified] => 2025-10-15 17:39:54 [post_modified_gmt] => 2025-10-15 17:39:54 [post_content_filtered] => [post_parent] => 0 [guid] => https://princetonhydro.com/?p=18379 [menu_order] => 0 [post_type] => post [post_mime_type] => [comment_count] => 0 [filter] => raw ) [1] => WP_Post Object ( [ID] => 5685 [post_author] => 3 [post_date] => 2020-12-22 19:35:49 [post_date_gmt] => 2020-12-22 19:35:49 [post_content] => Princeton Hydro has grown from a small, four-person firm operating out of a living room to a 60+ person business with six office locations in the Northeast and a satellite office in Colorado. Over the last two decades, we’ve restored many miles of rivers, improved water quality in hundreds of ponds and lakes, and enhanced thousands of acres of ecosystems in the Northeast. This year, we are feeling extra grateful for those who have supported our business and helped us further our mission during these difficult times. As we reflect on 2020 and set our sights on 2021, we have many successes to celebrate. Here's a look at our top 10 successes of the year: 1. RESTORED FISH PASSAGE ON SIX WATERWAYS [embed]https://youtu.be/b6FyQTu23lM[/embed] Our team installed one fish ladder and oversaw the removal of five dams in four states. In New York, in partnership with Riverkeeper, Princeton Hydro oversaw the removal of two dams on tributaries to the Hudson River: Strooks Felt Dam on the Quassaick Creek in Newburgh and Barrier #1 on Furnace Brook in Cortlandt. The dams were the first barriers for fish movement upstream from the Hudson River. In Connecticut, the Slocomb Dam along Roaring Brook in South Glastonbury was removed, restoring American eel and trout passage. In Massachusetts, the Horseshoe Mill Pond Dam in Wareham was removed, opening over 3 miles of fish habitat on the Weweantic River, Buzzards Bay’s largest freshwater river. Here, migratory fish can now swim unimpeded from Buzzards Bay to lay their eggs in fresh water upstream for the first time in 200 years. In New Jersey, we led the removal of Warren Hills Dam in Washington, NJ and partnered with the American Littoral Society to install a fish ladder at the Old Mill Pond Dam in Spring Lake Heights, NJ, which allows migratory fish to scale the dam and access spawning grounds that had been blocked-off for over 100 years. 2. LED THE LARGEST APPLICATION OF PHOSLOCK IN THE NORTHEAST ON NEW JERSEY'S LARGEST LAKE [embed]https://youtu.be/BU_lub2UR20[/embed] We implemented a variety of measures that helped Lake Hopatcong, New Jersey's largest lake, mitigate harmful algal blooms (HABs). We applied a clay-based nutrient inactivating technology called Phoslock, which was the largest Phoslock treatment to occur in the Northeastern US. This treatment along with HAB prevention measures like the installation of biochar bags, nanobubble aeration systems, and floating wetland islands proved successful in mitigating HABs and improving overall water quality in 2020. And to top it all off, The Washington Post was awarded a Pulitzer Prize for its explanatory reporting on a novel climate change story featuring Lake Hopatcong and our lake management work. 3. DESIGNED AND CONSTRUCTED WETLAND AND SHORELINE RESTORATION PROJECTS [embed]https://youtu.be/FLZL-G7J97s[/embed] We completed a shoreline restoration project at The Dunes at Shoal Harbor, a coastal residential community along the Jersey Shore that was severely impacted by Hurricane Sandy. In Linden’s Tremley Point neighborhood - another New Jersey community ravaged by Hurricane Sandy - we completed a green infrastructure and floodplain restoration project, the first restoration project to ever be implemented on NJDEP Blue Acres-acquired property. We transformed a densely developed, flood-prone, former industrial site in Bloomfield into a thriving public park with 4.2 acres of wetlands. Each of these three projects helped to restore valuable ecological functions and increase storm resiliency. 4. LAUNCHED A COMMUNITY SCIENCE MONITORING PROJECT FOR THE SCHUYLKILL RIVER On World Habitat Day, the nonprofit, Schuylkill River Greenways, in partnership with Berks Nature, Bartram’s Garden, The Schuylkill Center for Environmental Education, Stroud Water Research Center, and Princeton Hydro, kicked-off a Water Quality Monitoring Project for the Schuylkill River. This project aims to document the current ecological health of the river and engage a diverse set of river users and residents. As part of the campaign, the team is recruiting “Community Scientists” to conduct Visual Monitoring Assessments. Additionally, the stakeholder team is implementing water quality sampling and monitoring throughout 2021 at locations along the main stem of the Schuylkill River. 5. WELCOMED EIGHT NEW FULL-TIME TEAM MEMBERS This year, we added eight new full-time staff members and one intern with expertise and qualifications in a variety of fields, all of whom have a passion for water resource management and environmental stewardship. In March, we were thrilled to welcome Dr. Laura Craig to our team as the new Director of Natural Resources. She is an Aquatic Ecologist who has overseen 25 dam removals, co-founded the NJ Dam Removal Partnership, and has 10+ years of experience in river conservation and climate adaptation. Go here to learn about the career opportunities currently available with us. 6. COMPLETED A MAJOR ECOLOGICAL STUDY OF THE HUDSON RIVER The USACE Commanding General and 55th U.S. Army Chief of Engineers signed the Hudson River Habitat Restoration Ecosystem Restoration study, designating it as complete and making it eligible for congressional authorization. Princeton Hydro led the Integrated Feasibility Study and Environmental Assessment, which recommends three ecosystem restoration projects at sites along the river including Henry Hudson Park, Schodack Island Park, and Moodna Creek. The Hudson River Estuary is a significant habitat for fish, plants, and other wildlife, and this milestone marks progress toward the river’s return to a dynamic and self-regulating ecosystem. If constructed, these projects would restore almost 24 football-sized fields of wetlands in total. 7. EARNED THREE PRESTIGIOUS AWARDS The New Jersey Section of the American Water Resources Association honored Princeton Hydro with the “Excellence in Water Resources: Ecological Restoration Award” for the Linden Blue Acres Floodplain Restoration & Green Infrastructure project. This restored the ecological and floodplain function on former residential properties acquired by the NJDEP Blue Acres Program for the first time. The American Littoral Society and Princeton Hydro received the “Land Ethics Best Large-Scale Project Award” from Bowman’s Hill Wildflower Preserve for the work they did to restore the health and water quality of the Metedeconk River flowing through Ocean County Park in Lakewood, NJ. The Iowa Court and South Green Living Shoreline Project in Little Egg Harbor and Tuckerton, NJ, for which Princeton Hydro lead the sediment sampling/testing and hydrographic survey, received the “2020 Best Green Project Award” from Engineering News-Record. 8. GAVE OVER 20 PRESENTATIONS ON WATERSHED MANAGEMENT & RESILIENCY MEASURES During the Hudson River Estuary Program’s conference, Christiana Pollack, GISP, CFM presented on managing invasive Phragmites and restoring wetland habitats. And, at the Consortium for Climate Risk in the Urban Northeast, Christiana presented on a flood mitigation analysis project in a flood-prone Philadelphia community. As part of The American Sustainable Business Council’s “Clean Water is Good for Business” campaign, Marketing & Communications Manager, Dana Patterson, led a webinar, titled “Making the Business Case on Clean Water Issues to the Media.” At the 2020 Delaware Wetlands Conference, Senior Project Manager, Michael Rehman, presented a wetland restoration project that illustrates how a degraded urban area can be successfully rehabilitated. And, for a New York State Federation of Lake Associations webinar series, Senior Aquatic Ecologist, Chris Mikolajczyk, CLM, presented on a unique lake management initiative. And, our Director of Aquatics, Dr. Fred Lubnow, joined Rep. Debbie Mucarsel-Powell & other experts to discuss Harmful Algal Blooms at a virtual #ProtectCleanWater Town Hall hosted by the National Wildlife Federation Action Fund. 9. CELEBRATED A VARIETY OF STAFF ACHIEVEMENTS Our staff are repeatedly striving for personal growth and continue to amaze us. North American Lake Management Society chose Chris L. Mikolajczyk, CLM, Senior Aquatic Ecologist as the next President of the Board of Directors. Senior Ecologist, Michael Rehman, PWS, and Fluvial Geomorphologist, Paul Woodworth, became Certified Ecological Restoration Practitioners through the Society for Ecological Restoration. Emily Bjorhus and Robert George earned their Professional Wetland Scientist certification through the Society of Wetland Scientists program. In January, our Marketing & Communications Manager, Dana Patterson, received the Society of American Military Engineers New Jersey Post’s “Young Member Award” for her efforts in maintaining and advancing the objectives of the organization (pictured above). A national science journal published Environmental Scientist, Brittany Smith’s, graduate research study, which assessed “The Ecogeomorphic Evolution of Louisiana’s Wax Lake Delta.” Cory Speroff passed his Landscape Architecture exams and Andrew Simko earned his Professional Engineering license. And, Dr. Clay Emerson won our Earth Day Photo Contest with his incredible close-up of an Eastern Fence Lizard. 10. WE STAYED UNIFIED AND CONNECTED 2020 was a particularly challenging year, but the Princeton Hydro family stood together. With offices spread across the Northeast and collaboration between offices on a daily basis, we were unknowingly prepared for the shift to remote work during an unexpected global pandemic. But, it took more than just working laptops and VPN connections to keep us going. Because of our staff’s motivation and dedication to serving our clients, we were able to not only keep our firm open, but we continued to grow our geographic and service reach. Thank you for supporting Princeton Hydro and sharing our stories. We truly appreciate each and every one of our clients, partners, and friends. Cheers to a fruitful 2021 and beyond! [post_title] => Year in Review: Top 10 Successes of 2020 [post_excerpt] => [post_status] => publish [comment_status] => open [ping_status] => open [post_password] => [post_name] => 2020-success-stories [to_ping] => [pinged] => [post_modified] => 2025-11-04 02:41:32 [post_modified_gmt] => 2025-11-04 02:41:32 [post_content_filtered] => [post_parent] => 0 [guid] => https://www.princetonhydro.com/blog/?p=5685 [menu_order] => 0 [post_type] => post [post_mime_type] => [comment_count] => 0 [filter] => raw ) [2] => WP_Post Object ( [ID] => 5595 [post_author] => 3 [post_date] => 2020-12-10 14:23:04 [post_date_gmt] => 2020-12-10 14:23:04 [post_content] => As part of the multi-faceted effort to restore the vital Hudson River ecosystem, the USACE New York District launched the Hudson River Habitat Restoration. Princeton Hydro led the Hudson River Habitat Restoration Integrated Feasibility Study and Environmental Assessment for USACE. For this project, we established and evaluated baseline conditions through data collection and analysis; developed restoration objectives and opportunities; prepared an Environmental Assessment; and designed conceptual restoration plans for eight sites. This week, Lt. Gen. Scott A. Spellmon, USACE Commanding General and 55th U.S. Army Chief of Engineers, signed the Hudson River Habitat Restoration Ecosystem Restoration Chief’s Report, which represents the completion of the study and makes it eligible for congressional authorization. As stated in the USACE-issued news release, “The Chief’s Report recommends three individual ecosystem restoration projects including Henry Hudson Park, Schodack Island Park, and Moodna Creek within the 125-mile study area from the Federal Lock and Dam at Troy, NY to the Governor Mario M. Cuomo Bridge. These projects would restore a total of approximately 22.8 acres of tidal wetlands, 8.5 acres of side-channel and wetland complex, and 1,760 linear feet of living shoreline with 0.6 acres of tidal wetlands. The plan would also reconnect 7.8 miles of tributary habitat to the Hudson River through the removal of 3 barriers along Moodna Creek.” “The signing of this Chief’s Report is a significant milestone for the HRHR Project,” said Col. Matthew Luzzatto, USACE New York District Commander. “This has truly been a team effort and I want to thank our non-federal sponsors, New York State Department of Environmental Conservation and New York State Department of State, and all of our engineers, scientists, and partners at the local, state and federal level for their unwavering support.” Read the full press release here. And, for more background information on the Feasibility Study and proposed restoration work, check out our original blog post: [embed]https://www.princetonhydro.com/blog/hudson-river-habitat-restoration/[/embed] [post_title] => UPDATE: Hudson River Habitat Restoration Study Completed & Chief's Report Signed [post_excerpt] => [post_status] => publish [comment_status] => open [ping_status] => open [post_password] => [post_name] => update-hrhr [to_ping] => [pinged] => [post_modified] => 2025-01-02 14:19:23 [post_modified_gmt] => 2025-01-02 14:19:23 [post_content_filtered] => [post_parent] => 0 [guid] => https://www.princetonhydro.com/blog/?p=5595 [menu_order] => 0 [post_type] => post [post_mime_type] => [comment_count] => 0 [filter] => raw ) [3] => WP_Post Object ( [ID] => 4429 [post_author] => 3 [post_date] => 2019-12-20 16:26:07 [post_date_gmt] => 2019-12-20 16:26:07 [post_content] => Over the last two decades, we've restored many miles of rivers, improved water quality in hundreds of ponds and lakes, and enhanced thousands of acres of ecosystems in the Mid-Atlantic and New England regions. In 2019, we had our best year yet. As we reflect back on 2019 and set our sights on 2020, we have many successes to celebrate: 1. We Designed the Largest Dam Removal in New Jersey. The century-old Columbia Dam was removed and fish passage was restored on the 42-mile long Paulins Kill river, an important tributary to the Delaware River in northwestern New Jersey. On Earth Day 2019, just two months after the river finally flowed free, we were thrilled to discover the return of American shad upstream for the first time in over 100 years. 2. We Conceptualized Six Sites Along the Hudson River for Habitat Restoration. Our team completed a feasibility study for the U.S. Army Corps of Engineers (USACE), which identified and conceptualized restoration opportunities at six key sites. For this Hudson River Habitat Restoration Integrated Feasibility Study and Environmental Assessment, Princeton Hydro collected and analyzed data, reviewed existing conditions, and drafted conceptual restoration designs. Our final report was just highlighted by USACE at the 2019 Planning Community of Practice (PCoP) national conference at the Kansas City District as an example of a successfully implemented Ecosystem Restoration Planning Center of Expertise (ECO-PCX) project. 3. National and Regional News Outlets Featured Princeton Hydro Harmful Algal Bloom Experts. After a record-breaking number of HABs broke out in lakes across the region, our Aquatics Team was called upon for their expertise and insights into why the outbreak was happening, what could be done to treat it, and what preventative actions will lessen the likelihood of future outbreaks. In addition to being featured in various regional news outlets covering the HABs topic, Princeton Hydro experts were featured in the New York Times and the Washington Post for their leadership at the largest lake in New Jersey, Lake Hopatcong. (Photo credit: Washington Post) 4. Our Staff Presented, Exhibited, and Attended Over 50 Events. From galas to environmental conferences and river restoration tours to college courses, the Princeton Hydro team participated in more than 50 events throughout 2019. Dr. Clay Emerson, PE taught a Green Infrastructure Stormwater Management Course at Montclair University. Kelsey Mattison, Marketing Coordinator, presented at the 3rd Annual New Jersey Watershed Conference. And, at the New Jersey Land Conservation Rally, we had three presentations on citizen science, marketing strategy, and lake stewardship. Various team members rolled up their sleeves to volunteer to plant trees at Exton Park on Arbor Day, build a rain garden in Clawson Park, and restore eroding shoreline in Point Pleasant. Stayed tuned for more in 2020! 5. We’re Restoring the Northernmost Freshwater Tidal Marsh on the Delaware River. Mercer County’s John A. Roebling Memorial Park is home to the northernmost freshwater tidal marsh on the Delaware River, Abbott Marshland, an area containing valuable habitat for many rare species. Unfortunately, the area has experienced a significant amount of loss and degradation, partially due to the introduction of the invasive Phragmites australis. The Princeton Hydro team proudly removed this invasive species and is restoring the marsh to enhance plant diversity, wildlife habitat, and water quality. 6. We Upcycled Christmas Trees to Stabilize an Eroding Shoreline for the First Time in NJ. To prevent further erosion at the Slade Dale Sanctuary in Point Pleasant, dozens of volunteers helped stabilize the shoreline using recycled Christmas trees, a technique never been done before in New Jersey. The 13-acre Slade Dale Sanctuary is an important part of the local ecosystem and much work is being done there to restore the marsh and enhance the ecological function and integrity of the preserve. Princeton Hydro developed a conceptual and engineering design using living shoreline features, including tree vane structures to attenuate wave action, foster sediment accretion, and reduce erosion. 7. Princeton Hydro Earned Three Prestigious Awards. The Friends of the Presumpscot River awarded Laura Wildman, P.E., with its “Chief Polin Award” for her accomplishments and efforts in bringing life back to the Presumpscot River and rivers across the nation. The New Jersey Highlands Coalition honored Founding Principal Dr. Stephen Souza with a Lifetime Achievement Award, touting his dedication to preserving and protecting New Jersey’s watersheds and natural resources. And, our Pin Oak Forest and Wetland Restoration project earned the “Land Ethics Award of Merit” from Bowman’s Hill Wildflower Preserve for its remarkable restoration achievements. 8. We’re Converting an Urban, Flood-Prone Industrial Site into a Thriving Public Park. Along the Third River and Spring Brook, two freshwater tributaries of the Passaic River, a former industrial site that is highly-disturbed and flood-prone is being transformed into a thriving public park. The team broke ground on this important ecological restoration and urban wetland creation project in March and the restoration work continues. Princeton Hydro is serving as the ecological engineer to Bloomfield Township providing a variety of services and expertise. 9. Princeton Hydro Welcomed 12 New Staff and Added Two Key Positions. As part of the expansion of our growing business, Princeton Hydro added 12 team members with expertise and qualifications in a variety of fields. In July, we announced a new executive position in the firm, Director of Operations. We also created an internal Human Resources Department and hired Samara McAuliffe as Employee Relations Manager. Princeton Hydro has grown from a small, four-person idea operating out of a living room to a 65+ person qualified Small Business with six office locations in the Northeast region. 10. New Year, New Locations! We’re moving on up! In 2019, we moved our D.C. Regional Office down the road from Annapolis, MD to Bowie, MD expanding into a larger office space to accommodate our staff growth and providing opportunity for more growth in the region. And, in late 2019, through our strategic partnership with Merestone Consulting, we opened a sixth office in Wilmington, Delaware. Stay tuned for more information! Thank you for supporting Princeton Hydro and sharing our stories. We truly appreciate each and every one of our clients and partners. Cheers to a fruitful 2020 and beyond! [post_title] => 2019 Successes: A Year in Review [post_excerpt] => [post_status] => publish [comment_status] => open [ping_status] => open [post_password] => [post_name] => 2019-successes-a-year-in-review [to_ping] => [pinged] => [post_modified] => 2021-04-22 18:24:08 [post_modified_gmt] => 2021-04-22 18:24:08 [post_content_filtered] => [post_parent] => 0 [guid] => https://www.princetonhydro.com/blog/?p=4429 [menu_order] => 0 [post_type] => post [post_mime_type] => [comment_count] => 0 [filter] => raw ) [4] => WP_Post Object ( [ID] => 4296 [post_author] => 3 [post_date] => 2019-10-09 14:50:55 [post_date_gmt] => 2019-10-09 14:50:55 [post_content] => Way up in Northern New York, the St. Lawrence River splits the state’s North Country region and Canada, historically acting as an incredibly important resource for navigation, trade, and recreation. Along the St. Lawrence River is the St. Lawrence Seaway, a system of locks, canals, and channels in both Canada and the U.S. that allows oceangoing vessels to travel from the Atlantic Ocean all the way to the Great Lakes. Recently, the St. Lawrence Seaway Development Corporation (SLSDC) contracted Princeton Hydro to conduct analytical and geotechnical sampling on material they plan to dredge out of the Wiley-Dondero Canal. Before dredging, sediment and soils have to be tested to ensure their content is suitable for beneficial reuse of dredged material. In August, our Geologist, Marshall Thomas and Environmental Scientist, Pat Rose, took a trip up north to conduct soil sampling and testing at two different sites within the canal near Massena and the Eisenhower Lock, which were designated by the SLSDC. The first site was at the SLSDC Marine Base, which is a tug/mooring area directly southwest of Snell Lock. The second location was directly northeast of the Eisenhower Lock, which is also used as a mooring area. Both of these sites require dredging in order to maintain mooring access for boat traffic navigating the channel. During this two-day sampling event, our team, which also included two licensed drillers from Atlantic Testing Laboratories, used a variety of equipment to extract the necessary samples from the riverbed. Some of the sampling equipment included:
When most people think of engineering, they picture bridges, buildings, and dams rising above the landscape. Yet the performance and longevity of these structures depend just as much on the subsurface conditions beneath them. Geotechnical engineering is the discipline dedicated to investigating, analyzing, and characterizing soil, rock, landscape, and groundwater conditions, and applying that data to the design and construction of safe, resilient, and sustainable infrastructure and restoration projects.
At Princeton Hydro, our geotechnical and soils engineers design and execute customized, cost-effective investigations that provide the parameters needed for successful design. Because geotechnical services touch every stage of a project, our integrated approach of investigation, including soils laboratory testing, analysis, and design, all done in-house, ensures streamlined communication, efficiency, and technical excellence.
This blog offers a closer look at what geotechnical engineering entails, the specialized capabilities Princeton Hydro provides, and real-world examples of how our work supports resilient, sustainable design.
Geotechnical Investigations: Our engineers can perform subsurface investigation, identification, and assessment of accumulated sediment, subsurface soils, and rock, as well as slope stability and stabilization modeling. Our work ranges from foundation type and bearing capacity assessments to mitigation strategies for unsuitable materials. We also regularly conduct forensic geotechnical investigations, which focus on investigating soil-interaction-related failures of engineered infrastructure.
Laboratory Testing: We operate an American Association of State Highway and Transportation Officials (AASHTO) Accredited laboratory in Sicklerville, NJ. This allows us to complete 100% of geotechnical investigation planning and oversight, laboratory testing, analysis, design, and reporting in-house. Our geotechnical laboratory performs a full suite of soils and materials testing, including grain size analysis, plasticity index, organic content, moisture content, compaction characteristics of soil (Standard and Modified Proctor), California bearing ratio (CBR), one dimensional consolidation, and flexible and rigid wall permeability testing under constant or falling head conditions. With this capability, we can rapidly deliver high-quality data to inform project design and construction. Our laboratory is also a U.S. Army Corps of Engineers (USACE) Validated Laboratory. Click here to view Princeton Hydro’s complete accreditation listing and certificate. And, click here to learn more about the USACE Materials Testing Laboratories and Validation.
Field & Construction Services: Our engineers are experienced in construction requirements, design, and methodology for various structures, as well as field inspections and special testing. We have a Certified Construction Specifier (CCS) on staff and ACI-certified concrete field-testing technicians. Our team performs compaction testing of soil and asphalt using a nuclear density gauge, reinforcing steel inspections, and 2006 International Building Code (IBC) special inspections. We help determine foundation type, site improvements, and optimal construction techniques.
Dredging & Sediment Investigations: Over our 25-year history, we’ve managed more than 100 dredging projects across freshwater and estuarine systems. We specialize in beneficial reuse of dredged material for ecological restoration, including wetland creation, thin-layer placement, and living shorelines. Our team provides sediment characterization, slope stability modeling, and contaminant analysis in complex, developed watersheds.
To bring this work to life, we’ve chosen a few Princeton Hydro projects that showcase where our geotechnical expertise helped solve unique challenges:
At Spring Creek Park North in Jamaica Bay, New York, decades of urbanization and dredged material placement had degraded more than 40 acres of tidal marsh and uplands. To address this, Princeton Hydro provided subsurface investigations and design services for a large-scale ecosystem restoration led by the USACE New York District, in partnership with NYC Parks.
A key design assumption was the reuse of excavated material: soils removed from wetland areas were repurposed to construct upland hills, supporting both ecological function and cost-effective implementation. Our work included geotechnical borings, slope stability analyses, and hydraulic modeling, as well as the collection of topographic and bathymetric survey data, wetland delineations, vegetation assessments, and hydrodynamic measurements. This data informed the development of slope stability and hydraulic models and guided the restoration design.
The project advanced through a structured engineering design process — with 30%, 60%, 90%, and 100% design submissions — along with preparation of technical specifications, permit applications, and a detailed construction cost estimate. When complete, the project will restore more than 43 acres of marsh and upland habitat, improving water quality, enhancing biodiversity, and strengthening climate resilience in one of New York City’s most ecologically significant coastal systems.
Princeton Hydro was contracted by USACE Philadelphia District to perform offshore subsurface geotechnical investigations in support of reconstructing the Indian River Inlet jetty at Delaware Seashore State Park. Working under challenging marine conditions, our team successfully advanced deep geotechnical borings (to depths of 100 feet) from a lift boat platform, collected soil samples, performed laboratory testing including triaxial strength, consolidation, and direct shear tests; and delivered detailed soil data. Despite difficult sea states, we maintained close communication with USACE to ensure safety and project continuity.
The resulting data provided USACE with critical insight into subsurface conditions, helping inform design alternatives for the new jetty structure.
At the Killcohook Confined Disposal Facility (CDF), Princeton Hydro carried out a large-scale subsurface investigation to support USACE Philadelphia District’s plans for raising the site’s perimeter dikes. The project site, formerly a National Wildlife Refuge, is located in Pennsville, New Jersey, on the eastern bank of the Delaware River, to the north of Fort Mott State Park and adjacent to the Supawna Meadows Wildlife Refuge. Each cell of the CDF receives dredge material from the Delaware River. The subsurface explorations performed by Princeton Hydro were conducted along the existing dike comprising the border of Cell 1 of the CDF. Cell 1 consists of an area of approximately 710 acres with the entire CDF covering 1,200 acres.
For this exploration project, Princeton Hydro was tasked with the performance of thirty-one (31) geotechnical borings as well as sixty-five (65) cone penetrometer tests with porewater measurements (CPTu) soundings. Princeton Hydro also provided site safety oversight in accordance with USACE standards. Soil samples were logged and collected by Princeton Hydro and tested at their Sicklerville, New Jersey geotechnical laboratory, which is accredited under the AASHTO Accreditation Program and validated by USACE for soils testing.
The data collected is now being used by USACE to design the upgraded dike system, ensuring safe, resilient operation of the facility for future dredged material management.
At the 545-acre Pedricktown North Confined Disposal Facility in Oldmans Township, New Jersey, located on the Delaware River west of Route 130 between Porcupine Road and Pennsgrove-Pedricktown Road, Princeton Hydro conducted a comprehensive subsurface investigation in support of a dike raising project led by the USACE Philadelphia District.
As part of this field exploration, our team performed eight geotechnical borings, thirty-eight cone penetrometer tests with porewater measurement (CPTu) soundings, and collected five grab samples. These efforts provided critical soil strength and settlement data to inform USACE’s design of the upgraded dike system.
In addition to managing subcontractors and ensuring compliance with USACE safety protocols, Princeton Hydro oversaw the field program, coordinated directly with the Project Manager, and delivered the final geotechnical report. This investigation is supplying USACE with essential geotechnical data to guide the design and construction of the improved dike infrastructure.
Princeton Hydro has grown from a small, four-person firm operating out of a living room to a 60+ person business with six office locations in the Northeast and a satellite office in Colorado. Over the last two decades, we’ve restored many miles of rivers, improved water quality in hundreds of ponds and lakes, and enhanced thousands of acres of ecosystems in the Northeast.
This year, we are feeling extra grateful for those who have supported our business and helped us further our mission during these difficult times. As we reflect on 2020 and set our sights on 2021, we have many successes to celebrate. Here's a look at our top 10 successes of the year:
Our team installed one fish ladder and oversaw the removal of five dams in four states. In New York, in partnership with Riverkeeper, Princeton Hydro oversaw the removal of two dams on tributaries to the Hudson River: Strooks Felt Dam on the Quassaick Creek in Newburgh and Barrier #1 on Furnace Brook in Cortlandt. The dams were the first barriers for fish movement upstream from the Hudson River. In Connecticut, the Slocomb Dam along Roaring Brook in South Glastonbury was removed, restoring American eel and trout passage. In Massachusetts, the Horseshoe Mill Pond Dam in Wareham was removed, opening over 3 miles of fish habitat on the Weweantic River, Buzzards Bay’s largest freshwater river. Here, migratory fish can now swim unimpeded from Buzzards Bay to lay their eggs in fresh water upstream for the first time in 200 years. In New Jersey, we led the removal of Warren Hills Dam in Washington, NJ and partnered with the American Littoral Society to install a fish ladder at the Old Mill Pond Dam in Spring Lake Heights, NJ, which allows migratory fish to scale the dam and access spawning grounds that had been blocked-off for over 100 years.
We implemented a variety of measures that helped Lake Hopatcong, New Jersey's largest lake, mitigate harmful algal blooms (HABs). We applied a clay-based nutrient inactivating technology called Phoslock, which was the largest Phoslock treatment to occur in the Northeastern US. This treatment along with HAB prevention measures like the installation of biochar bags, nanobubble aeration systems, and floating wetland islands proved successful in mitigating HABs and improving overall water quality in 2020. And to top it all off, The Washington Post was awarded a Pulitzer Prize for its explanatory reporting on a novel climate change story featuring Lake Hopatcong and our lake management work.
We completed a shoreline restoration project at The Dunes at Shoal Harbor, a coastal residential community along the Jersey Shore that was severely impacted by Hurricane Sandy. In Linden’s Tremley Point neighborhood - another New Jersey community ravaged by Hurricane Sandy - we completed a green infrastructure and floodplain restoration project, the first restoration project to ever be implemented on NJDEP Blue Acres-acquired property. We transformed a densely developed, flood-prone, former industrial site in Bloomfield into a thriving public park with 4.2 acres of wetlands. Each of these three projects helped to restore valuable ecological functions and increase storm resiliency.
On World Habitat Day, the nonprofit, Schuylkill River Greenways, in partnership with Berks Nature, Bartram’s Garden, The Schuylkill Center for Environmental Education, Stroud Water Research Center, and Princeton Hydro, kicked-off a Water Quality Monitoring Project for the Schuylkill River. This project aims to document the current ecological health of the river and engage a diverse set of river users and residents. As part of the campaign, the team is recruiting “Community Scientists” to conduct Visual Monitoring Assessments. Additionally, the stakeholder team is implementing water quality sampling and monitoring throughout 2021 at locations along the main stem of the Schuylkill River.
This year, we added eight new full-time staff members and one intern with expertise and qualifications in a variety of fields, all of whom have a passion for water resource management and environmental stewardship. In March, we were thrilled to welcome Dr. Laura Craig to our team as the new Director of Natural Resources. She is an Aquatic Ecologist who has overseen 25 dam removals, co-founded the NJ Dam Removal Partnership, and has 10+ years of experience in river conservation and climate adaptation. Go here to learn about the career opportunities currently available with us.
The USACE Commanding General and 55th U.S. Army Chief of Engineers signed the Hudson River Habitat Restoration Ecosystem Restoration study, designating it as complete and making it eligible for congressional authorization. Princeton Hydro led the Integrated Feasibility Study and Environmental Assessment, which recommends three ecosystem restoration projects at sites along the river including Henry Hudson Park, Schodack Island Park, and Moodna Creek. The Hudson River Estuary is a significant habitat for fish, plants, and other wildlife, and this milestone marks progress toward the river’s return to a dynamic and self-regulating ecosystem. If constructed, these projects would restore almost 24 football-sized fields of wetlands in total.
The New Jersey Section of the American Water Resources Association honored Princeton Hydro with the “Excellence in Water Resources: Ecological Restoration Award” for the Linden Blue Acres Floodplain Restoration & Green Infrastructure project. This restored the ecological and floodplain function on former residential properties acquired by the NJDEP Blue Acres Program for the first time. The American Littoral Society and Princeton Hydro received the “Land Ethics Best Large-Scale Project Award” from Bowman’s Hill Wildflower Preserve for the work they did to restore the health and water quality of the Metedeconk River flowing through Ocean County Park in Lakewood, NJ. The Iowa Court and South Green Living Shoreline Project in Little Egg Harbor and Tuckerton, NJ, for which Princeton Hydro lead the sediment sampling/testing and hydrographic survey, received the “2020 Best Green Project Award” from Engineering News-Record.
During the Hudson River Estuary Program’s conference, Christiana Pollack, GISP, CFM presented on managing invasive Phragmites and restoring wetland habitats. And, at the Consortium for Climate Risk in the Urban Northeast, Christiana presented on a flood mitigation analysis project in a flood-prone Philadelphia community. As part of The American Sustainable Business Council’s “Clean Water is Good for Business” campaign, Marketing & Communications Manager, Dana Patterson, led a webinar, titled “Making the Business Case on Clean Water Issues to the Media.” At the 2020 Delaware Wetlands Conference, Senior Project Manager, Michael Rehman, presented a wetland restoration project that illustrates how a degraded urban area can be successfully rehabilitated. And, for a New York State Federation of Lake Associations webinar series, Senior Aquatic Ecologist, Chris Mikolajczyk, CLM, presented on a unique lake management initiative. And, our Director of Aquatics, Dr. Fred Lubnow, joined Rep. Debbie Mucarsel-Powell & other experts to discuss Harmful Algal Blooms at a virtual #ProtectCleanWater Town Hall hosted by the National Wildlife Federation Action Fund.
Our staff are repeatedly striving for personal growth and continue to amaze us. North American Lake Management Society chose Chris L. Mikolajczyk, CLM, Senior Aquatic Ecologist as the next President of the Board of Directors. Senior Ecologist, Michael Rehman, PWS, and Fluvial Geomorphologist, Paul Woodworth, became Certified Ecological Restoration Practitioners through the Society for Ecological Restoration. Emily Bjorhus and Robert George earned their Professional Wetland Scientist certification through the Society of Wetland Scientists program. In January, our Marketing & Communications Manager, Dana Patterson, received the Society of American Military Engineers New Jersey Post’s “Young Member Award” for her efforts in maintaining and advancing the objectives of the organization (pictured above). A national science journal published Environmental Scientist, Brittany Smith’s, graduate research study, which assessed “The Ecogeomorphic Evolution of Louisiana’s Wax Lake Delta.” Cory Speroff passed his Landscape Architecture exams and Andrew Simko earned his Professional Engineering license. And, Dr. Clay Emerson won our Earth Day Photo Contest with his incredible close-up of an Eastern Fence Lizard.
2020 was a particularly challenging year, but the Princeton Hydro family stood together. With offices spread across the Northeast and collaboration between offices on a daily basis, we were unknowingly prepared for the shift to remote work during an unexpected global pandemic. But, it took more than just working laptops and VPN connections to keep us going. Because of our staff’s motivation and dedication to serving our clients, we were able to not only keep our firm open, but we continued to grow our geographic and service reach.
Thank you for supporting Princeton Hydro and sharing our stories. We truly appreciate each and every one of our clients, partners, and friends. Cheers to a fruitful 2021 and beyond!
As part of the multi-faceted effort to restore the vital Hudson River ecosystem, the USACE New York District launched the Hudson River Habitat Restoration. Princeton Hydro led the Hudson River Habitat Restoration Integrated Feasibility Study and Environmental Assessment for USACE. For this project, we established and evaluated baseline conditions through data collection and analysis; developed restoration objectives and opportunities; prepared an Environmental Assessment; and designed conceptual restoration plans for eight sites.
This week, Lt. Gen. Scott A. Spellmon, USACE Commanding General and 55th U.S. Army Chief of Engineers, signed the Hudson River Habitat Restoration Ecosystem Restoration Chief’s Report, which represents the completion of the study and makes it eligible for congressional authorization.
As stated in the USACE-issued news release, “The Chief’s Report recommends three individual ecosystem restoration projects including Henry Hudson Park, Schodack Island Park, and Moodna Creek within the 125-mile study area from the Federal Lock and Dam at Troy, NY to the Governor Mario M. Cuomo Bridge. These projects would restore a total of approximately 22.8 acres of tidal wetlands, 8.5 acres of side-channel and wetland complex, and 1,760 linear feet of living shoreline with 0.6 acres of tidal wetlands. The plan would also reconnect 7.8 miles of tributary habitat to the Hudson River through the removal of 3 barriers along Moodna Creek.”
“The signing of this Chief’s Report is a significant milestone for the HRHR Project,” said Col. Matthew Luzzatto, USACE New York District Commander. “This has truly been a team effort and I want to thank our non-federal sponsors, New York State Department of Environmental Conservation and New York State Department of State, and all of our engineers, scientists, and partners at the local, state and federal level for their unwavering support.”
Read the full press release here. And, for more background information on the Feasibility Study and proposed restoration work, check out our original blog post:
Over the last two decades, we've restored many miles of rivers, improved water quality in hundreds of ponds and lakes, and enhanced thousands of acres of ecosystems in the Mid-Atlantic and New England regions. In 2019, we had our best year yet. As we reflect back on 2019 and set our sights on 2020, we have many successes to celebrate:
The century-old Columbia Dam was removed and fish passage was restored on the 42-mile long Paulins Kill river, an important tributary to the Delaware River in northwestern New Jersey. On Earth Day 2019, just two months after the river finally flowed free, we were thrilled to discover the return of American shad upstream for the first time in over 100 years.
Our team completed a feasibility study for the U.S. Army Corps of Engineers (USACE), which identified and conceptualized restoration opportunities at six key sites. For this Hudson River Habitat Restoration Integrated Feasibility Study and Environmental Assessment, Princeton Hydro collected and analyzed data, reviewed existing conditions, and drafted conceptual restoration designs. Our final report was just highlighted by USACE at the 2019 Planning Community of Practice (PCoP) national conference at the Kansas City District as an example of a successfully implemented Ecosystem Restoration Planning Center of Expertise (ECO-PCX) project.
After a record-breaking number of HABs broke out in lakes across the region, our Aquatics Team was called upon for their expertise and insights into why the outbreak was happening, what could be done to treat it, and what preventative actions will lessen the likelihood of future outbreaks. In addition to being featured in various regional news outlets covering the HABs topic, Princeton Hydro experts were featured in the New York Times and the Washington Post for their leadership at the largest lake in New Jersey, Lake Hopatcong. (Photo credit: Washington Post)
From galas to environmental conferences and river restoration tours to college courses, the Princeton Hydro team participated in more than 50 events throughout 2019. Dr. Clay Emerson, PE taught a Green Infrastructure Stormwater Management Course at Montclair University. Kelsey Mattison, Marketing Coordinator, presented at the 3rd Annual New Jersey Watershed Conference. And, at the New Jersey Land Conservation Rally, we had three presentations on citizen science, marketing strategy, and lake stewardship. Various team members rolled up their sleeves to volunteer to plant trees at Exton Park on Arbor Day, build a rain garden in Clawson Park, and restore eroding shoreline in Point Pleasant. Stayed tuned for more in 2020!
Mercer County’s John A. Roebling Memorial Park is home to the northernmost freshwater tidal marsh on the Delaware River, Abbott Marshland, an area containing valuable habitat for many rare species. Unfortunately, the area has experienced a significant amount of loss and degradation, partially due to the introduction of the invasive Phragmites australis. The Princeton Hydro team proudly removed this invasive species and is restoring the marsh to enhance plant diversity, wildlife habitat, and water quality.
To prevent further erosion at the Slade Dale Sanctuary in Point Pleasant, dozens of volunteers helped stabilize the shoreline using recycled Christmas trees, a technique never been done before in New Jersey. The 13-acre Slade Dale Sanctuary is an important part of the local ecosystem and much work is being done there to restore the marsh and enhance the ecological function and integrity of the preserve. Princeton Hydro developed a conceptual and engineering design using living shoreline features, including tree vane structures to attenuate wave action, foster sediment accretion, and reduce erosion.
The Friends of the Presumpscot River awarded Laura Wildman, P.E., with its “Chief Polin Award” for her accomplishments and efforts in bringing life back to the Presumpscot River and rivers across the nation. The New Jersey Highlands Coalition honored Founding Principal Dr. Stephen Souza with a Lifetime Achievement Award, touting his dedication to preserving and protecting New Jersey’s watersheds and natural resources. And, our Pin Oak Forest and Wetland Restoration project earned the “Land Ethics Award of Merit” from Bowman’s Hill Wildflower Preserve for its remarkable restoration achievements.
Along the Third River and Spring Brook, two freshwater tributaries of the Passaic River, a former industrial site that is highly-disturbed and flood-prone is being transformed into a thriving public park. The team broke ground on this important ecological restoration and urban wetland creation project in March and the restoration work continues. Princeton Hydro is serving as the ecological engineer to Bloomfield Township providing a variety of services and expertise.
As part of the expansion of our growing business, Princeton Hydro added 12 team members with expertise and qualifications in a variety of fields. In July, we announced a new executive position in the firm, Director of Operations. We also created an internal Human Resources Department and hired Samara McAuliffe as Employee Relations Manager. Princeton Hydro has grown from a small, four-person idea operating out of a living room to a 65+ person qualified Small Business with six office locations in the Northeast region.
We’re moving on up! In 2019, we moved our D.C. Regional Office down the road from Annapolis, MD to Bowie, MD expanding into a larger office space to accommodate our staff growth and providing opportunity for more growth in the region. And, in late 2019, through our strategic partnership with Merestone Consulting, we opened a sixth office in Wilmington, Delaware. Stay tuned for more information!
Thank you for supporting Princeton Hydro and sharing our stories. We truly appreciate each and every one of our clients and partners. Cheers to a fruitful 2020 and beyond!
Way up in Northern New York, the St. Lawrence River splits the state’s North Country region and Canada, historically acting as an incredibly important resource for navigation, trade, and recreation. Along the St. Lawrence River is the St. Lawrence Seaway, a system of locks, canals, and channels in both Canada and the U.S. that allows oceangoing vessels to travel from the Atlantic Ocean all the way to the Great Lakes.
Recently, the St. Lawrence Seaway Development Corporation (SLSDC) contracted Princeton Hydro to conduct analytical and geotechnical sampling on material they plan to dredge out of the Wiley-Dondero Canal. Before dredging, sediment and soils have to be tested to ensure their content is suitable for beneficial reuse of dredged material. In August, our Geologist, Marshall Thomas and Environmental Scientist, Pat Rose, took a trip up north to conduct soil sampling and testing at two different sites within the canal near Massena and the Eisenhower Lock, which were designated by the SLSDC. The first site was at the SLSDC Marine Base, which is a tug/mooring area directly southwest of Snell Lock. The second location was directly northeast of the Eisenhower Lock, which is also used as a mooring area. Both of these sites require dredging in order to maintain mooring access for boat traffic navigating the channel.
During this two-day sampling event, our team, which also included two licensed drillers from Atlantic Testing Laboratories, used a variety of equipment to extract the necessary samples from the riverbed. Some of the sampling equipment included:
Vibracoring equipment: this sampling apparatus was assembled on Atlantic Testing’s pontoon boat. To set up the vibracore, a long metal casing tube was mounted on the boat more than 10 feet in the air. The steel casing was lowered through the water approximately 17-20 feet down to the mudline. From there, the vibracore was then vibrated through the sediment for an additional 4-6 feet. For this project, vibracore samples were taken at 4 feet in 10 different locations, and at 6 feet in 3 different locations.
A track mounted drill rig: this rig was positioned along the shoreline to allow advancement of a standard geotechnical test boring close to existing sheet piling. Advancement of the boring was done by way of a 6-inch hollow stem auger. As the auger was advanced, it resembled a giant screw getting twisted into the ground. This drilling method allows the drilling crew to collect soil samples using a split spoon sampler, which is a 2-foot long tubular sample collection device that is split down the middle. The samplers were collected by driving the split spoon into the soil using a 140 lb drop hammer.
For our team, conducting sampling work on the St. Lawrence Seaway was a new experience, given most of our projects occur further east in the Mid-Atlantic region. The most notable difference was the hardness of the sediment. Because the St. Lawrence River sediments contain poorly sorted, dense glacial till, augering into it took a little more elbow grease than typical sediments further south do. The St. Lawrence River is situated within a geological depression that was once occupied by glaciers. As the glaciers retreated, they were eventually replaced by the Champlain Sea, which flooded the area between 13,000 and 9,500 years ago. Later on, the continent underwent a slight uplift, ultimately creating a riverlike watercourse that we now deem the St. Lawrence River. Because it was once occupied by a glacier, this region is full of glacial deposits.
For this project, our team was tasked with collecting both geotechnical and analytical samples for physical and analytical testing. Physical testing included grain size analysis, moisture content, and Atterberg limit testing. Grain size analysis helps determine the distribution of particle sizes of the sample in order to classify the material, moisture content testing determines exactly that -- how moist the sediment is, and Atterberg limits help to classify the fines content of the materials as either silt or clay. Analytical testing included heavy metals, pesticides, volatile organic compounds, and dioxins.
Our scientists were responsible for logging, testing, and providing a thorough analysis of fourteen sampling locations. The samples collected from the vibracore tubes filled with sediment were logged and spilt on-shore. In order to maintain a high level of safety due to the possible presence of contaminants, all of the sampling equipment was decontaminated. This process involves washing everything with a soapy water mixture, a methanol solution, and 10% nitric acid solution.
The samples collected at each vibrocore location were split into multiple jars for both analytical and physical testing. The physical test samples were placed into air and moisture tight glass sample jars and brought to our AASHTO accredited soils laboratory in Sicklerville, New Jersey for testing. The analytical samples were placed into airtight glass sample jars with Teflon-lined caps. These samples were then placed into an ice-filled cooler and sent to Alpha Analytical Laboratories for the necessary analytical testing.
Once all the laboratory testing was completed, a summary report was developed and presented to the client. This report was made to inform the SLSDC of the physical properties of each sediment sample tested and whether contaminants exceeded threshold concentrations as outlined in the New York State Department of Environmental Conservation (NYSDEC) Technical & Operation Guidance Series (TOGS) 5.1.9. This data will ultimately be used by the SLSDC to determine the proper method for dredging of the material and how to properly dispose of the material.
Princeton Hydro provides soil, geologic, and construction materials testing to both complement its water resources and ecological restoration projects and as a stand-alone service to clients. Our geotechnical laboratory, accredited under the AASHTO Accreditation Program (AAP), provides a full suite of soil, rock, and construction material testing for all types of projects. Click here for an inside look inside the lab and walk through “a day in the life” of our Soils Testing Lab expert Marissa Ciocco, PE
Have you ever wondered what it actually means to conduct construction oversight on a project? Our engineers regularly do so to ensure design plans are being implemented correctly. But, construction oversight requires a lot more than just the ability to oversee. Our engineers have to understand the ins and outs of the plans, be adaptable, fast-thinking, and incredibly capable of communicating with and coordinating various parties.
Let’s walk through a day in the life of one of our construction oversight engineers, Casey Schrading, PE, and outline the key components of his job:
SAFETY. When it comes to construction sites, safety always comes first. It is important to have the proper health and safety training before entering an active construction zone. On an active construction site, there could be many different hazards that workers encounter. Before heading to the site, Casey makes sure he has all his necessary safety equipment and protection gear. Personal Protection Equipment (PPE) usually includes a neon safety vest (visibility), hard hat (head protection), long pants (protective clothing), safety glasses (eye protection), and steel-toed boots (foot protection). In some cases, on construction sites with more risk factors, higher levels of PPE may be required including hearing protection, gloves, respiratory masks, fall protection equipment, and disposable Tyvek coveralls.
COORDINATION. For most construction projects, the day starts early. Upon arrival, Casey checks the site out to see if anything has changed from the day before and takes pictures of the site. He then checks in with the contractor to discuss the plan for the day and any outstanding items from the day prior.
Most of the day consists of a back and forth process between watching the construction workers implement the design and then monitoring and checking the design plans. In order for the contractor to properly implement the design, the oversight engineer must direct the workers during the installation process; for many designs, there are critical angles, locations, heights, and widths that features must be installed at. It is imperative for the oversight engineer to direct and work hand-in-hand with the contractor so those features are installed correctly for effective design implementation.
ON-SITE MONITORING. For certain projects, the day-to-day construction oversight tasks may get a little more involved. For instance, when conducting construction oversight for our Columbia Dam Removal project, Casey was tasked with taking turbidity samples every three hours at two locations along the Paulins Kill — one upstream of the site to collect baseline data and one downstream of the site to quantify the site’s effect on turbidity. If the turbidity readings downstream of the site came out too high, Casey would then have to determine how those high levels were affecting the turbidity in the Delaware River, which the Paulins Kill discharges into less than a quarter mile downstream of the site. If flooding in the Delaware River wasn’t enough to pose safety concerns, Casey would then take readings at two additional locations upstream and downstream of the Delaware River-Paulins Kill confluence. Again, the upstream reading served as a baseline reading for turbidity while the downstream reading showed the effects of the Paulins Kill on the Delaware River.
These turbidity samples were necessary because this project involved passive sediment transport, meaning the sediment that had built up behind the dam for over a century was going to slowly work its way downstream as the dam was notched out piece by piece, as opposed to it being dredged out before the barrier removal. It’s important to monitor turbidity in a case like this to make sure levels remain stable. The need for monitoring at construction sites further emphasizes the need for construction oversight engineers to be multifaceted.
ADAPTATION. In all construction projects, the goal is to have everything installed or constructed according to plan, but, with so many environmental factors at play, that rarely happens. Because of the ever-changing nature of most of our projects, it is essential that our construction oversight engineers have the keen ability to adapt and to do so quickly. Casey has experienced a range of changes in plan while conducting construction oversight. He says the skills he relies on most is communication. When something changes, it’s imperative that the onsite engineer knows exactly who to contact to work out a solution. Sometimes that might be Princeton Hydro’s internal project manager, or sometimes it might be a regulatory official from NJDEP.
WEEKLY MEETINGS. Another critical part of construction oversight is facilitating weekly coordination meetings. The weekly meeting is usually attended by the contractor, the engineering firm, and the client. The parties will discuss what has happened thus far at the site and what still needs to happen, allowing them to establish action items. Occasionally, other entities like organizations that provided funding for a project or regulatory agencies, will also be involved in those conversations. The weekly meetings are designed to keep everybody on task and help to ensure every party’s goals and needs are being met.
DOCUMENTATION. Anytime field work is being conducted, it is essential to document the happenings and the progress made. This documentation usually comes in the form of a Daily Field Report (DFR). A DFR includes information about the work performed on a given day, such as measurements, quantities of structures installed, and how that installation process went. Also included in the DFRs are clear and descriptive photographs.
COMMUNICATION. Working on any project, it’s important to make sure all involved parties understand the reason behind each installation. It is often easier for a construction team to implement plans correctly if they know and understand why each part of it is important and included in the project. Explaining why a task needs to be completed also helps relieve tension that could potentially arise between the engineer and the contractor. It is essential to make sure every person on the project team is on the same page.
PUBLIC OUTREACH. Another critical aspect of construction oversight is having the ability to successfully communicate with the public. Members of the community surrounding a site need to be kept apprised of the goings on so they can remain safe during the construction period and understand the goals of the project. When citizens understand the purpose and goals of a project, they are more likely to support and respect it.
REGULATORY COMPLIANCE. Understanding the permitting surrounding a project is also essential to success as a construction oversight engineer. The engineer has to understand the ins and outs of the permitting and regulations in order to be able to make decisions about changes in the plan and to be able to successfully point the contractor in the correct and compliant direction.
"Construction oversight is a tedious and incredibly important job, yet I really enjoy it because it gives me a new and better understanding of the engineering design process," explains Casey. He feels it gives him a much more practical understanding of engineering design, as he has seen what kinds of plans are actually implementable and what that process looks like. "Watching a design plan get implemented brings the project full circle and allows me to take that knowledge and experience back to the office and back into the design process."
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. Learn more.
...
Casey graduated from Virginia Tech in 2018 with a degree in Biological Systems Engineering and now works as a staff engineer for the firm with a focus in water resources engineering. He has experience in ecological restoration, flood management, water quality analysis, and best management practices. His experience also includes construction oversight for dam removal and restoration projects as well as design, technical writing, and drafting for a wide variety of water resources engineering projects. In his free time Casey very much enjoys travelling, hiking, skiing, and camping.
…
Walking through a park isn’t always a walk in the park when it comes to conducting stormwater inspections. Our team routinely spots issues in need of attention when inspecting stormwater infrastructure; that’s why inspections are so important.
Princeton Hydro has been conducting stormwater infrastructure inspections for a variety of municipalities in the Mid-Atlantic region for a decade, including the City of Philadelphia. We are in our seventh year of inspections and assessments of stormwater management practices (SMPs) for the Philadelphia Water Department. These SMPs are constructed on both public and private properties throughout the city and our inspections focus on areas served by combined sewers.
Our water resource engineers are responsible for construction oversight, erosion and sediment control, stormwater facilities maintenance inspections, and overall inspection of various types of stormwater infrastructure installation (also known as “Best Management Practices” or BMPs).
Our knowledgeable team members inspect various sites regularly, and for some municipalities, we perform inspections on a weekly basis. Here’s a glimpse into what a day of stormwater inspection looks like:
The inspector starts by making sure they have all their necessary safety equipment and protection. For the purposes of a simple stormwater inspection the Personal Protection Equipment (PPE) required includes a neon safety vest, hard hat, eye protection, long pants, and boots. Depending on the type of inspection, our team may also have to add additional safety gear such as work gloves or ear plugs. It is recommended that inspectors hold CPR/First Aid and OSHA 10 Hour Construction Safety training certificates.
Once they have their gear, our inspection team heads to the site and makes contact with the site superintendent. It’s important to let the superintendent know they’re there so that 1) they aren’t wondering why a random person is perusing their construction site, and 2) in case of an emergency, the superintendent needs to be aware of every person present on the site.
Once they arrive, our team starts by walking the perimeter of the inspection site, making sure that no sediment is leaving the project area. The team is well-versed in the standards of agencies such as the Pennsylvania Department of Environmental Protection, the Pennsylvania Department of Transportation, the New Jersey Department of Environmental Protection, and local County Soil Conservation Districts, among others. These standards and regulations dictate which practices are and are not compliant on the construction site.
After walking the perimeter, the inspection team moves inward, taking notes and photos throughout the walk. They take a detailed look at the infrastructure that has been installed since the last time they inspected, making sure it was correctly installed according to the engineering plans (also called site plans or drainage and utility plans). They also check to see how many inlets were built, how many feet of stormwater pipe were installed, etc.
If something doesn’t look quite right or needs amending, our staff makes recommendations to the municipality regarding BMPs/SMPs and provides suggestions for implementation.
One example of an issue spotted at one of the sites was a stormwater inlet consistently being inundated by sediment. The inlet is directly connected o the subsurface infiltration basin. When sediment falls through the inlet, it goes into the subsurface infiltration bed, which percolates directly into the groundwater. This sediment is extremely difficult to clean out of the subsurface bed, and once it is in the bed, it breaks down and becomes silt, hindering the function of the stormwater basin.
To remedy this issue, our inspection team suggested they install stone around the perimeter of the inlet on three sides. Although this wasn’t in the original plan, the stones will help to catch sediment before entering the inlet, greatly reducing the threat of basin failure.
Once they’ve thoroughly inspected the site, our team debriefs the site superintendent with their findings. They inform the municipality of any issues they found, any inconsistencies with the construction plans, and recommendations on how to alleviate problems. The inspector will also prepare a Daily Field Report, summarizing the findings of the day, supplemented with photos.
In order to conduct these inspections, one must have a keen eye and extensive stormwater background knowledge. Not only do they need to know and understand the engineering behind these infrastructure implementations, they need to also be intimately familiar with the laws and regulations governing them. Without these routine inspections, mistakes in the construction and maintenance of essential stormwater infrastructure would go unnoticed. Even the smallest overlook can have dangerous effects, which is why our inspections team works diligently to make sure that will not happen.
Our team conducts inspections for municipalities and private entities throughout the Northeast. Click here to read about a stormwater utility investigation and feasibility study we completed in the Town of Hammonton, New Jersey.
To prevent further erosion at the Slade Dale Sanctuary in Point Pleasant, dozens of volunteers helped stabilize the shoreline using a technique that has never been done before in New Jersey. On Saturday, American Littoral Society, in partnership with Princeton Hydro, Borough of Point Pleasant, New Jersey Nature Conservancy, New Jersey Corporate Wetlands Restoration Partnership, and the Point Pleasant Rotary Club, organized dozens of volunteers to restore the shoreline and prevent further erosion at the Slade Dale Sanctuary using recycled Christmas trees.
As one of only a few areas of open space left in Point Pleasant, the 13-acre Slade Dale Sanctuary is an important part of the local ecosystem and is home to a number of unique animals and plants. This waterfront preserve along the North Branch Beaver Dam Creek is predominantly tidal marsh, which provides habitat for various birds, including osprey, as well as passive recreation opportunities for the community.
Unfortunately, the Slade Dale Sanctuary is disappearing. Since 1930, the shoreline of Slade Dale Sanctuary has retreated approximately 300 feet, equal to the length of a football field, and the channels into the marsh have increased in number and size, according to a study we conducted on behalf of American Littoral Society, for which we provide engineering and natural resources management consulting services.
In order to stabilize the shoreline, restore the marsh, and enhance the ecological function and integrity of the preserve, Princeton Hydro developed a conceptual and engineering design using living shoreline features to enhance ecological value and reduce erosion. The final conceptual plan for restoration uses tree vane structures to attenuate wave action, foster sediment accretion, and reduce erosion along the coast.
To implement this vision and begin building back marsh, the project team is constructing several Christmas tree breakwaters and Christmas tree vanes that mimic naturally occurring debris structures in tidal systems and enhance habitat opportunity and shelter for aquatic life. Volunteers came together on Saturday, May 11 to help with the construction. The Mayor of Point Pleasant Robert A. Sabosik also attended the event, "The Barnegat Bay is an attribute that we all enjoy, and it's something we have to protect."
After the 2018 holiday season, the Good Sheppard Lutheran Church in Point Pleasant provided space to collect and store donated Christmas trees, which were then moved to the marsh a few days before the event. On the day of the event, recycled Christmas trees were transported from their staged locations on the marsh to the breakwater sections that were previously installed in the water. To transport them across the water to the pilings, volunteers used two methods: by walking a skiff boat loaded with trees through the water to the pilings or by forming assembly line from the shore to pilings to guide floating trees through the water (check out the album below!). Then, they stuffed the Christmas trees between the pilings, securely tied them down, and staked Christmas trees directly into the creek bottom. For extra assurance, the placed and tied heavy bags of used oyster shells on top of the tree line. Oyster shells were donated by local Monmouth County restaurants in an effort to reduce waste streams.
"We really enjoyed participating in this event with American Littoral Society and so many wonderful volunteers,” Christiana L. Pollack, GISP, CFM, Princeton Hydro's Project Manager for this restoration effort. “It is so wonderful to see this project coming to fruition. We’re so proud of our partnership with American Littoral Society and our combined efforts to revitalize and rehabilitate our precious coastal habitats.”
Many thanks to everyone who came out in support of this important restoration effort at Slade Dale Sanctuary American Littoral Society hosts volunteer events throughout the year. Go here to get involved.
Wreck Pond is a tidal pond located on the coast of the Atlantic Ocean in southern Monmouth County, New Jersey. The 73-acre pond, which was originally connected to the sea by a small and shifting inlet, got its name in the 1800s due to the numerous shipwrecks that occurred at the mouth of the inlet. The Sea Girt Lighthouse was built to prevent such accidents. In the 1930s, the inlet was filled in and an outfall pipe was installed, thus creating Wreck Pond. The outfall pipe allowed limited tidal exchange between Wreck Pond and the Atlantic Ocean.
In the 1960s, Wreck Pond flourished with wildlife and was a popular destination for recreational activities with tourists coming to the area mainly from New York City and western New Jersey. In the early spring, hundreds of river herring would migrate into Wreck Pond, travelling up its tributaries — Wreck Pond Brook, Hurleys Pond Brook and Hannabrand Brook — to spawn. During the summer, the pond was bustling with recreational activities like swimming, fishing, and sailing.
Over time, however, the combination of restricted tidal flow and pollution, attributable to increased development of the watershed, led to a number of environmental issues within the watershed, including impaired water quality, reduced fish populations, and flooding.
Throughout the Wreck Pond watershed, high stream velocities during flood conditions have caused the destabilization and erosion of stream banks, which has resulted in the loss of riparian vegetation and filling of wetlands. Discharge from Wreck Pond during heavy rains conveys nonpoint source pollutants that negatively impact nearby Spring Lake and Sea Girt beaches resulting in beach closings due to elevated bacteria counts. Watershed erosion and sediment transported with stormwater runoff has also contributed to excessive amounts of sedimentation and accumulations of settled sediment, not only within Wreck Pond, but at the outfall pipe as well. This sediment further impeded tidal flushing and the passage of anadromous fish into and out of Wreck Pond.
In 2012, Hurricane Sandy caused wide-spread destruction throughout New Jersey and the entire eastern seaboard. The storm event also caused a major breach of the Wreck Pond watershed’s dune beach system and failure of the outfall pipe. The breach formed a natural inlet next to the outfall pipe, recreating the connection to the Atlantic Ocean that once existed. This was the first time the inlet had been open since the 1930s, and the reopening cast a new light on the benefits of additional flow between the pond and the ocean.
Hurricane Sandy sparked a renewed interest in reducing flooding impacts throughout the watershed, including efforts to restore the water quality and ecology of Wreck Pond. The breach caused by Hurricane Sandy was not stable, and the inlet began to rapidly close due to the deposition of beach sand and the discharge of sediment from Wreck Pond and its watershed.
Princeton Hydro and HDR generated the data used to support the goals of the feasibility study through a USACE-approved model of Wreck Pond that examined the dynamics of Wreck Pond along with the water bodies directly upland, the watershed, and the offshore waters in the immediate vicinity of the ocean outfall. The model was calibrated and verified using available “normalized” tide data. Neighboring Deal Lake, which is also tidally connected to the ocean by a similar outfall pipe, was used as the "reference" waterbody. The Wreck Pond System model evaluated the hydraulic characteristics of Wreck Pond with and without the modified outfall pipe, computed pollutant inputs from the surrounding watershed, and predicted Wreck Pond's water quality and ecological response. The calibrated model was also used to investigate the effects and longevity of dredging and other waterway feature modifications.
As part of the study, Princeton Hydro and HDR completed hazardous, toxic, and radioactive waste (HTRW) and geotechnical investigations of Wreck Pond's sediment to assess potential flood damage reduction and ecological restoration efforts of the waterbody. The investigation included the progression of 10 sediment borings conducted within the main body of Wreck Pond, as well as primary tributaries to the pond. The borings, conducted under the supervision of our geotechnical staff, were progressed through the surgical accumulated sediment, not the underlying parent material. Samples were collected for analysis by Princeton Hydro’s AMRL-accredited (AASHTO Materials Reference Library) and USACE-certified laboratory. In accordance with NJDEP requirements, sediment samples were also forwarded to a subcontracted analytical laboratory for analysis of potential nonpoint source pollutants.
In the geotechnical laboratory, the samples were subjected to geotechnical indexing tests, including grain size, organic content, moisture content, and plasticity/liquid limits. For soil strength parameters, the in-field Standard Penetration Test (SPT), as well as laboratory unconfined compression tests, were performed on a clay sample to provide parameters for slope stability modeling.
The culvert construction and sediment dredging were completed at the end of 2016. Continued restoration efforts, informed and directed by the data developed through Princeton Hydro's feasibility study, are helping to reduce the risk of flooding to surrounding Wreck Pond communities, increase connectivity between the pond and ocean, and improve water quality. The overall result is a healthier, more diverse, and more resilient Wreck Pond ecosystem.
To learn more about our geotechnical engineering services, click here.
On the Paulins Kill, the 100-year old Columbia Lake Dam has almost been completely removed, and fish passage has been restored! Since the first cut was executed on the main dam in August, many exciting advances have been made towards restoring the Paulins Kill back to its natural state. Check out the video below, courtesy of the New Jersey Nature Conservancy Volunteer Drone Team.
Piece by piece, the dam was notched out throughout the fall season and is now completely removed with the exception of the dam apron, the horizontal concrete structure that sits downstream of the dam, and the section of the dam that sits below the riverbed. The part of the dam in the riverbed is now being removed all the way down to three feet under the ground. The full removal is estimated to be complete by mid-March. In mid-August, the first cut was widened to 80 feet, allowing for better management of high flows during storm events, which had been posing a challenge immediately following the first cut.
In late August, the installation of rock vanes at the Brugler Road Bridge began. Rock vanes are engineered, in-stream structures that help to stabilize a channel while enhancing aquatic habitat and movement.
The rock vanes installed at the Brugler Road Bridge site are cross vanes. Cross vanes consist of a set of boulders angled upstream on a river, with another section of smaller rocks placed upstream. The taller sections of the cross vanes deflect the streamflow away from the banks, decreasing scouring effects. Instead, the flow travels over the rock walls and concentrates down the center of the channel, creating a deep and elongated pool in the middle of the stream.
Velocities between the notches in the rock vanes were evaluated using a velocity meter in accordance with the design specifications originally proposed. Based on the U.S. Fish and Wildlife Service fish passage design criteria, velocities in the notches could not be greater than 8.25 feet per second. All of the velocity measurements in this rock vane were below the maximum thresholds, ensuring no blockage of fish passage is made through the vanes.
Since the removal of the dam began, vegetative growth from the natural seedbed of the upper impoundment has been observed (see photo below).
In October, scour protection installation commenced at the Warrington Road Bridge site. After the team conducted geotechnical test pits, they discovered that a concrete scour wall that slopes out to the Paulins Kill was present and deep enough to be able to install rock at the necessary depth. They also found that the existing gabions, caged baskets filled with rock or concrete often used to protect against erosion, were intact and could be left in place. The team installed four (4) feet of riprap under and around the bridge in the riverbed and tied it into the existing grade of the banks.
The original notch in the dam was lowered one foot per day starting in mid-December, reducing water surface elevations down to the apron elevation during the month of January.
To accommodate NJ Fish and Wildlife’s request for animal passage under the I-80 bridges, an area of the previously installed riprap on the northwest abutment wall was flattened out and filled in with river cobble. This path will promote wildlife movement under the bridge as opposed to through the existing tunnel.
Currently, rock vanes are being installed under the I-80 bridges specifically to enhance fish passage. These structures vary slightly from the rock vanes at the Brugler Road Bridge site, as they are designed to slow river flow, helping migrating fish travel upstream and traverse a 5-foot elevation difference in the streambed, much like a fish ladder.
These rock vanes are more than halfway completed and are on track to be finished in time for fish populations to make full use of them. The next steps are to finish the demolition of the dam and the construction of the fish passage rock vanes under the I-80 bridges, plant vegetation throughout the upper impoundment, create a recreational trail through the upper impoundment, and plan for fishing and boating access! Stay tuned for more exciting developments on this incredible project.
Thank you to our project partners: The Nature Conservancy, American Rivers, U.S. Fish and Wildlife Service, and NJDEP Division of Fish and Wildlife Service.
Princeton Hydro has designed, permitted, and overseen the reconstruction, repair, and removal of a dozens of small and large dams in the Northeast. To learn more about our fish passage and dam removal engineering services, visit: bit.ly/DamBarrier.
Your Full Name * Phone Number * Your Email * Organization Address Message *
By EmailBy Phone
Submit
Δ
Couldn’t find a match? Check back often as we post new positions throughout the year.
PRINCETON HYDRO
PRINCETON HYDRO