Environmental Journeys 17: SediMite Part 2 — demonstrating in-situ treatment of contaminated sediment

Part 1 of this story describes the SediMite concept and establishing the proof of concept in the laboratory. SediMite Part 2 shares experiences with early demonstration projects and the subsequent commercialization of the technology. I end by acknowledging individuals, companies, and organizations who contributed to the development and success of the technology. (If I inadvertently missed someone or an organization, please let me know so I can update this story with that information.)

Showing efficacy of SediMite treatment of contaminated sediments in pilot field studies was a critical step. Fortunately, we had three opportunities. One involved a research grant from the National Institute of Health to UMBC. The demonstration took place at Bailey Creek, a tidal system adjacent to Fort Eustis along the James River where sediments were contaminated with PCBs. My first introduction to contaminants in sediments involved Kepone in the James River. So, the Bailey Creek demonstration project was a nice positive way to be involved with that river system.

Ben Amos filling up the Vortex spreader with SediMite. Upal and Ben are shown delivering the SediMite to the treatment area in Bailey Creek at Fort Eustis in Virginia.

The second demonstration project involved Canal Creek at the Aberdeen Proving Ground in Maryland where sediments and adjacent wetlands were contaminated with mercury, PCBs, and pesticides. Funded through the Environmental Security Technology Certification Program (ESTCP), the project showed that PAC delivered by SediMite substantially reduced exposures to PCBs and pesticides.

Canal Creek demonstration site at APG. SediMite was applied to the wetlands and to the creek.

The ESTCP team has guided and funded many useful environmental projects involving remediation and restoration of contaminated sediments among other issues relevant to the military including climate change resiliency and dealing with munitions. I acknowledge some of the team members with this photo.

A third demonstration project was undertaken to treat PCBs and mercury in the meadowlands of New Jersey. This work involved an excellent mercury chemist — Cynthia Gilmour from the Smithsonian Environmental Research Center (SERC) who was brought to the project by my colleague Betsy Henry (now with Anchor QEA) — the UMBC team, Ben Amos (Sediment Solutions), Exponent (me, Susan Kane Driscoll, Ken Cerreto, and Konrad Kulacki), and Parsons. The work was carried out in a Phragmites marsh bordering a tidal creek and involved multiple plots and treatment methods. This project showed that PAC delivered by SediMite effectively reduced exposures to PCBs and mercury and exceeded the efficacy of granulated activated carbon (GAC) .

Our team working in a vegetated marshes adjoining bordering a tidal creek. From left to right: Ben Amos, Jose Gomez-Eyles, Upal Ghosh, Hilda Fadaei, Carmen Yupanqui, Ken Cerreto, and Charlie Menzie. Our team included about 30 people.

Sediment Solutions and the onset of commercial applications

Upal and I formed Sediment Solutions in 2008. At this time, I was also a Practice Director at Exponent but had an agreement that allowed me to pursue commercialization of intellectual property (i.e., the UMBC/Menzie patent). So, it worked out well and Exponent was involved in a number of the remediation demonstration projects. Ben Amos became the Operations Manager and later a business partner in Sediment Solutions.

We began by talking about the SediMite concept with the U.S. EPA, natural resource trustees such as U.S. Fish and Wildlife and NOAA, sediment remediation companies and companies in need of remediation. This low-impact approach was attractive to natural resource entities as well as business entities. It minimized natural resource damages (NRD) and made it possible to treat valuable natural resource areas without creating damage to those systems. Defense departments such as the Navy and Army appreciated the ability to apply amendments to hard to reach areas around docks and pilings. Industry appreciated a cost-effective technology.

The Interstate Technology and Regulatory Council (ITRC) was at the forefront of state activities to advance remedial technologies and conceptual thinking about sediment remediation. We were honored to contribute to the writing of their guidance document with regard to in-situ treatment within the ITRC Guidance Document on Remedy Selection. It was rewarding to share our scientific expertise and experience from developing SediMite. (John Cargill from the Delaware Department of Natural Resources and Environmental Control [DNREC] was an ITRC team leader and our involvement with ITRC helped DNREC become familiar with the technology.) As indicated in the paper below, In-situ treatment of sediments with PAC has been satisfactorily demonstrated and has emerged as an accepted practice with U.S. EPA developing its own guidance. It is downloadable from IEAM.

Our first commercial venture was led by Upal through UMBC with Sediment Solutions providing the SediMite. It involved restoring Mirror Lake in Dover Delaware; the video shows the beginning of the project funded by the state and involving scientists Rick Greene and John Cargill from the Delaware Department of Natural Resources and Environmental Control (DNREC). They were pleased with the results.

A telebelt was the main method DNREC’s contractor BrightFields used for delivering SediMite to Mirror Lake. Jack Markell, the governor of Delaware, did throw out handfuls of SediMite to kick off the project.

As the remediation field progressed combinations of technologies became attractive. In addition to the in-situ remediation that we originally envisioned, SediMite is being used as an easy way to handle the more effective finer-particle treatment amendments such as PAC for use in amendment caps:

Barge with supersack bags of SediMite for use in an amended cap for the Elizabeth River in Virginia. This project was supported by the Living River Trust and led by the engineering firm AnchorQEA. The SediMite was applied by BrightFields.

Amendments also now have a role as a polishing agent for some remediation projects involving dredging. Dredging can leave behind residual contamination which may be more bioavailable and bioaccessible, at least for a period of time. Managing that residual has become became a part of some dredging remedial alternatives. On a project at Scanlon Reservoir in Minnesota, a thin layer of SediMite was laid down to arrest and reduce exposures from residual dioxins following dredging. Natural sedimentation with clean sediments is being relied upon to cover the excavated area. This project was conducted as part of the Great Lakes Restoration Initiative and the project team included Sevenson Environmental Services Inc., Kemron-Arrowhead Joint Venture, and Anchor QEA.

Image from the Scanlon Reservoir project where SediMite was applied. Photo and news piece credited to Brady Slater.

SediMite has been delivered by pneumatic systems, telebelts, and barges. Those are all familiar within the sediment remediation world. A more unusual delivery method involved a helicopter at a contaminated sediment site adjacent to the St. John’s Landfill in Portland Oregon. The lower weight and higher amendment concentration provided by SediMite made this delivery technology attractive and affordable for this project carried out by Jacobs Engineering.

Applying SediMite via helicopter at St. John’s Landfill, Portland, OR. Photo: Jacobs Engineering

The future: other contaminants, climate change resiliency, and restoration

Polyfluorinated substances (PFAS) are among the more prominent emerging contaminants in the 21st century. To help control the entry into and remediate the presence of PFAS compounds in sediments and overyling water, SediMite has been engineered with a mixture of amendments designed to treat these chemicals. The design accounts for the fact that accumulation of PFAS into fish tissues involves different biological mechanisms and physiologies than for the more familiar lipophilic chemicals such as PCBs, PAHs, and dioxins. Designed to target PFAS compounds that are persistent and bioaccumulate in fish, the goal of the new design is on reducing risks to people and the environment. At this writing, we are planning for demonstration projects for various types of environments. We are seeking collaborations in this important area.

The vulnerability of our coastal areas has brought a focus on strengthening climate change resiliency and advancing habitat restoration. Restoration involving the use of SediMite is getting attention by environmental trusts and watershed stewards such as in the Middle Branch in Baltimore (see below) and the Penobscot River in Maine.

We have joined with a group of scientists and engineers regarding a plan on the reuse of dredged materials with low levels of contamination for habitat restoration and for strengthening climate change resiliency. For this approach, amendments would be used to address low-level exposures of contaminants that might otherwise limit the reuse of the dredged material for marsh creation and shoreline protection. This is an exciting opportunity with broad application as many vulnerable coastal areas border locations where such sediments are present.

An example of coastal marsh creation using sediments pumped to the location. This is the Cameron Meadows Marsh Creation Project in Louisiana. While SediMite is not being used here, the concept we are exploring is extending the use of sediments with low levels of contamination by blending amendments into the reuse sediment stream for dredged materials and other sediments with low levels of contamination.

The NIEHS Superfund Research Program has been supporting SediMite-related research involving the delivery of microorganisms that degrade PCBs. This effort is led by UMBC and RemBac. To learn more about this extended SediMite technology you can Read the Full Story and See the Video.

NIEHS through its Superfund Research Program has funded SediMite-related work contributing to the development of a low-cost technology for cleaning up contaminated sediment sites

Acknowledgments

I close by acknowledging the ongoing scientific and engineering leadership of Upal Ghosh and the operations and project execution expertise of Ben Amos. We are also fortunate that investments made in the manufacturing production lines for SediMite have increased the supply to cover multiple projects at short notice.

We were all pleased when Upal and Sediment Solutions were recognized for the SediMite technology development and its subsequent success.

From Upal “Sediment Solutions was recognized as one of the fastest growing small businesses started by University at Buffalo alumni. Honored to receive the award from President Tripathi at the UB Fast 46 event. Also thanks to my Ph.D. Advisor and now Provost, Scott Weber, for the mentoring over the years! Also thanks to the wonderful partnership with Charles Menzie and Bennett Amos”

Our progress on SediMite as a technology for remediation and restoration of contaminated sediments and for enhancing climate resiliency goals has benefited from many people. We thank state agencies and people such as John Cargill and Rick Greene of Delaware’s DNREC; the U.S. EPA including Marc Greenberg, Doug Tomchuk, and Bruce Pluta; a special thanks to Steve Brown; the military research organization ESTCP with special thanks to their deep team of experts from their program staff and from the Army, Airforce, and Navy; the Engineer Research and Development Center (ERDC) and especially David Moore and Todd Bridges (now at University of Georgia); ERDC teamed with Sediment Solutions and UMBC to demonstrate the long-term efficacy of activated carbon treatment and have supported studies with laboratory bioassays; Brett Berkley of the Middle Branch Resiliency Initiative and the company GreenVest for innovative insights on restoration; John Bleiler and others at AECOM for collaborations; Tim Thompson of SEE LLC for his continued guidance and encouragement; Bruce Fidler of the Louis Berger Groups and now with WSP USA Inc. for helping secure the Bailey Creek project as an opportunity; John Collins (AquaBlok) for helping advance use of activated carbon delivered as agglomerates; The Army Aberdeen Proving Ground for making itself available for the Canal Creek pilot studies with special thanks to Allison O’Brien; Ken Simon of Envirosystems; John Dwyer and others at Kemron Environmental Services; Arrowhead Contracting Inc.; Betsy Henry, Clay Patmont, Ram Mohan, Chris Overcash, Paul LaRosa and other teaming partners at Anchor QEA; Marian Young and others at Brightfields Inc. Environmental Services for SediMite delivery; Sevenson Environmental Services Inc. for SediMite delivery; Andrew Timmis of J.F. Brennan for his useful advice; Cynthia Gilmour of the Smithsonian Environmental Research Center (SERC) for her involvement with SediMite applications to reduce exposures to mercury; Helder Costa and others at Haley and Aldrich for their long-term support and friendship; Dick Luthy from Stanford who with Upal developed the activated carbon treatment technology for sediments; my colleagues at Exponent; and Danny Reible of Texas Tech University for his ongoing research and advice on sediment treatment and augmenting sediment caps. Danny co-authored a paper with Darya Kupryianchyk and others that nicely provides a framework for the use of activated carbon for sediment remediation.