Clean-up of Radioactive Material in Port Hope Finally Underway

After decades of study and planning, the clean-up or radioactive contamination in the community of Port Hope, Ontario is finally underway.  The Town of Port Hope, located approximately 100 km (60 miles) east on Toronto on Lake Ontario, has an estimated 1.2 million cubic metres (1.5 million cubic yards) of historic low-level radioactive waste scattered at various sites throughout the town.

The contaminated soil and material will be excavated to moved to the LongTerm Waste Management Facility, which is essentially an engineered aboveground landfill where the waste will be safely contained, and the long-term monitoring and maintenance of the new waste management facility.

Other historic low-level radioactive waste – primarily soil contaminated with residue ore from the former radium and uranium refining activities of Eldorado Nuclear — and specified industrial waste from various sites in urban Port Hope will be removed and safely transported to the new facility.

The historic low-level radioactive waste and contaminated soil, located at various sites in the Municipality of
Port Hope, are a consequence of past practices involving the refining of radium and uranium by a former federal Crown Corporation, Eldorado Nuclear Limited, and its private-sector predecessors. These waste materials contain radium-226, uranium, arsenic and other contaminants resulting from the refining process.

The historic waste and surrounding environment are monitored and inspected regularly to ensure the waste does not pose a risk to health or the environment. As part of the Port Hope Area Initiative (PHAI) construction and clean-up phase, the waste will be excavated and relocated to the new Port Hope long-term waste management facility.

In an interview with CBC, Scott Parnell is the General Manager of the Port Hope Area Initiative, which is in charge of the cleanup. He says that after decades of planning, the first loads of an estimated 1.2 million cubic metres of historic low-level radioactive waste will be on the move.

Scott Parnell, general manager of the Port Hope Area Initiative, stands near the town’s harbour.

“There’s been a lot of planning a lot of studies a lot of determination into how to approach the work safely, but this will be the first time we will be removing waste from the community,” said Parnell, who has overseen similar operations in Washington state and Alaska.

The $1.28-billion cleanup operation is a recognition by the federal government that the waste is its “environmental liability.” The radioactive tailings were the byproduct of uranium and radium refining operations run by Eldorado, a former Crown corporation, between 1933 and 1988.

Parnell says that the tailings were given away for free, which helps explain how the contamination was spread through the town.

“So, basically they offered it up and it was used for fill material to level up people’s backyards, for building foundations, for those kinds of things. So, that’s how the material got spread around the community,” Parnell said.

Parnell says an estimated 800 properties may be affected, but says there’s no indication the low levels of radiation are dangerous.

“There’s little human risk associated with the waste that’s identified here in Port Hope,” he said.

The first wastes to be remediated are currently stored under tarps at three locations including the Centre Pier, the Pine Street North Extension in the Highland Drive Landfill area and at the municipal sewage treatment plant. The Centre Pier is the first site to be remediated.

Aerial image of the first locations to be remediated. (source: Canadian Nuclear Laboratories)

 

 

Environmental charges laid against Husky Energy Inc. and Husky Oil Operations Limited

Environment Canada and Climate Change (ECCC) recently laid a number of charges against Husky Energy Inc. and Husky Oil Operations Limited relating to the blended heavy crude-oil spill, in July 2016, which impacted the North Saskatchewan River, near Maidstone, Saskatchewan. The Government of Saskatchewan also filed a charge under the Environmental Management and Protection Act, 2010. These charges result from a 19-month joint federal-provincial investigation.

There are a total of ten charges which include one charge under subsection 36(3) of the federal Fisheries Act, one charge under subsection 38(5) of the federal Fisheries Act, six charges under subsection 38(6) of the federal Fisheries Act, one charge under the federal Migratory Birds Convention Act, 1994, and one charge under Saskatchewan’s Environmental Management and Protection Act, 2010.

The first appearance was at the end of March at the Lloydminster Provincial Court office.  According to the Premier of Saskatchewan’s office, the company faces a possible maximum $1 million fine.

Shoreline cleanup for the Maidstone-area oil spill (Jason Franson/Canadian Press)

Saskatchewan Minister of Environment Dustin Duncan said the spill led to significant changes in the provincial Pipelines Act; changes that include greater regulation, auditing powers, penalty provisions and licensing flowlines.

“We take this very seriously. There, to my knowledge, hasn’t been a charge with respect to the unintended release of oil from a pipeline in the province’s history,” he told reporters in late March.

Duncan said the site cleanup was completed by the end of last year, but Husky will have to work with the province’s Water Security Agency and the Ministry of Environment to make sure nothing else is required.  He said he expects full co-operation.

“In the last year, despite a very unsettling situation, Husky was very responsive when it came to the cleanup but also responding to the concerns by First Nations, by communities along the river, as well as to the requests that were made by the government department,” Duncan said.

All charges are currently before the Court, and they have not yet been proven. Under Canadian law, those charged are presumed innocent until proven guilty. Therefore, Environment and Climate Change Canada and Saskatchewan’s Water Security Agency, which has a responsibility for the specific charge under the provincial Environmental Management and Protection Act, 2010, will not be commenting further at this time.

 

New Brunswick Southern Railway pleads not guilty to charges related to oil transport

As reported by the CBC, New Brunswick Southern Railway has pleaded not guilty to 24 charges related to the transportation of oil.  Defence lawyer Catherine Lahey entered the pleas on the Irving-owned company’s behalf during a brief appearance in Saint John provincial court on earlier this month.

The charges against the railway, a subsidiary of J.D. Irving Ltd., stem from a Transport Canada investigation triggered by the 2013 derailment that killed 47 people in Lac-Mégantic, Que., prosecutors have said.  Twelve of the charges under the Transportation of Dangerous Goods Act relate to failing to create proper shipping documents for the purpose of transporting petroleum crude oil.  The other 12 charges relate to having unqualified personnel handling dangerous goods — crude oil.

The offences are all alleged to have occurred between Nov. 3, 2012, and July 5, 2013, at or near Saint John.  Irving Oil would have imported about 14,000 cars of crude for its Saint John refinery during that period.

New Brunswick Southern Railway is part if NBM Railways, a subsidiary of J.D. Irving Ltd., which also includes Cavendish Farms, Kent Building Supplies and Irving Pulp & Paper.

A trial date will be set on June 4.  Judge David Walker said the Crown is expecting to take about three weeks to present its case.  There is no word on how long the defence will take.  Pleas were delayed last month because the defence was still in the process of receiving an estimated 9,000 disclosure documents from the Crown.

The rail cars full of crude that exploded in Lac-Mégantic, Que., in July 2013 were destined for Irving Oil’s refinery in Saint John. (CBC)

In October 2017, Irving Oil was ordered to pay $4 million after pleading guilty to 34 charges under the same act.  Those charges related to failing to properly classify the crude oil it transported by train and inadequately training its employees in the transportation of dangerous goods.

The crude oil in the derailed rail cars that exploded in Lac-Mégantic was destined for Irving’s refinery in Saint John.

New Brunswick Southern Railway, along with its sister railways — Maine Northern Railway and Eastern Maine Railway — operates 883 kilometres of railway in New Brunswick and Maine.

Quebec Town Fined $100,000 for Violating Canadian PCB Regulations

Earlier this year, the Town of Amos, located in northwestern Quebec, pleaded guilty in court to one charge and was fined $100,000 for violating the PCB Regulations, thereby committing an offence under the Canadian Environmental Protection Act, 1999 (CEPA).

Amos is located 110 km northeast of Rouyn-Noranda in northwestern Québec. The Town has a population of 13,000.  Its main resources are spring water, gold, and wood products, including paper.

Charges were laid against the Town of Amos after an investigation conducted by staff from Environment Canada and Climate Change (ECCC) showed that, in April 2015, the Town of Amos sold products containing PCBs in a concentration of 50 mg/kg or more, which is in violation of the PCB Regulations.

The amount of the fine will be directed to the Environmental Damages Fund (EDF) administered by Environment and Climate Change Canada.

What are PCBs?

PCBs (Polychlorinated Biphenyls) are a group of man-made organic chemicals consisting of carbon, hydrogen and chlorine atoms. The number of chlorine atoms and their location in a PCB molecule determine many of its physical and chemical properties.  Due to their non-flammability, chemical stability, high boiling point and electrical insulating properties, PCBs were used in hundreds of industrial and commercial applications including:

  • Electrical, heat transfer and hydraulic equipment
  • Plasticizers in paints, plastics and rubber products
  • Pigments, dyes and carbonless copy paper
  • Other industrial applications

Although no longer commercially produced in North America, PCBs may be present in products and materials produced before the 1979 PCB ban. Products that may contain PCBs include:

  • Transformers and capacitors
  • Electrical equipment including voltage regulators, switches, re-closers, bushings, and electromagnets
  • Oil used in motors and hydraulic systems
  • Old electrical devices or appliances containing PCB capacitors
  • Fluorescent light ballasts
  • Cable insulation
  • Thermal insulation material including fiberglass, felt, foam, and cork
  • Adhesives and tapes
  • Oil-based paint
  • Caulking
  • Plastics
  • Carbonless copy paper
  • Floor finish

The PCBs used in these products were chemical mixtures made up of a variety of individual chlorinated biphenyl components known as congeners. Most commercial PCB mixtures are known in the North America by their industrial trade names, the most common being Arochlor.

Canadian Government’s Role in the Management of PCBs?

Health Canada and Environment Canada have taken strong and effective steps under the Canadian Environmental Protection Act (CEPA) to control the use, importation, manufacture, storage and release of PCBs.

CEPA states that PCBs are toxic, and Environment Canada is working on revisions to CEPA that would further strengthen controls over all PCBs in service or in storage anywhere in Canada.

The Government has also established regulations regarding hazardous wastes and has signed a number of international agreements, such as the Canada-USAgreement on PCBs, and the Basel Convention, which are all aimed at the safe use, storage, transport and disposal of PCBs, both nationally and internationally.

In addition, Health Canada continues to monitor the amount of PCBs in food, air and water to ensure that Canadians are not exposed to levels that pose a health risk. Health Canada also tracks and assesses ongoing research about the health effects of exposures to PCBs.

Funding available for Cleantech Demonstration Projects in Ontario

BLOOM is issuing a call for funding applications to support the completion of low carbon, clean technology demonstration Projects in Ontario.  BLOOM is a private, not-for-profit federally incorporated company that brings together public and private sector stakeholders to achieve sustainable outcomes that manage risk and deliver economic, environmental and social benefit.

As a requirement, applications must be submitted by 2 co-applicants: a cleantech solution provider and a customer host that is representative of a broader sector.

BLOOM will be providing grant funding on a 50:50 cost-share basis, up to a maximum of $150,000 per Project.  BLOOM is responsible for managing this Program to support Ontario’s Climate Change Action Plan and transition to a low carbon economy.  Ideally, proposed Projects have strategic partners to support the roll-out and market adoption of the low carbon cleantech solution, following completion of the demonstration Project.

Applications are due by May 31, 2018. Successful co-applicants will be notified by June 30, 2018. Demonstration projects must be completed by March 15, 2019.

For additional information, click here.

Court Rejects Environmental Consultant’s Third Party Claim Against Prior Owner/Occupants

by Stan Berger, Fogler Rubinoff

On March 22, 2018 the Ontario Superior Court of Justice in MVL Leasing Ltd. v CCI Group Inc. 2018 ONSC 1800 granted Rule 21 motions striking third party claims brought by an environmental consultant who was being sued by a purchaser of property for professional negligence and breach of contract. The lawsuit alleged that the plaintiff was led into closing the sale by the consultant’s Phase 1 and Phase 2 Environmental Site Assessments. The property turned out to be contaminated. The consultant in turn alleged that the contamination was caused by one or more businesses operated by the third parties. The consultant requested contribution indemnity from the third parties on 6 different grounds: nuisance, loss or damage caused by a spill pursuant to s.99 of Ontario’s Environmental Protection Act, the occupier’s duty under the Occupiers’ Liability Act to ensure the safety of persons entering upon the property, negligence, liability under the Negligence Act and unjust enrichment. The consultant argued that if found liable in the main action, it would have incurred pecuniary losses as a direct result of the spill, those damages being the plaintiff’s remediation costs and or the decrease in the property’s value.

Court’s Reasons for Rejecting the Third party Claims

The nuisance claim was rejected on the basis that the consultant did not own, occupy or possess the property, or any adjacent or nearby property impacted by the alleged contamination. The s.99 EPA claim was only available where the damages were directly caused by the spill and that was not the case. The occupier liability claim was rejected because the consultant suffered no damages as a result of entering the property in question. With respect to the negligence claim, the Court refused to impose a new duty of care upon the third parties. There was no proximity in the relationship between the consultant and the third parties. The potential economic harm to the consultant was not a reasonably foreseeable consequence of the alleged acts or omissions of the previous third party owners/occupiers. The Negligence Act claim was rejected on the basis that the consultant and the third parties did not meet the test under the Act of being concurrent tortfeasors for contribution and indemnity to be available. The plaintiff’s actual or potential causes of action against the consultant and the third parties were entirely different in nature. The damages allegedly caused by the third parties were different and discrete from those caused by the consultant. Finally, the unjust enrichment claim was rejected as the consultant had not pleaded any direct conferral of a benefit upon the third parties and the consultant had not suffered a corresponding detriment. If the consultant had incurred a detriment in the future by the plaintiff succeeding with its action, that detriment only related to the breach of contract and/or negligence of the consultant and the third parties were not parties to that relationship.

What can we take away from this Decision?

In order to sustain a third party claim against historic owners or occupiers of contaminated property, environmental consultants who are sued by a purchaser of contaminated property, will have to show that that the historic owners/occupiers were somehow responsible for or at least connected to the contractual breach or negligence which the purchaser alleges against the consultant.

This article was previously published by Fogler, Rubinoff LLP and can be found on the firm’s website.

About the Author

Stanley Berger is certified by the Law Society of Upper Canada as a specialist in Environmental Law.  He was called to the Ontario Bar in 1981.  He joined the law firm of Fogler Rubinoff in 2013.

 

SJC Clarifies Statute of Limitations for Contaminated Property Damage Claims but Raises Questions of Application

by Marc J. GoldsteinBeveridge & Diamond PC

Plaintiffs with property damage claims under the Massachusetts cleanup law have more time to bring their claim than might be expected under the three-year statute of limitations according to a recent ruling by the top Massachusetts court.  The Supreme Judicial Court ruled that the statute of limitations begins running when the plaintiff knows that there is damage to the property that is “permanent” and who is responsible for the damage, pointing to the phases of investigation and remediation in Massachusetts’ regulatory scheme as signposts for when a plaintiff should have that knowledge.  Grand Manor Condominium Assoc. v. City of Lowell, 478 Mass. 682 (2018).  However, the Court left considerable uncertainty about when the statute of limitations might begin for arguably more temporary property damages such as lost rent.

In this Google image, the Grand Manor condominium complex is visible at the center-right.

In this case, the City of Lowell owned property that it used first as a quarry and then as a landfill in the 1940s and 50s before selling the property in the 1980s to a developer.  The developer constructed a condominium project on the site and created a condominium association soon thereafter. As part of work to install a new drainage system in 2008, the contractor discovered discolored soil and debris in the ground.  Subsequent sampling indicated that the soil was contaminated and that a release of hazardous materials had occurred.  The condo association  investigated in early 2009, and MassDEP issued notices of responsibility to both the condo association as well as the city in May 2009.  The city assumed responsibility for the cleanup and worked the site through the state regulatory process known as the Massachusetts Contingency Plan (MCP).  In the city’s MCP Phase II and III reports in June 2012, it concluded that the contamination was from the city’s landfill operations, that it would not be feasible to clean up the contamination, and proposed a pavement cap and a deed restriction.

The condo association and many of its members filed suit in October 2012 for response costs under Chapter 21E, § 4 and damage to their property under G.L. c. 21E, § 5(a)(iii).  At trial, the jury awarded the plaintiffs response costs under Section 4 but found that the plaintiffs had failed to prove that their property damage claim was brought within the three-year statute of limitations for such claims under G.L. c. 21E, § 11A.  The Supreme Judicial Court took the case on direct appellate review.

Section 11A provides that an action to recover damage to real property “be commenced within three years after the date that the person seeking recovery first suffers the damage or within three years after the date the person seeking recovery of such damage discovers or reasonably should have discovered that the person against whom the action is being brought is a person liable…”  Quoting Taygeta Corp. v. Varian Assocs., Inc., 436 Mass. 217, 226 (2002), the Court summarized this as a requirement that the claim must be brought within three years of when plaintiff “discovers or reasonably should have discovered [1] the damage, and [2] the cause of the damage.”

The Court quickly agreed that “the damage” referred to in Section 11A was, for these purposes, the property damages of Section 5 and moved on to the plaintiffs’ contention that the limitations period should not run until they discovered or reasonably should have discovered that the damage was “permanent” or, in other words, not reasonably curable.  Until that time, they argued, they could not know if they had a property damage claim because the site could be fully remediated.

The Court examined the application of the statute of limitations in the context of the statutory scheme for investigating and remediating sites in Massachusetts.  The Court found that the primary purpose of Chapter 21E is to clean up environmental contamination and to ensure responsible parties pay for the costs of that cleanup.  As a result, the statute prioritizes “performance and financing of cleanup efforts, and then considers the calculation of property damage that cannot be cured by remediation and remediation cost recovery.”

In interpreting the statute of limitations, the Court crystalized the question as “whether the word ‘damage’ in § 11A(4) refers specifically to damage under § 5, that is, damage that cannot be cured and compensated by the cleanup and cleanup cost recovery processes defined by the MCP and §§ 4 and 4A, such that the limitations period does not begin to run until the plaintiff knows there is residual damage not subject to remediation and compensation.”  In order to have knowledge that a plaintiff has suffered damage that is not curable by the MCP remediation process, the MCP process must have run sufficiently to know that § 5 damages exist – that there is contamination that will not be addressed through remediation leaving the property at a diminished value.  Since the liable party is required to determine the extent of the damage in Phase II and evaluate available remedies in Phase III of the MCP, as the Court noted, “[i]t would make little sense to require the plaintiff to independently determine whether residual property damage exists prior to the completion of these reports.” As a result, the Court concluded that the statute of limitations did not start to run until the plaintiff became aware that the site would not be fully remediated in the Phase II and III reports in June 2012 months before they filed their lawsuit.  Exactly what constitutes full remediation remains to explored in further cases, as the range of outcomes from achieving background conditions, implementing deed restrictions, reaching temporary solutions, or even leaving just a few molecules of contamination left behind could impact this analysis.

The Court contended that this interpretation of the statute of limitations provides a “prescribed and predictable period of time” within which claims would be time barred, given that there are timetables associated with the production and submission of MCP Phase II and III reports.  Under normal circumstances, the Court expected that a plaintiff will know it has a claim within five years of notifying MassDEP of contamination.

Despite the Court’s pronouncement that it had provided predictability for these types of claims, the statute of limitations for non-permanent property damages, such as lost rental value, or for sites where there is a long-term temporary solution in place, remain uncertain.  Lawyers and clients evaluating how and when to bring claims for temporary and permanent damages will need to carefully evaluate a range of potential options in pursuing a preferred single case for property damage without unacceptable risk that an uncertain statute of limitation may have run.

The article was first published at the Beveridge & Diamond website.

Beveridge & Diamond’s Massachusetts office assists parties at all phases of contaminated sites, guiding clients through the MCP investigation and remediation process and prosecuting and defending claims in court for cost recovery and property damage.  For more information about this practice, contact Marc Goldstein or Jeanine Grachuk.

About the Author

Marc Goldstein helps clients resolve environmental and land use disputes and to develop residential, commercial, and industrial projects. He serves as the Managing Principal of Beveridge & Diamond’s Wellesley, Massachusetts office and the Chair of the firm’s Technology Committee.

Marc provides practical, cost-effective advice to clients with environmental contamination issues, whether those clients are cleaning up hazardous materials and seeking contribution from previous owners or adjacent landowners or facing claims under Chapter 21E or Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) for their alleged role in contamination.

U.S. EPA’s Enforcement of the Lead-Based Paint Renovation, Repair and Painting Rule

By Dianne R Phillips, Holland & Knight

On March 28, 2018, the Office of the Inspector General (OIG) of the U.S. Environmental Protection Agency (EPA) issued a Project Notification indicating its plans to begin preliminary research to evaluate the EPA’s implementation and enforcement of the Lead-Based Paint Renovation, Repair and Painting Rule (RRP Rule). The RRP Rule, which is part of the federal Toxic Substances Control Act, is intended to ensure that owners and occupants of pre-1978 “target housing” and “child-occupied facilities” receive information on lead-based paint hazards before renovations begin, that individuals performing such renovations are properly trained and certified, and that renovators and workers follow specific lead-safe work practices during renovations to reduce the potential for exposure to lead. Although use of lead-based paint in dwellings was prohibited after 1978, EPA estimates it is still present in approximately 30 million homes across the United States. The RRP Rule is intended to protect children and others vulnerable to lead exposure due to the health effects associated with lead poisoning.

Enforcement of the RRP Rule, along with the other lead-based paint rules, has been a priority of EPA. For fiscal year ending 2017, according to EPA’s Oct. 27, 2017 press release from October 2016 through September 2017, EPA finalized 121 civil settlements for alleged violations of one or more of the three lead-based paint rules–the RRP Rule; the Lead Disclosure Rule; and the Lead-based Paint Activities Rule for abatements–and filed three complaints for ongoing actions. EPA and the U.S. Department of Justice also prosecuted one criminal case involving violations of lead paint laws and finalized two Clean Air Act settlements that included lead paint abatement projects in local communities. The OIG Project Notification indicates that the “objective for this project is to determine whether EPA has an effective strategy to implement and enforce the lead-based paint RRP.” Only time will tell what is meant by that.

____________________________

About the Author

Dianne R. Phillips is an attorney in Holland & Knight’s Boston office who concentrates her practice in litigation, regulatory, energy and environmental law. As former assistant general counsel for Suez LNG North America LLC (now known as Engie North America) and its wholly owned subsidiary, Distrigas of Massachusetts LLC, Ms. Phillips was involved in all aspects of regulatory compliance for the nation’s oldest, continuously operating liquefied natural gas (LNG) import terminal located in Everett, Mass., including safety and security. Her LNG experience includes advising clients with respect to specialized regulatory compliance under 49 C.F.R. Part 193 and NFPA 59A.

U.S. Environmental Industry generates $388 billion in revenues in 2017

The U.S. environmental industry generated revenues of $388 billion in 2017, up from $370 million in 2016, according to preliminary estimates by Environmental Business International Inc. (EBI), publisher of Environmental Business Journal (EBJ). The environmental industry’s annual growth rate of 4.8% in 2017 represents a steady increase from 3.6% in 2016 and 2.1% in 2015.

Every year, EBJ’s Annual Industry Overview presents estimates and forecasts for 13 business segments, in addition to offering perspective on how the environmental industry is responding to changing macroeconomic conditions and regulatory and policy trends. This year’s summary reviews conditions one year into the Trump Administration.

To purchase EBJ’s Annual Industry Overview and receive statistical summaries of the industry in 13 segments with multiple charts featuring revenues, growth, number of companies, forecasts, growth factors and revenue breakdowns by client, media and function, visit the EBI website.

Chemical and Biological Remediation Tetrachloroethene – Case Study

Tetrachloroethene is the systematic name for tetrachloroethylene, or perchloroethylene (“perc” or “PERC”), and many other names.  It is a manufactured chemical that is widely used in the dry-cleaning of fabrics, including clothes. It is also used for degreasing metal parts and in manufacturing other chemicals. Tetrachloroethene is found in consumer products, including some paint and spot removers, water repellents, brake and wood cleaners, glues, and suede protectors.

Tetrachloroethene is a common soil contaminant. With a specific gravity greater than 1, tetrachloroethylene will be present as a dense nonaqueous phase liquid(DNAPL) if sufficient quantities are released. Because of its mobility in groundwater, its toxicity at low levels, and its density (which causes it to sink below the water table), cleanup activities are more difficult than for oil spills (which has a specific gravity less than 1).

In the case study, researchers from Manchester Geomicro, a geo-microbiology and molecular environmental science research group affiliated with the University of Manchester, used combined chemical and microbiological contaminant degradation processes to remediate tetrachloroethene at a contaminated site in Germany.

In the study, the researchers used Carbo-Iron®, an applied composite material consisting of colloidal activated carbon and embedded nanoscale zero valent iron (ZVI). In a recent long term study of a field site in Germany, it was injected into an aquifer contaminated with tetrachloroethene (PCE). Carbo-Iron® particles accumulated the pollutants and promoted their reductive dechlorination via a combination of chemical and microbial degradation processes.

Schematic illustrating Carbo-Iron® particle structure and key chemical and microbial dechlorination pathways

The presence of the dominant degradation products ethene and ethane in monitoring wells over the duration of the study indicates the extended life-time of ZVI’s chemical activity in the composite particles. However, the identification of the partial dechlorination product cis-dichlorethene (cis-DCE) at depths between 12.5m and 25m below ground level one year into the study, suggested additional microbially mediated degradation processes were also involved.

Hydrogen produced by the aqueous corrosion of ZVI contributed to a decrease in the redox potential of the groundwater up to 190 days promoting organo-halide reducing conditions that lasted for months after. The long lasting reducing effect of Carbo-Iron® is crucial to efficiently supporting microbial dehalogenation, because growth and activity of these microbes occurs relatively slowly under environmental conditions. Detection of increased levels of cis-DCE in the presence of various organohalide reducing bacteria supported the hypothesis that Carbo-Iron® was able to support microbial dechlorination pathways. Despite the emergence of cis-DCE, it did not accumulate, pointing to the presence of an additional microbial degradation step.

The results of state-of-the-art compound specific isotope analysis in combination with pyrosequencing suggested the oxidative degradation of cis-DCE by microorganism related to Polaromonas sp. Strain JS666. Consequently, the formation of carcinogenic degradation intermediate vinyl chloride was avoided due to the sequential reduction and oxidation processes. Overall, the moderate and slow change of environmental conditions mediated by Carbo-Iron® not only supported organohalide-respiring bacteria, but also created the basis for a subsequent microbial oxidation step.

This study, published in Science of the Total Environment (Vogel et al. 2018, vol. 628-629, 1027-1036) illustrates how microbes and nanomaterials can work in combination for targeted remediation. The work was led by collaborators (Katrin Mackenzie and Maria Vogel) at the Helmholtz Centre for Environmental Research in Leipzig, Germany, and adds to a growing portfolio of research highlighting the potential of Carbo-Iron® as an in situ treatment for contaminated groundwater.