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TPH Risk Evaluation at Petroleum Contaminated Sites

Written by Abimbola Baejo, Staff Reporter

This report is from a webinar conducted by the Interstate Technology and Regulatory Council (ITRC) Total Petroleum Hydrocarbon Risk Evaluation Team and the US EPA Clean up Information Network on the 19 of June 2019. https://tphrisk-1.itrcweb.org/

The webinar was made to facilitate better-informed decisions made by regulators, project managers, consultants, industries and stakeholders, on evaluating the risk of TPHs at petroleum contaminated sites.

What is TPH?

In environmental media, crude oil and individual refinery products are typically characterized as TPH. They are made up of hydrocarbons along with other elements such as nitrogen, oxygen, sulphur, inorganics and metals. The refining process generates various commercial products such as kerosene, diesel, gasoline; with over 2,000 petroleum products identified. These products are made up of various number of carbon atoms which may be in straight or branched chain forms.

TPHs can be found in familiar sites such refineries, air- and seaports, offshore sheens, terminals, service stations and oil storage areas. Hydrocarbons can be broadly classified into aliphatic (e.g. alkanes and alkenes) and aromatic (e.g. benzene and naphthalene) hydrocarbons.

For TPH assessment at contaminated sites, relevant properties to consider are water-solubility, polarity, boiling point and evaporation ranges. Aliphatic hydrocarbons are non-water soluble, non-polar, have lower boiling points and are more prone to evaporation compared to the aromatic hydrocarbons. At a typical petroleum contaminated site, substances such as fuel additives (such as oxygenates), naturally occurring hydrocarbon components, metabolites from degraded substances and individual petroleum constituents (such as BTEX).

TPHs are made up of various constituents with similar or different carbon atoms. This means that there is the challenge of analytically separating TPH constituents in a risk assessment context since hydrocarbon constituents from a specific range of carbon atoms could be a challenge, especially if they are diesel, jet fuel or petroleum. With this knowledge, one can conclude that bulk TPH analysis, though a good screening method, is not a suitable method for TPH risk evaluation. A good way of summarizing this is in shown below.

Chromatograms of samples from the same analysis. Sample 1, 2 and 3 are Gasoline, Diesel fuel and South Louisiana Crude respectively. The analysis method used was EPA method 8015. (Image courtesy of ITRC, 2019)

The same concentration of TPHs in different areas of a site might be composed of different products; which in turn, may present different risks to the ecological environment. Therefore, we can safely say that TPH is:

  • a complex mixture with an approximate quantitative value representing the amount of petroleum mixture in the sample matrix
  • is defined by the analytical measure used to measure it, which varies from  one laboratory to another.
  • is either made up of anthropogenic products freshly released into the environment (or weathered) or natural products from ecological activities
  • not totally of petroleum origin and may simply be detected by the analytical method used.

This definition then enhances the challenges faced with TPH risk assessing such as dealing with continual changes in TPH composition due to weathering brought on by site-specific conditions, trying to analyze for hundreds of individual constituents in the mixture and having limited data on the toxicological effects of the various constituents.

To overcome the challenge of drawing erroneous conclusions about a contaminated site therefore, the project manager should not focus only on TPH individual constituents when making remedial decisions, which mostly degrade before the toxic fractions do, but should collect samples for both fractions and individual constituents. A detailed Conceptual Site Model (CSM) is suggested as a good guide in assessing TPH risks as it shows where the the remediation focus should be, away from human exposure routes; and periodic revision of this CSM will assist in documenting contaminant plume changes and identifying areas with residual contamination.

TPH ANALYSES

Due to the complexity of TPH mixtures, analytical methods should be selected based on the data quality objective, application of the results (whether to delineate a contaminated area or to conduct a risk assessment), the regulatory requirements, the petroleum type and the media/matrix being tested. As long as the method is fit for its purpose and cost effective. TPH mixtures require separation and most laboratories use GC as a preferred method as it separates I the gas phase based on its volatility. Since it is difficult to evaluate risk for a TPH mixture, most methods suggest separation into fractions. Guidelines are usually provided on what methods suit a purpose best by governmental records but if such records are inaccessible, getting information from seasoned chemists is the best option. 

Prior to TPH mixture separation, removing method interferences, such as non-petroleum hydrocarbons, is ideal for more accurate results. US EPA method 3630C describes the use of silica gel to remove polar, non-PH and naturally occurring compounds from the analysis. This gel cleanup leaves only the hydrocarbons in the sample which is the analyzed for bulk TPH. The silica gel used is a finer version  of the common ones found in clothing accessories and using it in a gel column setup is most effective at removing non-hydrocarbons. Quality controls using laboratory surrogates is also advised. Cleaning up prior to bulk TPH analysis is ideal in determining the extent of hydrocarbon impact, biodegradation locations and knowing where to focus remediation activities.

Silica gel can also be used to fractionate samples into aliphatic and aromatic fractions; and the technique can be applied to all matrices. However, alternative fractionation method is suggested for volatile samples. The eluted fractions are then run on the GC instrument  to obtain information on the equivalent carbon ranges. It is good to note that fractionation is more expensive compared to bulk TPH analyses as it provides a more detailed information, removes non-hydrocarbons from the analyses and raises reporting limits.

Chromatograms provide information such as sample components, presence of non-hydrocarbons, presence of solvents, presence of non-dissolved hydrocarbons, poor integration and weathering. They can also be used to compare samples with interferents as shown below:

Chromatograms from the same sample collected at different times showing an unweathered sample (above with red asterisk) and weathered samples (below). (Image courtesy of ITRC, 2019)
Chromatograms from the same TPHd contaminated groundwater sample comparing analysis before silica gel cleanup (left image, TPHd=2.3mg/l)) and after silica gel cleanup (right image, TPHd = <0.05 mg/l). The hump centered around the C19 internal standards and the non-uniform peaks indicate the presence of non-hydrocarbons, as confirmed after silica gel cleanup. (Image courtesy of ITRC, 2019)

Methods used to analyze TPH in contaminated samples can yield different results when compared with one another, as well as the presence of non-petroleum hydrocarbons being quantified as TPHs.  To overcome this, use field methods such as observed plume delineation during excavation, PID analysis of bag headspaces and oil-in-soil analysis for semi-volatiles, as well as the CSM to get valuable information, before using laboratory methods and chromatograms to confirm conclusions made from the field observations.

ENVIRONMENTAL FATE OF TPH

Determining the environmental fate of TPH is critical to understand how the vapor composition and dissolved plumes differ from the source zone  due to partitioning and transformation processes. TPHs partition to vapor as well as water. When partitioning to vapor, the smaller hydrocarbons are more volatile and therefore dominate the vapor composition. A more complex process is involved when TPH is partitioning to water because the smaller hydrocarbons are more soluble, based on their molecular structure. Aliphatic hydrocarbons are less soluble compared to the aromatics which are likely to dominate the soil water fractions. TPH weathering on the other hand, contributes exceedingly to TPH mass reduction in the environment may be due to aerobic or anaerobic biodegradation processes in the soil or photooxidation processes; to generate petroleum metabolites which may be further degraded. Petroleum metabolites produced have oxygen atoms in their molecules, making them polar in nature and partition preferentially in water. These metabolites are measured primarily via TPH analysis without silica gel cleanup, and are identified using chromatogram patterns, understanding the solubility of the parent compound and using CSMs maps. most TPH components found in groundwater are metabolites and their toxicity characteristics are usually different from their parent compounds.

The use of TPH fraction approach with fractionation methods is considered best for assessing TPH risks because it provides accurate hydrocarbon quantitation along with the toxicity values as well as the chemical or physical parameters involved. To determine the fractionation composition in a TPH, the fuel composition and the weathering conditions are determined.

For example, Non-Aqueous Phase Liquid (NAPL) undergoing weathering process overtime will first have the mobile hydrocarbons partition out while at the same time, further NAPL depletion will occur with the generation of metabolites  by continual biodegradation. There is the migration of vapor plumes to thin zones around the NAPL as well as heavily impacted media due to aerobic degradation in the unsaturated zone. Contaminated ground water could be made up of mostly small aromatic hydrocarbon fractions, some small aliphatic hydrocarbon fractions as well as medium aromatic hydrocarbon fractions.

Along a groundwater flow path, a differential fate affects the TPH composition which in turn affects the exposure.

Fate of TPH composition in Groundwater. (Image courtesy of ITRC, 2019)

TPH  composition changes along the path of flow  could be due to:

  • – differential transport and sorption of individual hydrocarbons,
  • – different susceptibilities of hydrocarbons to biodegradation and
  • – different redox zones along the path of flow.

On the other hand, bulk TPH composition show highest hydrocarbon concentrations near the surface and diminish downwards along the gradient while the metabolites generated via biodegradation, increase in concentrations downgradient of the source area and highest parts of the dissolved hydrocarbon plume. Over time, metabolite concentrations may increase near source, shifting the apex of the triangle to the right.

ASSESSING HUMAN AND ECOLOGICAL RISK FROM TPH

TPH risk assessment is done in three tiers where the first tier is a screening-level assessment; and the  site-specific assessment comprises the second and third tiers.

Screening-level assessment involves preliminary CSM development (source characterization and initial exposure pathway assessment) and initial data review (regulatory requirement evaluation, existing TPH data review).

Site-specific assessment involves more detailed assessment which includes the identification of data gaps from data obtained from screening-level assessment and collecting additional field data such as bulk TPH  data and chromatograms, indicator compounds and fractions, and CSM updates.

An environmental risk assessment may not be necessary if viable habitats are absent at the TPH contaminated site, if no contamination is found below the root zones and below the burrowing zones of ecological receptors; and there is no potential release of the contaminant to nearby viable ecological habitats. However, risk assessment is necessary if it is a regulatory requirement, if the screening level values are available and if the available levels are appropriate for the site conditions or the type of release.

Site-specific assessment, therefore, is required when screening levels are lacking or exceeded; and at complex sites with multiple media, sensitive habitats and receptors. Such an assessment  should focus on direct exposure,  contaminant bioaccumulation and toxicity assessment which evaluates the ecological risk, physical and chemical toxicity effects and the metabolites produced.

STAKEHOLDER CONSIDERATIONS

The stakeholders involved are affected property owners or communities with regard to the risks that are specific to petroleum contamination as measured by TPH. Communicating with them requires sensitivity and a timely approach  in order to help them understand facts and clear their confusions and concerns about TPH risk assessment. This could be done through factsheets, posters, outreach meetings, websites and internet links on TPH information. There should be public notification prior to sampling as well as the provision of post sampling TPH data results with appropriate explanations.  Technical information and public health issues should be translated and communicated in a format that is easily understood by the general public.

Similar sensitivity should be shown to other TPH assessment impacts to public property, including property value, access, and private property rights. A major concern is the fear of property devaluation as a result of possible residual TPH and a Monitored Natural Attenuation (MNA) remedy. The fears can be effectively addressed by explaining why the selected remedy is protective and effective (especially MNA), describing how all activities are done with agency oversight (that is local organizations and government agencies); and individual property owners concerns  should also be addressed.

Overall, a successful TPH risk evaluation project requires an appropriate technical approach, careful review of analytical methods chosen, a complete CSM with regular updates during remediation as well as stakeholders’ engagement.

Nanoremediation of soil contaminated with Arsenic and Mercury

Researchers in Spain recently published a paper describing the utilization of nanoremediation technology to clean-up soil at the Brownfield site heavily contaminated with arsenic and mercury.

The research draws on a several lab-scale experiments that have shown the use of nanoscale zero-valent iron (nZVI) to be effective in reducing metal(loid) availability in polluted soils.


The core-shell model of zero-valent iron nanoparticles. The core consists of mainly zero-valent iron and provides the reducing power for reactions with environmental contaminants. The shell is largely iron oxides/hydroxides formed from the oxidation of zero-valent iron. The shell provides sites for chemical complex formation (e.g., chemosorption).

The researchers evaluated the capacity of nZVI for reducing the availability of As and Hg in brownfield soils at a pilot scale, and monitored the stability of the immobilization of these contaminants over a 32 month period. The researchers contend that their study is the first to apply nZVI to metal(loid)-polluted soils under field conditions.

In the study, two sub-areas (A and B) that differed in pollution load were selected, and a 5 m2 plot was treated with 2.5% nZVI (by weight) in each case (Nanofer 25S, NanoIron). In sub-area A, which had a greater degree of pollution, a second application was performed eight months after the first application.

Overall, the treatment significantly reduced the availability of both arsenic and (As) and mercury ((Hg), after only 72 h, although the effectiveness of the treatment was highly dependent on the degree of initial contamination.

Sub-area B (with a lower level of pollution) showed the best and most stable immobilization results, with As and Hg in toxicity characteristics leaching procedure (TCLP) extracts decreasing by 70% and 80%, respectively. In comparison, the concentrations of As and Hg in sub-area A decreased by 65% and 50%, respectively.

Based on the findings, the researchers contend that the use of nZVI at a dose of 2.5% appears to be an effective approach for the remediation of soils at this brownfield site, especially in sub-area B.

U.S. Business Opportunity: Site Clean-up

The United State Department of Labor seeks the services of a qualified service-disabled veteran-owned small business to perform soil remediation services at the Gainesville Job Corps Center’s facilities in Florida.

Interest in this pre-solicitation announcement is open to all service-disabled veteran-owned small business (SDVOSB) businesses relative to the primary NAICS code 562910 with a Small Business Standard of $20.5 million and/or 750 employees.  The magnitude of this procurement is between $100,000 and $250,000.

Execution of the Florida Department of Environmental Protection (FDEP) Remedial Action Plan includes site demolition, placement of clean soil, soils compaction, site restoration, and notifications and reporting to the FDEP.

The work involves construction services to address the impacts of metals, PCBs, and PAHs that exceed FDEP Soil Cleanup Target Levels. Oversight of the work and reporting will be provided by a Florida Licensed Professional Engineer. Offers are due by 2:00 PM ET on June 5, 2019.

For more information, visit:https://www.fbo.gov/spg/DOL/ETA/OJC/1630DC-19-Q-00028/listing.html

Windsor provides $10.5 million in incentives to develop brownfield site

Farhi Holdings Corporation has been approved for almost $10.5 million in financial incentives from the City of Windsor as part of the Brownfield Redevelopment Community Improvement Plan.

The developer has owned a 24.5 hectare (60 acre) piece of vacant land next to the WFCU Centre, Windsors sports and entertainment complex, since 2005. It had been zoned industrial and had been the home of a GM trim plant and other industrial operations.

Farhi is working toward developing the site as office/retail/commercial space that will include 119 detached residential lots, four townhouse blocks, five multiple dwellings buildings, and a hotel. Approximately 3.1 hectares will remain for commercial development. The redevelopment is estimated to cost $59 million. The company is anticipating that work at the site will begin in the Fall.

The 24.5 hectare property represents approximately 11 percent of the City of Windsor’s brownfield inventory. It’s location next to the WCFU Centre makes it an ideal redevelopment opportunity.

The Windsor Brownfield Redevelopment Community Improvement Plan is designed to encourage the development of brownfields by offering incentives for development. In case of the Farhi Holdings property, the
$10.5 million in incentives from the City of Windsor will be in the form of tax breaks over a 13 year time period.

Farhi Holdings had a consultant conducted an environmental site assessment and estimate the cost of remediation. The environmental report estimates that 31,215 cubic metres of contaminated soil will need to be removed and replaced with clean fill. The total estimated cost for remediation and demolition work at the property is $6.4 million.

One section of the property (the area for the proposed hotel) has already been remediated and is not part of brownfield redevelopment incentive agreement. The hotel, once built, would generated between $380,000 to $450,000 in annual property tax revenue to the City.

A search of the Record of Site Condition (RSC) registry shows that one has not yet been filed for the property – 1600 Lauzon Road. Typically, an RSC is required prior a property zoning being changed. An RSC is a record of the site conditions and includes information on any remedial activity and the level of contamination at a site.

Farhi Holdings Corporation is a real estate and development company based in London, Ontario. The company was founded in 1988.

Saskatchewan Accepting Applications for government funding of Contaminated site Clean-ups

The Environment Ministry of Saskatchewan recently announced that it was accepting applications from municipalities for funding to clean-up contaminated sites.

Critics claim the paltry $178,000 in the fund is barely enough to cover the costs of the clean-up of one site. The source of money in Saskatchewan’s Impacted Sites Fund are the fines collected under The Environmental Management and Protection Act, 2010. 

Administered by the Saskatchewan Ministry of Environment, the fund provides financial support to municipal governments to clean up these sites so they can be used for future economic or social development opportunities.  An abandoned, environmentally impacted site is an area, such as a former gas station or laundromat, that has been contaminated.

“In addition to the obvious environmental and human health benefits of cleaning up contaminated sites, the Impacted Sites Fund will allow communities to use those sites for other, economically beneficial purposes,” Environment Minister Dustin Duncan said.

Municipalities can apply for funding at the Saskatchewan Environment Impacted Sites Fund web page. Municipal governments and municipal partnerships, which may include municipally owned corporations, not-for-profit organizations, and private companies, are eligible to apply for project funding to clean up the contaminated sites using the Impacted Sites Fund. 

Applications are not funded on a first-come, first-served basis.  The Ministry of Environment will assess and rank the applications according to environmental, social, and economic factors.  First priority will be given to sites that pose the greatest risk to human or ecological health.

AI Software Firm Specializing in Smart Remediation receives Canadian Government Support

WikiNet, a Quebec-based software firm that claims to have the world’s first
first soil remediation solution using Cognitive Artificial Intelligence (AI), recently received $254,000 in funding from the Canadian government through its Quebec Economic Development Program and its Regional Economic Growth through Innovation Program.

The $254,000 in government funding will help WikiNet diversify its markets, thereby increasing its sales and exports. The contribution will go toward prospecting, producing promotional tools and registering a patent. Fifteen jobs will be created once the government funded project is completed. A sum of $109,000 is a repayable contribution.

WikiNet was founded in 2016 to provide innovative software solutions for the environment sector. It offers niche applications, including a smart management tool for the transportation and management of contaminated soils and an application that uses both a database and artificial intelligence to guide environmental experts in choosing the best site remediation technologies.

WikiNet is developing WatRem, a system that learns from past environmental cleanup efforts to provide automated expert recommendations for treating contaminated sites worldwide.

WikiNet’s artificial intelligence product was one of over 150 projects from 36 countries selected as part of the global IBM Watson AI Xprize for Good competition. The winners of the IBM competition will be announced in 2020.

WikiNet has also developed a smart tool called “Trace” for offsite contaminated soil disposal and certification. ​”Trace” is a cognitive tool to support environmental sustainability by offering a smarter and safer way for off-site soil disposal. It allows stakeholders involved in a remediation project to manage offsite disposal of soils and dangerous materials with live GPS traceability.

U.S. Mining Sites – Legacy of Contamination Needs to be Addressed

https://www.thechronicleherald.ca/news/world/us-mining-sites-dump-50m-gallons-of-fouled-wastewater-daily-285939/

Rimini, Montana – Every day many millions of gallons of water loaded with arsenic, lead and other toxic metals flow from some of the most contaminated mining sites in the U.S. and into surrounding streams and ponds without being treated, The Associated Press has found.

That torrent is poisoning aquatic life and tainting water supplies in Montana, California, Colorado, Oklahoma and at least five other states.

The pollution is a legacy of how the mining industry was allowed to operate in the U.S. for more than a century. Companies that built mines for silver, lead, gold and other “hardrock” minerals could move on once they were no longer profitable, leaving behind tainted water that still leaks out of the mines or is cleaned up at taxpayer expense.

Using data from public records requests and independent researchers, the AP examined 43 mining sites under federal oversight, some containing dozens or even hundreds of individual mines.

The records show that at average flows, more than 50 million gallons of contaminated wastewater streams daily from the sites. In many cases, it runs untreated into nearby groundwater, rivers and ponds — a roughly 20-million-gallon daily dose of pollution that could fill more than 2,000 tanker trucks.

The remainder of the waste is captured or treated in a costly effort that will need to carry on indefinitely, for perhaps thousands of years, often with little hope for reimbursement.

The volumes vastly exceed the release from Colorado’s Gold King Mine disaster in 2015, when a U.S. Environmental Protection Agency cleanup crew inadvertently triggered the release of 3 million gallons (11.4 million liters) of mustard-colored mine sludge, fouling rivers in three states.

At many mines, the pollution has continued decades after their enlistment in the federal Superfund cleanup program for the nation’s most hazardous sites, which faces sharp cuts under President Donald Trump.

Federal officials have raised fears that at least six of the sites examined by AP could have blowouts like the one at Gold King.


Mine waste mixes with runoff at the Gold King Mine. (Provided by the U.S. Environmental Protection Agency)

Some sites feature massive piles or impoundments of mine waste known as tailings. A tailings dam collapse in Brazil last month killed at least 169 people and left 140 missing. A similar 2014 accident in British Columbia swept millions of cubic yards of contaminated mud into a nearby lake, resulting in one of Canada’s worst environmental disasters.

But even short of a calamitous accident, many mines pose the chronic problem of relentless pollution.

AP also found mining sites where untreated water harms the environment or threatens drinking water supplies in North and South Carolina, Vermont, Missouri and Oregon.

Tainted wells

In mountains outside the Montana capital of Helena, about 30 households can’t drink their tap water because groundwater was polluted by about 150 abandoned gold, lead and copper mines that operated from the 1870s until 1953.

The community of Rimini was added to the Superfund list in 1999. Contaminated soil in residents’ yards was replaced, and the EPA has provided bottled water for a decade. But polluted water still pours from the mines and into Upper Tenmile Creek.

“The fact that bottled water is provided is great,” said 30-year Rimini resident Catherine Maynard, a natural resources analyst for the U.S. Department of Agriculture. “Where it falls short is it’s not piped into our home. Water that’s piped into our home is still contaminated water. Washing dishes and bathing — that metal-laden water is still running through our pipes.”

Estimates of the number of such abandoned mine sites range from 161,000 in 12 western states to as many as 500,000 nationwide. At least 33,000 have degraded the environment, according to the Government Accountability Office, and thousands more are discovered every year.

Officials have yet to complete work including basic risk analyses on about 80 percent of abandoned mining sites on federal lands. Most are controlled by the Bureau of Land Management, which under Trump is seeking to consolidate mine cleanups with another program and cut their combined 2019 spending from $35 million to $13 million.

An abandoned mining site in Clear Creek County. (Jesse Paul, The Colorado Sun)

Perpetual pollution

Problems at some sites are intractable. Among them:

  • In eastern Oklahoma’s Tar Creek mining district, waterways are devoid of life and elevated lead levels persist in the blood of children despite a two-decade effort to clean up lead and zinc mines. More than $300 million has been committed since 1983, but only a small fraction of the impacted land has been reclaimed and contaminated water continues to flow.
  • At northern California’s Iron Mountain Mine, cleanup teams battle to contain highly acidic water that percolates through a former copper and zinc mine and drains into a Sacramento River tributary. The mine discharged six tons of toxic sludge daily before an EPA cleanup. Authorities now spend $5 million a year to remove poisonous sludge that had caused massive fish kills, and they expect to keep at it forever.
  • In Colorado’s San Juan Mountains, site of the Gold King blowout, some 400 abandoned or inactive mine sites contribute an estimated 15 million gallons (57 million liters) of acid mine drainage per day.

AP also found mining sites where untreated water harms the environment or threatens drinking water supplies in North and South Carolina, Vermont, Missouri and Oregon.

This landscape of polluted sites occurred under mining industry rules largely unchanged since the 1872 Mining Act.

State and federal laws in recent decades have held companies more accountable than in the past, but critics say huge loopholes all but ensure that some of today’s mines will foul waterways or require perpetual cleanups.

To avoid a catastrophe like Gold King, EPA officials now require advance approval for work on many mining sites. But they acknowledge they’re only dealing with a small portion of the problem.

“We have been trying to play a very careful game of prioritization,” said Dana Stalcup, deputy director of the Superfund program. “We know the Superfund program is not the answer to the hundreds of thousands of mines out there, but the mines we are working on we want to do them the best we can.”

The 43 sites examined by AP are mining locations for which officials and researchers have reliable estimates of polluted water releases. Officials said flow rates at the sites vary.

Average flows were unavailable for nine sites that only had high and low estimates of how much polluted water flowed out. For those sites, the AP used the lower estimates for its analysis.

Questions over who should pay

To date, the EPA has spent an estimated $4 billion on mining cleanups. Under Trump, the agency has identified a small number of Superfund sites for heightened attention after cleanup efforts stalled or dragged on for years. They include five mining sites examined by AP.

Former EPA assistant administrator Mathy Stanislaus said more money is needed to address mining pollution on a systematic basis, rather than jumping from one emergency response to another.

“The piecemeal approach is just not working,” said Stanislaus, who oversaw the Superfund program for almost eight years ending in 2017.

Democrats have sought unsuccessfully to create a special cleanup fund for old hardrock mine sites, with fees paid by the mining industry. Such a fund has been in place for coal mines since 1977, with more than $11 billion in fees collected and hundreds of sites reclaimed.

The mining industry has resisted doing the same for hardrock mines, and Republicans in Congress have blocked the Democratic proposals.

Montana Mining Association director Tammy Johnson acknowledged abandoned mines have left a legacy of pollution, but added that companies still in operation should not be forced to pay for those problems.

“Back in the day there really wasn’t a lot known about acid mine drainage,” she said. “I just don’t think that today’s companies bear the responsibility.”

In 2017, the EPA proposed requiring companies still operating mines to post cleanup bonds or offer other financial assurances so taxpayers don’t end up footing cleanup bills. The Trump administration halted the rule , but environmental groups are scheduled to appear in federal court next month in a lawsuit that seeks to revive it.

“When something gets on a Superfund site, that doesn’t mean it instantly and magically gets cleaned up,” said Earthjustice attorney Amanda Goodin. “Having money immediately available from a responsible party would be a game changer.”

City of Brantford gets loan for completed brownfield project

As reported by Susan Gamble in the Brantford Expositor, The City of Brantford, Ontario is securing a $4.6 million load to cover the expenses related to the remediation of the Sydenham Pearl Brownfield Site.

The site has already been remediated. City Councillors recently voted in favour of the $4.6 million debenture from the Ontario Infrastructure and Lands Corporation with a 20-year interest rate of 3.4 per cent. The agreement will mean the city repays the loan at a rate of $322,878 a year.

The debenture was approved, along with the project, in 2012 and the remediation at the site is complete, but the money has to be returned to the city’s capital project fund, which has been fronting the money.

Joelle Daniels, the city’s director of finance, explained to the Brantford Expositor that the city had been able to finance the costs of the project over the last six years from working capital since the cash flow was available.

“Typically we have an interim balance and that allows us to not issue the debenture until we know the final cost of the project. We wouldn’t have wanted to borrow the money up front and then carry the interest longer.”

The city has about a dozen outstanding debentures, most of them with the Ontario Infrastructure Lands Corporation but others through the Federation of Canadian Municipalities or regular lending institutions.

The Sydenham-Pearl Brownfield Site is a 6 acre property that had most recently owned by two industrial companies, namely Domtar and Crown Electric, which is surrounded by residential properties, a public playground, a vacant school property, and a rail line.


Crown Electric Manufacturing 17 Sydenham Street
Image Source: (City of Brantford Records Department)

Prior to remediation, soil testing and groundwater testing had shown high levels of industrial chemicals, including but not limited to trichloroethylene and its breakdown products, ethylbenzene and vinyl chloride. 

As is the case with many brownfields, the Sydenham-Pearl Brownfield site has its history rooted in industrial purposes.  The properties have changed hands many times over the course of several decades, and have survived many changes in environmental policies.  Policies including the disposal of hazardous waste and even what chemicals are considered to be hazardous in the first place.

The remediation took 8 weeks to complete and included: the removal of underground storage tanks; excavation and offsite disposal of petroleum hydrocarbons in soil; and in situ soil mixing to break down volatile organic compounds in soil and groundwater.

With remediation activities complete, Phase 3 soil capping and berm construction began. Installation of the soil cap was a requirement of the Ontario Environment Ministry in accordance with the Risk Assessment completed for these properties. Milestone Environmental Contracting completed soil capping and berm construction.

Work at the Sydenham Pearl Brownfield Remediation project was completed in 2017 with required certificates received from the province last spring. The city is currently finishing off sampling and monitoring of the site as required by the Ministry of Environment Conservation and Parks.

The project, which took in 17 and 22 Sydenham, involved removing more than 3,000 cubic metres of contaminated soil to a provincial landfill.

Formerly the site of Crown Electric and Domtar, which made roofing materials, the site was an eyesore, inhabited by squatters and an invitation for fires.

Large fires in 2001 and 2004 meant the city spent hundreds of thousands of dollars to level buildings and clear the area. The properties were seized for tax sales and a remediation plan was created.

Milestone Environmental Contracting spent $2.4 million of the budget on the remediation and another $2.2 million was set aside for the greening process and contingency funding.

The Uses of 3D Modeling Technology in the Environmental Remediation Industry

By: Matt Lyter (Senior Staff Geologist at St-John-Mitterhauser & Associates, A Terracon Company) and Jim Depa (Senior Project Manager/3D Visualization Manager at St-John-Mitterhauser & Associates, A Terracon Company)

Three-dimensional (3D) modeling technology is used by geologists and engineers in the economic and infrastructure industries to help organize and visualize large amounts of data collected from fieldwork investigations.  In the oil and gas industry, petroleum geologists use 3D models to visualize complex geologic features in the subsurface in order to find structural traps for oil and natural gas reserves.  In the construction industry, engineers use 3D maps and models to help predict the mechanics of the soil and the strength of bedrock for construction projects.  In the mining industry, economic geologists use high resolution 3D models to estimate the value of naturally occurring ore deposits, like gold, copper, and platinum, in a practice known as resource modeling.

All of the models are built in almost the same exact way: 1) By collecting and analyzing soil samples and/or rock cores; 2) Using a computer program to statistically analyze the resulting data to create hundreds or even thousands of new (or inferred) data points; and 3) Visualizing the actual and inferred data to create a detailed picture of the ground or subsurface in three dimensions.  These models can be used in the economic and infrastructure industries to help predict the best locations to install an oil or gas well, predict the size of an oil or natural gas reserve, assist in the design of a road, tunnel, or landfill, calculate the amount of overburden material needing to be excavated, or help to predict the economic viability of a subsurface exploration project.

However, because of the significant amount of computing power needed to create the models, usage of the technology by regulatory driven industries has been limited.  But continuing technological advancements have recently made 3D modeling technology more accessible and affordable for these regulatory driven industries, including the environmental investigation and remediation industry.  Complex 3D models that previously may have taken several days to create using expensive high-end computers, can now be made in several hours (or even minutes) using the technology present in most commercially available desktops.  Because of these advancements, subsurface contamination caused by chemical spills can be visualized and modeled in 3D by environmental geologists at a reasonable price and even in near real-time.

3D Models of Soil Contamination

Some of the applications of 3D modeling technology in the environmental investigation and remediation industry are only just beginning to be utilized, but they have already helped to: 1) Identify data gaps from subsurface investigations, 2) Describe and depict the relationship between the geologic setting of a site and underground migration of a contaminant, and 3) Provide a more accurate estimate of the amount of contamination in the subsurface.  The models have also helped contractors design more efficient remediation systems, assisted governmental regulators in decision making, and aided the legal industry by explaining complex geologic concepts to the non-scientific community.  This is especially true when short animations are created using the models, which can show the data at multiple angles and perspectives – revealing complexities in the subsurface that static two-dimensional images never could.

The consultants at St. John-Mittelhauser and Associates, a Terracon Company (SMA), have used 3D modeling technology on dozens of sites across the United States, most recently, at a large-scale environmental remediation project in the Midwestern United States.  Contamination from spills of trichloroethylene (TCE), a once widely used metal degreaser, were identified at a former auto parts manufacturer during a routine Phase 2 investigation.  Dozens of soil samples were collected and analyzed in order to define the extent of contamination, and once completed, traditional 2D maps and a series of cross-sections were created.  One of the cross sections is shown in the image below:

Cross-section of soil contamination

Traditional Cross-section Showing Geologic Units and Soil Sample Results

The maps and cross sections were presented to remediation contractors with the purpose of designing a remediation system precisely based on treating only the extent of the contaminated soil.  The lowest bid received was for $4.2 million dollars (USD), however, it was evident to SMA that all of the proposed designs failed to take into account the complexity of the subsurface contamination.  Specifically, large portions of the Site, which were not contaminated, were being proposed to be treated.  Therefore, using a 3D dimensional modeling program, SMA visualized the soil sample locations, modeled the extent of the contaminated soil in 3D, and created an animation showing the model at multiple perspectives and angles, at a cost of $12,000 (USD).  A screenshot of the model is provided below:

3D dimensional modeling program results

3D Side View of TCE Contamination in Soil (15 PPM in Green, 250 PPM in Orange)

The project was resubmitted to the remediation contractors with the 3D models and animation included, resulting in a guaranteed fixed-price bid of $3.1 million dollars – a cost savings of over $1.1 million dollars for the client. Additionally, an animation showing both the remedial design plan and confirmatory sampling plan was created and presented to the United States Environmental Protection Agency (the regulatory agency reviewing the project) and was approved without any modifications.  To date, the remediation system has removed over 4,200 pounds of TCE from the subsurface and completion of the project is expected in 2019.  A short animation of the 3D model can be viewed on YouTube.


3D Models Showing PCE Contamination in Soil

The 3D modeling software has also been used to help determine the most cost-effective solution for other remediation projects, and has been able to identify (and clearly present) the sources of chemical spills.  The following link is an animation showing three case studies involving spills of perchloroethene (a common industrial solvent) at a chemical storage facility, ink manufacturer, and former dry cleaner: https://www.youtube.com/watch?v=0IlN_TIXkGk

The most cost-effective remediation option was different for each site and was based on the magnitude of the contamination, maximum depth of contaminated soil, geologic setting, and the 3D modeled extent of contamination.  Specifically, the contamination at the chemical storage facility was treated using electrical resistance heating technology, chemical oxidants were used to treat the soils at the ink manufacturer, and soil vapor extraction technology was used at the dry cleaner.

However, several barriers remain which prevent the wide-spread use of 3D modeling technology.  The various modeling programs can cost upwards of $20,000, as well as yearly fees for software maintenance.  There are also costs to organize large datasets, build the necessary files, and create the models and animations.  It also must be noted that the 3D models are only statistical predictions of site conditions based on the available data, and the accuracy of the models is wholly dependent on the quantity, and more importantly, the quality of the data.  Even so, 3D modeling technology has proven to play an important role in the environmental remediation industry by helping project managers to understand their sites more thoroughly.  It has also provided a way to disseminate large amounts information to contractors, regulators, and the general public. But, perhaps, most-importantly, it has saved money for clients.


About the Authors

Matt Lyter (Senior Staff Geologist at St-John-Mitterhauser & Associate, A Terracon Company) provides clients with a wide range of environmental consulting services (Environmental litigation support; acquisition and transaction support; site specific risk assessment, etc.), conventional and state-of-the-art environmental Investigation services, and traditional to advanced environmental remediation services.

Jim Depa (Senior Project Manager/3D Visualization Manager at St-John-Mitterhauser & Associate, A Terracon Company) has over 12 years of experience as a field geologist, project manager, and 3D modeler.  He is well-versed with a variety of computer programs including: C-Tech’s Earth Volumetric Studio (EVS), Esri’s ArcGIS, AQTESOLV, MAROS, Power Director 16, and Earthsoft’s EQuIS

Top Environmental Clean Up Projects throughout Canada

by David Nguyen, Staff Writer

1. The Randle Reef Contaminated Sediment Remediation Project – Hamilton, Ontario

Cost: $138.9 million

Contaminant: polycyclic aromatic hydrocarbons (PAHs), heavy metals

Approximately 60 hectares in size and containing 695 000 cubic metres of sediment contaminated with polycyclic aromatic hydrocarbons (PAHs) and heavy metals, the Randle Reef restoration project is three decades in the making. The pollution stems from various industries in the area including coal gasification, petroleum refining, steel making, municipal waste, sewage and overland drainage.1

Slated to be completed in three stages, the first stage involved the completion of a double steel sheet-piled walled engineered containment facility (ECF) around the most contaminated sediments, with stage 2 consists of dredging of the contaminated sediments into the ECF. Stage 3 will involve dewatering of the sediments in the ECF and treating the wastewater to discharge back into the lake, and the sediments will be capped with 60 cm of sand and silt enriched with organic carbon. This cap will both the isolate the contaminated sediments from the environment and form a foundation or future port structures. The ECF will be capped with layers of several material, including various sizes of aggregate, geo-textile and geo-grid, wickdrains, and asphalt and or concrete. This isolates the contaminants and provides a foundation for future port structures.

The project is expected to be completed by 2022 and cost $138.9 million. The Hamilton Port Authority will take over monitoring, maintenance, and development responsibilities of the facility for its expected 200-year life span. It is expected to provide $151 in economic benefits between job creation, business development, and tourism.

The Canada–United States Great Lakes Water Quality Agreement listed Hamilton harbour (which contains Randle Reef) as one of 43 Areas of Concern on the Great Lakes. Only 7 have been removed, 3 of which were in Canada.

2. Port Hope Area Initiative – Port Hope, Ontario

Cost: $1.28 billion

Contaminant: low-level radioactive waste (LLRW), industrial waste

The town of Port Hope, Ontario has about 1.2 million cubic metres of historic LLRW across various sites in the area. The soils and materials contain radium-226, uranium, arsenic, and other contaminants resulting from the refining process of radium and uranium between 1933 and 1988. Additional industrial waste containing metals, hydrocarbons, and dried sewage and sludge with copper and polychlorinated biphenyl (PCBs) will also be contained at the new facility.

The material was spread across town as the tailings were given away for free to be used as fill material for backyards and building foundations. An estimated 800 properties are affected, but the low-level radiation poses little risk to humans. The Port Hope Area Initiative will cost $1.28 billion and will include monitoring before, during, and after the construction of a long term management waste facility (LTMWF).

The LTWMF will be an aboveground engineered storage mound on the site of an existing LLRW management facility to safely store and isolate the contaminated soil and material, as well as other industrial waste from the surrounding area. The existing waste will also be excavated and relocated to the engineered mound. Leachate collection system, monitoring wells, and sensors in the cover and baseliner will be used to evaluate the effectiveness of the storage mound, allowing for long term monitoring of the waste.

The facility also contains a wastewater treatment plant that will treat surface water and groundwater during construction of the facility, as well as the leachate after the completion of the storage mound. The plant utilizes a two stage process of chemical precipitation and clarification (stage 1) and reverse osmosis (stage 2) to treat the water to meet the Canadian Nuclear Safety Commission requirements for water discharged to Lake Ontario.

3. Marwell Tar Pit – Whitehorse, Yukon Territory

Cost: $6.8 million

Contaminant: petroleum hydrocarbons (PHCs), heavy metals

This $6.8 million project funded by the governments of Canada and Yukon will remediate the Marwell Tar Pit in Whitehorse, which contain 27 000 cubic metres of soil and groundwater contaminated with hydrocarbons, such as benz[a]anthracene and heavy and light extractable petroleum hydrocarbons and naphthalene, and heavy metals such as manganese. Some of the tar has also migrated from the site.

Contamination began during the Second World War, when a crude oil refinery operated for less than one year before closing and being dismantled. The sludge from the bottom of dismantled storage tanks (the “tar”) was deposited in a tank berm, and over time other industries and businesses added other liquid waste to the tar pit. In the 1960s the pit was capped with gravel, and in 1998 declared a “Designated Contaminated Site.”

The project consists of three phases: preliminary activities, remedial activities, and post-remedial activities. The preliminary phase consisted of consolidating and reviewing existing information and completing addition site assessment.

The second phase of remedial activities began in July 2018 and involves implementing a remedial action plan. Contaminated soil segregated and heated through thermal conduction, which vaporizes the contaminants, then the vapours are destroyed by burning. Regular testing is done to ensure air quality standards are met. The main emissions from the site are carbon dioxide and water vapour. Remediated soil is used to backfill the areas of excavation. This phase is expected to be completed in 2019-2020.

The final phase will involve the monitoring of the site to demonstrate the remediation work has met government standards. This phase is planned to last four years. The project began in 2011 and is expected to be completed in 2020-2021.

4. Boat Harbour – Nova Scotia

Cost: approx.$133 million

Contaminant: PHCs, PAHs, heavy metals, dioxins and furans

The provinces largest contaminated site, Boar Harbour, is the wastewater lagoon for the local pulp mill in Abercrombie Point, as well as the discharge point for a former chemical supplier in the area. Prior to 1967, Boat Harbour was a saltwater tidal estuary covering 142 hectares, but a dam built in 1972 separated Boat Harbour from the ocean, and it is now a freshwater lake due to the receiving treated wastewater from the mill since the 1967.

The wastewater effluent contains contaminants including dioxins and furans, PAHs, PHCs, and heavy metals such as cadmium, mercury, and zinc. In 2015, the government of Nova Scotia passed The Boat Harbour Act, which ordered that Boat Harbour cease as the discharge point for the pulp mill’s treated wastewater in 2020, which allows time to build a new wastewater treatment facility and time to plan the remediation of Boat Harbour.

The estimated cost of the cleanup is $133 million, which does not include the cost of the new treatment facility. The goal is to return the harbour to its original state as a tidal estuary. The project is currently in the planning stages and updates can be found at https://novascotia.ca/boatharbour/.

5. Faro Mine – Faro, Yukon

Cost: projected$450 million

Contaminant: waste rock leachate and tailings

Faro Mine was once the largest open-pit lead-zinc mine in the world, and now contains about 70 million tonnes of tailings and 320 million tonnes of waste rock, which can potentially leach heavy metals and acids into the environment. The mine covers 25 square kilometres, and is located near the town of Faro in south-central Yukon, on the traditional territory of three Kasha First Nations – the Ross River Dena Council, Liard First Nation and Kaska Dena Council. Downstream of the mine are the Selkirk First Nation.

The Government of Canada funds the project, as well as leads the maintenance, site monitoring, consultation, and remediation planning process. The Government of Yukon, First Nations, the Town of Faro, and other stakeholders are also responsible for the project and are consulted regularly to provide input.

The entire project is expected to take about 40 years, with main construction activities to be completed by 2022, followed by about 25 years of remediation. The remediation project includes upgrading dams to ensure tailings stay in place, re-sloping waste rock piles, installing engineered soil covers over the tailings and waste rock, upgrading stream diversions, upgrading contaminant water collection and treatment systems.

6. Sylvia Grinnell River Dump – Iqaluit, Nunavut

Cost: $5.4 million

Contaminant: PHCs, polychlorinated biphenyls (PCBs), pesticides

Transport Canada awarded a contract of over $5.4 million in 2017 for a cleanup of a historic dump along the mouth of Sylvia Grinnell River in Iqaluit, Nunavut. The dump contains metal debris from old vehicles and appliances, fuel barrels, and other toxic waste from a U.S. air base, and is a site for modern day rogue dumping for items like car batteries. This has resulted in petroleum hydrocarbons, polychlorinated biphenyls (PCBs), pesticides, and other hazardous substances being identified in the area.

The Iqaluit airfield was founded in Frobisher Bay by the U.S. military during World War 2 as a rest point for planes flying to Europe. During the Cold War, the bay was used as part of the Distant Early Warning (DEW) Line stations across the north to detect bombers from the Soviet Union. When the DEW was replaces by the North Warning System in the 1980s, these stations were abandoned and the contaminants and toxic waste left behind. Twenty-one of these stations were remediated by the U.S. Department of National Defence at a cost of about $575 in 2014.

The Sylvia Grinnell River remediation project is part of the Federal government’s responsibility to remediate land around the airfield that was transferred to the Government of Nunavut in the 1990s.The contract was awarded in August 2017 and was completed in October. The remaining nontoxic is sealed in a new landfill and will be monitored until 2020.

7. Greenwich-Mohawk Brownfield – Brantford, Ontario

Cost: $40.78 million

Contaminant: PHC, PAC, heavy metals, vinyl chloride

The City of Brantford have completed a cleanup project of 148 000 cubic metres of contaminated soil at the Greenwich-Mohawk brownfield site. The area was historically the location of various farming manufacturing industries that shut down, leaving behind contaminants like PHC, PAC, heavy metals like lead, xylene, and vinyl chloride.

Cleanup began in 2015, and consisted coarse grain screening, skimming, air sparging, and recycling of 120 000 litres of oil from the groundwater, using biopiles to treat contaminated soil onsite with 73% of it being reused and the rest requiring off site disposal.

Barriers were also installed to prevent future contamination from an adjacent rail line property, as well as to contain heavy-end hydrocarbons discovered during the cleanup that could not be removed due to the release odorous vapours throughout the neighbourhood. The 20 hectare site took two years to clean and costed only $40.78 million of the allocated $42.8 million between the all levels of government, as well as the Federation of Canadian Municipalities Green Municipal Fund.

8. Rock Bay Remediation Project – Victoria, British Columbia

Cost: $60 million

Contaminant: PAHs, hydrocarbons, metals

Located near downtown Victoria and within the traditional territories of the Esquimalt Nation and Songhees Nation, the project entailed remediating 1.73 hectares of contaminated upland soils and 2.02 hectares of contaminated harbour sediments. The site was the location of a former coal gasification facility from the 1860s to the 1950s, producing waste products like coal tar (containing PAHs), metals, and other hydrocarbons, which have impacted both the sediments and groundwater at the site.

Remediation occurred in three stages. From 2004 to 2006, the first two stages involving the remediation of 50 300 tonnes of hazardous waste soils, 74 100 tonnes of non-hazardous waste soils, and 78 500 tonnes of contaminated soils above commercial land use levels. In 2009, 250 tonnes of hazardous waste were dredged from two sediment hotspots at the head of Rock Bay. About 7 million litres of hydrocarbon and metal impacted groundwater have been treated or disposed of, and an onsite wastewater treatment plant was used to return treated wastewater to the harbour.

Construction for the final stage occurred between 2014 to 2016 and involved:

  • installing shoring along the property boundaries to remove up to 8 metres deep of contaminated soils,
  • installing a temporary coffer dams
  • draining the bay to remove the sediments in dry conditions, and
  • temporary diverting two storm water outfalls around the work area.

Stage three removed 78 000 tonnes of contaminated and 15 000 tonnes of non-contaminated sediment that were disposed of/ destroyed at offsite facilities.

Final post-remediation monitoring was completed in January 2017, with post-construction monitoring for 5 years required as part of the habitat restoration plan to ensure the marine habitat is functioning properly and a portion of the site will be sold to the Esquimalt Nation and Songhees Nation.

9. Bushell Public Port Facility Remediation Project – Black Bay (Lake Athabasca), Saskatchewan

Cost: $2 million

Contaminant: Bunker C fuel oil

 Built in 1951 and operated until the mid-1980s, the Bushell Public Port Facility consist of two lots covering 3.1 hectares with both upland and water lots. The facility supplied goods and services to the local mines, and petroleum products to the local communities of Bushell and Uranium City. Historical activities like unloading, storing, and loading fuel oil, as well as a large spill in the 1980s resulted in the contaminated soil, blast rock, and bedrock in Black Bay that have also extended beyond the waterlot boundaries.

The remediation work occurred between 2005 to 2007, and involved excavation of soil and blast rock, as well as blasting and removing bedrock where oil had entered through cracks and fissures.

Initial remediation plans were to crush and treat the contaminated material by low temperature thermal desorption, which incinerates the materials to burn off the oil residue. However, opportunities for sustainable reuse of the contaminated material came in the use of the contaminated crush rock for resurfacing of the Uranium City Airport. This costed $1.75 million less than the incineration plan, and saved the airport project nearly 1 million litres of diesel fuel. The crush was also used by the Saskatchewan Research Council in the reclamation of the Cold War Legacy Uranium Mine and Mill Sites. A long term monitoring event is planned for 2018.

10. Thunder Bay North Harbour – Thunder Bay, Ontario

Cost: estimated at upwards to $50 million

Contaminant: Paper sludge containing mercury and other contaminants

 While all of the projects discussed so far have either been completed or are currently in progress, in Thunder Bay, the plans to clean up the 400 000 cubic metres of mercury contaminated pulp and fibre have been stalled since 2014 due to no organization or government designated to spearhead the cleanup.

While the water lot is owned by Transport Canada, administration of the site is the responsibility of the Thunder Bay Port Authority, and while Transport Canada has told CBC that leading the cleanup is up to the port, the port authority was informed by Transport Canada that the authority should only act in an advisory role. Environmental Canada has participated in efforts to advance the planning of the remediation work, but is also not taking the lead in the project either. Further complications are that the industries responsible for the pollution no longer exist.

Industrial activities over 90 years have resulted in the mercury contamination, which range in concentrations between 2 to 11 ppm on surface sediments to 21 ppm at depth. The thickness ranges from 40 to 380 centimetres and is about 22 hectares in size. Suggested solutions in 2014 include dredging the sediment and transferring it to the Mission Bay Confined Disposal Facility, capping it, or building a new containment structure. As of October 2018, a steering committee lead by Environment Canada, Transport Canada, Ontario’s environmental ministry and the Thunder Bay Port Authority, along with local government, Indigenous groups, and other stakeholders met to evaluate the remediation options, as well as work out who will lead the remediation.

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