Concrete capture

“If the wind is right, emissions from Lafarge’s main stack blow across this inlet and in the winter we’ll see the dust settling here on the ice and in between the reeds along the shoreline,” says Lydia Sorflaten, pointing to a small pond-like inlet on Shortts Lake, adjacent to the Lafarge cement plant in Brookfield. 

Sorflaten has lived on the lake for nearly 20 years and is part of Citizens Against the Burning of Tires (CABOT), a group that formed nearly 15 years ago when the government began to entertain Lafarge’s proposal to include scrap tires in its fuel mix, displacing some of the coal and petroleum coke — an arrangement that would also see the cement-giant receive a portion of the environmental-fee collected by Divert NS from Nova Scotians when they purchase new tires.

But as was laid out in Part 1 of this series, while the province originally decided that using tire-derived-fuel (TDF) wasn’t in the cards, at least not in the “foreseeable future,” it did an about-face in 2017 when then Environment Minister (now Premier) Iain Rankin approved Lafarge’s one-year pilot to burn roughly 350,000 tires in its kiln, despite concerns raised by government scientists in the internal review of the company’s EA registration document.

As part of the pilot project, tires were added to Lafarge’s fuel mix in August 2019 and the company, which was granted a 14-month extension on the pilot, is allowed to burn them until October 2021. As part of the conditions for approval, baseline testing (without tires) was conducted in July 2019 and emissions testing with tires was done in October 2019 and again in October 2020. According to Lafarge the results of all the testing will be made public this spring. ^[1]As previously stated, while the one-year pilot officially ended in August 2020, NSE granted the company a 14-month extension until October 2021 because of time lost during their winter shutdown and … Continue reading

For Sorflaten, the Minister’s decision was a real blow. Not only did it demonstrate the lax oversight on the part of the government, but it dismissed the serious health and environmental concerns raised by CABOT about the potential impact of burning tires.

It also indicated how the government seemed more than willing to give Lafarge the benefit of the doubt, allowing the project to go ahead despite there being little evidence that the results would be “beneficial to benign” — as the company claimed.

But Rankin’s decision also ignored something else that Sorflaten wants people to know about: the pollution associated with cement-making predated the burning of scrap tires.  

Standing next to Shortts Lake, Sorflaten recalls the day back in the winter of 2007 — long before tires were added to Lafarge’s cement kiln — when two NSE officials collected samples of the particulate matter that had settled on the ice near her home. Sorflaten says when the analysis came back it found the particulate contained some highly toxic compounds including lead, thallium, and chromium. 

The Halifax Examiner contacted NSE and was able to obtain a copy of the 2007 analysis by Maxxam Analytics. According to Barbara MacLean, the department’s spokesperson, inspectors visited Sorflaten and sent samples of cement kiln dust (CKD) from Lafarge’s landfill as well as a sample of snow collected from the lake to be analyzed. The analysis of the snow “demonstrates all parameters are at or below the Canadian Council of Ministers of the Environment (CCME) Environmental Quality Guidelines when compared to both residential parkland soils and fresh water sediments criteria,” says MacLean. 

However — and this is important — the sample taken from Lafarge’s cement kiln dust (CKD) landfill was “material not appropriate for disposal in a municipal landfill, nor is it sent there,” says MacLean. 

Part 3 of this series will look more closely at Lafarge’s CKD problem: while it may not be appropriate for landfill (and isn’t sent there), the startling reality is it’s currently being sold by the cement company as a soil amendment, making its way onto farm fields in the province. 

Inlet on Shortts Lake where emissions “dust” collects on the ice in the winter. In the winter of 2007 some researchers from Nova Scotia Environment (NSE) visited the lake. Samples of the particulate on the snow was shown to contain a number of elements, including lead, thallium, and chromium. Photos courtesy Lydia Sorflaten. 

Pollute first, rectify later

Back in September of 2014 — before tires were added but after Lafarge had started using waste fuels—residents complained that for more than five hours, a plume of fumes and smoke came out of the main stack and settled over Shortts Lake, “gagging everybody out,” forcing people, including children, into their homes. The plant manager at the time said the fumes were created during start-up of the cement kiln, following a regularly scheduled shutdown, and that “they were blending fuels and there must have been a downdraft and there must have been something that residents could smell.” 

Residents said it wasn’t an isolated occurrence, and that it happened “every time they shut down, every time they start up” and it was “getting worse.” A follow up investigation found the excess pollution was the result of burning waste oils when the kiln wasn’t hot enough.  

Then in 2020 (after tires were added) bad air from Lafarge’s stack made the news again when a cement-like “dust” had settled on the cars and houses of Shortts Lake residents. One person, who reported he couldn’t get the white residue off his car, was Sorflaten’s son Jason. In an interview with the Halifax Examiner, Jason said that while the incident last September was particularly bad, it wasn’t the first time it had happened. 

“The air temperature dropped down during the night and there was a layer of moisture on the vehicle, something for the cement dust to bind to,” he explains. “When I complained, [Lafarge] told me to wash it with vinegar, and they sent out an insurance adjuster, but I never heard back from anybody, not the head office, not their field plant or their insurance agents,” he says. “The paint has been ruined on parts of the car,” he says.  

According to Robert Cumming, Lafarge’s director of environment and public affairs, two residences were affected and “our instructions to the cleaning company was that anyone who contacted us was to have their property cleaned. To our knowledge this was extended to all who contacted us. The offer remains in the event that someone was missed.” 

Asked about the incident, NSE spokesperson Barbara MacLean said Lafarge reported an “opacity” incident to the department, which resulted in the release of “clinker dust,” a form of coarse cement powder, said MacLean. As per the terms and conditions of the approval, “the situation was rectified immediately,” said MacLean. 

“When an event happens, the ‘continuous emissions monitoring’ (CEM) system signals to the operator that a correction is needed. The electronic failure was corrected and the kiln was restarted.” 

According to Cumming, “The kiln system was operating normally and partly fueled by scrap tire when a critical control card in the automation system that controls the kiln system failed and shutdown the plant, leading to the release of dust into the atmosphere. This type of equipment failure is extremely rare.” 

This may be true, but shut downs, startups, and kiln “upsets” are not rare, and can also result in “opacity incidents” like these. They are just a part of industrial processes like cement-making and can happen with, or without tires. But when these dramatic releases of particulate matter do happen, how dangerous are they? 

I’ve been told by a number of those I’ve interviewed for this series that without knowing exactly what the “dust” was composed of, it’s not possible to draw any conclusions. Some of the particles that make up particulate matter can be extremely complex, and toxic, but the particles that stuck to Jason’s car, for instance, were probably too big to actually breath in. Larger particles tend to be heavy and fall out of the air the fastest. They also tend to be the ones that contribute to throat and eye irritation, and can also coat vegetation and impact surface water. But it’s the fine particles, the ones you can’t see, that you have to be worried about. They’re the ones that can deposit deep in your body and contribute to systemic effects. 

Industry making the rules

The day I met Sorflaten at her home on Shortts Lake, I had just come from a site tour at the cement plant. My timing wasn’t great as the plant was in its annual “winter shutdown” when maintenance on the machinery takes place, so I wasn’t able to witness first-hand what the tire-derived-fuel process looks like when it’s running. But as Jessica Assaf, Lafarge’s manager of corporate communications in eastern Canada pointed out, it was “a good opportunity to get a sense of scale and better understand how our systems work.” And, because the company’s official spokespeople were both out of the province at the time, Assaf also said it would be an “off-the-record engagement.” 

But even so, the tour provided a fascinating glimpse of the world of cement-manufacturing.

When it’s running, fuels are injected into the lower end of a long horizontal kiln — much larger than I had ever imagined — while the raw mix of various rocks enter at the elevated end. At the top of the TDF injection unit, I stood overlooking the spot where the scrap tires are fed into the kiln. I was brought to see the control room lined with computer screens, including the continuous emissions monitor (CEM), and was walked through the various systems that exist for quality control, and how all the bits of information are meant to feedback through the system to ensure a consistent product. 

Our dependence as a society on these large industrial processes is a complex one, and the argument can be made that cement is essential in many ways. But a distinction needs to be made here. To criticize the pollution-creating reality of cement manufacturing is not to simultaneously be against using cement, or employing people who make cement, or even wishing for a world without cement.

The crux of the issue is that the industrial sector overall has been allowed to externalize costs at the expense of human and environmental health, and governments have become captured by vested interests, leaving citizens groups like CABOT virtually powerless. 

“You want to know the air you breathe and the water you drink and the environment you live in isn’t going to threaten your life,” says Sorflaten. “But industry is making the rules for industry, and there should be regulation.” 

“If they’re going to burn tires, there should be better pollution controls on their stacks,” says Sorflaten, “and plants that do have them are forced to by environmental standards.”

Standing on the shore of Shortts Lake, Sorflaten says that normally, when the plant is operating, she can hear Lafarge’s pollution control system working. She describes the sound coming from the electrostatic precipitator (ESP), “It sounds like a bang,” and it happens every time it releases the particulate matter. 

Cumming tells me Lafarge’s ESP was first installed in 1966 and was upgraded about five years ago. “A huge amount of charge [is generated] between the plates that attracts particles in the waste gas coming out of the kiln. The particles line the plate and when they stop the charge, the particulate falls down,” he explains.

Any ESP will work more efficiently when the plant is also running that way. In other words, if there’s a “kiln upset” or something to cause the combustion of fuels to be incomplete, then an ESP can be overwhelmed and particulate matter that might normally be collected — including dangerous fine particulate — will be released to the atmosphere through the stack. 

Lafarge Brookfield is equipped with what’s called a “dry” ESP, which is designed to remove particulate matter, assuming it’s in good working order and the plant is running optimally. But even under optimal conditions, there are certain things dry ESPs just cannot do. They can’t remove toxic gases and vapours like volatile organic compounds, they can’t collect dioxins and furans, or very small “submicron” particulates, or handle any emissions that might be moist or sticky. 

An engineer familiar with industrial pollution abatement equipment, but unwilling to speak publicly, told me that scrubbers working in tandem with a dry ESP would work better at removing gases and particulate matter than a dry ESP alone.

A wet ESP would also work better, but they are more expensive, he said, because of the “exotic” metals required due to the high degree of moisture involved. He also pointed out that ESPs require a lot of maintenance to work properly and that burning coal — which the Lafarge plant has done for roughly five decades — creates a lot of sulphur emissions, which can corrode an ESP “to the point where there’s nothing left basically except the metal.” 

I ask Cumming if the plant has any other pollution abatement equipment besides its aging ESP. He says that the process of making cement itself “scrubs” some of the SO2 out of the emissions and traps it in the clinker. Other mineral components, including iron and silica which are found in the fuels, “form a portion of the cement produced,” he says.  

“We also take a pollution prevention approach wherein we use scrap tires to prevent NOx formation. And, by replacing coal with cleaner, low carbon fuels we also prevent landfill pollution and lower CO2 emissions,” Cumming adds. 

The claim that scrap tires are a “low carbon” fuel isn’t without its detractors. We’ll return to it in Part 3 of this series.  

The need for ambient air monitors

No one in Canada has written more studies on ultrafine particles or nanoparticles than Scott Weichenthal. He’s an assistant professor in the Department of Epidemiology, Biostatistics and Occupational Health at McGill University’s Faculty of Medicine.

His 2019 study, linking brain cancer with fine particulates, was the first of its kind, though there had been earlier studies showing that nanoparticles can get into the brain by inhaling and can carry carcinogens with them. 

In an interview with the Halifax Examiner, Weichenthal says nanoparticles haven’t been measured historically so there isn’t much exposure data to date. “They’re not regulated at all, so there’s a chicken and the egg thing, we need the evidence base to develop a regulation.” But he says Canada has some of the best data in the world linking nanoparticles to poor health outcomes, and “the evidence base is building.” 

Weichenthal has no specific knowledge about the emissions from the Lafarge cement plant, but was willing to speak to me about industrial air emissions in general. 

“From a public health point of view, you would have to do some measurements and figure out who is actually being impacted by this.” But as Weichenthal points out, that’s easier said than done since most of the systems in place involve modelling, and they don’t actually measure what people are exposed to.

As previously discussed, there are essentially three ways air emissions are tested at the Lafarge plant. There are annual stack tests which measure the emissions that have passed through the ESP, and are about to exit the stack. These emission values, however, don’t tell us what people downwind are breathing in. For that, air dispersion models have been created — where stack emission data are inputted into a model, along with other parameters, to predict how each contaminant might disperse downwind and in what concentrations. As well, as part of the conditions of the TDF approval, Lafarge had to install a continuous emissions monitoring system (CEM), which involves putting sensors in the stack to measure, in real time, the stack’s main emissions of concern. If the levels on the computer monitor go above a certain threshold an alarm goes off and workers investigate kiln conditions and the fuel mix and adjust them to bring the levels down to whatever threshold has been set. But the CEM system doesn’t tell you what people downwind have been exposed to and in what concentrations either. 

Then there’s the National Pollutant Release Inventory (NPRI). It’s a tracking program created under the Canadian Environmental Protection Act (CEPA) whereby facilities, like Lafarge, are required to self-report any pollution it releases into the environment.

In 2009 Canada’s Auditor General audited Environment Canada to find out what it was doing to ensure that industry’s self-reported emissions data were accurate, and it found that the department was “unable to assess the accuracy and completeness of the data,” did not require third party verification of pollutant release information, and did not conduct routine on-site visits to verify data. It also pointed out there was “little incentive for facilities to improve data quality.” ^[2]It’s not clear if there have been any improvements since then.

So keeping this in mind, according to the NPRI, Lafarge reported that in 2017, the most recent year data were available, its largest emissions were nitrogen oxides (888 tonnes), sulphur dioxide (611 tonnes), and carbon monoxide (199 tonnes). The company also reported emissions of mercury, particulate matter (PM10 and total), lead, and dioxins and furans. Cement manufacturing also produces volatile organic compounds (VOCs), particularly during episodes of incomplete combustion, start-up, or abnormal or “upset” conditions, but none were reported by Lafarge to the NPRI.  ^[3]Emissions to air from cement manufacturing found on pp. 54-94 here. 

Weichenthal says that all the annual emissions reported to the NPRI by industries are modelled as well. 

“Just think about it, how else would you get a measurement of tonnes per year? They’re not out there capturing all the particles and weighing it.” Weichenthal says industries know what they’re burning, how efficient they are and what they expect — based on a chemical model — the weight of these emissions will be in a year. 

“The only way to really know what the impact of an exposure you’re interested in is on the public, is to surround the area with [ambient air] monitors.”

The National Air Pollution Surveillance (NAPS) Program is a joint federal-provincial-territorial initiative that began in 1969 and tracks the emissions of 340 toxic compounds, some of them on a continuous basis, at 260 sites across the country. According to the NSE web site, Nova Scotia has 10 NAPS stations, but none of them is located near Brookfield. 

Anyone skeptical about the dangers posed by fine particulate matter and nanoparticles need look no further than Health Canada’s 2019 report, which found that air pollution is the largest environmental risk to health — responsible for 14,600 premature deaths every year, 260 of them in Nova Scotia — 60% of which are a result of fine particulate matter emissions. ^[4]Nova Scotia premature mortality count attributable to air pollution found in Table 4 of Health Canada’s 2019 study. Globally, air pollution is the fifth leading cause of death, responsible for 8.7% or 4.9 million premature deaths in 2017. ^[5]The Health Canada analysis of air pollution health impacts focuses on fine particulate matter (PM2.5), NO2, and O3. “These three pollutants have been most consistently associated with mortality in … Continue reading

Despite this astonishing toll, the federal and provincial governments do not have legally enforceable air quality standards for toxic substances in the air we breathe.

All provinces have their own way of handling air pollution and in Nova Scotia, polluters’ emission limits are set on a case-by-case basis, for each facility, through an approval process.

At the federal level there are no legally binding guidelines for air pollution, only voluntary guidelines. The Canadian Environmental Protection Act (CEPA) outlines national air objectives and emissions standards for certain industries, but nothing is legally enforced, unlike the US, UK, and the EU, where national air quality standards do have legal teeth.

Air modelling for tire-derived fuel “inadequate”

Recall from Part 1, that in response to the 2017 approval of Lafarge’s plan to burn tires, CABOT filed an application for a judicial review arguing the aging cement kiln was not designed for burning tires and there was a “strong potential for adverse effects” on surface water, groundwater, and human health. The group requested new evidence from an internationally renowned toxicology expert, Douglas Hallett, be admitted as part of the evidence. But the court rejected the motion and eventually denied the group’s appeal, slapping them with court costs of $5,000 each to Lafarge and to the Crown. ^[6]The costs associated with the judicial review, including the lawyer’s fees and court costs were paid by an anonymous donor.  

Hallett has spent his career — one that spans five decades — assessing and testing the impact of toxic chemicals on humans and the environment. In his affidavit to the court, he lays out in detail why the “record” or the information produced by NSE does not support the minister’s decision that the tire-burning project could be operated without adverse effects. In fact, his affidavit raises questions about whether Lafarge has ever operated without causing adverse effects, tires or no tires. 

Hallett also points to air dispersion modelling included in the EA registration document and asks, “Does the Record contain air dispersion modelling of the current and proposed emissions at the Lafarge plant?” To his own question, Hallett answers: 

There is no such modelling. This is an important consideration because until such modelling is completed no-one can even predict what the key points of impingement are and what the impact will be on them in the future. The Record is inadequate in modelling air dispersion of current and future emissions associated with tire combustion.

In Part 1 of this series you were introduced to Mark Gibson, an engineer and former Dalhousie University researcher whose 2015 study provided Lafarge with the credibility it needed to get NSE approval for its one-year pilot to burn scrap tires. In order to predict what the emissions would be from Lafarge’s kiln stack if the company burned scrap tires, Gibson had the tires, coal, and petroleum coke sent away to an independent lab to be analyzed for chlorine, carbon, hydrogen, nitrogen, sulphur, and ash content. ^[7]After Part 1 was published, I received an email from Mark Gibson in which he asked that the following information be included: “Dr. Michael Pegg’s report from 2005 was in favor of using scrap … Continue reading

“Knowing these results, knowing the kiln operating characteristics and the kiln feed material used to make the clinker, one can estimate the resulting emissions of the chemical species,” he explains in an interview. Gibson also used a tube furnace — “a mini cement kiln” —  in his Dalhousie lab to see what emissions would result from the burning of each type of fuel. 

“From the experimental you can then extrapolate to a bigger kiln,” he explains. 

Gibson found that when 30% of the coal-coke fuel mixture is replaced with TDF there would be a 21% decrease in SO2, 23% decrease in NOx, and a 1% decrease in CO2 emissions. When 100% of the fuel was scrap tires, there was a 71% reduction in SO2, a 77% reduction in NOx, and a 3% reduction in CO2 (compared with 100% coal-petcoke mixture). 

Hallett points out that Gibson’s calculations were for 30% use or 100% use of TDF, while Lafarge’s actual proposal was for 5, 15, and 20% use of TDF. “Therefore, at best these reductions [in NOx and SOx], if they occur at all, will be considerably less.”

By all accounts, Gibson’s 2015 study was the linchpin in Lafarge’s TDF approval. Not only did it show reductions in some of Lafarge’s main pollutants, but GHD — the consulting firm hired by Lafarge to do the air dispersion modelling — claimed that when the emission rates were incorporated into its air dispersion model it resulted in “modelled, maximum off-site concentrations of contaminants… all well below applicable health based air standards.”

But here’s the thing. Were TDF emission values even incorporated into GHD’s air dispersion model?

When GHD was developing air emission estimates for modelling the use of TDF as a fuel source — “to determine the change from existing condition emission rates when using TDF as fuel” — it said it used a combination of data sets: Gibson’s “theoretical” lab-derived emission results (with tires), as well as stack test emission rates (without tires) from the plant, some dating as far back as 13 years. 

As previously reported, stack tests from 2004, 2010 and 2014 were said to represent “baseline conditions” at the cement plant, though specific fuel compositions were never publicly disclosed. What GHD says in Lafarge’s EA registration document is that it modelled emission estimates “while using TDF” but on closer inspection, it’s unclear where or how Gibson’s results factored in, if at all. 

GHD’s modelling report — located in the appendix of Lafarge’s EA document — indicates that for the emissions Gibson reported on (SO2, NOx, CO2, and H2O) GHD opted instead to use the “existing emissions estimates,” which would have come from Lafarge’s earlier stack tests (2004, 2010, 2014), when the company was not burning any tires at all. It appears that the only TDF-specific emission estimate incorporated into GHDs model, according to its own report, was the higher chlorine concentration in tires. ^[8]GHD Air Dispersion Modeling Report, p. 2 (of Appendix F in Lafarge’s EA Registration document, 2017).

In other words — unless I’m missing something — it appears that GHD mostly used old emissions estimates from years when no tires were being burned, to predict what air emissions would be like with tires being burned. 

In an attempt to make some sense of this, I contacted NSE, but the matter was not resolved prior to publication. I also reached out to Mark Gibson, who reviewed and signed off on the GHD air modelling report for Lafarge.

I asked, “It appears that the only TDF-specific emission estimate incorporated into the model, according to GHD’s report, was the higher chlorine concentration in tires. So, if this is the case, how does its air dispersion modelling predict what the air emissions would be like downwind with TDF? Am I’m missing something?”

Gibson’s reply: “All the info is in the GHD report.”

Returning to Hallett’s affidavit, he points to several technical issues that were not considered by NSE, including whether it accurately considered the “realities” of cement kiln production — conditions on start-up, shut-down, and during upset conditions. 

Hallett says these “occur frequently from kilns of this age,” and when they do “a plume of black soot will be visible coming from the stack…[which] contains products of incomplete combustion, including cancer-causing chemicals.” If Hallett would have been permitted by the court, he would have written a report assessing the impact of these conditions. 

Hallett also questioned the operational reliability of the plant including the frequency of upsets over its operational history. He also pointed to the availability of data regarding the toxic chemical impact of the plant (without tires) and that if these data were not readily available “is there a reasonable basis to conclude that the project can operate [with tires] without adverse effects?”

Hallett was additionally concerned that the introduction of whole tires into a cooler zone halfway up the kiln would create chemicals that would be “blown by the combustion air up the barrel…ultimately through the electrostatic precipitator which is not designed to remove them, and out into the ambient environment.” He also said injecting tires mid-kiln would “interrupt the steady state operation of the kiln every rotation, resulting in high emissions of products of incomplete combustion.” 

Hallett concludes: 

The deficiencies…cannot be adequately addressed by deferring them to a test or experiment period. Monitoring a kiln does not mitigate the environmental impact it is causing.

Part 3 will look at the acrobatics involved in the claim that scrap tires are a “cleaner” fuel. It will also investigate how cement kiln dust containing a probable human carcinogen is making its way onto Nova Scotia farm fields.]

Cover photo: Lydia Sorflaten has been a resident of Shortts Lake for 19 years. Sorflaten says her family doesn’t drink the water from the lake but they do use it for bathing and some cooking. Photo: Linda Pannozzo