Will the sun soon set on concrete?

Also published on Resilience

At the mention of our “fossil economy” or “fossil civilization”, most of us probably think immediately of “fossil fuels”. But as Mary Soderstrom’s recent book points out, not only our energy supply but also our most important building material has origins in fossilized ancient life.

Concrete, by Mary Soderstrom, is published by University of Regina Press, October 2020. 272 pages.

In Concrete: From Ancient Origins to a Problematic Future, Soderstrom shows us why cement is the literal foundation of nearly every strand of the capitalist economy. She also explains that, just as the fossil fueled industrial complex is deeply dependent on concrete for its infrastructure, so too the concrete industry is deeply dependent on fossil fuels. And these dependencies can’t be unwound easily or quickly, if at all.

By weight, of course, concrete is primarily made from sand, gravel and water – but the all important ingredient which turns the slurry into “manufactured rock” is cement. And cement, Soderstrom writes, “is in large part made from rocks laid down hundreds of millions of years ago when the shells and carapaces of organisms settled in the bottom of seas.” (Concrete, page 3)

The particular rock is limestone, which is abundant, widely distributed, and relatively easy to quarry and crush. But to make a cement from limestone takes energy – a lot of energy.

Ancient Greeks and Romans invented one form of concrete, and some of the resulting buildings and aqueducts still stand today. Quicklime was the basis for their concrete, and production of this lime needed only the heat from firewood. Making lime, Soderstrom says “had a large impact on the forests of any region where people had figured out how to make the substance.” (Concrete, page 44)

For uses such as marine piers and aqueducts, early concrete also depended on particular types of sand that had been forged in the heat of volcanos. The best such sand came from Pozzuoli, near Vesuvius, and such sands are still known as pozzolans. That kind of sand is not so abundant nor so widely distributed, and the global dominance of concrete as a building material had to await more recent technological developments.

This limestone quarry and cement production plant on the north shore of Lake Ontario is operated by St. Marys Cement, a subsidiary of Brazilian corporation Votorantim Cimentos. February 2016.

A key step came in the nineteenth century through the work of French engineer Louis Vicat. In his efforts to recreate the intense heat of volcanos, he developed kilns that chemically transformed crushed limestone into a forerunner of today’s ubiquitous Portland cement. These industrial volcanos had their own serious implications:

“The temperatures required for doing this are nearly twice as high as that needed to make quicklime, about 1,450 degrees C, and therein lie two of the great problems created by our enormous use of modern concrete: where to get the energy to attain those temperatures, and what to do with the greenhouse gases emitted in the process.” (Concrete, page 25-26)

The primary fuel for cement production remains coal, supplemented in some areas with pet coke (a dusty carbon residual from petroleum refining), ground up tires, plastic, even some wood byproducts. To date, renewable energy sources are not up to the challenge of producing good cement at quantity. That is because, Soderstrom writes “the end product of hydro, solar, nuclear, tidal, and wind power is electricity .… [S]o far it doesn’t produce temperatures high enough to make cement from the basic rock.” (Concrete, page 47)

Another key development arose because concrete, as hard as it may be, does not have great tensile strength and therefore doesn’t, by itself, span gaps very well. The skyscrapers and bridges essential to our cities and transportation systems need the addition of steel to concrete. Ridged steel rods, woven into forms before the concrete is poured, are commonplace today, but Soderstrom writes that it took much trial and error to produce a steel that would adhere to concrete in the right way. That steel was also very expensive until development of the Bessemer furnace in the 1850s. Only then could concrete take its place at the foundation of the industrial economy.

Vancouver Public Library central branch, British Columbia, October 2016.

Flashy constructions of glass, steel and concrete throughout our cities are one face of concrete’s dominance. But Soderstrom reminds us that concrete is equally important in humble abodes around the world. Do-it-yourself builders in edge cities rely on a bag of cement, a few buckets of gravel, and an old barrel in which to mix up a slurry – and the result may be a new wall or a solid floor in an improvised one-room dwelling. The government of Mexico, she notes, helped combat the spread of parasites by paying for $150 of supplies, allowing small home owners to replace their dirt floors with concrete.

“The desire to provide sanitary housing for ordinary working families has been the motor for concrete construction since the middle of the nineteenth century,” Soderstrom writes. (Concrete, page 69) There are echoes of this trend everywhere. In American suburbs, even where the walls and roofs are made of lumber, the homes nearly all stand on concrete foundations. Concrete was critical in rapidly reconstructing urban housing in Europe following World War II. And such construction continues on a gargantuan scale in contemporary China: “the United States used 4.5 gigatons of cement between 1901 and 2000, while China, as it ramped up its housing and infrastructure offensive, consumed 6.6 gigatons in only four years.” (Concrete, page 102)

Roads, bridges, houses, apartments, offices, factories – if concrete was important only in those categories of infrastructure, it would be a big enough challenge to replace. Yet Soderstrom illustrates how concrete is closely implicated in the food we eat and the water we drink. The formerly desert valleys of California, which now supply such a huge proportion of fruits and vegetables for North America, only became an oasis – perhaps a temporary one – due to massive concrete dams and hundreds of kilometres of concrete aqueducts and concrete irrigation ditches.

In other areas hundreds of millions of people live in areas that would frequently flood were it not for concrete flood control structures – and which might flood, catastrophically, if these structures are not maintained. Meanwhile hundreds of millions more depend for their drinking water on concrete canals that divert water away from its natural flow. This is true in the US southwest, for example, but on an even greater scale in China. “Already, Beijing is getting 70 percent of its water” from the South North Water Diversion,” Soderstrom writes – and this project is far from completion.

Truck route to Port of Valencia, Spain. October 2018.

An attempt to paint a full picture of concrete’s history and current importance is necessarily wide-ranging, and boundaries around the subject would necessarily be subjective. In the discussions of military strategy, social housing policy, and the politics of carbon taxes, there were many points in the book where I felt the focus on concrete was getting a bit too soft. Yet Soderstrom’s goal is much appreciated: she wants us to understand the vast scope of the challenge we face in transforming our concrete civilization into something sustainable.

It is now widely realized that the production of concrete is a major source of carbon emissions, and that we must reduce those emissions to net zero in the next few decades or face imminent collapse of the planetary life-support systems. Concrete: From Ancient Origins to a Problematic Future gives us glimpses of many efforts to reduce the environmental impact of concrete, through use of different fuel mixes, carbon sequestration, or technological enhancements that reduce the amount of Portland cement needed in a given project. None of these experiments sound reassuring, given the rapidity with which we must transform this critical industry, and given that it would be difficult if not impossible to simply forgo the use of concrete, within decades, without mass casualties.

Other books are better positioned to discuss the technical challenges involved in making sustainable concrete, or making sustainable infrastructure without concrete. But Soderstrom has performed a real public service in showing us the rich history of the seemingly dull material that undergirds our way of life.


Photo at top of page: Exponential Growth of Bridges – a Canadian Pacific rail line runs under ramps for the new Highway 418 expressway near Courtice, Ontario. January 2021. (Full-size image here.)

 

Acoustic conditions, conservation planning, and the St. Marys mine

St Marys mine – Article Index

How much external noise can you add to a wetland environment before the wildlife inhabitants really start to suffer?

Relatively little scientific research appears to have been conducted on this subject. Yet an understanding of cumulative noise pollution is essential to properly assessing the long-term impact of the proposed St. Marys Cement under-the-lake mine south of Bowmanville.

A recently published research paper found biochemical markers of increased stress levels, as well as reduced hatching success, among birds chronically exposed to industrial noise. We’ll get to that paper below, but first, here’s a refresher on the setting for the mine proposal.

The St. Marys mine proposal (official Project Description here) describes a mine-entrance tunnel near the bottom of the existing limestone quarry on the Lake Ontario shoreline. The tunnel will lead to under-the-lake caverns, which will be excavated over a 100-year period.

The project site is adjacent to two Provincially Significant Wetlands, Westside Marsh and Bowmanville Marsh. These wetlands are among the remnants of what was once a very extensive array of coastal wetlands all around Lake Ontario. The remaining coastal wetlands are still of key importance to resident and migratory bird populations and to many freshwater fish species who depend on the wetlands at some stage of their life-cycles.

If the project is approved as proposed, 4 million tonnes of limestone will be blasted and hauled out from these caverns each year. The operation will require ventilation fans moving fresh air into the mine and exhaust air back out, to enable work to be conducted throughout a network of chambers that will eventually extend approximately 14 square kilometers under the lake.

Mining trucks will carry the limestone out of the mine and into the quarry, where it will be crushed into aggregate suitable for construction use. Then approximately 500 truckloads per day (based on seven days/week haulage) will leave the St. Marys site carrying aggregate to the primary market on the east side of the Greater Toronto Area.

The environmental viability of the project must be assessed by looking at the cumulative effects. The blasting, drilling, ventilation fans, trucks and crushers will add noise to an environment that is already anything but quiet.

At present both Westside Marsh and Bowmanville Marsh are subject to significant anthropogenic noise levels on a 24-hour basis. The operations of St. Marys are just one component of that noise.

Noise from St. Marys existing operations comes from blasting and hauling limestone immediately to the west of Westside Marsh, trucking of cement products, and major excavation and berm-building directly north of Westside Marsh.

Another constant noise source is Highway 401, just to the north. At present the traffic noise consists of a constant loud hum, punctuated by accelerating trucks, motorcycles, and sirens. The St. Marys mine would add to that traffic noise, as 500 or more additional trucks come and go every day. (The route in and out of the St. Marys property, and on and off the 401, are shown in yellow on the above map.)

One of the busiest rail lines in Canada passes directly north of the quarry, about 500 meters north of Westside Marsh, and through the north end of Bowmanville Marsh.

Above, an eastbound CN freight train skirts the St. Marys quarry and cement plant. Below, a CN freight train on the bridge over Soper Creek at the north end of Bowmanville Marsh.

 

Noise and stress in bird populations

A recent paper published in the Proceedings of the National Academy of Sciences (US) notes that noise pollution “alters habitats, degrades natural acoustic conditions, and partially or fully excludes species that are sensitive to noise exposure from affected areas.”1

Among the species that remain in noise-affected environments, the effects on survival and fitness are complex. One way to study this is to correlate measured noise levels with measured levels of baseline circulating stress hormones (glucocorticoids) in birds. The paper notes,

To date, no studies have simultaneously examined relationships among noise, GCs [glucocorticoids], and fitness in animals that settle and breed in natural areas exposed to chronic anthropogenic noise.

The paper looked at three species of cavity-nesting birds with different noise tolerances, in a New Mexico wildland which is now interrupted by an array of natural gas compressors. The evidence “strongly suggests that chronic anthropogenic noise induces stress and hypocorticism in birds.” Furthermore, with one of the studied species, the western bluebird, increased noise was correlated with a lower rate of hatching success.

There are a number of explanations for the stress response.

At lower exposure levels, anthropogenic noise is more likely to elicit stress responses indirectly by increasing the difficulty of coping with external challenges (e.g., territory defense) or by creating anxiety through reduced detectability and predictability of threats (e.g., acoustic masking of predator alarm sounds), or both.

Given the capacity for chronic noise to consistently mask biologically relevant cues, animals living in areas with high levels of noise may fail to receive information about their local habitats, leading to a continual state of perceived unpredictability and reduced security.

Citing a range of other studies, the authors further explain how chronic noise pollution disrupts the normal sensory perceptions of wildlife.

The distance over which birdsong and other sounds are effectively transmitted, their ‘active space’, is significantly reduced by increases in ambient background noise. Anthropogenic noise, acting as an acoustic blanket, can reduce or inhibit detection of hetero- and conspecific vocalizations that birds and other animals use to gain information about predation threats. For example, the presence of birdsong and chatter is thought to signal the absence of nearby predators.

How does noise pollution affect the wildlife in Westside and Bowmanville Marshes? Are there species which would otherwise make these wetlands home, if it weren’t for chronic noise levels? With increasing noise levels, will some of the existing species be driven out, or will the populations be weakened due to lower reproduction rates? These are complex questions – but they must be answered before the impacts of additional noise, due to a major mining/extraction project, can be properly assessed.

In spite of huge environmental challenges these wetlands remain home to a wide variety of species. Within this small area there are cattail marshes, open water, wetland forest, upland forest, and even a small fen. Among the many species that live here are various waterfowl, fish, wading birds, osprey, kingfisher, beaver, muskrat, and predators including otter, weasel, marten, raccoon, coyote and fox. These wetlands are also vital staging areas for the many migratory birds which fly over Lake Ontario in the spring and fall.

Raccoon on the bank of Westside Creek at the north end of a beaver pond; ospreys which nest each year on platforms in Westside Marsh; juvenile Black-Crown Night Heron photographed in Bowmanville Marsh.

These wetlands are officially designated as “Provincially Significant Marshes”. The review process for the St. Marys under-the-lake mine must make us ask, how much significance does the province actually afford to this environment?

The authors of the paper on noise pollution and avian stress levels note,

In this era of unprecedented, large-scale human-driven environmental change, preservation or recovery of natural acoustic conditions should be a key aspect of conservation planning and is a critical step toward successful conservation of protected species.

Given the importance of natural acoustic conditions to conservation planning, should the province of Ontario give the OK to increased noise pollution from St. Marys Cement?

 


1“Chronic anthropogenic noise disrupts glucocorticoid signaling and has multiple effects on fitness in an avian community”, Proceedings of National Academy of Sciences, 14 November 2017

St Marys Underground Expansion: Will a mine be a good neighbour to a marsh?

St Marys mine – Article Index

Where do you draw the line between “moderate” and “significant” environmental effects?

Are the dust and diesel emissions from a large mining operation likely to affect the health of an adjacent wetland?

In the case of the St Marys Underground Expansion proposal, those questions would appear to be closely linked.

Under Ontario rules for screening of proposed projects, a Category C project, judged at the outset to have “Moderate Potential Environmental Effects”, faces a less stringent consultation and approval process than a Category D project, which is judged at the outset to have “Significant Potential Environmental Effects”. (See A Class Environmental Assessment for Activities of the Ministry of Northern Development and Mines under the Mining Act.)

The St Marys Underground Expansion has been slotted as Category C. The determination that the project will have only “moderate potential environmental effects” appears to be based substantially on the claim that nearly all of the activities will take place underground, and the surface footprint of the current operation will not change.

But the Project Description doesn’t give serious consideration to the cumulative effects of limestone dust and diesel emissions produced by a doubling of the scale of the extraction activities.

The St Marys operation in Bowmanville is adjacent to a conservation area which includes two marshes – the Westside Marsh and Bowmanville Marsh. Both are designated as provincially significant wetlands, and both are downwind from St Marys when the prevailing westerly and southwesterly winds are blowing.

Graphic adapted from Bowmanville Expansion Project Description, page 12. The lines at bottom marked “Declines” represent the tunnels in and out of the proposed mine.

The current quarrying operation takes out about 4 million tonnes of limestone annually, and the underground mine is projected to take out an additional 4 million tonnes.

The initial plans call for mining and primary crushing to take place underground. All the air that is pumped into the mine will be pumped back out via the exhaust tunnel. There is the potential for dust produced underground to come out with the exhaust flow; the Project Description gives little detail on how dust will be managed.

There will be additional processing of the mined limestone above ground, so there is the potential for more limestone dust being swept up in the wind.

Last but certainly not least, several hundred trucks per day will be required to haul the limestone off to market – at 20 tonnes per truck, the 4 million tonnes per year would fill 200,000 trucks.

How can we be sure that the dust and diesel particulate emissions from all this crushing and trucking will have no “significant environmental effects” on the adjacent marshes? The Project Description neither asks nor answers this question.

In a table discussing Potential Project Effects, the document repeats the same basic phrases in regards to “Areas of ecological importance, including protected areas”, “Views or aesthetics”, “Aquatic species or habitat”, “Terrestrial species or habitat”, “Endangered species”, “Migratory bird species”, “Surface water quality”, and “Soils – contaminants, sedimentation, erosion”. Regarding all these concerns, the Project Description says there will be no significant effects “since all activities will occur beneath the bed of Lake Ontario or within the existing licensed quarry area”.

It is important that in the next phase of the project screening, the possible effects of emissions get more attention in order to ensure that years of marsh rehabilitation work do not go for naught.

Central Lake Ontario Conservation Authority (CLOCA) has this vision for the Westside and Bowmanville Marshes in 2026: “The Marshes are Clean, Green, Blue, Peaceful …. All living things enjoy the protected, tranquil area of the Bowmanville/Westside Marshes Conservation Area. The wooded, old field and wetland areas of the Bowmanville/Westside Marshes provide attractive habitat for abundant wildlife, and a diversity of trees and plants. … Neighbors are implementing effective plans to minimize disruption and noise ….” (Bowmanville/Westside Marshes Conservation Area Management Plan)

But CLOCA reports also make clear that a lot of improvement is needed. A 2006 report indicated that the wetland areas of Westside and Bowmanville Marsh both ranged from “poor to good health”. A 2014 Public Information Centre on Bowmanville Marsh Restoration reported “submerged aquatic vegetation and amphibians in poor condition”, and “birds in fair condition, but showing signs of decline”.

Frogs are thought to be especially sensitive to environmental contaminants, and frogs are remarkably scarce in these marshes now. How much more air-borne pollution will settle in the marshes due to a doubling of heavy equipment emissions at the adjacent quarry/mine? Will frogs, other amphibians, and the many other inhabitants of the marshes be affected?

If the Bowmanville Underground Expansion goes ahead, will “All living things enjoy the protected, tranquil area of the Bowmanville/Westside Marshes”?

Snapping turtle at edge of Bowmanville Marsh, June 21, 2015.

Top photo: St Marys Cement quarry and kiln, February 14, 2016.

St Marys Underground Expansion: A whole lotta truckin goin on

St Marys mine – Article Index

Can the current Waverly Road/Highway 401 interchange handle a doubling of truck traffic to and from the St Marys Cement quarry?

Given that the Waterfront Trail shares the road in this section with the St Marys traffic plus the Highway 401 on/off traffic, can the Waterfront Trail be promoted as a safe and healthy recreational feature?

What mitigation measures will St Marys Cement propose to compensate for a large increase in heavy truck traffic which will affect commuters as well as recreational cyclists?

These are key questions raised by the Project Description for the Bowmanville Expansion Project.

A previous post (Special Delivery: Moving 4,000,000 Tonnes) provided rough estimates for the number of shiploads or truckloads of limestone aggregate the project would move each year.

The Project Description says that the aggregate will be moved “using existing road, rail and/or dock infrastructure”. But at the project’s Public Information Centre in Bowmanville on December 5, St Marys representative David Hanratty made clear that for the foreseeable future, the aggregate would go out by truck, not by ship or rail, primarily to customers on the east side of the Greater Toronto Area.

It is simply not cost-effective to load the aggregate onto ship, then load it again onto trucks enroute to construction projects, Hanratty said. Rail freight is now too expensive for a low-cost product like limestone aggregate, he added, in addition to the problem of needing to reload the material onto trucks for the “last mile” in any case.

So the 4,000,000 tonnes of limestone will all go out by truck. At 20 tonnes per truck, that would mean 200,000 truckloads per year, or 770 truckloads per day if the aggregate is hauled five days/week.

(Put another way, truck traffic in and out of St Marys is likely to more than double. While the current quarry extracts a similar amount of limestone as the underground expansion is projected to add, much of the current output is in the form of cement clinkers shipped out on the Capt. Henry Jackman. With a capacity of 30,000 tonnes, this ship can carry the equivalent of 1500 20-tonne truckloads each time it leaves port. But the aggregate shipments from the new underground mine will all go by truck.)

The timing of shipments to market will also affect traffic volume. If buyers are not prepared to stockpile aggregate through the winter, the hauling might be concentrated in the summer construction season – meaning the impact on the Waverly Road/Highway 401 interchange, and on the Waterfront Trail, could be especially heavy during summer.

The current Highway 401 on- and off-ramps in this location are far from ideal. On the south side, traffic coming off the eastbound 401 has to get past two stop signs before making it onto Waverly Road. The left turn onto Waverly Road will be more difficult when several hundred more trucks per day are heading north on Waverly.

Traffic getting off the eastbound 401 faces two stop signs before turning onto Waverly Road (red Xs), causing frequent back-ups along the off-ramp. Assuming most of the loads of aggregate from St Marys will go to the eastern GTA, the loaded trucks will travel north along Waverly Road (red arrow) to the 401 westbound ramp, making it more difficult for Bowmanville-bound traffic to turn onto Waverly Road from Energy Drive. The volume of traffic on the eastbound off-ramp will also be increased, due to empty aggregate trucks returning from GTA markets via the eastbound 401. (Image from Google Maps, December 13, 2016)

Perhaps this interchange can be re-engineered to handle the new traffic load. Is St Marys prepared to fund this reconstruction as part of its impact mitigation efforts?

As for the Waterfront Trail, the addition of several hundred more trucks per day to the section of shared Trail/roadway will make the Trail less attractive and less safe. Two changes might be made to mitigate this impact.

First, perhaps the Trail could be rerouted here to eliminate the sharing of congested roadway on Waverly Road and Energy Drive. Ironically, Google Maps currently shows an incorrect routing for the Waterfront Trail as shown below; could this route become reality in the future?

Although the Waterfront Trail is currently routed on Waverly Road and then along Energy Drive (as shown by the red arrows), Google Maps incorrectly shows a routing along the north edge of the St Marys property (the solid blue line). Could this route become reality in the future? (Image from maps.google.ca, December 13, 2016) click for larger view

Second, there is no safe and attractive route between the Waterfront Trail and most of the populated areas of Bowmanville. Cyclists from the north side of the 401 have two choices, both poor, for routes across the 401 to the Waterfront Trail (see Getting across the 401). One of these routes is Waverly Road, which will be more dangerous for cyclists if there is a major increase in truck traffic without an appropriate “complete streets” redesign.

Perhaps St Marys can mitigate the expansion project’s negative impact on the Waterfront Trail by funding a separate walking/cycling overpass or underpass at the 401. Such a routing would be a significant improvement to Bowmanville’s recreational trails, which currently offer no safe connection to the Waterfront Trail.

Top photo: Bumper-to-bumper traffic on off-ramp to Waverly Road from eastbound 401, December 13, 2016

Special Delivery: Moving 4,000,000 Tonnes

St Marys mine – Article Index

The St Marys Cement Underground Expansion Project envisions extracting 4 million tonnes of limestone each year from a new mine beneath Lake Ontario on the south side of Bowmanville.

To understand the scope of the project and its possible environmental effects, it helps to look at the logistics: how much transport capacity does it take to move 4 million tonnes per year?

St Marys says that the limestone will be shipped out as aggregate “using existing road, rail and/or dock infrastructure.” These three shipment methods have very different environmental effects, and presumably there will be further detail on the likely mix of shipping modes in the Environmental Assessment.

In coming to terms with the quantities involved, however, marine shipping is the easiest to picture. The bulk carrier Capt. Henry Jackman is a frequent visitor to the St Marys dock. It carries up to 30,550 tons of cargo (source: boatnerd.com) or 27,715 tonnes. To haul away 4 million tonnes, the Capt. Henry Jackman (or similar-sized ship) would need to make 144 trips. This would equal about 4 trips per week during an eight-month shipping season.

Since outgoing shipments of aggregate would be in addition to all the current in- and out-going shipments at the St Marys dock, one key question is: how many boatloads of aggregate could be shipped out each year assuming there are no significant changes to the docking infrastructure?

While marine transport is by far the most efficient in terms of fuel consumed per tonne per kilometer, the market for aggregate may not favour bulk port-to-port shipment. If most of the limestone aggregate is destined for construction projects scattered all around the Greater Toronto Area, then trucking will be the most cost-effective shipping method.

Suppose all the aggregate were trucked to market. Using a round figure of 20 tonnes per truck load, the 4 million tonnes would be 200,000 truckloads per year – about 770 loads each day if the hauling is done five days/week, or about 550 loads per day if hauling continues every day of the week.

There is a wide variance in truck capacity, from tri-axle dump trucks, to dump trucks with secondary trailers, to full-length tractor-trailers. However, unless most of the aggregate is sent by some combination of marine transport and rail, there will be hundreds of truckloads per day of aggregate exiting the quarry, in addition to the current shipments of cement.

The connection between the St Marys quarry and the road network is shown on the Google Maps image below.

waterfront-trail-waverly-annotated2

Drivers who frequently use the Waverly Road/Highway 401 interchange just north of the quarry will attest that traffic frequently backs up at the on/off ramps for eastbound traffic (on the south side of the 401). What effect would a few hundred extra trucks/day have on this traffic?

A major recreational feature, the Waterfront Trail, would also be impacted by the additional traffic. The Waterfront Trail is routed along Waverly Road and Energy Drive just north of the quarry:

Looking west on Waterfront Trail, at junction with Waverly Road.

Looking west on Waterfront Trail, at junction with Waverly Road.

Users of the Waterfront Trail share the road with traffic entering and exiting the 401 in this interchange:

Looking west from Waverly Road along Energy Drive, with on/off ramps for 401 eastbound traffic.

Looking west from Waverly Road along Energy Drive, with on/off ramps for 401 eastbound traffic.

Truck traffic going north on Waverly Road and County Road 57, or going to the westbound 401, will use the narrow bridge over the 401:

Waverly Road bridge over Highway 401 to Bowmanville and to westbound 401 access ramp.

Waverly Road bridge over Highway 401 to Bowmanville and to westbound 401 access ramp.

This bridge is part of one of the two current cycling routes between Bowmanville and the Waterfront Trail (see Getting Across the 401). The combination of a narrow bridge with merging and turning traffic on either side of the bridge makes this a dangerous passage for cyclists, even without adding several hundred more heavy trucks each day.

The transport of 4,000,000 tonnes of limestone aggregate may have significant implications re traffic congestion and danger to vulnerable road users. When coupled with the wear and tear on roads and the emissions from diesel engines, the impact of transportation will be an important part of the Environmental Assessment of this project.

 

Top photo: the Capt. Henry Jackman approaching the St Marys dock, August 2016.

St Marys Cement environmental assessment: does climate policy matter?

St Marys mine – Article Index

A proposal to excavate hundreds of millions of tonnes of limestone from beneath Lake Ontario raises many questions, starting with a big one: should we be planning for the continued expansion of the concrete industry, given what we already know about climate change?

St Marys Cement, a Canadian branch of Brazilian multinational Votorantim Cimentos, operates a limestone quarry and cement factory on the shore of Lake Ontario at Bowmanville, Ontario. The company wants to expand by tunnelling under Lake Ontario from the existing quarry, and removing up to 4 million tonnes of limestone a year for the next 100 years. (The Project Description for the expansion is here.)

Graphic from St Marys project description at http://bowmanvilleexpansion.ca/wp-content/uploads/2016/Bowmanville_Expansion_Project_Description.pdf

Graphic from St Marys Project Description

(A note on terminology: in this article I use “cement” to refer to the white powder that is mixed with gravel and water, and “concrete” to refer to the construction material that results when the gravel-cement mixture reacts with water and solidifies.)

While concrete is one of the most important and ubiquitous materials in modern life, the cement industry is a major source of greenhouse gas emissions, accounting for 8% of global carbon emissions (Macleans, 7 March 2016). The emissions occur because when limestone is cooked to transform it into cement its natural carbon content is released, and because it takes prodigious amounts of heat to effect this chemical transformation. That is why the St Marys plant in Bowmanville burns both coal and bitcoke (the black powder left over from bitumen after refining) by the shipload.

Not only is cement production carbon-emissions intensive, but the way we use cement tends to encourage further carbon emissions. The biggest share of cement in Ontario goes into concrete pavement which is used to widen roads and add new parking lots – which in turn promotes greater use of cars and trucks.

Which brings us back to the St Marys expansion plan. The company is not saying it will expand its cement production in Bowmanville, but the additional limestone will most likely be used with cement. For further clarity, the limestone extracted from under Lake Ontario will be marketed in industry parlance as “aggregate” – what most people refer to as gravel. And that aggregate will mostly be mixed with cement, to form concrete, or used as a base layer underneath slabs of concrete. In other words, the quarrying of limestone for aggregate will complement St Marys core business of quarrying limestone for cement.

Is a major new source of aggregate needed in the Toronto area? St Marys says in their Project Description:

Over the past 20 years, Ontario has consumed over 3 billion tonnes of aggregate and limestone or about 164 million tonnes per year on average. Given expected levels of economic and population growth, Ontario’s consumption of aggregates and limestone for cement is projected to average about 186 million tonnes per year over the next 20 years.” (Project Description, page 8) [emphasis mine]

The key phrase here is “given expected levels of economic and population growth”. If the economic trends of the past 20 years continue on the same track for the next 20 years, aggregate use will go up by 13 per cent – from 164 million tonnes per year to 186 million. In other words, if we continue Business As Usual, we will need more aggregate.

How is this aggregate used?

Aggregate and limestone are used for a wide range of applications in Ontario; however, the primary use is in construction work, either directly on construction sites, or in the manufacturing of concrete and other building products. Roads (provincial highways, as well as municipal and private roads) account for the largest share of aggregate used in construction work.” (Project Description, page 8) [emphasis mine]

In recent decades the area of pavement has grown faster than the population has grown, because urban sprawl has been the dominant form of development. If we project that “Business As Usual” scenario into the next generation, we’ll need to build a lot more roadway, we’ll need a lot more aggregate, and we’ll need a lot more cement.

But the “Business As Usual” scenario collides head-on with Canada’s official climate policy commitments. Although no one thinks we can or should stop using cement (or fossil fuels) tomorrow, it is clear that we should be making every effort to reduce our carbon emissions immediately, and reduce those emissions at a faster rate with each passing year. That means we should be planning to reduce, not increase, the role of car-dependent sprawl in our urban developments; reduce, not increase, the amount of new pavement we place atop our land each year; and reduce, not increase, the amount of cement we need to cook up and mix with aggregate for concrete each year.

The Business As Usual scenario means we don’t take seriously the climate science consensus that continued growth in carbon emissions will be catastrophic for our grandchildren, and we don’t take seriously our government’s commitment to an economy-wide reduction of emissions.

St Marys Cement notice of Public Information Centre, Monday December 5, 2016

St Marys Cement notice of Public Information Centre, Monday December 5, 2016

Yet there is no evidence in the St Marys Project Description that anything other than a Business As Usual scenario is being considered. Regarding the carbon emissions of the project, the most substantive comment is that the quarry will have “reduced GHG [Green House Gas] emission intensity compared to other quarries that are located further from market.” The report does note, however, that “potential effects on climate change as a result of the Project will be characterized through the EA [Environmental Assessment] process.”

When this Environmental Assessment process gets underway, will St Marys be required to show that the expansion project is consistent with Ontario’s and Canada’s official climate policies? Stay tuned.

 

 

Top photo: The Peter Cresswell docked at the St Marys Cement port on Lake Ontario near Bowmanville.