A little over a month ago, I had an informal meeting Eric Duchemin, Associate Professor of Science and the Environment at UQAM, who has intelligently fostered entire classes of students working in urban agriculture for several years now. I participated in the École d’été sur agriculture urbaine in its second year, and learned (and forgot) some of what I know now – it was a challenge at times to keep up with the blistering pace of some French parole, and it can sometimes be more of a challenge to insert oneself into a conversation, but I did my best.
The meeting was prompted by a grad student giving a talk about the urban agricultural history of Montreal, and I took the opportunity to ask Eric some questions about remediating urban land and returning it back to primary use – forestry and agriculture.
He did not say “Impossible,” but that is what it essentially comes down to. There are two reasons why. When it comes to agriculture, the Province immediately declassifies built land into a class that you cannot farm on. The process of developing land, the things that happen on that land while it is built on and occupied, and the process of demolition all poison and destroy the soil. The legal process and cost of remediating that soil is prohibitively expensive. The gist of it was something about having to excavate the soil, install a certain kind of liner (this boggles my mind: why do we allow anything to happen to soil, that in each case, we must compartmentalize it away from the original, underlying geology, in order to protect what remains?), and then replace the soil with new soil (from where?) or else ship out that soil, remediate it for metals (hydrocarbons being rather easy to biodegrade), and then put it back in place.
This is before you farm it. Though you might have animal agriculture, provided you bring in the food from somewhere else, because the animals will not be getting enough forage from compacted city soil and the tracts of land will not be big enough to support enough livestock… at least if you’re going to make a blanket statement about it. I’m a pessimist in some things, but I do think that Environment, Health & Safety (workplace EHS) can be a legalistic cult at times. Here I err on the side of optimism, science, and heritage values: I believe we can find a practical mix of crops, livestock, and supplies that would allow farming on former city land.
And I have some reason to be optimistic. This is an image that’s going to get this blog post a few hits. It shows you the relative availability of metallic nutrients, depending on the pH of the soil solution (water in soil):
|12 Essential organic and metal nutrients, availability by pH, Follett et al. 1981|
You can see from the graph that the general availability of metals for uptake by plants is strongest as the soil gets more acidic or more basic (cadmium is not on this graph). If you keep testing your soil – as I have not done this year! – you should be able to keep the metals in the ground and not in your foliage. Or, if you do decide to do something about chelation, or mess with the pH and put an acid-loving plant in place, you may be able to impact in some very small way the metallic content of the soil. But one factoid should be kept in mind: Don’t amend this soil with cow manure. It contains a lot of trace metals, as a consequence of biomagnification.
- The state of Victoria in Australia has a good guide to soil health here.
The only other alternative to redeveloping a brownfield in Quebec is restore it to parkland and forests. And, apparently, this is seriously vexing, city people don’t like forests. I don’t believe this. (But if I did, that’s a case where I say to hell with democracy, because why should we allow people in a majority to continue to prefer what is obviously bad?) But what would be true is that the forest would have to be privately owned by a wealthy person, or put under a conservation easement, or managed by the city as a woodlot, with the understanding that it is that way for the benefit of the environment and people. Montreal isn’t the only city that can’t be brought to be so forward-minded.
A few weeks ago,
I watched the landscapers opposite my mom’s house do the yard of a well-cared-for century home. I watched the arrival of the mini-dozer and the men with the shovels with a great deal of trepidation. There were paving bricks as part of the company’s logo, and my hometown is pavement-happy, they never met a piece of land that they didn’t think was improved by paving, and this century home still had a gravel driveway (my favourite).
The men made quick work and the progress, as the day approached noon, alleviated my fears. They moved a bunch of cedars, put in a patio pad behind them where the young children were already playing on a jungle gym, and in the front they installed a walk way without extending the walkway paving further into the yard or the driveway, which was (yes!) left as gravel. However, they installed a bunch of plants in little patches bordering the walk.
|You might agree: this still looks
like an alien. And it actually is.
Now, I love plants, all kinds, but, these were not native, and with the exception of the miniature Japanese maple (see right), they mimicked the “aliens” that James Howard Kunstler joked about in his hilariously incendiary TED talk on how bad architecture wrecked cities.
Hey, it could be worse. Landscapers work expediently; nature takes over from there. Maybe those aliens are going to grow and bush out and begin to look natural. Hopefully they’ll inspire the owners to garden more. There was certainly an arc getting me from box-hedge-and-yard to the glorious semi-wild space I have now.
In the end, what bothered me the most about their work was the fast and efficient way the dozer went to town, turning the yard from a flat surface with a slight hill downward to the sidewalk, to something that had a consistent 3º-5º slope.
It alarmed me quite a bit, actually. Here’s why: before the grading, the lawn would receive rain, and the rain would sink down the 1.5-2′ (feet) into the lawn’s soil, and run off the surface only at the bank meeting the sidewalk that looked like this:
When they dozed it, they scooped up all that earth that couldn’t be compacted into that gentle slope of ≈4º, and put it into the dumpster that you know they would reuse on some job site where they needed clean fill (I wonder: where does potting soil come from, anyway?). So… they compacted the soil, and took it away. And this is a century home, so that’s soil that was there when the house was first built…now gone, rendering the yard just as fertile as that of any suburban pack-em-in development.
–> While on my soapbox: I did two image searches to try to show you how ugly Bradford is when you’re looking at the backside of their housing projects – after all, “projects” is how it makes you feel, when you knew how pretty it was before they did whatever they did to it – but I couldn’t find any with “townhouse development in Bradford, ON.” I searched “Images of backside of subdivision development” and found no pictures of any town’s backside; the closest I came to ugly were the aerial shots of subdivisions, which are certainly ugly but banal in comparison to eye-level view. Or is that vice-versa? One thing is clear: few pictures were taken – or they want to be hidden!
The secondary thing is not only is that sloped-land-missing-soil now not going to retain water or the ability to grow much more than sod without effort: since the lawn is now sloped, the water is now going to run off into the street. That creates two demands on the town: treatment for output to the lake, and treatment for input of the water they’re now going to use for their lawn and garden. (You would think that paving it might be better, but that only increases the urban heat island effect, and makes folks hide inside with their air conditioning, which only exacerbates the problem.)
I know that developers don’t give a… (I’ll let Kunstler link above speak for me) but landscapers? You gotta handle the soil better than this.
When you consider how long it takes the geologic processes of this world to form soil, it is no surprise to me that we have to treat it gently. And stop building on farmland, wetland, and forest.