Urban agriculture has a number of benefits for cities, including enlivening communities, improving citizen physical and mental health, and ultimately reducing the collective carbon footprint. It has been recognized as an opportunity to engage city residents, create employment, as well as improve food security and health with access to fresh, culturally appropriate produce at a low cost. With such potential in mind, there has been tremendous effort in Toronto to increase urban agriculture. The Metcalf Foundation published a report on Scaling Up Urban Agriculture in Toronto in 2010, and the Toronto Food Policy Council and its community partners followed up with the GrowTO Urban Agriculture Plan for Toronto in 2012, which was a central document in a recent landmark report to Toronto City Council on the Toronto Agriculture Program in November 2013. One of the barriers identified in expanding urban agriculture was the necessity, yet difficulty, of proper soil testing. While the Greater Toronto Area has some of the best soil available, city land is exposed to contamination from surrounding buildings and cars, and may have had other uses prior to being a potential gardening space. The City of Toronto has recognized this as a way to support the movement, and Toronto Public Health (TPH) has recently put out a guideline for urban soil assessment, in collaboration with Parks, Forestry and Recreation (PF&R), and in consultation with the Toronto Environment Office (TEO).
On Toronto’s Environmental Pollutants (Lead) Soil and Gardening page, you can find the staff report for action from April 2011, which includes a discussion of the rationale, as well as further plans for community gardens and allotment plots. You can also find the technical report, Assessing Urban Impacted Soil for Urban Gardening: Decision Support Tool Technical Report and Rationale, its summary. Development of the information-dense, peer-reviewed, 71-page technical report was led by TPH’s Josephine Archbold, where a number of organizations and individuals were consulted, such as municipal organizations in Canada, Health Canada, Ontario Ministry of the Environment as well as urban farmers. The most recent version of the finalized Guide for Soil Testing in Urban Gardens was published in October 2013. The aim of the guide is to provide information that is easy to access and understand on why and how to assess soil to be used for gardening. The City aims to educate and empower people, be it new gardeners, experienced gardeners wary of producing food from their garden, or the “guerilla gardeners” who want to put wasted green spaces around the city to use. The document also addresses unique safety concerns to various demographics of gardeners, such as young children (who, they mention, may eat the dirt) and pregnant women. Soil testing has traditionally been complex and expensive – upwards of thousands of dollars per plot – which is debilitating to individuals or small, community funded projects. This guide provides a comprehensive multi-step process, and dramatically cuts costs to a few hundred dollars.
There are three basic steps: establish a level of concern, test the soil, and take action to reduce risk. The first step is to research past and present use of the land. Then you determine which of the three concern levels applies: high, medium, and low. High concern areas are those that are likely to have been exposed to harsh chemicals, such as those from dry cleaners or autobody shops. Soil in high concern areas should be avoided by making raised bed or container gardens, planting only fruit and nut trees, and reducing dust exposure by covering the ground with mulch. Medium concern areas include commercial land or those within 30 metres of a rail line or arterial (high use) road line, and these are the ones that require soil testing. There is a simple diagram on how to obtain an accurate sample of the soil, and once you have your sample, the guide lists labs to send it to and the contaminants to test for. After receiving lab results, you can compare them to TPH soil screening values (SSVs) provided for each contaminant. If you are within the safety zone, you simply take steps to reduce exposure, such as adding compost and manure to the garden, peeling root vegetables, and avoiding plants that accumulate contaminants. If one or more contaminants are above the threshold, it is advised to follow the practices for high concern areas. The good news is, land that is taken care of tends to improve over time, and can be used in the future. Low concern areas are places like parks and school plots (as long as there was never any medium or high risk land use in these areas), which do not require testing, only minimal risk management such as washing your hands and the produce before eating. Toronto Public Health notes that interior and exterior house paint contained significant amounts of lead until the early 1990s. The soil surrounding buildings painted with lead-based paint may be contaminated with lead. Using raise bed or container gardens is the best way to avoid exposure to lead contaminated soil, adding clean soil and compost every year and plant non-edibles directly beside buildings.
In an interview for the TYFPC, Josephine Archbold discussed putting together the initial technical report and the recent guide, as well as what the City aims to accomplish with its publication. First and foremost, they wanted to make it easy and accessible to understand how to handle urban soil, in order to entice more people to garden and encourage all citizens to use safe gardening practices. Intriguingly the aim of the document is to introduce a “paradigm shift.” Archbold notes that “we’re moving away from safe/unsafe – unsafe you don’t garden, safe you garden and you never think about urban contaminants.” Instead, the City wants to encourage people to garden everywhere but to take action to reduce the risks of an urban environment. They wanted to collect the knowledge housed in the tool kits of experts, such as engineers and government officials, and to give these tools to the general public – to empower them – to use and make their own. After publishing the Guide, the goal was to reach out to as many people as possible. They presented the information to numerous community groups in an engaging way. “We’d like to get as many people as possible growing food in Toronto,” says Archbold.
Public feedback and involvement is essential to further development of the guide. The City has acknowledged that there is a limitation to how much can be accomplished with research alone, and the last page of the document urges users to provide feedback. The guide, in many ways, is an invitation to grow. “You can grow food anywhere in Toronto. With the right information and the right knowledge, there’s nowhere in Toronto you should feel like you shouldn’t be growing food,” Archbold encourages, “so there’s opportunities under your feet everywhere you go to do this.” This is a great step, and a future action plan, towards enhancing urban agriculture in the City of Toronto. The movement is picking up speed, and for many good reasons. As Archbold puts it, “this isn’t about growing a couple of carrots in my backyard, this is about making the City of Toronto a better place to live.”