Solutions to contaminated soil
Updated: Oct 17, 2019
The state of soil in Saint Boniface is one of great concern. 24 properties near the Mission Industrial Park have tested positive for lead contamination and were found to have levels that exceeded the Canadian Council of Ministers of the Environment guidelines for soil quality. This is not an anomaly in Winnipeg. Several other heritage neighbourhoods have had positive test results for heavy metal contamination. Little information is available with regard to the level of contamination of public spaces such as parks and boulevards. According to one report the possible causes of the contamination can be attributed to historic use of leaded gas, previous operation of lead smelters, scrap recycling yards, the nearby rail yards and metal manufacturing operations.
The first two suspected causes are no longer an issue as gas is now unleaded and there are no lead smelting operations within the City of Winnipeg. I have along with many others made the case for rail relocation (you can read my proposal on that topic here), we do however still have scrap recycling yards and metal manufacturing operations adjacent to residential properties.
Thanks to the tireless efforts of the members from the South Saint Boniface Resident's Association we now know that enforcement of environmental laws are fast and loose with many people continually passing the buck.
I think further research needs to be performed expediently to determine how much of a current threat these operations have on our local air quality, as well as the threat these operations currently pose to further soil and water contamination, with the Seine river being in close proximity to the industrial area.
Every human being has a right to clean air, water and soil. It is an absolute embarrassment that people in 2019, in a modern city have to fight tooth and nail to ensure they aren't being poisoned due to government officials not performing their duties. First and foremost we need all levels of government to act and ensure environmental and zoning laws are abided by and air quality is maintained.
So, how do we move forward from the damage done?
Soil remediation is often thought of as a costly and invasive operation, not always feasible in urban settings. However there is an process that can help solve multiple environmental issues we are currently facing. The process is called gasification and the product it produces is called biochar. Biochar has immense potential to absorb heavy metals from contaminated soils and render them inert and benign to humans, essentially locking up the hazardous component of the soil in the porous structure of the biochar.
So how do you make biochar? Well in short any carbon based substance can be turned into biochar via the process of gasification which involves burning the intended fuel source in an oxygen deprived environment, producing a substance very similar to charcoal.
So how does this solve multiple environmental issues?
There are many different substances that can be turned into biochar, and each substance has a different effect on the soil in which it is used to amend. It just so happens that biosolids (read: manure, either animal or human) happens to be the best type of biochar to remediate soils contaminated with heavy metals. Now it is at this juncture I will mention that via the charring process the initial substance, in this case biosolids, is turned into a black, granular, odourless substance.
From the City of Winnipeg to the Lake Winnipeg drainage basin
The City of Winnipeg is currently dealing with an aging sewage system and has been dumping diluted sewage into our river systems. It is working on a 27 year plan to greatly reduce the number of combined sewer overflows. In 2018 alone, it is estimated that 8.65 billion litres of combined sewage overflowed into the Red and Assiniboine rivers.
Currently the city utilizes a waste treatment process that involves several different steps, including anaerobic digestion and finally disposing of the biosolids via the Brady road landfill.
This in itself is problematic as this method is slowly leaching valuable nutrients from our fertile soils and quite literally throwing them in the garbage. Not only from a human perspective but also when you consider all of the livestock and agriculture operations that operate within the Lake Winnipeg watershed and how they deal with fertilizer and manure management. Agriculture operations account for 32% of the present day phosphorus load within the Lake Winnipeg watershed.
The use of gasification and biochar could have positive impacts on multiple fronts here in Manitoba alone.
Biochar used to amend soils in agricultural applications to retain nutrients, thus better protecting our watersheds and cutting costs for farmers
Biochar created from manure/biosolids used in urban applications to help remediate contaminated soils
Gasification used to treat and re-purpose municipal biosolids
Byproducts of gasification could be used for heating or production of electricity via steam
Cost avoidance on the part of livestock producers for having to dispose of animal manure
There are no quick fixes or easy solutions to solve climate change and reduce carbon emissions, however I believe gasification and biochar can and should be a piece of the puzzle. A circular economy means reducing the creation of waste and minimizing the need for constant resource input. It means a healthier greener future for our agriculture and food systems and a more innovative way of healing our earth and water by using biochar made from waste. We can take these tangible steps now and save our soil, our air and our waters. The time is now, let's take the steps necessary to protect our back yards and our planet. -Ben Linnick
I would like to acknowledge that I was first made aware of Biochar/Gasification via the excellent and entertaining U.S. crop scientist and podcaster Dr. Sarah Taber. Her podcast is called Farm to Taber and is highly informative on agriculture and food systems and she can be followed on twitter @SarahTaber_bww