Revisit, Remediate and Reuse are the real keys to the re-birth of the West Harbour. This article will focus on Remediation while discussing the other two R's.
By Mark Richardson
Published January 22, 2011
We all now know by rote the three great R's of re-cycling: Reduce, Reuse and Recycle. I would like to present the application of three new R's that could spur the re-vitalization of a city.
More and more I am hearing a new refrain pertaining to the West Harbour. It goes something like this, "I know a stadium isn't the best thing to put on the Harbour lands, but it's the best option we've got."
I thought the same thing for quite some time; with the money on the available from outside sources a new stadium is our best shot for the harbor and to spur growth in and around the city core.
That was before I really educated myself on stadiums, the Harbour and our city. I have come to understand that a stadium will be no magic bullet for the Harbour and that there are many much more exciting development plans available through Setting Sail.
At a recent discussion sponsored by Rethink Barton-Tiffany, David Schellingerhoudt, an architectural student, presented a different vision for the harbour, albeit one that required a much more patient approach than has been discussed recently. David talked of the possible Bioremediation of contaminated Harbour lands. This piqued my interest and I decided to do some research.
Bio-remediation is the process of using plants and natural occurring microbes to remediate soil in-situ (in place). Traditional remediation involves the removal of contaminated soil, trucking it off site and either incinerating it and simply using it as landfill untreated. Sometimes a small amount of soil is removed and a 'cap' is installed, this is the $3-5 million dollar option we keep reading about for the West Harbour.
The key to Bioremediation is knowing what is in the soil and in what concentrations. My councillor, Brad Clark, has been trying to provide me with the soil study done on the West Harbour in 2003 before Brad was a councillor.
Brad has kindly taken that ball as far as he can for me and I will have to play some red tape games with city staff for the actual report. I must note that Brad has been a great help, even after I disclosed that the report was needed for a Raise The Hammer article!
Without being informed on what exactly is in the West Harbour soil we can simplify the discussion, contaminants can be divided into two categories: Organics (hydrocarbons) and In-organics (metals). Organics can be broken down naturally with microbes and In-organics have to be removed or stabilized.
I have seen microbe remediation in action when I worked at the Petro-Canada refinery in Oakville, now closed. Sludge that could not be processed further from the Waste Water plant was accumulated in a pond. Yearly that sludge was injected on a 'land farm' on site, about 6-8 inches below the soil surface. Microbes in the soil, now very abundant due to years of land farming, broke down the hydrocarbons.
Microbes degrade hydrocarbons (organic compounds) by using the contaminant for their own growth and re-production. Organics provide carbon for cell construction and provides electrons which the microbes use to obtain energy.
Testing by the Ministry of Environment and Petro-Canada showed that almost all of the organics were broken down in the land farm, usually within a year.
A similar process is occurring in the West Harbour lands as you read this article. Microbes are using and breaking down organics constantly. The issue is whether it's happening fast enough and if not, how can we speed it up?
Plants and trees have been proven to amplify the effectiveness of microbe activity through The Rhizosphere Effect. The Rhizosphere Effect occurs in the soil 1-5mm from root surface. Plant roots excrete compounds (root exudates) which concentrate microbiological activity around the root. Microbiological activity is 5-100 times greater in this zone than in the general soil.
It has been reported in studies that populations of the microbes that break down the un-holy industrial contamination trinity of benzene, toluene, xylene were 5 times higher in the rhizosphere of Popular trees than in the general soil in the area.
Microbe remediation can also be accelerated through the use of microbe seeding (adding microbes to the soil for the known contaminant) and adding nutrients and oxygen to the soil.
One possible cheap in-situ remediation strategy for metal contamination is Immobilization.
Immobilization can be achieved by mixing soil with lime, the solubility of metals such as Cd, Cu, Zn and Ni are reduced due to the formation of insoluble hydroxides. Immobilization will render the soil useless due to a high ph (base or caustic). Microbes die and the soil will not support plant life.
Another option for in-situ metal remediation is the use of plants, or phytoremediation. Plants have constitutive and adaptive mechanisms for accumulation or tolerating high metal contaminant concentrations in their rhizospheres. Most plants that survive in toxic soils do so by either avoiding heavy metals or accumulating them in their tissues. The key to metal remediation is in choosing the plant species that will accumulate metal in their tissues.
400 types of 'hyper-accumulators' have been identified as of the year 2000. These plants tend to be contaminant specific to a certain type of metal. These plants tend to have shallow roots which are a benefit as heavy metals tend to accumulate near the top layer of the soil. According to the year 2000 studies the accumulators also tend to grow slowly and have a low biomass, which is a detriment to the process. Further studies and improvements in plant species selection have occurred since 2000.
*The pros of plant remediation: it has a low start-up cost, it's a mostly unmanned process, energy is free (solar), the harvest is cheaper to handle and ship than soil (drier and lighter) and it does not harm the soil ecosystem in place.
Using this remediation method, the biological properties and physical structure of the soil is maintained, the technique is environmentally friendly, cheap, visually pleasing and offers the possibility of bio-recovery of the heavy metals through further off site processing of the harvest.
The cons: longer time required (minimum of 5 years), disposal of plants after harvest and possible risks to any animals using the plants as food. It is obvious that the plants would have to be tested on a regular basis and harvested before concentrations became a risk to wildlife.
I'd like to close Bioremediation with an example of the cost. "Remediation of 10 acres contaminated with lead using current technologies could cost as much as $12 million. This includes planning and documenting the project, as well as the actual decontamination process. In comparison, potential phytoremediation methods for the same area could cost as little as $500,000.
In addition, many phytoremediation costs can be spread out over the life of the project (which may be years), whereas traditional remediation technologies typically call for large up-front expenditures."
Actually Adaptive Reuse would be the better term. Look at the size of the Rheem building. What amazing and creative things could Hamiltonians dream up for that space? Davis S. managed to have a picture of the inside of the Rheem building and it is stunning, a piece of our industrial heritage really.
Inside the Rheem Factory
Soaring ceilings, bright and high chain sash windows, stunning structural metal... this building has everything needed for a great adaptive reuse. Leave it up and no remediation is needed where it stands. An indoor playground, retail space for artists, another good cafe, an interactive industrial museum... what can you envision in there?
There are other options to revitalize the West Harbour than the stadium mania that has gripped many of us. These West Harbour development options can be cheap, organic, environmentally friendly, and educational and provide more of a catalyst for growth than stadium.
Growth along this path will require patience, application of ideas and a faith in Mother Nature... what could really be better for Hamilton?