Turning Brownfield Liabilities into Opportunities
Contaminated sites can be redeveloped safely and economically using solidification/stabilization (S/S) with cement to treat and contain toxic materials in soil, sediment and sludge, on or off-site.
A brownfield site is an abandoned or under-utilized property that cannot be easily redeveloped because it is contaminated with hazardous substances. Solidification/stabilization (S/S) using portland cement can turn such environmental liabilities into economic opportunities. S/S has been applied successfully at many brownfield areas in North America, allowing the treated soil to be reused safely at the site. This reduces the need to remove hazardous materials and to transport such materials through communities. A variety of S/S application methods make the treatment suitable for a wide range of projects. With S/S, environmentally contaminated sites that once were thought unusable can be redeveloped safely and economically.
Watch a video on solidification/stabilization .
Emphasis on sustainability shines spotlight on S/S
Sustainable construction methods are no longer merely a trend; they are rapidly becoming the norm. As a technology that is protective to human health and the environment, cement-based S/S can play a key role in sustainable development. In fact, the Canadian Green Building Council’s Leadership in Energy and Environmental Design (LEED® Canada) Green Building Rating System currently offers points towards certification to projects that rehabilitate and build on brownfield sites.
Proven Cost-Effective Solution
Dockside Green, with a planned total of 1.3 million square feet of mixed residential, office, retail and industrial space, represents the largest development of city land in Victoria’s history at time of project.
Solidification/Stabilization (S/S) with cement is a common method for the safe treatment, management and reuse of contaminated waste. Developed in the 1950s, the technology is widely used today to treat industrial hazardous waste and contaminated sites. S/S is being chosen for use on key sites in Canada, contributing to the sustainable redevelopment of both urban and industrial properties.
S/S, which involves mixing portland cement into contaminated material, protects human health and the environment by immobilizing hazardous constituents within the treated material. The cement reacts chemically with water in the material being treated, creating changes in the physical and chemical properties of the treated materials preventing the escape of hazardous constituents into the environment. Solidification refers to changes in the physical properties of the waste, including an increase in its compressive strength that enables it to support more weight, a decrease in its permeability that reduces water infiltration, and encapsulation of hazardous constituents. Stabilization refers to chemical changes in the hazardous constituents in the waste, that convert them into a less soluble, mobile or toxic form.
S/S is being chosen for use
on key sites in Canada,
contributing to the sustainable
redevelopment of both urban
and industrial properties.
The popularity of S/S is due to the fact that it can be used for a wide variety of contaminants in many types of contaminated material. Soil, sediment and sludge impacted with an array of organic and inorganic contaminants have been treated successfully using this versatile technology. There are two distinct methods for the treatment of contaminated material. Cement may be mixed directly into hazardous material on-site or it may be excavated and transported off-site for treatment. Afterwards, the treated material may be safely reused on-site or disposed in a landfill.
S/S provides an economically viable means of treating contaminated sites. Because this technology can treat and contain contaminated soil on site, it often reduces the need for landfill disposal. It protects surrounding communities and water resources by preventing leaching of contaminants into groundwater.
The advantages of cement in S/S
S/S with portland cement has benefits that make it more economical and easier to use than other methods:
- Cement is manufactured under strict CSA and ASTM Standards, ensuring uniformity of quality and performance
- Cement’s success in S/S is supported by more than 50 years of use in a variety of projects
- Cement has a long-term performance record
- Cement usage can minimize volume increase compared with other reagents
- Cement is a non-proprietary manufactured product, readily available across the country in bag or bulk quantities
S/S: An Established, Accepted Treatment Technology Proven Effective in the U.S.
The U.S. Environmental Protection Agency (EPA) has identified S/S with cement as a Best Demonstrated Available Technology for more than 50 Resource Conservation and Recovery Act (RCRA) listed wastes. This means that the technology is an accepted treatment to ensure safe land disposal of these wastes. For years, S/S has been used to treat such wastes, eliminating their hazardous characteristics, lowering the hazard class of the material and cutting the cost of disposal. Furthermore, S/S is a common remediation technique for American Superfund sites. Since that program’s inception in 1980, 23% of selected Superfund site source-control remedies have included S/S.
Examples of success with S/S in the U.S can be found here.