Contaminated Buildings And Hazardius Materials Flashcards
When do buildings become hazardous?
In some building pollutants may cause problems with odour or air quality. That’s is when it is on the borderline of hazardous materials.
What are some of the hazardous materials that are found in buildings ?
PCB
Heavy metals,
Asbestos
Tar materials in insulation and roofing materials,
Fungi and mould
Coolants in air conditioning
Flame retardants in plastic,
Chromium 6+ in concrete
Wood weathered with CCA.
Mercury
Lead
Cadmium
What happens to PCB and Asbestos in old buildings before demolition or before change of use ?
PCB and Asbestos have to removed before any building is demolished. However if there is a change in use of a building then there will have to be a risk assessment of how these materials or substances affect the new use of the building.
What are the steps involved in remediation of a contaminated building
Gather all available data about building and building site .
Visit and investigate the site : here you visit the site , take down information and samples.
Document all findings for assessment and evaluation.
Evaluate the risk of the contamination,determine if it is hazardous to human health ,or the environment.
Prepare a report with all your findings and information gathered.
Draw a plan for waste handling or demolition.
Although Sweden is big on circular construction there are a few problems with circular construction. Name them.
- The number one problem is building logistics and regulations.sometimes old materials may not meet the requirements of Modern buildings in terms of quality and efficiency.
- Chemicals in old materials might be a risk . For instance they used to fill old doors with flame retardants, which can be a hazardous substance.
- Sometimes acquiring the right materials at the right time can be a challenge.
- Requires a lot of room to store these old materials which cost a lot.
What are some facts about valen.
An attractive place for recreation.
Surrounded by expensive residential buildings.
Leaching water from sludge creates lime which also creates a hard concrete like surface. Also smells of sewage.The bay of valen was heavily polluted with effluents from a sewage plant .in 1974 the bay was dredged to get rid of polluted sediments and this might have been the firs environmental restoration of a salt water bay . On the around the bay a containment wall was built and the sediments from the bay was pumped onto the land area. Approximately 0.5 meters of dredged sediment covered the land (30,000m^2). The sediments layer on the land was then covered with fresh sludge from a sewage plant.this sludge was mixed with lime .
Currently there is about 120,000m^2 of contaminated mass on the valen land fill and 70% of it is sludge that comes from Rya(the second sewage plant)
What is the methylation of mercury.
This is a biological process that is caused by bacteria in an oxygen free environment. Methylation is also enhanced by nutrient rich aquatic environments. When the bay was dredged the sediments containing HG were dumped on the landfill , sewage from RYA also contain HG was dumped ontop of it , oxygen was used up rapidly and degradation of the sludge stopped.
What are some of the suggested solutions for the Valen situation?
Covering with clay ( has low permeability which will contain the contamination)
Total containment by :
Putting up containment walls with passive filters
Stabilisation /solidification ( this involves adding materials to the contaminated sites to stop reduce mobility and spread.
What is the ongoing problem there aside what has already been mentioned?
There significant levels of PCB ,that is being transported into the bay as well. The source of this is unknown.causing there to be PCB sediments in the bay.
What is sustainable remediation?
This is the use of sustainable practices throughout the remediation process from the inventory, investigation , sampling to the actual remediation process and clean up with the aim of balancing economic viability, conserving natural resources and biodiversity as well enhancing the quality of life of surrounding communities .
