Significant amounts of concrete rubble are generated by the demolition of buildings in the
Christchurch Central Business District. This concrete can be a useful resource for landowners, for instance to stabilise farm tracks. However, what may look like clean, and is often sold as cleanfill, might be contaminated with lead, arsenic, cadmium or other heavy metals. And more often than not: asbestos. Even if the demolished building did not contain asbestos, as cross contamination is common.
One positive asbestos result and the asset of several thousand tonnes of crushed concrete becomes a legacy.
When conducting asbestos testing, the team at Eliot Sinclair take a representative number of stratified targeted samples in a grid pattern across stockpiles and analyse them.
In one example, we found that only some of the stockpiles in an area were contaminated with loose asbestos fibres. To remediate this, we designed an engineered containment cell and covered the crushed concrete with 1-2m of clean soil. In another case, we removed asbestos cement material (ACM) from soil with a 20mm power screen .
Most contamination we find is small-scale and can be easily removed. While remediation often involves removing contaminated soil and disposing it in a landfill, sustainable, and more cost-effective remediation may also be achieved by managing the contamination in-situ, or simply guiding future land use and thereby avoiding adverse effects on human health and the environment.
Eliot Sinclair will guide you throughout the process of investigation assessment and if appropriate remediation works.