Remediation should be safe, effective and consultative, says ARCADIS

A representative from Amsterdam-based engineering company ARCADIS has claimed that government and industry need to think twice and involve local citizens before they rush in and remove toxic contaminants from a polluted site.

Speaking at the CleanUp 2015 Conference in Melbourne this week, ARCADIS Senior Consultant Hans Slenders said the decision for remediation needs to be transparent and easily understood by the public. He stated, “Sometimes, treating or keeping the contaminants where they are can be a lot less risky and costly than getting them off-site — and many people do not realise this.

“For example, a big clean-up project might involve removing 10,000 truckloads of contaminated soil, dumping it elsewhere and then bringing clean soil back to the site.

“Apart from a lot of noise and traffic in the neighbourhood, the excavation of the soil can release foul smells, burn a lot of fossil fuel and release large amounts of carbon dioxide into the air. There is also the risk of accidents — in a previous remediation, a person was hit by a truck and died. And this was after we advised the clean-up industry to go for another, less risky approach.

“So while we want to build a cleaner and safer world for ourselves and for the future generation, we need to keep a clear balance between the benefits of the clean-up of the pollutants and the risks of cleaning them up or shifting them elsewhere.”

Slenders claimed that three pillars — the social, economic and environmental impacts — must be considered before any clean-up project starts. Besides preventing accidents, reducing the use of non-renewable resources, waste and carbon dioxide, the plan should also assess whether the project is cost-effective.

For example, restoring a brownfield — an abandoned industrial site — to a housing area can require a more thorough clean-up, leading to high costs and emissions. In many cases, it might be more cost-effective to consider what the land will be used for, then determine the necessary restoration.

“This is when we need to be prepared to hold discussions with those who are most affected by the remediation, such as owners or perhaps nearby neighbours,” Slenders said. “We should be transparent about all the impacts of the remediation to the public and workers.”

The team at ARCADIS used the three pillars to evaluate a soil excavation that was carried out in 2008 for a railway in Eindhoven, the Netherlands. Slenders said, “We found that while the excavation could result in increased land use and real estate value as well as creating more jobs, it was 13 times more expensive than monitoring the site.

“Also, the clean-up process was long, the carbon dioxide emission was more than 100 times higher and the risk of fatal accidents was six times higher than monitoring the site. More importantly, the contamination did not pose a risk to humans before the remediation.

“The project could have been improved if the differences between the various remediation scenarios were made clear at the start, and if the residents, local authorities and municipality were considered as stakeholders — instead of an obstacle — in the beginning.”