In Denmark, the regulations on contaminated soil and groundwater are rather comprehensive and well established. This is in particular true when it comes to contamination from privately owned storage tanks for domestic heating. The Danish EPA has made detailed guidelines and rules for investigation and remediation. The guidelines are based on best practice from more than 1,400 remediated sites of this kind. Because of the well-known pattern for contamination from heating oil, the EPA has added a new feature: a lower threshold limit for hydrocarbons in the subsurface (10 kilograms) to prevent overdoing remediation. The limit is based on mass, and not on concentration.

The presentation shows how the lower threshold limits can be used, and how it has affected the way we now remediate in a sligthly more sustainable way. Examples from the EPA guidelines and from actual cases where the threshold limits have been used resulting in site closure will be presented.

Any cleanup effort is, in itself, polluting (fuel, traffic, CO2 etc.) and our activities should be justified from an environmental point of view. The mass based “good enough” limit can be a way to avoid overdoing it.

Primary Author/Conference Presenter:
Jacob H. Christiansen
Chief Project Manager
COWI
Denmark