Contaminated land

Groundwater may be adversely impacted if contaminants on land find their way into groundwater. The risk of groundwater contamination is increased where the contaminant is mobile, by virtue of its solubility in water or its viscosity, and if there is a pathway to groundwater. Having entered groundwater, the impact of a chemical will depend on its toxicity and persistence. Some contaminants are therefore more likely to impact on groundwater than others.

Not all groundwater is equally vulnerable to the risk of pollution since the natural characteristics of soil and rocks and the depth to groundwater control the likelihood of groundwater pollution.
Contaminated land investigation activities, including the drilling of boreholes, can pose a threat to groundwater by creating preferential pathways. Contaminated land and groundwater remediation may also pose a threat to groundwater because it may move or increase the mobility of contaminants.

This page provides links to the main legislation and policy guidance relating to groundwater and contaminated land.