Research reveals promising results for innovative purification of contaminated groundwater


A new sustainable method for treating contaminated groundwater has taken shape in a PhD study headed by Bente Højlund, COWI. Major advantages: 1) No chemicals or bacterial cultures are injected and 2) zero groundwater is extracted. With millions of contaminated sites around the world and the subsequent risk of drinking water pollution, sustainable and low-cost cleaning methods are in high demand.

Several years of research into a cheaper and more sustainable way of treating contaminated groundwater reveals very promising results as an attractive alternative to existing methods.

The new method goes like this: You treat groundwater contaminated with carcinogenic chlorinated solvents using an electric current. In practical terms, this means establishing electrochemical zones in the groundwater by installing electrodes in the groundwater reservoir itself.

The PhD project has been headed by PhD student Bente Højlund Hyldegaard, COWI’s department for Waste and Contaminated Sites, and carried out in collaboration with Technical University of Denmark, the Capital Region of Denmark and U.S. Army Corps of Engineers.

Niels Døssing Overheu, M.Sc., environmental engineer and special consultant in Capital Region of Denmark, applauds that a more sustainable method for dealing with groundwater contamination is now taking shape.

Watch video below to know why.


  • Project period: 2016 – 2019.
  • Bente Højlund will defend her doctoral thesis 'Electrochemical Zone for Degradation of Chlorinated Solvents in Aquifers' on 28 November 2019.
  • In 2018, Bente Højlund was awarded among the most capable and talented research students in Denmark.
    Department head Torben Kristiansen commented: “COWI and all of the staff are proud of this recognition given to Bente, which we also see as an acknowledgement of the department’s innovation work to safeguard groundwater and soil quality.”
  • Funding has been received from COWIFonden and InnovationsFonden

Get in contact

Lars Nissen
Vice President
Environment and People, Denmark

Tel: +45 56404954