Thousands of Danish streams contaminated with zinc and copper

Nearly four out of five Danish streams are contaminated with zinc, and almost half contain excessive levels of copper, according to a DR analysis of Environment Ministry data covering nearly 6,700 stream segments.

Environment Minister Maria Reumert Gjerding called the figures “far too high” and said they must be taken seriously. She told DR the findings underscore the need for government plans to reduce pig farming, which would lower demand for animal feed and manure laced with the heavy metals.

Most of the zinc and copper in waterways originates from agricultural fertiliser, ministry data show. The metals have been added to pig feed for decades, entering the environment through manure spread on fields and subsequent runoff.

The minister said she would incorporate the new data into ongoing work to restructure the pork sector and assess further measures to cut zinc and copper emissions in upcoming water framework plans.

Denmark, like other EU members, is required to achieve good ecological status in its water bodies by the end of next year—a target officials already admit is unattainable. John Jensen, a senior researcher in ecotoxicology at Aarhus University, called the goal “fundamentally unrealistic” given the scale of contamination. Danmarks Naturfredningsforening agreed, noting additional pollutants beyond zinc and copper must also be addressed.

Industry group Landbrug & Fødevarer said farmers have complied with existing rules on zinc and copper use but acknowledged the environmental impact was not fully recognised. A 2022 ban on medicinal zinc in pig feed is expected to reduce contamination, though researchers doubt this alone will solve the problem.