Denmark to slash nitrate limits in drinking water, easing concerns in high-risk areas

The Danish government will cut the maximum allowed nitrate level in drinking water from 50 milligrams per litre to 6 milligrams per litre, following new health recommendations, according to its newly published policy platform.

The move aims to reduce the risk of colorectal cancer linked to nitrate exposure, with experts estimating the stricter limit could prevent 50 to 70 cases annually. “From a public health perspective, this is clearly positive,” said Lasse Olsen (EL), chair of Aalborg Forsyning, the municipal utility in Aalborg, where nitrate levels have long exceeded national averages due to porous soil accelerating agricultural runoff into groundwater.

Aalborg has already begun drilling new wells and blending water sources to dilute contamination, but officials warn the transition will require significant investment. “We’ve been waiting for this decision,” said Pernille Stampe Jakobsen, the utility’s chief consultant. “We’ll meet the target, but we need clarity on timelines and funding—this can’t just become an extra bill for Aalborg residents.”

Unresolved questions remain, including whether farmers will face restrictions on fertiliser use near vulnerable aquifers and how costs will be shared. Aalborg Forsyning is currently suing the state for over 1 billion kroner to cover past filtration expenses, arguing that national policy failures—rather than local ratepayers—should bear the burden. “This is a challenge for all of Denmark, not just one region,” Olsen said.

Colorectal cancer, one of Denmark’s most common malignancies with roughly 4,500 new cases yearly, has been linked to nitrate in studies cited by the expert panel behind the new guidelines. Aalborg’s groundwater already exceeds the current 50 mg/l limit in multiple wells, forcing pre-treatment before distribution.