Denmark Must Ban Pesticides to Save Drinking Water, Report Says

A new report from Denmark’s Ministry of the Environment confirms that efforts over the past 27 years to protect groundwater have failed. Pesticides now appear in more than half of all tested drinking water wells nationwide. In the Copenhagen area, HOFOR, the regional utility company, detected traces of agricultural pesticides in drinking water from five out of nine waterworks. The ministry identifies a national ban on pesticide spraying in vulnerable groundwater recharge zones as the most effective solution. Local green tripartite plans recently released aim to convert farmland into nature to cut nitrogen and greenhouse gas emissions. While these plans include groundwater protection as a side benefit, HOFOR’s data shows they offer minimal defense for areas supplying water to over one million people in the capital region. For instance, Denmark’s largest waterworks in Køge, which serves 200,000 residents and is vital for regional supply security, receives almost no protection under current land conversion strategies. Widespread water treatment may become necessary. The ministry estimates nationwide purification would cost 6 to 18 billion kroner annually, plus high energy use, water waste, and toxic byproducts. In contrast, a spraying ban would cost roughly 360 million kroner per year. The minister also signaled readiness to lower nitrate limits in drinking water due to cancer risks. He urged a full prohibition on pesticide use in sensitive zones, a move he called a historic step toward securing future drinking water.