The quality of our drinking water is at risk. The groundwater and surface water in drinking water extraction areas are becoming contaminated with more and more substances, including medicine residues. This is the conclusion of the research done by KWR, institute of the drinking water sector.
Our drinking water is purified and extracted from surface water (35%) and groundwater (65%).
The institute warns of a “steady and probably irreversible deterioration” of groundwater quality. Medicines, nitrates, pesticides and old soil contamination are increasingly found in groundwater. And more than half of our tap water is extracted from that water. Underground activities, such as geothermal heat extraction, also pose a risk to our drinking water.
The surface water is not much better. Rivers are increasingly contaminated with chemical substances and medicine residues. There are also ongoing studies into the health risks of microplastics, nanomaterials and veterinary medicines (such as antibiotics) in drinking water. Climate change also causes new threats, such as salinization. Finding new water extraction areas is becoming increasingly difficult. The study provides a worrying picture and measures will have to be taken to improve the quality of drinking water sources.
Every year, more than 140 tons of medicine remains in the surface water in the Netherlands. Treatment plants remove about 65 percent of the medicines in the sewage, the rest ends up in the surface water with the purified water. Around 90% of all medicine residues come from residential areas. It enters the sewer through our urine and faeces. We also flush unused medication down the toilet. The remainder comes from care institutions and hospitals, and Dutch cattle also bring medicines into the surface water through their excrement. Moreover, through rivers and canals from abroad, medicine residues enter our surface water. About 200 types of medicine have been detected in Dutch surface water and previous research has shown that this is harmful to life in that water.
Quality of drinking water
15 medicines were found in drinking water itself and carbamazepine and painkiller acetylsalicylic acid are the most common. According to Peter van der Velden, chairman of the Association of Water Companies in the Netherlands, we do not have to worry about the quality of the drinking water that comes out of the tap: “That is optimal. But it takes ever greater efforts to get the water purified.” Yet the long-term effects of exposure to such low drug concentrations or to mixtures of such agents are still unknown.