Most sewage treatment systems don't remove all medicines before wastewater is discharged back into rivers or turned into sewage sludge + spread on farm fields. In fact, some meds get more concentrated by the treatment process, study finds. Not all bacteria are killed by current treatment processes either, so we're discharging bacteria + antibiotics into rivers - perfect breeding grounds for treatment resistant bacteria. When Watershed tested English bathing water sites last year we found antibiotic resistant genes present in the water at several. Sewage sludge, used as a fertiliser on some farmland, is treated to kill disease but not enough to remove medicines + chemicals. Meds in discharged wastewater can impact the health + behaviour of fish + water insects - even at very low levels. In England, if a sewage treatment plant serves fewer than 2000 people, sewage only gets treated once. If you live in an area with a higher population, your sewage should be treated twice. Neither method is enough to kill all diseases or remove all medicines + recreational drugs from sewage. Treating sewage three times (tertiary treatment) is needed to remove all medicines, all recreational drugs, all diseases + most chemicals from sewage. Since this treatment method was introduced in Switzerland, the health of their rivers has soared. But even tertiary treatment is not enough to remove PFAS forever chemicals. Swiss Water authorities say removing PFAS from water is so difficult, energy intensive + costly the only way to prevent PFAS pollution in water is to stop making PFAS. They join EurEau + Water UK in calling for a ban on PFAS to protect our drinking water sources, our rivers, lakes, streams + seas. phys.org/news/2025-09-wastew…