The concentrations of most of the medications (anti-depressants, contraceptives, antibiotics, etc.) are large in relation to drinking water, but small in relation to the ecosystem into which they&#x27;re discharged.<p>Any animal that eats them can usually break them down given their low concentration and half-life, using liver enzymes, and since the majority of the chemicals are human-targeted, they often have much affect on local flora or fauna.<p>We have bigger problems biggest waster water management anyway. When it rains, your town probably dumps raw sewage into the nearest river through a CSO (Combined Sewer Overflow), which is... less than ideal.<p>The previously mentioned mechanisms are actually considered eco-friendly approaches in comparison.<p>So yes, it is a very weird world.