No prescriptions in the potty and no drugs down the drain.“We need to try to get away from people flushing medicines,” said McMinnville Water and Sewer Department director Anthony Pelham.When they are flushed down the toilet or sink, some of these chemicals pass through treatment plants or septic systems and can end up in the river, says Pelham. “A lot of medicines and pharmaceutical products don’t biologically break down so they just inertly pass through our system and then go back into the river at our discharge. That’s something that’s growing in a lot of places.”A recent study by U.S. Geological Survey has shown 80 percent of U.S. streams contain small amounts of human medicines, which adversely affects fish and other aquatic animals.