Just the town of Nokia. In 2007 it turned out that years ago, someone had designed a stupid arrangement at the wastewater treatment facility where a freshwater pipe was used to flush the sewage side. But if a maintenance man left the tap on, and put the sewage process going, some of the sewage would go backwards, into the freshwater side. A couple of thousand people were infected by norovirus or campylobacteria. Highly unusual.