Introduction

Just before Christmas 1983, Pennsylvania’s Department of Environmental Resources declared that contaminated drinking water was the cause of an epidemic of giardiasis—a gastroenteric disease—then raging in the Kingston-Pittston area of Luzerne County in northeastern Pennsylvania. The department advised residents to boil tap water before using it. Before the episode was over, this outbreak of giardiasis would become one of the largest yet experienced, with an estimated 6,000 people falling ill, 75,000 people advised to boil tap water for drinking, and a host of businesses prohibited from using unboiled tap water for drinking or food preparation, in some areas for as long as nine months.