Introduction

In 1991, members of local, State, and Federal governments, as well as industry and interest groups, formed the Ground-water and Pesticides Strategy Committee (GPSC) to prepare the State of Wyoming Generic Management Plan for Pesticides in Ground Water. Little existing information was available describing pesticide occurrence in ground water; therefore, statewide baseline ground-water sampling was considered a high priority by the GPSC.

The GPSC identified 20 pesticides and degradates for baseline ground-water sampling (referred to herein as focal pesticides). Sampling focused on the State’s most vulnerable ground water (Wyoming Ground-water and Pesticides Strategy Committee, 1999) as determined by Hamerlinck and Arneson (1998; fig. 1). Ground-water vulnerability is based on inherent sensitivity of the hydrogeology (such as a shallow water table or highly permeable aquifer materials) and overlying land use.

Posted March 12, 2009