Introduction

The McKenzie River is the source of drinking water for approximately 200,000 people in the Eugene area of Oregon (fig. 1). To protect this critical resource, the Eugene Water and Electric Board (EWEB) completed a plan in August 2000 to protect the McKenzie River as the sole source of drinking water for its customers (Eugene Water and Electric Board, 2000). The overall goal of the source protection program is to “measure the balance between watershed health and human use over time and implement actions that maintain a healthy balance for production of exceptional water quality.” One component necessary to achieve this goal is monitoring water in the McKenzie River basin for the presence of anthropogenic organic contaminants.

Among the organic compounds of interest are those that may have significant ecological and(or) human-health consequences at concentrations that are orders of magnitude less than the detection limits associated with conventional water-sampling techniques. In addition, many compounds of interest may be present only during episodic events. As part of a U.S. Geological Survey (USGS)–EWEB cooperative study of water quality in the McKenzie River (U.S. Geological Survey, 2008), two types of passive samplers—polar organic chemical integrative samplers (POCIS) and semipermeable membrane devices (SPMDs)—were used to address these challenges. Both POCIS (Alvarez and others, 2004, 2007) and SPMDs (Huckins and others, 2006) are well suited to overcoming the difficulties of measuring low analyte concentrations and recording episodic analyte loading.

In order to evaluate the use of passive samplers in long-term monitoring for organic compounds in the McKenzie River basin, passive samplers were deployed at three sites in the basin for 35 days during September–October 2007. This report presents the design and results of this sampling effort.