scope:

INTRODUCTION

All water suppliers strive to provide their customers with sufficient quantities of high-quality water at affordable rates. The drinking water industry uses a multiple-barrier approach to achieve this goal. The multiple-barrier approach involves several consecutive steps, including selection of high-quality source water(s), source water management and protection, optimized water treatment as necessary, distribution system management, and water quality monitoring. Optimization of each step in this process is a logical and prudent approach in responding to high customer expectations for drinking water quality, increased regulatory requirements, and uncertainties associated by the growing number of drinking water contaminants and climate change.

Given the great importance of SWP as one of the components of the multiple-barrier approach for providing safe drinking water, ANSI/AWWA Standard G300, Source Water Protection, was published in 2007 (AWWA 2007a). This standard provides a framework through which utilities can be assessed in terms of their effectiveness at SWP. The standard was established to provide a general framework for drinking water systems of any size and circumstances to develop SWP programs that are locally specific and highly variable in scope.

This guide focuses on SWP and does not specifically address source water selection or certain aspects of source water management (e.g., treatment of reservoir water to control algal growth and stratification). The objective is to provide utilities with a guide for developing SWP activities and a tool for assessing the completeness and effectiveness of their SWP programs. This guide is not intended as a comprehensive how-to guidance manual (e.g., a cookbook), nor does it have any regulatory linkage. Many other resources are available to assist in the planning, development, and implementation of SWP programs, and many of these resources are listed in Appendix A (Select Web Sites Related to Source Water Protection), Appendix B (Annotated Bibliography for Select Information Sources), Appendix C (Case Studies for Source Water Protection), and the bibliography (Sec. 7).