Water is a necessity for human survival, and access to safe drinking water is a required cornerstone of public health.a In concert with improved pasteurization and refrigeration of foods and childhood immunizations, modernized sanitation methods and access to potable water have increased the life span and improved the general health of American citizens more than any other advancement in the field of medicine.1 Conscientious water quality management and access to renewable water resources are vital to every sector of our industrialized society and every sector of our nation's agricultural economy.2 Early American settlements located near water and water reserves were generally sufficient for our country's development and prosperity during initial phases of growth. However, even during these early periods of U.S. history, there were recorded instances where communities disappeared as a result of declining or contaminated water supplies. Currently, there is a water crisis in the United States that has resulted from population growth and urbanization placing pressure on fixed sources of freshwater available locally and, at times, regionally. These water access pressures have resulted in insufficient quantity and deteriorating quality of water supplies in many regions of the United States.
These water quantity and water quality challenges have arisen from the fact that the amount of water in the world is fixed at approximately 3.59 × 1020 gallons in all. Of this amount, only about 0.2 % is freshwater that is readily available for human use. Through the hydrologic cycle, freshwaters run to the sea and become saline, but evaporation of water from the sea and precipitation on land restores these freshwaters continuously so that the quantity of freshwater is also relatively fixed and limited. Ongoing stewardship and an increasing prioritization of water quality management will be essential in order to ensure access to a water supply that provides both the quantity and quality necessary to preserve this precious environmental resource.
Preservation of water quality and prevention of water-borne disease is a complicated task requiring a coordinated effort from many diverse stakeholders including health-care providers, local and national public health authorities, water utility practitioners and engineers, water quality and regulatory specialists, environmental scientists and engineers, basic science researchers, and water consumers. In order to work together to maintain and improve water quality management in the United States, each stakeholder must understand (a) the basic parameters of water use and sources; (b) the challenges of water source protection and water contamination; (c) the trends in water-borne disease and the health effects associated with exposure to contaminated waters; and (d) the provision of safe drinking water and the treatment of wastewaters. The intent of this chapter is to provide an overview of each of these essential components of water quality management in the United States and the subsequent impact on water-borne disease and public health.