Quality Criteria for Reclaimed Water

Abstract

The applicability of reclaimed water for any particular use depends on its physical, chemical, and microbiological quality. The effects of physical and chemical parameters for nonpotable uses of reclaimed water are, for the most part, well understood and criteria have been established. Health-related microbiological limits are more difficult to quantify, as evidenced by widely varying standards and guidelines throughout the world. This paper presents existing reclaimed water quality limits for various uses, and compares the California Wastewater Reclamation Criteria, which are typical of health-related standards in industrialized countries, to WHO guidelines, which are directed principally at developing countries. The California regulations are considerably more restrictive than the WHO guidelines. Because of unknowns concerning the presence, identification, concentration, and health significance of many chemical constituents that may be in reclaimed water, quality criteria for potable reuse are not well developed and are not addressed in this paper.