Potable versus Reclaimed: Water Quality, Regulatory Issues, Emerging Concerns

The Dublin San Ramon Services District (DSRSD) has constructed a 2.5 mgd tertiary treatment facility composed of microfiltration, reverse osmosis, and ultraviolet disinfection. The facility has been approved by the California Department of Health Services and the California Regional Water Quality Control Board for production of water for groundwater injection into a potable water aquifer. In an effort to mitigate public concerns regarding the injection of recycled water, DSRSD has carried out intensive and comprehensive water quality tests, including a wide variety of organic and inorganic compounds, endocrine disrupting compounds, disinfection by-products, seeding for virus challenge studies, toxicity tests, and testing for radioactive components. The results of the testing program are compared with the quality of local potable water and ground water to allow an evaluation of the effectiveness of the treatment processes in producing potable quality water.