Wastewater epidemiology is an emerging field of research that is proving its value in detecting the spread of diseases and informing efforts to mount defenses against threats to public health. Wastewater monitoring is in some ways a relatively new endeavor, so the legal and ethical parameters — including matters of privacy rights — to guide its use should be explored, says Fulton Schools Professor Rolf Halden, a pioneer in the field. But while those issues need to be worked out, Halden asserts that this should not put the brakes on a diagnostic method that is clearly becoming a potent force in protecting large populations from the worst ramifications of epidemics and other risks to the quality of life in vulnerable communities.