Occurrence of trace inorganic contaminants in drinking water distribution systems

Many trace inorganic contaminants (e.g., lead, arsenic, nickel, vanadium, and uranium) can accumulate on the surface of or be occluded within corrosion scales formed in drinking water distribution systems (DWDSs). However, few data are available on the actual concentrations of these contaminants beyond system entry points. An investigation was conducted to determine the occurrence levels and patterns of 11 trace inorganic contaminants in DWDSs. Among the trace inorganic contaminants found in practically all studied samples of intact corrosion scales and solids mobilized during hydrant flushing, barium was the most concentrated on a mass basis, followed by, in decreasing order, lead, nickel, vanadium, arsenic, chromium, uranium, cadmium, antimony, selenium, and thallium.