AWWA WSC67778

In March 2008, an accidental contamination event occurred in the Pittsburgh Water and Sewer Authority drinking water distribution system. During a warehouse fire, firefighters accidentally pumped fire suppression foam in the reverse direction into the Pittsburgh water distribution system. The foam was quite visible to customers and contaminated a significant portion of the downtown business area of the city. While the foam itself was not highly toxic, an analysis of the spread of the contaminant, and the response on the part of the water utility and government agencies, provides information that may be useful for future events in which drinking water systems may be contaminated, accidentally or intentionally, by more serious toxic chemicals, pathogens, or radioactive substances. In addition to the case study of the fire suppressant foam contamination, this paper discusses several earlier contamination threats and incidents that have occurred in Pittsburgh. Includes 2 references, tables, figures.