Water Technology: Is granular activated carbon the most effective method to remove PCBs from water? Are there any other known treatment options available for this contaminant?

Joseph Cotruvo: GAC or PAC are effective methods for removing PCBs, if present. However, PCBs are so hydrophobic that they are at least partially removed by any process that involves media contact.

Water Technology: What are the most common ways PCBs get introduced to groundwater, what steps should be taken to determine if PCBs are present and how often should dealers test for PCBs?

Joseph Cotruvo: PCBs are unlikely to be present in most groundwaters because of their affinity for particulates so they do not migrate in soil or underground very effectively. Monitoring is probably not necessary unless there is an indication of possible PCB contamination such as a nearby hazardous waste site. Using drinking water from a public water supplier obviates monitoring. The U.S. banned production and essentially all uses of PCBs in 1979, except for some capacitors and transformers.

Dr. Joseph Cotruvo is president of Joseph Cotruvo and Associates, LLC, Water, Environment and Public Health Consultants. He holds a Ph.D. in Physical Organic Chemistry and is a member of the World Health Organization's Guidelines for Drinking-water Quality Committee and expert advisory groups on drinking water quality, desalination, wastewater and water reuse. He is a former director of the USEPA Drinking Water Standards Division.