25 years ago: A memorandum from the state Department of Health Services issued in June 1986, said the agency was alerted to the possibility that submersible pump motors manufactured before 1978 have been contaminated with Polychlorinated biphenyls, a suspected carcinogen commonly known as PCBs. Town officials warned homeowners and instructed them to have their submersible pump motors that predated 1978 tested for the PCB contamination.