City Councilor Joseph J. Bevilacqua. (WHAV News file photograph.) Haverhill residents do not have to worry about a chemical, known as PFAS, in their drinking water. That was the assessment of the city’s Deputy Public Works Director Robert E. Ward at a City Council meeting this week. The chemicals, known formally as polyfluoroalkyl substances, are found in food packaging, household cleaners, electronics and other products. Ward told councilors, although it is a concern because these chemicals can last for thousands of years, so far, Haverhill has seen no issues. “We’re a surface water supply. We have, you know, reservoirs as opposed to many communities that have ground water. The PFAS problems are occurring in ground water sources much more so than surface water supplies,” he explained.