WESTFIELD, Mass. (The Westfield News) — A site investigation is underway this week at Barnes Air National Guard to further evaluate the issue of contaminants in city water and a potential link to the base. The site investigation is part of a multi-step process being done by the Guard, as outlined from the Environmental Protection Agency (EPA) and the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA), also known as Superfund, according to John Richardson, Base Environmental Coordinator for the site. The investigation is related to the contamination of Westfield groundwater with perfluorinated compounds Perfluorooctanoic acid (PFOA) and Perfluorooctanesulfonic acid (PFOS). The investigation began on June 26, Richardson said, and is expected to continue until June 30. Results are expected Nov. 30. According to Richardson, this is the second step in a five-step process that is outlined by CERCLA and the EPA. The next step after this one would be remedial/investigation feasibility, which according to the EPA’s Superfund website “…involves an evaluation of the nature and extent of contamination…