The Riverdale Park Tract Community Service District (RPTCSD) has notified the Stanislaus County Board of Supervisors that levels of perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) in local groundwater have exceeded state notification levels, according to a letter submitted for discussion at the next board meeting. … While these levels surpass the notification standard, they remain below the response level of 70 ppt, which would require immediate action to remove the water source from service.