The families, in a lawsuit filed Monday in Washington County Circuit Court, contend the July 17 spill in the Town of Jackson caused property, health and emotional damage, the Milwaukee Journal Sentinel reported.
In addition to monetary compensation, the families want West Shore Pipe Line Co. of Arlington Heights, Ill., and Buckeye Partners LP of Breinigsville, Pa., and Houston, to set up a medical monitoring fund to pay for cancer screening for area residents.
A lawyer for Buckeye Partners said the firm would have no comment on the case.
Family members say they have suffered nausea, vomiting, diarrhea and other ill health effects.
Tests found contaminants in 27 residential drinking water wells and two non-residential wells since the 10-inch-diameter pipeline leaked.
State health officials have advised people living in the area to use bottled water or water from a known safe source for drinking, cooking and making ice.