Several environmental groups moved Wednesday to sue the Phillips 66 refinery in the South Bay, accusing it of years of mismanaging hazardous waste that could pose a health risk to people living near its Wilmington and Carson facilities. The groups’ planned lawsuit comes four years after the U.S. Environmental Protection Agency first raised concerns about the oil refinery’s practices. Environmental advocates said their decision to take legal action was the result of frustration with what they said was lax oversight by federal and state regulators. “These violations are significant,” said Mary Greene, deputy director of the Environmental Integrity Project, one of the organizations that plans to sue. “This screams of sloppy housekeeping and poor environmental management.”