The San Diego County Board of Supervisors voted Tuesday to join the growing legal campaign to force the federal government to do more to stop sewage from spilling over the border from Tijuana that routinely fouls South Bay beaches. “Enough is enough,” Supervisor Greg Cox, whose district includes border region with Mexico, said in a statement. “We’ve exhausted all our efforts to resolve this terrible situation and it’s time we force those responsible to once and for all fix this problem.”