On Tuesday, Homewood trustees will consider joining a new group of 11 south suburban municipalities that plan to explore the feasibility of obtaining water from Lake Michigan through Hammond, Ind.Flossmoor trustees voted in December to join the group. Public Works Director John Schaefer said the exploratory project does not necessarily indicate a plan to switch water suppliers. He said the village is interested in having more control over water costs and it hopes to determine what its options are. Rates charged by Chicago have gone up significantly in recent years, he said. Homewood receives Lake Michigan water . . .