SUMMERVILLE -- Water and sewer rates will increase for Commission of Public Works customers starting in September.

The minimum monthly residential water bill will rise from $12 to $13.75; the monthly sewer bill will rise from $19 to $21.25, according to a Summerville CPW news release. The rate hikes will appear on the October bill.

The increases affects 24,100 water customers and 18,700 sewer customers, but do not affect customers of Dorchester County or other public works providers. A number of people in the county obtain the individual services from more than one provider.

The increases are expected to bring in $1.2 million more in revenue to deal with rising operational and capital-project costs.

The last increase was in June 2008, the release said. The CPW board approved the increases this week.