The Washington Suburban Sanitary Commission yesterday formally approved water and sewer rate increases of 23 percent and 9 percent, respectively. They are expected to raise the bill of an average family of four in Montgomery and Prince George's counties by $32 annually.

The rate increases, which were approved unanimously by the WSSC's six members, will take effect July 1, according to WSSC spokeswoman Alice Cleary.

The money generated by the rate increases will be used to support this year's $352 million budget, which has increased 22 percent over last year's budget, Cleary said.

The rate increases and the budget were previously approved by the county councils in the two jurisdictions served by the WSSC.

The new rate increases will be applied to the WSSC's 100-step pricing scale that imposes higher rates on the users of greater amounts of water.

The cost of using water will now increase from a range of 36 cents to $1.05 for each 1,000 galloons to a minimum of 54 cents and a maximum of $1.23 per 1,000 gallons, Cleary said.

Sewer rates will increase from the current rate of 45 cents to $1.31 per 1,000 gallons to the range of 54 cents to $1.40 per 1,000 gallons, Cleary said.

Under the current rate system, an average family of four using 240 gallons of water each day pays about $140 annually for water and sewer service.

Under the new system, the [WORD ILLEGIBLE]family using the same amount of water and sewer service will be about $172 annually, Cleary said.