NORTH ATTLEBORO -- A sewer and water rate increase proposed for the coming fiscal year would boost the average sewer bill by about 20 percent and the average water bill by about 9 percent.

The board of public works held a public hearing on the proposed rate increases on Tuesday, but has not yet voted on the measure. Chairman Michael Thompson said his board will publicize when it intends to vote on the rates, which will go into effect for the 2007 fiscal year.

Currently, the average sewer bill is about $268 a year and would increase by $53 to $321 if the rate hike is approved. The average water bill is about $245 a year and would increase by $21 to $267.

Department of Public Works Director Michael Stankovich explained that the sewer rate increase is higher because the town has only 5,200 sewer users while water users total about 8,800.

Sewer users have to pick up the tab for all capital projects related to the sewer system; water users pay for all projects related to that utility. While the town's water plants are fairly new and need little work in the coming years, the wastewater treatment plant is undergoing a multi-year $10 million rehabilitation project.

Stankovich said the town is in the fourth year of the project and spends about $1.5 million a year to upgrade the equipment at the 25-year-old facility.

In addition, the town will be required to obtain a new federal National Pollution Elimination System permit this year, which will add to the cost of running the sewer system.

Other factors included increased costs for fuel, chemicals and security upgrades to protect facilities against vandalism.

Even with the rate increase, North Attleboro's water and sewer rates are lower than or comparable to what other communities were charging in 2004 -- the latest year for which figures are available from a 140-community study completed by Tighe and Bond Engineering.