ATTLEBORO -- Water and sewer rates are spiking with rising debt and personnel costs on top of soaring energy prices, Mayor Kevin Dumas told the city council Tuesday night.

Wastewater ratepayers would see an increase of 30 percent from $5.06 to $6.59 per 100 cubic feet of usage under Dumas' proposal.

Water customers would be hit with a 13.7 percent increase, from $2.91 per 100 cubic feet to $3.31.

Costs related to the renovation of the city's wastewater treatment plant are the biggest reason for the spiraling wastewater rate, Dumas said.

The mayor predicted three years ago that the rate would increase at least $1 a year for three years to pay for the $30 million in borrowing needed to construct the plant. While the rate hike is bad news, Dumas said he expects the rate to stabilize next year.

`` I'm anticipating that anything further will be much less than this year,'' he said.

The debt costs will go up about $853,000 next year, bringing the annual debt costs for the wastewater department to almost $5 million out of a total budget of $8.9 million.

That's up 16 percent over the current year.

Costs for energy, fuel and labor also contributed to the increase in the wastewater rate and are the main causes for the water rate hike, Dumas said.

The water budget is scheduled to be $7.1 million next year, a 13 percent increase in spending.

Both departments are run on the enterprise system, which means all operating money must be raised from fees for the service.

Public hearings on each budget are scheduled for June 6.