MERRIMAC — Light & Water commissioners are considering raising the water rate by 10 cents per 100 gallons. If approved, it would become effective in October.

The increase to an average customer using 15,000 gallons per quarter would be $15 per quarter, or $60 per year, and the total average annual bill would rise to $408 per year for water usage, according to Light & Water Department Manager Dan Folding.

Folding said this increase would be the first since last October when rates rose by 5 cents. Prior to that, the rates went up by 13 cents in January of 2003.

The main reason behind the change, Folding said, is the skyrocketing price of potassium hydroxide, a chemical used to raise the pH of the water at the Bear Hill Pumping Station and East Main Street plant. The 212 percent jump from fiscal year 2008 to fiscal year 2009 will cost the Water Department an additional $37,682 in just one year.

"We can't even come close to absorbing that in our budget," Folding told commissioners at their meeting last week. He said he assumed that the price increase was a result of the rising price of oil, but he said no explanations were provided. He noted that the new chemical prices already include bulk discounts and that the bid was fairly competitive.

Commissioner Norman Denault suggested, "There are other types of chemicals that we could possibly replace that with." Folding agreed to contact SGC Engineering for a review.

Folding added that the rate increase is also needed because "I don't think we've kept pace" with the department's overall expenses. "I was hoping to see a lot more revenue." He explained that revenue drops when there is a dry summer with a water ban or a wet summer with reduced pumping.

He said that with the proposed rate hike, "We're assured of getting at least the revenue" to cover rising costs. Folding pointed out that Haverhill has recently proposed a 17 percent increase in their water rates.

Before the new rate can be approved, a public hearing is required. In the meantime, Folding urged the commissioners, "I'd like you to really think about what we're up against."

"I'm all for it," Chairman Louis Bibeau said. "We have to do what we have to do."

"I'm not for it, but we can't run on a deficit," Denault said.