MAPLETON — For the past two years, the city's sewer fund has been in the red, and now city officials are considering a rate increase.

"It looks like we'll have to make an adjustment," city administrator Bob Bradshaw said recently.

During the 2009-2010 budget hearings, city leaders knew the sewer fund was in the red, Bradshaw said. But the council may wait until the 2010-2011 budget session to fix it.

The city added to the shortfall when it stepped up preventive maintenance and refurbishing work on the 15-year-old sewer. That cost about $80,000 over the last two years, he said.

Several years ago the City Council lowered the monthly sewer fee from about $42 to $40 a month for the city's 2,000 homes, but the surplus the city had then has slowly eroded away, Bradshaw said.

During the 2007-2008 fiscal year, the fund came up short by $68,813, while last fiscal year the red ink intensified, leaving Mapleton's sewer fund $199,194 in arrears, according to city records the Deseret News obtained through a Government Records Access and Management Act request.

Mapleton's sewage goes to the Spanish Fork treatment plant. The city owns 24 percent of the plant's capacity.

Spanish Fork financial officer Kent Clark said that, last fiscal year, Mapleton paid Spanish Fork $111,000 for operation and maintenance. Councilman Brian Wall said the city had to fork out another $400,000 to meet its share of a Spanish Fork sewer system upgrade. The city was unprepared for that, and some of the payment may have come from the general fund, which makes the shortfall unclear, he said. (A recent audit found that the general fund surplus was excessive.)

"That's a liability we have to pay when it occurs," Wall said of the upgrade. "We need to maintain a sewer fund surplus."

The city has requested an increase of capacity to 27 percent to cover a proposed boundary line adjustment that would bring some 600 acres into Mapleton from Spanish Fork.

The hotly contested adjustment carries with it a proposal to develop Ensign-Bickford land at the mouth of Spanish Fork Canyon for industrial, commercial and residential uses, but some residents and Wall are digging in their heels.

"If that doesn't happen, the sewer expansion won't happen either," Spanish Fork city attorney Junior Baker said.

Developers typically pay for such expansions, but some residents are questioning whether that will happen this time.

Ensign-Bickford and other companies manufactured explosives on the site for more than 60 years. Ensign-Bickford is now partnered with developer Jack Evans and has been working with the state to clean it up.

Wall, who takes over the mayor's seat in January, stood alone in opposing the city's move toward the boundary adjustment in a recent council vote, saying not enough is known. Both Mapleton and Spanish Fork have scheduled public hearings in December that could lead to approving the adjustment before the end of the year.

Wall unseated Mayor Laurel Bradley in the Nov. 3 election.