Spirit Lake voters will decide a $1.8 million bond levy proposal on May 15 for wastewater treatment improvements.

The bond would add a 25 million-gallon lagoon, increase efficiencies to the land application irrigation system and enhance the biological treatment process.

"This is really important that the public knows the situation," Mayor Renee Eastman said.

The city last year imposed a growth moratorium that still is in effect due to sewer capacity issues.

If approved, the 40-year bond will increase the monthly sewer bill $2 to repay the construction loan.

The city also plans this summer to increase the sewer rate $3 per month for maintenance and operation of the system. That will be implemented regardless whether the bond passes, and a specific date has not been determined. The two hikes would increase monthly sewer bills from $26 to $31.

"Communities in North Idaho with similar systems have rates of $45 to $50 per month," a city press release states.

A vote of at least 51 percent approval is needed for the proposal to pass.

Since the last improvement to the city's wastewater treatment facility in 2002, population has grown 57 percent, according to city officials. As a result, the facility is at capacity, which forced the city to issue a sewer moratorium on new growth.

The wastewater facility is a land-based system in which, after treatment, the effluent is irrigated onto agriculture fields and forest crops.

The system is meeting requirements that protect the aquifer, the region's underground drinking water source, but exceeds Idaho Department of Environmental Quality standards for land-application requirements.

A wastewater facility plan prepared by consultant James A. Sewell and Associates in January is being reviewed by the IDEQ. The upgrades will eliminate health and safety threats, minimize possible future impacts to the aquifer and provide a 20-year design as required by IDEQ.

The bond amount is based on recommendations from the consultant and IDEQ.

A USDA Rural Development loan would fund the improvements. The interest rate is set when and if the levy passes. The rate is currently 3 percent.

The next open house on the bond levy proposal will be May 8 at City Hall from 2 to 6 p.m. There will be information displays, engineers and city staff at the open house.