Hoping to end the debate over the Waconia ballroom septic system, Carver County's commissioners on Tuesday sanctioned an immediate conversion of the ballroom's septic tank into a holding tank while the staff considers options for replacing the faulty septic system.

Closing the drains on the septic tank and converting it to a holding tank will cost about $2,500. It also will require weekly pumping of the tank at a cost of about $10,400 a year, county commissioners were told on Tuesday.

Installing a new septic system at the ballroom, which the county bought last year for $2.5 million, would cost between $75,000 and $100,000, county staff members said. But if the Metropolitan Council would allow the county to connect the ballroom to a sewer main near the property, the county would pursue that option instead, County Administrator Dave Hemze said. He doesn't yet know how much that would cost.

The septic system has been a bone of contention among County Board members since Commissioner Tom Workman called for a new inspection and other commissioners resisted the idea.

After Workman provided documents to the Minnesota Pollution Control Agency to question whether the system met state requirements, the agency recommended a new inspection that was completed in mid-November. The inspection revealed that the system was not far enough from the groundwater to prevent pollution, because it lacks the necessary 3 feet of separation between the drain field and the underground water table.

Digging pits into the ground to examine soil conditions, Matrix Soils & Systems Inc. found that the separation between the drain field and water table varied between 0 and 2 feet. The faulty setup is not considered an imminent health threat, county officials said.

Last year, an inspector who used soil borings to check the drain field certified that the septic system was working properly. Soil boring inspections are typically used in the area to check septic systems, and Carver County relied on that finding when it purchased the property overlooking Lake Waconia. That inspection was provided by an inspector hired by the former owners of the ballroom property, Rick, Patty and Lucille Wagener .

The commissioners agreed to ask the PCA what to conclude about the first inspection. If it was done improperly, that might be grounds for the county to recover some of the money it paid for the property, Hemze has said.

Ultimately, the county would like to connect the ballroom -- which is also known as the Lake Waconia Event Center -- as well as restrooms for the adjacent park, to the Waconia sewer system, Hemze said. If the county were to wait for development to extend the city's sewer line close to the event center, it would cost about $220,000 to hook up to the sewer, the county staff reported.

Hooking up the event center to the sewer before the development would cost $600,000 to $700,000, the county estimates. Connecting to the sewer main would cost less than that, Hemze said.

As the county dealt with its own septic system problems on Tuesday, Carver County Attorney Jim Keeler was announcing the resolution of a three-year legal battle to force an elderly couple to replace their septic system.

Keeler said a new septic system has been installed on Lowell and Janet Carlson's property in Camden Township. The county had taken the Carlsons to court, and a judge had threatened to jail them if they did not replace their system.

Laurie Blake • 612-673-1711