Mediation could be the next step for two north metro cities that share an interconnected water system and are sparring over water-quality issues.

Blaine and its much smaller neighbor Lexington have been locked in a battle for nearly two years, unable to agree on a plan to operate the distribution system that has been jointly owned by both cities for more than 50 years.

Blaine in recent years has spent $40 million to improve water quality, including opening a fourth water treatment facility last summer. Officials in Lexington, which does not have treated water, claim Blaine simply took over and made changes to the joint system without consulting them, and accuse the city of installing valves to control the amount of water flowing into Lexington.

"They spent lots of money to build it and they should have done that collaboratively with Lexington," said Lexington City Attorney Kurt Glaser. "They forget they have to work with their neighbor."

The dispute took on a new tone last week, when the Lexington City Council passed a resolution stating Blaine "exceeded its authority by implementing recent changes to the joint water system" and the council would authorize changes to the system only if they provided for a safe, adequate and reliable water supply equal to that provided to Blaine residents. The resolution also said any changes in "operation, maintenance and planning related to the system must occur in a cooperative manner."

The resolution states splitting the system into two parts would cost up to $10 million and take Lexington three to five years to build infrastructure that is already in place in the joint system. If Blaine separates and operates the system, there would be decreased water capacity to fight fires in Lexington, Glaser said.

Blaine supplies water to Lexington most of the year, but Lexington turns on its wells during the summer months and sends water back to Blaine "to pay us back," said Blaine Mayor Tim Sanders. But Lexington's water is inferior to that of Blaine's, the mayor said, and Blaine no longer wants Lexington's untreated water mixing with its treated water.

"We have the goal of providing the highest quality of water at the lowest cost to Blaine businesses and residents," Sanders said. "We are committed in that we are not going to have water quality issues in Blaine. We remain steadfast and unapologetic in that."

Sanders said Blaine has offered to sell water to Lexington at a wholesale rate, something Glaser disputes as a price has never been agreed on. Sanders also would like to see meters installed to track how much water is flowing into Lexington.

Lexington City Council's resolution states it wants to "be a good neighbor" by working with Blaine on proposed changes. Sanders said getting back to the table to talk face to face would be a good start.

No talks are imminent, and if the disagreement between the cities persists, "there is the potential for mediation," Glaser said. "The best thing for the taxpayers is to work this out. We are going to work this out."

Nobody will lose water service as the flap continues, but "there has to be a solution that works. We just want resolution," Sanders said.

Glaser said Lexington has contacted Rep. Donald Raleigh, R-Circle Pines, to secure some federal infrastructure money.

"If we had treated water, we could end this," Glaser said.