This map shows service areas for Fairfax Water and other water systems operated by municipalities in Fairfax County. Each lightly shaded area shows where municipal water utilities serve Fairfax County residents. (Fairfax County Board of Supervisors)

CORRECTION: The town of Vienna is not dismantling its water utility, but it is going to buy its water from Fairfax Water and has dismissed its suit against Fairfax County.

Fairfax City authorities said Monday that they are ready to get out of the water business. After operating its own water utility for many years, and charging rates far higher than those charged to Fairfax County residents, Fairfax City has reached a tentative agreement with the Fairfax County Water Authority to join the county water system. The city says this will provide its residents with cheaper, higher quality water.

And this could be the third and final battlefront to end in what was a very messy war between Fairfax County and the independent water utilities operated by Falls Church City, the town of Vienna and Fairfax City. At this time last year, all four parties were either issuing declarations or filing lawsuits over water. Now Falls Church, Vienna and Fairfax City have all taken steps in recent months to dismantle their water utilities and join Fairfax Water in one large water company that would serve everyone in Fairfax County.

Fairfax City will have to pay Fairfax Water $20 million to join its system, City Manager Robert Sisson said. But the city hopes to sell its own reservoir and treatment plan in Loudoun County and recover most if not all of that cost. The city plans to have public hearings on March 21 and April 6, and then its city council will vote on the idea on April 9. If approved, “Fairfax City would get out of the water business,” Mayor Scott Silverthorne said.

This will end a water rate disparity that has existed, and angered many, for years. In 2011, one study showed, Fairfax Water residential customers had an average quarterly bill of $57.31. But Falls Church customers, including 30,000 actually located in Fairfax County, paid $86.55 per quarter. Vienna customers paid $100.16 per quarter (its county residents paid even more) and Fairfax City customers paid $103. Fairfax City has about 8,300 customers in the city, and about 3,250 in the county, though the city expected that number to dwindle.

The dominoes started to fall in September, when Vienna announced an agreement to begin taking Fairfax Water water, and connect to Fairfax completely by 2015, at a cost of $15 million. In November, Falls Church, which had been battling Fairfax County in the courts for years, agreed to sell its utility to Fairfax for $40 million, subject to a voter referendum this November. And now Fairfax City is trying to get on board.

“Hopefully, in the end,” said Fairfax Board Chairman Sharon Bulova, ”we’ll have peace on earth with uniformly low rates and improved delivery of water to all of our residents within the footprint of Fairfax County.”

Fairfax City Mayor Scott Silverthorne and City Councilman Dan Drummond discuss the possibility of ending the city's own water utility and joining with Fairfax (County) Water. (Tom Jackman/The Washington Post)

The peace on earth was partly brokered by U.S. Magistrate Judge Theresa C. Buchanan, who was thrown into the middle of a complicated federal lawsuit. Tired of seeing Fairfax County residents pay much more for water just because they were served by Falls Church, Vienna or Fairfax City, Bulova and Fairfax County issued a decree (or “ordinance”) that the county would set the water rates for all of its residents. Falls Church, Vienna and Fairfax City responded by suing Fairfax County.

The county and the municipalities went into mediation with Buchanan, and both Falls Church and Fairfax City credited her with helping them reach agreements with Fairfax County.

Fairfax City was in a tough spot. Its 50-year-old treatment plant in Ashburn and 23-mile transmission pipe to Fairfax City need a $45 million upgrade, which would require a bond referendum, at additional cost to its customers. In 20 years, the plant would need to be replaced, at a further cost of an estimated $84 million.

At present, Fairfax City is charging its residential customers $4.61 per 1,000 gallons, compared to Fairfax Water’s rate of $2.51. At an estimated use of 100,000 gallons per year, that’s $461 for city residents and $251 for county residents. With annual cost increases of seven percent plus the bond issue, the city’s annual cost was estimated to rise to $894 per residential customer, versus about $340 for Fairfax Water.

In addition, Fairfax Water has already upgraded its treatment facilities, and any further costs would be spread over a much larger customer base than Fairfax City’s 11,500, of which about 1,300 are commercial users. “This is putting money back in people’s pockets,” city Councilman Dan Drummond said, “with cheaper, higher quality water and with more certainty in the future.” He said it was equivalent to a 10-cent reduction in the real estate tax.

“This is a good deal for anyone who gets water from us,” Drummond said. He and Silverthorne acknowledged that many city residents had a sense of civic pride about the city running its own water system, but since they have an option to go cheaper and cleaner, they are putting it out to the public. If approved, rate changes still might not be seen until 2015.

This is not about Fairfax Water becoming a monopoly, by the way, because there wasn’t true competition for water in the first place. You pretty much get the water that serves your neighborhood, and that hasn’t changed for a long time in Fairfax County.

Vienna is already on board. Now the citizens of Falls Church and Fairfax City will decide if the Great Water Wars of Fairfax County truly are over.