Water districts in Gardiner and Hallowell may vote to merge by mid-December, setting off a process that could take another year to finish.

A consultant for the districts said if they merge — a possibility they’ve studied since 2009 — their 4,100 customers shouldn’t see much of a change in service. But doing so would require the Legislature’s approval, which would be followed by referendums in Gardiner, Hallowell, Farmingdale and Randolph, where nearly 99 percent of the utilities’ customers live.

The Gardiner and Hallowell districts have cooperated for years. A report for the district prepared earlier this year by Frank O’Hara, a consultant from Planning Decisions, said the two districts have a purchase-and-sale agreement for water and share labor and equipment for repairs and other duties. Hallowell contracted with Gardiner earlier this year to get an employee to help monitor natural gas expansion in the city.

On Wednesday, O’Hara said the district boards should finish presenting their plans to municipal boards in ratepayers’ cities and towns in the first half of December, collecting public comments and concerns ahead of a Dec. 17 meeting of the two district boards. At that meeting, they could decide initially to merge, O’Hara said.

The change is expected to provide administrative efficiencies, with one superintendent running the new district, which could be called the Central Maine Water District. Paul Gray now runs the Gardiner district and Dennis Kinney is in charge in Hallowell. That’s the smaller district, serving just 830 customers, which would be only about a fifth of the customers in a combined district.

What it wouldn’t change — in the short term, at least — are rates.

“We’re promising stable rates — not a rapid hike, but not reductions either, because there’s a lot of infrastructure that needs to be fixed,” O’Hara said.

If the boards approve the merger next month, they’ll need to get a bill through the Legislature and hold referendum votes, which O’Hara said would happen in 2015 if all goes as planned. If the plan is approved, the new district probably would take effect on the first day of 2016, he said.

The districts, which now are governed by three-person boards, are proposing a five-person board for the new district, with two members from Gardiner, which would have 46 percent of the combined district’s customers. Hallowell, Randolph and Farmingdale would get one member. Pittston and Chelsea, where just total 83 customers of both districts live, wouldn’t be represented under the district’s plan.

The plan, which could be changed by the Legislature, also would change the way board members are elected. City and town councils appoint members now; the boards now want to have directly elected representatives.

Hallowell’s district has merged services before, with mixed results. In 2007, the Greater Augusta Utility District took over the city’s sewer system, but their relationship has been contentious. In 2013, the city lost a lawsuit against the district after claiming Hallowell ratepayers were being overcharged for Augusta-specific work.

O’Hara said while the water district merger makes sense for the districts, it’s never easy to change entrenched institutions, and there could be problems later that can’t be seen now.

“There’s always issues that come up that aren’t always public policy issues, but they might be personality issues,” he said.

Michael Shepherd — 370-7652

mshepherd@centralmaine.com

Twitter: @mikeshepherdme