BATH, Maine — The Bath Planning Board on Tuesday unanimously approved the development of five condominium buildings along the Kennebec River, on the vacant site of the historic “Coal Pocket” property.

JHR Development — which has projects that include Brunswick Station and the Mid Coast Medical Group center at 108 Centre St. — received site plan, developmental subdivision and historic district approvals for the project.

The 4.6-acre waterfront parcel has about 1,000 feet of Kennebec River access, according to a CB Richard Ellis real estate listing from 2011, when the parcel was on the market. The 133 Commercial St. property also has Front Street frontage.

The property also was offered as two 2.3-acre lots, for $750,000 each. Hilary Rockett Jr., JHR president, has agreed to buy both from the David Mahoney Revocable Trust, which owns the property. The agreement was contingent on the project receiving city approvals; Rockett on Tuesday declined to disclose what the purchase price would be.

Forty condominiums will be developed in five buildings of eight units each, according to a June 11 memo from planning director Andrew Deci to the planning board. The first floors will have interior parking. Two buildings will have frontage on Front Street, and two on Commercial Street, while one will be between a Sewall oil company building and the riverfront.

“The amount of frontage on the Kennebec River is just spectacular,” Rockett said Tuesday before the meeting. “It’s clearly underutilized.”

Interest in the proposal has been significant, showing demand for that kind of project, the developer added.

Public reactions to the proposal were mixed, Deci said Wednesday. Some neighbors, particularly along Front and North streets, expressed concern about its size and scale, as well as its effect on their views of the river.

The two Front Street buildings were pushed back from the street and toward the river about 20 feet, to help address that concern, Deci said.

But there also were those who spoke in favor “on a more macro level, talking about the impact of 40 units within our downtown footprint,” the planner said, as opposed to a vacant gravel area.

Rocket said at the meeting that he hopes to begin construction within three months, Deci said.

In the late 1990s, the Coal Pocket was where the segments were cast for the Sagadahoc Bridge. A coal gasification plant operated on the property in the 19th century, and the gas was used for heating and cooking and to illuminate street lights.

The coal ash was left behind on primarily the northern end of the site. The Mahoney trust received city approval in 2007 to clean the site, and Central Maine Power Co. funded the cleanup. CMP was the last in a line of successors to the Bath & Brunswick Power & Light Co., which had operated the plant.