SEARSPORT, Maine — A consultant hired by the planning board to provide an independent economic analysis of the effect a 23-million gallon liquid propane tank would have on the town said property values could be diminished, depending on the proximity of homes to the tank.

Nancy Fannon of the firm Meyers, Harrison and Pia LLC said among industrial developments, oil and gas facilities have a significant, negative effect on property values.

At the same time, she said that since DCP Midstream’s tank is planned for an existing fuel tank “farm” of some 31 tanks, the effect could be understood as incremental.

“Adding incrementally to an already industrial zone has an incremental effect,” she told the board.

Fannon later acknowledged that since the DCP Midstream tank, at 110 feet in height and visible from U.S. Route 1, would be different in character from the other tanks. None of the other tanks are easily seen from Route 1.

She said homes at a distance of two miles from the tank would see no reduction in value, while those within half a mile would lose 8 percent of value.

Fannon explained that her analysis focused, as requested by the board, on the project’s effect on municipal services, property values, tourism and property taxes.

Most of her work drew from existing studies of industrial developments such as wind turbines, electric transmission lines, toxic waste sites and nuclear plants. Such developments brought environmental risks, noise, traffic, distorted scenic views and safety concerns.

She concluded the tank would have a minimal effect on municipal services, with just the police department incurring the hiring of two more officers at $85,000 for each in the first year and $55,000 for each in subsequent years.

“The town believes it will have only a modest increase in municipal services related to the project,” she said.

The tank’s effect on tourism would be similar to the effect on property values, Fannon said, again noting that the project “will not be alien to the landscape,” describing the setting as “an industrial backdrop.”

Property taxes now assessed at a mill rate of $19.80 could drop to $17.95 with the $50 million new facility, she said. But factoring in additional town spending and the reduction of property taxes would likely leave the mill rate at $18.61, she said.

Jamie Kilbreth, the attorney for DCP Midstream, argued that fuel tanks such as those in South Portland and the Wyman Station power plant on Cousins Island in Yarmouth have not diminished home values.

Ed Bearor, an attorney representing Albert “Buddy” Hall, owner of Angler’s Restaurant and Bait’s Motel, which abut the tank site, argued that the tank would be closer to his client’s businesses than to the other, existing tanks.

Fannon conceded after being questioned by Bearor that Hall’s property would sustain “significant” negative effect in value. An assessor’s review of Hall’s properties concluded that the businesses and real estate, now valued at about $897,000, would lose more than $748,000 in value if the tank is built.