SEABROOK — The potential abutters of a proposed methadone clinic in Seabrook have been adamant they don't want a facility that treats drug addicts anywhere near their Start Road homes or businesses.

They told selectmen recently they fear having the clinic and its opiate-addicted patients near them will increase crime in their neighborhood, be a hazard to their children playing in their yards and even decrease their property value.

But town officials have said if it follows regulations and conditions, they have little hope in preventing the clinic from locating in Seabrook. Given that the site for the proposed clinic is in the industrial zone off Route 107, and that Seabrook zoning permits medical facilities — like the clinic — in office buildings in that industrial zone, there isn't anything the town can do legally to keep this clinic out.

Although an abutter's lawyer asked selectmen to "put the brakes on the Planning Board" and order its members to deny approval, selectmen made it clear they couldn't and wouldn't. Under New Hampshire law, they noted, there is no role for selectmen in this process; jurisdiction belongs to the Planning Board.

Further, said Selectman Bob Moore, if the town decides to change its zoning to prohibit methadone clinics now, it might prevent future facilities from locating in Seabrook. But, he said, such changes would have no effect on the case currently before the Planning Board.

"The horse has already left the barn on this one," Moore said.

Hampton attorney John Ryan has expertise in the land use field, and although he's unfamiliar with the specifics of this methadone clinic case, he said Moore pretty much has it right.

"Speaking generally, if someone has a plan before the Planning Board with a disclosed use that's permitted, it's too late to make changes that can impact that plan," Ryan said. "The town can't make retroactive changes of that nature."

Local building inspectors and planning boards decide if a use is permitted after interpreting land use regulations when a plan is first filed, Ryan said. When uses are permitted, plans go before planning boards for site plan reviews to judge their compliance with the town's regulations or to make the needed changes to ensure conformity.

Planning boards can deny approval if the site plans don't comply, and they can approve if they do. They can even make approval based on a list of conditions the applicant must follow. But there are issues that are not intrinsic to planning boards' consideration when doing their reviews.

"In general, whether a permitted use impacts the property value of abutters is not relevant to planning boards in their consideration of site plans," Ryan said.

Seabrook is no stranger to appeals of its Planning Board's decisions to Superior Court when projects have been denied. The abutters to the proposed Seabrook Target development off Lafayette Road appealed the Planning Board's approval of that plan within a month of the board's final vote.

Abutters who appeal planning boards' decisions to the courts may do so on the basis of two issues, Ryan said.

"Direct abutters have the legal right to appeal a planning board's decision to the Superior Court," Ryan said. "But they have to prove the approval was either unlawful — that it legally shouldn't have been done — or unreasonable."

Direct abutters are those that border the development, he said. The farther abutters are from the site in question, the harder it usually is to gain legal standing with the court, Ryan said.

In addition, it is usually more difficult to prove a planning board's approval was unreasonable, he said.

"When appealing on the grounds an approval was unreasonable, there is a fairly sizable burden of proof to overcome," he said.

The Seabrook Planning Board is still reviewing the proposed plan for the methadone clinic and may continue its review of the plan on Aug. 5.