OLD ORCHARD BEACH —The town of Old Orchard Beach has moved a step closer to approving restrictions on medical marijuana production facilities that would provide commercial space for caregivers to grow the drug.

The Planning Board voted 3-1 Thursday night in favor of ordinance changes that restrict commercial marijuana production facilities to specific zones, outline a process for review by town officials and limit the number of caregivers who can grow the drug in a single building.

The move to change the ordinance was prompted by a local man’s plan to open a facility for research and development on the therapeutic use of cannabis while providing space for registered caregivers to grow the drug.

Old Orchard Beach is one of the first Maine towns to grapple with how to regulate clusters of marijuana growers using commercial buildings. In November, York voters approved new rules restricting where growers can operate and prohibiting more than one grower from using a single property. Those changes stemmed from a legal fight over a warehouse where nine caregivers rent separate units to grow marijuana.

State law bans small-scale caregivers from collaborating or forming collectives for larger scale cultivation or distribution. But it doesn’t prohibit multiple caregivers from growing marijuana in the same commercial facility.

Marietta D’Agostino, state program manager for medical marijuana, said it is “somewhat common” for her program to receive questions and complaints about collectives, which are prohibited under state law. State medical marijuana regulators are prohibited by law from providing details of suspected collectives to any entity except law enforcement.

“Just because you have multiple people renting separate secure areas in one building doesn’t make them a collective,” D’Agostino said. “As long as they are not sharing space, then it meets the letter of the law.”

There are 1,704 caregivers registered with the state. The state does not track whether they grow marijuana in their homes or on commercial properties.

The review of Old Orchard Beach policy was prompted by a proposal from Pierre Bouthiller to convert a former post office building on Saco Avenue into a secure facility for medical marijuana growers. The building would provide separate space for each grower and a research facility to study the medicinal effects of marijuana.

After Bouthiller first asked town officials about his plan, the Town Council in July enacted an emergency 60-day moratorium on the cultivation of medical marijuana in commercial facilities to give town officials time to develop rules outlining what zone would be most appropriate for that type of business. The council has since extended the moratorium three times.

An initial outline of the proposed changes would have limited production facilities to the General Business District 1 – the zone that allows the widest range of businesses – but three planning board members supported extending that use to the second general business zone and a zone intended for mixed-use development. Dispensaries still would be limited to General Business District 1.

Board member Win Winch cast the lone vote against the change, citing concerns about the density of the second business zone and the potential for odors that might bother neighbors.

Under the proposed changes, no more than four growers would be allowed to use a single production facility, and each facility must be at least 250 feet away from schools, churches, parks and day care centers. Any sign with the word “marijuana” or an image of the plant would be prohibited.

The zoning changes require each production facility to be located at least 250 feet from a similar facility to “prevent a concentration of these facilities and help ensure compliance with the state prohibition against collectives.”

The changes do not apply to caregivers who grow marijuana in their homes.

A public hearing before the Planning Board’s vote drew few comments from residents. Bouthiller spoke in favor of allowing production facilities. Three other residents asked questions of board members and praised the restriction on signs on the outside of marijuana production facilities.

“There is no need for advertising,” resident John Bird said.

The vote by the Planning Board was to recommend adoption of the changes, which ultimately must be approved by the Town Council.

Bouthiller, who was upset the second business zone had been excluded from the initial proposal, said he was happy with the Planning Board’s recommendation.

“It’s a very solid step forward,” he said.