ROCKLAND, Maine ― A lottery system could determine which six vendors can operate recreational marijuana stores in the city. Rockland City Council is expected to vote next month on regulations that will outline how and where recreational marijuana stores can operate in the city. Through these regulations, city officials are trying to get a head start on establishing a municipal process for these businesses to open and operate as the state begins to accept applications for retail marijuana stores. The regulations being considered by the council would limit the number of retail marijuana stores operating in Rockland to six, Rockland City Manager Tom Luttrell said. Preference would be given to the four medical marijuana businesses that have been approved to operate in Rockland within the last year.