LYNN – Garelick Farms plans to bring a mobile wastewater treatment plant to its Lynnway facility as a possible remedy to the pervasive stink that has plagued the city’s waterfront through most of the summer.”They’re working on it,” said Michael Donovan, director of the city’s Inspectional Services Department. “They filed for and have received a building permit from the city to construct a concrete slab where they set up the equipment.”Donovan said a tractor-trailor truck will park on the slab, its equipment connected to the dairy. “That will allow them to run their wastewater through the mobile processing unit,” he said.The permit was issued Monday for the 21-foot square slab.Earlier this month the city threatened to file a criminal complaint against the company unless it found a solution to suppressing the stench. Garelick has claimed it tried six times to fix the problem.The odor drove merchants indoors and forced motorists along the Lynnway to roll up their windows. It also proved a municipal embarrassment at a time when the city is attempting to develop its waterfront.