In a relatively placid community like Brookline, a quality-of-life issue like off-leash dog permits can become a full-blown controversy. That's not to diminish the strong feelings on both sides of the issue: Some dog owners are barking about the town's proposed charge for those who wish to let their pups roam leash-free in town parks. A year-long permit would cost residents $50 and non-residents $100, and professional dog walkers would have to pay considerably more. Residents and town officials have been trying for years to address a long-standing source of tension: how to accommodate both dogs and other park users. The number of licensed dogs has spiked over the past decade - it now stands at 2,100 - and so too have costs to maintain and clean the town's 14 parks. Because past efforts to mediate dog-related conflicts have broken down, the town wants to hire a park ranger. Ideally, Brookline could pay for the position through its general fund. But money is tight. Organized groups like sports leagues already pay for permits to use the grounds. While dog owners may see themselves as individual park users, the city can't afford to. Leveling a fee on dog owners that amounts to less than $1 a week is a better choice than simply ignoring one of the town's longstanding bones of contention. 