We travel with two dogs, and always tote the doggy bag when we take them for a walk, so we never leave waste behind. If I was going to be at that park for a month, I might consider the fee. However, I would most likely go elsewhere, feeling as though I am paying for the bad apples. Why not place security cameras in the most troublesome locations? They're cheap. You get a violator, go back to the video and you have your man, or dog. BTW, I'm going to guess the turnaround time for the DNA sample is at least a week, maybe 2, not including the fecal shipping. Video seems much more practical and time efficient.