Orchard Park is a nice township park with a few fields, tennis courts, basketball courts, and a baseball diamond. The Edgar Felix Bikeway Trails trail runs next to the park as well.
One day in 2008, we found a group of people gathered in a field/open grassy area letting their dogs run around without a leash. They said that they were all from a Meetup.com dog walkers group and met at Orchard to let their dogs run and play. They also mentioned that this was a well known place to come and let your dogs out for a run. But with no fence or sign that this was a "dog area", I was not comfortable doing that myself.
Since that visit, a handful of other people have mentioned that Orchard Park has a "dog park". Though the Wall, NJ website does not mention anything about it, locals seem to love coming here for some play time with their pets :)