The initial functioning of a biodrying process on an 85 cow dairy farm in the New York City (NYC) Watershed is described. This system started operation in the fall of 2001. The startup challenges and preliminary operational data on the forced air system, and establishing a procedure for processing the manure are described. The objective is to use the heat generated by aerobic composting to provide the energy to reduce 12% DM manure to a 60% DM residual. Forced air composting, under a roof, with the airflow controlled carefully should optimize this process. Using forced air to compost four foot high layers of manure/amendment mix in 21 days have shown the feasibility of this process. Moisture loss, density changes, and porosity changes are shown.