Brian, running oversized air line is far cheaper than electric. A long run on the electric will increase the amp load and require a heavier guage wire as well. I would say 10 guge wire would be the safe minimum size.

Adding a properly designed aeration system will definately help deacy the detritus faster than without it. If your watershed is farmed land, I suspect you have a large amount of soil in there as well. Largebuffer strips for the run-off to flow through will reduce this a great deal.