Down the Drain

"We're #1 in the #2 Business". So proclaims a local business that will clean out the tanks in the photo below. Yes, these are the septic tanks, and this is the place to where all the dirty business will flow out of the house. The next step in this process is to create the leach field, which is a series of tubes (much like the Internet, according to Alaska senator Ted Stevens) set in gravel and sand, which will allow liquid flowing from the system to slowly percolate and be cleaned by some sort of bacterial magic. We're in the process of determining what will be the best plantings to place over the field. Here's what we know so far: trees and other things with deep moisture seeking tap roots can plug the perforated tubes that comprise the field. And, we don't want to be operating heavy equipment frequently over this area. I'm thinking a bunch of Little Bluestem might be a nice way to cover the area. Any feedback from botanical experts, or anyone who's had experience in this area?