This thread caught my attention! On our quarter-acre (although rural) lot, the only place we could find for our enclosed chicken run- the one attached to their night coop- was right smack over the septic tank pump-out access. We only need to get it pumped every 3 years or so, and next time we do, it's "clean out the ol' run really well!" time. We're probably the only people who need to clean up before the septic tank pump-out guys come over.
I had it pumped right before we got our chicks in April 2012, and the guys and I hung around and talked chickens while they pumped! So that was fun.
I put landscaping fabric over the tank tops, and then about 12 inches of wood chips. I scrape the top 3-4 inches off every 4 months or so and put it in the compost, then put fresh chips on top. Necessity is the mother of invention, and all that.
I put an electric poultry fence around the drainfield,. The 14 chickens and 4 ducks have that to free range on, and also have part of the backyard too, for during the day. So far, I've be able to keep them from slaughtering all of the grass on the leach field. The geese were pretty hard on it, though. (They moved to a bigger farm in the country.)
Congratulations to Quailsong on becoming a homeowner- best thing we ever did. 25 years later, my husband says (a bit ruefully?) that it's his life's work.... but, we do have people walking by on the road calling compliments to us all the time- so we are doing something right, or at least pretty....