OK, in answer to the first couple of posts, this house was built in the 70's, so the tank has been in use for quite a while. Water backed up out of the basement washer drain so we called a plumber. They told us the tank was full & needed to be drained. Within three days we were back to where we started with the tank totally full, pushing water out of the cap to cover the tank by a foot or so in the hole I dug to get to the cap. Roto-Rooter has advised me that the drainage field must be saturated, but they will have to pump the tank again to make sure. If it fills up again (without any water draining from the house), then they want to dig up the leech field & replace it. This is house that I'm having the easement issue with, so far I haven't been able to reach the neighbor, but I'm going to try running into him this weekend to talk to him before sending the certified-letter-from-hell to him demanding the clearance of the property.