A "sh*tty" job

We came across our first major glitch and realized why the house was settling in one corner. As Rob, our contractor, was digging for the foundation, he discovered that the house was built on top of an old septic tank! The result: a 7' wide x 8' deep hole with some 'remnants.' After filling it with 8.5 yards of concrete, the only hole left now is in our pockets. The digging continues and we're praying for no more surprises...