Our tank was emptied on the 17 Oct.2017. We had a sewer backup on 19 January 2018. We had to tear down part of the ceiling and walls and rip up the carpet. WHAT A MESS !!!
We hired a plumber to clear the pipe thinking that was the problem. Two weeks later another flood. Deducing the problem was the tank, we had Gascon back to empty it again less than 4 months later. The filter and the pipe exit from the house were both blocked.WOW! Great job Gascon...Now we have to repair...