Last week I finally got the septic tank installed. It is 1000 liters biological one with two compartments. After the bacteria acts in the first stage, water moves and filters in the second one to finally be released to the ground.
It took only a couple of hours to digg the trench, add all rhe pipes and, burry back the whole system. Yes, no air is coming out so we can avoid potential smels, we were told about that from the professionals but still we decided to get the tank quite far away from the house.
Here you van see the draining water hose after the cleaning process is done. The trees around have constant waterng.
An additional benefit you get from this system is no maintenance for almost 25 years for a family of three. We intend to spend only several months a year so I suppose we may get even a longer period than that.