The plumber is a reliable and experienced guy. The dirt needed to remove is again less than the estimation.
We did dig 3m deep and 8m width. It really looks like a little (much deep) pool for two water tanks
We still left over dirt. Hopefully, JD will help to remove it very soon. I just was unhappy with their communication but VERY happy with their price and work quality.
That dirt is supposed to use for fill the tank. Hopefully, that amount will be right estimation, otherwise we have more dirt to remove
1) install the tank
2) fill the tank
****3) decide which level of the area behind the tank should be our best choice