148 ft of water is ~64 psi (4.4 bar). Challenges are probably not so big once the thing is constructed. External earth and groundwater pressure offsets interna

148 ft of water is ~64 psi (4.4 bar). Challenges are probably not so big once the thing is constructed. External earth and groundwater pressure offsets internal water pressure I would assume and the real challenge is actually designing for when the thing is empty so that it doesn’t fail due to external loads. Lots of this is dependent on geology of the adjacent soil and geometry of the hole. Pictures seem to show sheet piles so we know it’s soil.