The clay should seal around it. What will you do if the runoff water is more than the sheetpiling can hold back? I'm assuming that they will use a pneumatic hammer to install it?

As for cost, I haven't a clue. Dad and I installed something like that at the lake house in the late '70's. It's somewhere between 1/4" and 3/8" thick. We installed it using a garden hose and a piece of copper pipe. We washed it down, stopping about 6"-12" above where we wanted the level to be and used sledgehammers to pound it down.

IIRC the pieces are about 6'-8' long. We capped it with 3"x3" or 4"x4" 3/16" or 1/4" thick angle.







Stainless ladder.

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