10-01-2009, 09:09 AM
Insurance requirements depend on the individual insurer. 10k is the standard however. We have been building ferrocement water tanks on the island since 1986. www.pacificgunite.com. They are fully enclosed, with a manhole. We build up to 100,000 gallons. You'll see our tanks in the Hawaii State rainwater catchment guideline book. Concrete has many advantages over plastic.