11/10/2011 7:11 PM
I purchased ConVault, double wall concrete units at my last gig for just over $25,000 for a double 500-gallon unit. My current course, we purchased double wall steel, 2,000 gallon tanks for about $4,000 a piece. A big difference in price. The steel will last you about 20 years with no issues. The ConVault, they'll be there long after you are gone. Either way, with them you need no containment pad. You can go with single wall as long as you build a containment around them, seal them, and do annual maintenance. In Florida, if you are under 550 gallons you aren't required to be inspected, etc....you might want to check with your state DEP to see what minimum requirements are if you want to fly under the radar.