Following their model, I'm guessing that a built-in-place ferrocement tank
would outperform them all in a similar analysis. Certainly much less
cement, sand and steel, assuming they are talking about a massive type
cast concrete tank rather than ferrocement.
Wattle and clay tanks maybe instead of strawbale and plastic liner...I
once found some info and pictures online for some traditionally made ones
in Africa...
John Schinnerer - MA, Whole Systems Design
------------------------------------------
- Eco-Living -
Whole Systems Design Services
People - Place - Learning - Integration
john@eco-living.net http://eco-living.net