NORWESCO septic tanks are available in 500-gallon to 1,500-gallon sizes. They are manufactured by means of the rotational molding process that produces a one-piece, seamless and watertight tank. The tanks are made with polyethylene, which is unaffected by soil chemicals and gases, so the tanks will not rust or corrode. NORWESCO septic tanks are backed by a full three-year warranty and have been approved by state and local health departments nationwide. NORWESCO, Card No. 199
