Norwesco
Rotationally molded, one-piece septic, cistern, holding, and vertical storage tanks — a TankHolding brand, since 1980.
What LibertyCES specifies from Norwesco
Rotationally molded, one-piece, seamless construction, 200–10,000 gal. Legacy ribbed tanks carry a real hard constraint: must be kept full (or 1/4 full) at all times.
25–15,500 gal. Black/Dark Green line is explicitly rated water-only — not for chemicals, fertilizers, or any other product.
EPDM standard gasket with Viton offered "when EPDM may not be suitable" — a direct vendor acknowledgment of EPDM compatibility limits.
Frequently Asked Questions
Can Norwesco Black/Dark Green vertical tanks store chemicals?
No — per Norwesco's own catalog, verbatim: these tanks "are rated at 8 pounds per gallon, which means that they are for WATER STORAGE ONLY! They should not be used for chemicals, fertilizers or any other product." The dark color is specifically for limiting light penetration to reduce algae growth in water storage, not chemical compatibility.
What is the install constraint on Norwesco Legacy septic and cistern tanks?
Legacy (ribbed) septic tanks must be kept full at all times, and Legacy cistern tanks 600 gallons and larger must be kept at least 1/4 full at all times — the rib design relies on internal counter-pressure against external soil pressure, and getting this wrong can cause tank collapse.
When would I choose Viton over EPDM for a Norwesco bulkhead fitting?
Norwesco offers Viton as a standard option specifically "when EPDM may not be suitable for your application" — relevant for strong oxidizers like sodium hypochlorite, where EPDM has known compatibility limits versus fluoroelastomers.