The Norwesco 120 Gallon Black Vertical Storage Tank (SKU 40318B) is a compact polyethylene vertical tank built for above-ground water storage where floor space is tight. At 38 inches square on the footprint and 31 inches tall, it holds 120 gallons in a stable, low-profile cylinder. The black resin blocks sunlight, which limits algae growth in standing water - a practical reason buyers running irrigation supply, rural water reserves, transfer-and-fill setups, or stored-reuse water like greywater, captured rainwater, and HVAC condensate choose the black tank over a translucent one for this norwesco vertical storage tank.
Will it work for your job?
This is a 120-gallon vertical storage tank with a 38 x 38 inch footprint and a 31-inch height, so it fits under most eaves and inside utility rooms or on a trailer deck. Plan for clearance above the 31-inch top for the lid and fill, and treat the 38-inch square as the minimum fully-supported pad or deck dimension. Full of water it carries roughly 1,001 pounds, and the tank is rated to a 1.5 specific gravity, meaning it can safely hold contents weighing up to about 1,501 pounds. That specific-gravity headroom is the figure to check before you store anything denser than water - run your stored liquid's weight against the 1,501-pound rated ceiling, not just the gallon count. The drawing shows a sump with a 4-segment base and a revised lid thread; see the technical drawing on this page for the molded-in fitting and lid detail. A threaded lid and any sump or bulkhead outlet need a matching gasket or seal sized to the as-molded thread, so confirm the thread on the drawing before you order adapters or a pump fitting. If you are matching this tank to a daily-demand or reserve volume, the Tank Sizing Calculator and Tank Sizing Guide will help you confirm 120 gallons is the right step.
Mounting and pad
A vertical tank this size wants a flat, fully supported base. With more than half a ton of water bearing on a 38-inch square, the load needs an even surface - a level concrete pad or a continuously supported deck, not point supports. Our guide on concrete pad sizing for above-ground polyethylene tanks walks through the ACI 360R-10 framework if you are pouring a new pad. For rural water-reserve and fire-supply planning, the fire-water reservoir design guide covers freeze protection and NFPA 22 sizing discipline for cold-climate sites. If you are aggregating greywater, rainwater, or condensate, the industrial water-reuse tank topology guide covers quality-banded storage trains.
The mistake to avoid
The common error on a small vertical tank is treating the 1.5 specific-gravity rating as a license to fill it with any heavy liquid. The rating sets a weight ceiling, not a chemical clearance - and this is a water-service tank. Confirm your liquid's weight stays under the 1,501-pound rated contents figure, and seat the tank on a base that supports the full 38-inch footprint so the molded sump and base segments are not bridging a gap. Skipping the level base is what cracks a poly tank, not the water itself. If your stored liquid's weight approaches or crosses the 1,501-pound ceiling, this is not the right unit - call 866-418-1777 and we will size a higher-rated tank for the load.
This tank ships LTL freight, quoted live to your ZIP from the nearest Norwesco plant - for this SKU that is Fairfield, TX; Griffin, GA; Hanford, CA; Lancaster, OH; Owego, NY; Shawnee, OK, or Sheldon, IA. Because Norwesco molds at plants across the country, freight is quoted from the closest one to your ZIP, which usually shortens the LTL lane and lowers the rate. Get an exact figure with the Freight Cost Estimator, or call us at 866-418-1777 and we will quote the freight and confirm the fitting layout before you buy.
