The Norwesco 1000 Gallon Multi-Use Underground Liquid Storage Tank (SKU N-41820) is the IAPMO-approved body built for buried service, molded from heavy-wall polyethylene in blue. At 1,000 gallons it stands 63" tall and runs 60" wide by 102" long, giving a 60" x 102" footprint to plan your excavation around. This is the underground 1000 gallon Norwesco that crews search for when they need belowgrade storage that carries the IAPMO listing for plumbing-code work rather than a surface tank dropped into a hole.
Will it work for your site?
Use the 63" x 60" x 102" envelope to size your excavation, bedding, and backfill before the tank arrives. Filled to capacity with water, this tank carries roughly 8,340 lb of liquid load, so the surrounding soil and any pad or anchoring detail has to be designed for that mass on top of burial loads. Underground polyethylene tanks rely on proper bedding and uniform backfill to resist soil pressure, so treat the excavation as part of the install, not an afterthought. The Tank Sizing Calculator and Tank Sizing Guide help you confirm 1,000 gallons matches your draw and refill cycle before you commit to digging.
What this tank is rated for
The "Multi-Use" designation paired with the IAPMO approval makes this a code-recognized underground liquid storage body. The specific-gravity rating is marked "No," which means it is not published with a heavier-than-water SG rating, so keep it to water and water-like liquids rather than dense chemical service. If your project sits in a Canadian or cross-border jurisdiction, the Norwesco IAPMO and CSA B66 approvals guide walks through how these listings map against US plumbing codes. For rural fire-water or reservoir planning, the fire-water reservoir design guide covers NFPA 22 sizing discipline and freeze protection for cold-climate sites.
The mistake to avoid
The most common error on a tank like this is treating an underground IAPMO tank like an aboveground one. Because the SG rating is "No," do not press it into dense-liquid or chemical duty it was never published for - confirm your application is water or a water-equivalent liquid. Confirm the actual fitting and inlet configuration with us before you trench plumbing to the tank, since outlet placement drives your pipe runs. Then check the published height, width, and length one more time against your excavation plan; the buried footprint is unforgiving once the hole is dug.
This tank ships LTL freight from the Norwesco plant in Hanford, California, quoted live to your ZIP - a Northeast or Midwest delivery should plan for real cross-country LTL cost. Get your number from the Freight Cost Estimator or call 866-418-1777 to confirm specifications, fitting layout, and delivery before you order.
