The Norwesco 1500 gallon one-compartment septic tank is built low and wide so it drops into a shallow excavation where headroom, a high water table, or a shallow ledge would rule out a tall vessel. At 51 inches tall on a 69-by-157-inch footprint, it sets into a shallower trench than a standard 1500-gallon septic tank, which is the single reason most installers reach for this SKU. It is rotationally molded in green polyethylene as a one-compartment vessel and carries IAPMO certification, the listing inspectors look for when a plastic septic tank goes in the ground.
Will it work for your install
This is a 1500 gallon single-compartment septic tank measuring 157 inches long, 69 inches wide, and 51 inches tall. It ships with loose plumbing, and the technical drawing on this page calls out the outlet plus a 1-inch top-of-outlet tee. Set that tee to your line elevations during install rather than working around a fixed factory configuration. Filled to capacity with water it weighs roughly 12,510 pounds. Spread over the 69-by-157-inch footprint, that is on the order of 165 pounds per square foot of bearing load when full, so the excavation bedding and native soil have to carry that mass evenly - set the tank on properly compacted bedding, never on point loads or rock. Norwesco does not publish a specific-gravity rating on this tank because it is a domestic-wastewater septic vessel, not a chemical-storage application. For depth-of-bury, riser, and inlet/outlet elevation planning, the Tank Sizing Calculator and Tank Sizing Guide help you confirm the tank suits the field before the hole is dug.
Plumbing, approvals, and the mistake to avoid
Because the plumbing arrives loose, the only factory-called-out connection is the 1-inch top-of-outlet tee. The inlet baffle or tee, riser, and any gaskets or grommets are not listed as included, so plan to supply and field-set them to your own line elevations and local code. The most common install error is tying in the outlet without confirming the tee elevation and the burial and cover requirements your local code and the IAPMO listing assume. IAPMO is the listing inspectors look for on a plastic septic tank, so confirm your local code accepts the IAPMO listing before you dig. For how the inlet, outlet, vent, and overflow tie together, walk the Tank Plumbing System Design walkthrough. If you are installing in Canada or near the border, the Norwesco IAPMO and CSA B66 Septic Tank Approvals guide explains how the IAPMO listing maps to CSA B66 and US plumbing codes. Crews running these low-profile units in the field will also find the Norwesco low-profile series field operations guide useful for handling and placement.
Freight
This tank ships LTL freight, quoted live to your ZIP from the nearest of six Norwesco plants - Lancaster, OH, Owego, NY, Shawnee, OK, St. Bonifacius, MN, Tooele, UT, or Washougal, WA - which keeps the freight leg as short as possible on a vessel this size. Listed at the price shown, with freight quoted separately to your address. Get a freight quote with the Freight Cost Estimator or call 866-418-1777 and we will quote it to your ZIP.
