The Norwesco 1500 Gallon Two Compartment Septic Tank is a low-profile, IAPMO-certified polyethylene tank built for septic systems where burial depth and trench geometry matter. At 51 inches tall with a 69 x 157 inch footprint, it holds 1,500 gallons across two compartments in a single green polyethylene body, giving you the dual-chamber settling and clarification a code-compliant septic system needs without the depth of a taller tank.
Will it work for your install?
This is a dedicated low-profile septic tank, not a general-purpose storage tank. The two-compartment design separates the primary settling chamber from the secondary clarification chamber, which is what most plumbing codes and the IAPMO listing require for residential and light-commercial septic service. It carries no specific-gravity rating and is intended for septic effluent service only, so do not repurpose it for chemical or high-density liquid storage. The tank arrives with loose plumbing, meaning the plumbing is supplied to be configured on site rather than pre-installed. The technical drawing on this page documents the 20-inch lid and the outlet, plus the exact dimensions for laying out your excavation and tie-ins; confirm the exact loose-plumbing components, inlet provisions, and any gaskets with us at 866-418-1777 before you spec your tie-ins. Because it ships with loose plumbing, plan your connections before the tank is set; our tank plumbing system design walkthrough covers how those connections fit together. If you are weighing chamber count for your flow and bedroom count, the single compartment vs two compartment septic tank guide and the Tank Sizing Calculator will help confirm 1,500 gallons across two compartments is right for your site.
Certification and code scope
This tank carries the IAPMO certification, which matters for permitting and inspection. IAPMO listing scope and how it relates to Canadian CSA B66 and US plumbing codes is covered in our Norwesco IAPMO and CSA B66 septic tank approvals guide. Confirm with your local authority that an IAPMO-listed polyethylene septic tank is accepted in your jurisdiction before you buy, since acceptance of plastic septic tanks varies by county. The low-profile geometry is the same engineering family Norwesco uses across its low-profile line; our Norwesco low-profile series field operations and procurement guide has more on how these bodies are specified.
Weight, handling, and the mistake to avoid
Empty, this is a manageable polyethylene tank, but filled to 1,500 gallons it carries roughly 12,510 pounds of water weight, so your bedding, backfill, and anti-flotation provisions have to be sized for a tank that heavy in service. The most common mistake on a low-profile septic install is under-preparing the excavation: a shallow, wide tank needs level, well-compacted bedding across the full footprint, with the 157-inch length and 69-inch width as the two trench dimensions to lay out, plus proper backfill to resist flotation in high water tables. Set it on uniform bedding, follow Norwesco's burial and backfill instructions, and do not overlook the loose plumbing step before the tank is covered.
This tank ships LTL freight, quoted live to your ZIP code. It ships from the nearest Norwesco plant to you among Lancaster, OH; Owego, NY; Shawnee, OK; St. Bonifacius, MN; Tooele, UT; and Washougal, WA. Get your freight quote with the Freight Cost Estimator, or call us at 866-418-1777 to confirm plant of origin, lead time, and offload requirements. For sizing help, see the Tank Sizing Guide.
