The Norwesco 300 Gallon Deep Bury Septic Pump Tank is a polyethylene tank built for below-grade septic and pump-chamber service where a compact, deep-burial footprint matters. It holds 300 gallons in a near-cubic body measuring 51 inches in height, width, and length, giving you a 51.0 x 51.0 inch footprint to plan your excavation around. As a deep-bury design, it is intended to be installed below grade for septic and pump-chamber duty rather than set on a pad or above grade.
Will this tank work for your install?
For a 300-gallon pump tank, the body geometry is the first thing to confirm: at 51 inches square, this tank needs a square excavation roughly that size plus working room for backfill and bedding. Filled to capacity it carries 2,502 pounds of water alone on the bedding, on top of the backfill and any water-table uplift acting on a buried tank, so your bedding and backfill have to be properly placed and evenly compacted to carry those loads over time. Use the Tank Sizing Calculator and the Tank Sizing Guide to confirm 300 gallons is the right pump-chamber volume for your daily flow and pump cycle before you order.
Septic and pump-tank approvals
Septic and pump tanks live and die by local code, and approvals are not universal across jurisdictions. We do not list a specific state septic approval for this model, so confirm acceptance with your local health or permitting authority before you commit. Our guide on Norwesco IAPMO and CSA B66 Septic Tank Approvals walks through how these listings work and where their scope ends, so you do not assume a listing covers a use it was never tested for.
The mistake to avoid
The most common error with a deep-bury pump tank is treating burial depth and backfill as an afterthought. A tank intended for below-grade burial still depends on correct bedding, even compaction, and adherence to the manufacturer's burial instructions to handle ground and water-table loads. Confirm your excavation depth, your inlet/outlet elevations, and your riser height against the manufacturer's installation documentation before the tank goes in the hole, because correcting any of that after backfill is expensive. We do not publish the as-built port and fitting layout for this model on this page, so match your plumbing connections and any riser or pump-access fittings to the manufacturer's specified port layout rather than assuming a standard configuration, and call 866-418-1777 to confirm the port and gasket configuration before ordering. Review the technical drawing on this page alongside the manufacturer's installation guide as you plan the connections.
This tank ships LTL freight from Shawnee, OK, quoted live to your ZIP code. Get a freight quote with our Freight Cost Estimator, or call 866-418-1777 to confirm fit, approvals, and freight before you order.
