The Norwesco 225 Gallon Underground Septic Pump Tank is a black polyethylene below-grade tank built to hold effluent for pumped septic systems. The numbers to plan around: 225 gallon capacity, 50 inch height, and a square 48 x 48 inch footprint that drops into a smaller, shallower excavation than a long horizontal tank of the same volume. If you are spec'ing a pump chamber, dose tank, or added underground septic capacity, this is the tank buyers reach for when they search "underground septic pump tank" by the Norwesco name.
Will it work for your install?
Key specs: 225 gallons, 50 inches tall, 48 x 48 inch base. Filled with water this tank weighs about 1,876 pounds, and that number does double duty. It tells you the bearing load your bedding carries once the tank is full and operating, and it is the reference point for flotation planning: an empty polyethylene tank is light enough to float in saturated soil or a high water table, so you size your anti-flotation measures against the difference between that ~1,876 lb operating weight and the empty shell. Set the tank on a level, compacted, rock-free base, and backfill evenly around all four walls so they are supported as the chamber fills. To match pump-chamber volume to your dose cycles, run the numbers through our Tank Sizing Calculator, and the Tank Sizing Guide walks through how to think about capacity for a septic application. For exact inlet, outlet, and access-riser placement, see the technical drawing on this page before you set grommets or bulkhead fittings.
Codes and approvals
Septic tank acceptance is driven by local plumbing and health-department codes, and approvals vary by jurisdiction and by country. Before you order, confirm this tank meets the requirements where you are installing it. Our guide on Norwesco IAPMO and CSA B66 Septic Tank Approvals covers the Canadian cross-border scope versus US plumbing codes so you can check the approval landscape before committing.
Freight and how to order
This tank ships LTL freight from Griffin, GA, so your quote is driven by the distance from Georgia to your site. Get a real number before you buy with our Freight Cost Estimator, or call 866-418-1777 and we will help you confirm sizing, approvals, and the freight cost to your ZIP. Listed price is before freight.
