Norwesco 525 Gallon Plastic Septic Pump Tank

Where it goes in the system

Septic tank first, pump tank second, drainfield last. The septic tank settles the solids; the pump tank receives the clear effluent and doses it to the drainfield in measured volumes set by the float switches. A 525 gallon chamber gives the installer room for a working dose plus reserve storage above the high level alarm, which is the volume the household has to live on while a failed pump is replaced. The tank is round, 64 inches across, so the hole is a circle plus working room, and at 62 inches tall it sets the invert depth the designer has to work to. Our guide to Norwesco septic tank approvals and how they map to US plumbing codes explains how state approvals, IAPMO and CSA listings differ and which one your inspector will ask for.

What to check before you buy

1. Your state. Norwesco lists this tank for septic use in Alabama, Georgia, North Carolina, South Carolina and Tennessee. Outside those states, confirm with your county health department before you order; a tank the inspector will not pass is not a bargain.
2. The dose volume. The design tells you the working dose and the reserve; together they have to fit inside 525 gallons with the floats where the designer put them. If they do not, you need a bigger chamber, not a smaller dose.
3. The openings. The 20 inch lid is the access we list. The inlet, the discharge and the conduit penetration are cut and sealed by the installer to suit the system; confirm the fittings and risers you need before the order, and ask us to put them on the same order.
4. Burial and groundwater. A polyethylene tank is light and wants to float when the hole is wet and the tank is empty. Backfill per Norwesco's instructions, fill as you backfill, and plan for anti-flotation where the water table is high. Norwesco's installation documentation, not this page, is the authority on burial depth and backfill.

Norwesco's drawing for the tank, linked on this page under Technical Drawing, shows the lid position and the body profile.

Related tanks

For waste that is held above ground and pumped out by truck rather than dosed to a field: the 300 gallon above ground septic holding tank. The 525 gallon spherical liquid storage tank shares the capacity but is a liquid storage tank, not a septic tank; do not substitute one for the other. The tank sizing calculator and tank sizing guide help with the volume question.

Shipping and receiving

The tank ships LTL, NMFC 156600-02, from Norwesco's Griffin, Georgia plant, 64 by 64 by 62 inches and 164 lb. Two people can roll it off the truck and into the yard; a strap on the excavator sets it in the hole. The listed price is before freight; the freight cost estimator gives the lane cost to your ZIP, or request a written quote for a purchase order. At the tailgate, check the part number against 44831 on the bill of lading, look over the whole body for gouges or cracks before you sign, and water test it per the inspector's requirement before backfill.

Questions before you order? Call 866-418-1777.