A 1250 gallon one compartment septic tank with gaskets, tees and a manhole cover
The Norwesco 1250 gallon plastic one compartment septic tank with gaskets, tees and 1 manhole cover, part number 44476, is a yellow polyethylene septic tank 116 inches long, 55 inches wide and 70 inches tall, weighing 355 lb empty. It is a single chamber tank sold ready to plumb: a 4 inch gasketed PVC tee assembly at the inlet, a 4 inch gasketed PVC tee assembly at the outlet, and a 20 inch gasketed manway on top with its cover. The gasketed connections are the point of this version; the pipe pushes into a seal at each end instead of being solvent welded to an adapter, which is what some inspectors and many installers prefer for a watertight joint. Norwesco lists the tank as IAPMO approved, and lists state septic approvals for Minnesota, Ohio, Oklahoma and Utah. Your county health department has the final say on what is accepted at your address, so confirm with them before you order. The service limit is 130 F and Norwesco backs the tank with a 3 year warranty. At 355 lb two people and a strap can set it in the hole; 1250 gallons of water weighs about 10425 lb once it is full.
Ordering for a job or a bid? Request a written quote with freight to your ZIP, or add a single tank to your cart above with freight quoted to your ZIP.
One compartment, and when that is the right call
A one compartment tank is accepted as the primary tank in some jurisdictions and used as a second tank in series, a pump tank or a holding tank in others. Which one applies to you is set by the design your installer or engineer is working to and by what your state and county accept, not by the tank. Our guide to single compartment versus two compartment septic tanks lays out the difference and who requires what. Size the tank to the house or the load with the tank sizing calculator and the tank sizing guide, then check the result against the county's own minimum, which wins. If you need the two compartment version of this shell, or the same tank without the gasketed tees, tell us and we will point you to the right part number.
Putting it in the ground
Follow Norwesco's installation instructions for this tank for the excavation, the bedding, the backfill material and the water filling sequence; the instructions are specific to the shell and your inspector will expect them. The universal points: the excavation floor has to be flat along the full 116 inch length, because a moulded tank bears where it touches and a void under one end is carried by the wall; the tank needs to be filled with water as it is backfilled so the walls are supported from both sides; and the inlet has to sit higher than the outlet so the system flows by gravity. Depth of cover, traffic loading, groundwater and risers are set by the drawing for your site and by your installer, not by this page. The 20 inch manway is where a riser goes if the tank sits deep; plan the riser so the cover finishes at or above grade and can be opened for pumping without digging.
Openings and fittings
- Inlet. A 4 inch gasketed PVC tee assembly. The pipe pushes into the gasket; the tee directs the incoming flow down below the scum layer. Lubricate the gasket and push the pipe home square, never at an angle.
- Outlet. A 4 inch gasketed PVC tee assembly. The outlet tee draws from the clear zone between the scum and the sludge, which is what keeps solids out of the drainfield.
- Manway. A 20 inch gasketed manway on top with 1 manhole cover included, for pumping and inspection.
- Drawing. Norwesco's drawing for this tank, linked under Technical Drawing on this page, shows the inlet and outlet invert heights and the manway position for setting the tank to grade.
Shipping and receiving
The tank ships LTL, NMFC 156600-02, from the nearest of Norwesco's plants that make it: Lancaster, Ohio; Owego, New York; Tooele, Utah; or Washougal, Washington. On the trailer it is 116 by 55 by 70 inches and 355 lb. The listed price is before freight; the freight cost estimator gives the lane cost to your ZIP. At the tailgate, check the part number 44476 against the bill of lading, check that both gasketed tees and the manhole cover are present, and look over the shell for transit damage before the driver leaves. Keep the tees out of the sun and the dirt until they go in; a gasket with grit in it is the usual cause of a leak at the inlet.
Questions before you order? Call 866-418-1777 with your county and the system design.
Freight and documents
Ships from: Owego, NY; Lancaster, OH; Tooele, UT; Washougal, WA. LTL freight is quoted to your ZIP with the freight cost estimator or by phone at 866-418-1777. The listed price is before freight.
Technical drawing (PDF) for Norwesco 44476.
See this tank
Product video. Watch the Norwesco 1250 Gallon Plastic One Compartment Septic Tank with Gaskets, Tees, and 1 Manhole Cover - IAPMO Certified video (69 seconds) with dimensions, fittings and shipping notes.
Ready to order?
Add it to your cart at the top of this page, get LTL freight to your ZIP, request a written quote, or call 866-418-1777. The listed price is before freight.
