A 1250 gallon two compartment septic tank with adapters and two manhole covers
The Norwesco 1250 gallon plastic two compartment septic tank with adapters and 2 manhole covers, part number 41743, is a yellow polyethylene septic tank 116 inches long, 55 inches wide and 70 inches tall, weighing 387 lb empty. It is a two chamber tank supplied with the parts that usually get bought separately: a 4 inch adapter with a PVC tee assembly at the inlet, a 4 inch adapter with a PVC tee assembly at the outlet, and 2 manhole covers for the 20 inch gasketed manway openings, so each compartment can be opened for pumping. Norwesco lists the tank as IAPMO approved. Your state and county health department have 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 387 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? Call 866-418-1777 with your county and the system design, or add it to your cart above with freight quoted to your ZIP.
Why two compartments, and why this version
A two compartment tank gives the solids a second chance to settle before the effluent reaches the drainfield, which is why many states and counties require it on a new system. Whether yours does is set by the design your installer or engineer is working to and by the local code. Our guide to single compartment versus two compartment septic tanks lays out the difference and who requires what. This version is the one to buy when the plan calls for access to both compartments at grade, because the second cover is in the box rather than a separate line on the order. For the approvals themselves, including how IAPMO and the Canadian CSA B66 listing relate to US plumbing codes, see our note on Norwesco IAPMO and CSA B66 septic tank approvals. 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.
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, both compartments together, so the walls and the baffle 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. Set the tank so the inlet end is at the house side; a two compartment tank only works one way round.
Openings and fittings
- Inlet. A 4 inch adapter with a PVC tee assembly, into the first compartment. The tee directs the incoming flow down below the scum layer.
- Outlet. A 4 inch adapter with a PVC tee assembly, out of the second compartment. The outlet tee draws from the clear zone between the scum and the sludge, which is what keeps solids out of the drainfield.
- Manway covers. 2 manhole covers for the 20 inch gasketed manway openings, one over each compartment, so the pumper can reach both chambers without lifting a riser apart.
- Drawing. Norwesco's drawing for this tank, linked under Technical Drawing on this page, shows the inlet and outlet invert heights, the baffle position and the manway locations for setting the tank to grade.
The rest of the family
Same shell with one compartment: the 1250 gallon one compartment septic tank. The two compartment tank without the extra cover: the 1250 gallon two compartment septic tank. One size down: the 1000 gallon septic tank. One size up: the 1500 gallon septic tank.
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 387 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 41743 against the bill of lading, count both tees and both manhole covers, and look over the shell for transit damage before the driver leaves.
Questions before you order? Call 866-418-1777.
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 41743.
See this tank
Product video. Watch the Norwesco 1250 Gallon Plastic Two Compartment Septic Tank with Adapters and 2 Manhole Covers - 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.
