A 1250 gallon one compartment plastic septic tank from Norwesco
The Norwesco 1250 gallon plastic one compartment septic tank, part number 41741, is a yellow polyethylene septic tank 116 inches long, 55 inches wide and 70 inches tall, weighing 363 lb empty. It is a single chamber tank: wastewater enters through a 4 inch inlet with a PVC tee assembly, settles in one compartment, and leaves through a 4 inch outlet with a matching tee. Access is a 20 inch gasketed manway on top. Norwesco lists the tank as IAPMO approved, and lists state septic approvals for Arkansas, Connecticut, Delaware, the District of Columbia, Idaho, Indiana, Kentucky, Maine, Maryland, Michigan, Minnesota, Montana, Nebraska, New Hampshire, New York, North Dakota, Ohio, Rhode Island, South Dakota, Utah, Virginia, West Virginia, Wisconsin and Wyoming. 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 363 lb two people and a strap can set it in the hole without a crane; 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 or two
Norwesco makes this shell as a one compartment and a two compartment tank, and the choice is set by the design your installer or engineer is working to and by what your state and county accept. Many jurisdictions call for two compartments on a new system; others accept a single compartment, especially as a second tank in series or a pump tank. Our guide to single compartment versus two compartment septic tanks lays out the difference and who requires what. 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 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 risers and the access lid go; plan the riser height so the lid finishes at or above grade.
Openings and fittings
- Inlet. A 4 inch adapter with a PVC tee assembly. The tee directs the incoming flow down below the scum layer.
- Outlet. A 4 inch adapter with a 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 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.
The rest of the family
Same shell with two compartments: the 1250 gallon two compartment septic tank, and the 1250 gallon two compartment septic tank with adapters and 2 manhole covers. 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 363 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 41741 against the bill of lading, check that both tees and the manway lid are present, and look over the shell for transit damage before the driver leaves.
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 41741.
See this tank
Product video. Watch the Norwesco 1250 Gallon Plastic One Compartment Septic Tank - IAPMO Certified video (71 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.
