Norwesco 7500 Gallon Plastic Containment Tray

What it is for

Secondary containment is the vessel under and around the tank that holds the contents if the tank fails. The usual rule a regulator or an insurer applies is that it holds at least the full volume of the largest tank inside it, with an allowance for rain if it is outdoors; the exact figure is set by your state and your permit, so check it before you buy. At 7500 gallons this basin covers a single tank up to that size, or a smaller tank with a generous rain and overfill margin. The 144 inch square footprint takes one vertical tank whose base fits well inside it, and the 110 inch wall is tall enough that the tank inside is mostly hidden: plan the level gauge, the fill connection and the valve access so that nobody has to climb into the basin to read or operate the tank.

What to check before you buy

1. The floor. A basin is a flat bottomed moulding and cannot bridge anything. It needs a flat, continuous, swept slab across the whole 144 by 144 inches, designed for the full weight of the tank inside it plus whatever the basin itself may one day hold. A stone under a basin carrying a full tank becomes a permanent pressure point.
2. The tank's base. Measure the tank's base diameter, not its widest point, and keep it inside the flat floor, away from the radius where the wall meets the bottom.
3. Getting the tank in. Everything goes in over a 110 inch wall. Work out the crane or the forklift mast height before the basin is set, because once a tank is standing in it the basin is not moving again.
4. Rain and pump-out. Outdoors it collects rain. Roof it, pump it down on a schedule, or allow for it in the volume; no drain is moulded in, and any you add is your design and your responsibility.
5. The liquid. Polyethylene handles water, most fertilizers and many common chemicals. For anything aggressive, check the liquid against the material before you order, and ask us if you are not sure.

Norwesco's drawing for the basin, linked on this page under Technical Drawing, gives the wall profile and the inside dimensions at the floor.

Shipping and receiving

At 144 inches square and 110 inches tall the basin is oversize freight: it travels on a flatbed as freight class OVS, NMFC 156600-02, from Norwesco's Hanford, California plant, 144 by 144 by 110 inches and 1500 lb. It needs a crane or a large forklift and straps at your end, and a route from the truck to the slab with no overhead obstruction below 110 inches. The listed price is before freight; the freight cost estimator gives the lane cost to your ZIP. At the tailgate, check the part number against 45379 on the bill of lading and walk the whole rim, wall and floor for cracks or gouges before you sign; a basin with a crack is not containment. Put a few inches of water in it the first time to confirm it holds before the tank is set inside.

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