The Norwesco 300 Gallon Above Ground Septic Job Shack Holding Tank is a 300 gallon black polyethylene holding tank built for above-ground waste capture at job-shack and temporary jobsite installations. It measures 95 inches long by 56 inches wide by 16 inches high, giving it a low 16-inch profile and a 56.0 x 95.0-inch footprint that sits flat and stable rather than standing tall. Rated to 1.5 specific gravity, it is engineered to carry dense holding-tank contents, well above the 1.0 of plain water, so you get rated margin for typical septic and waste density without stepping up to a heavier-wall tank.
Will this 300 gallon tank work for your install?
This holding tank holds 300 gallons. Full of plain water it carries roughly 2,502 pounds; at its 1.5 specific gravity rating the contents can reach about 3,753 pounds, so size your pad and supports for the loaded weight, not the empty shell. Spread across the 56 x 95-inch footprint (about 5,320 square inches), a fully loaded tank distributes to roughly 0.7 psi - low, but only if the bearing surface is flat and continuous under the whole base. Access is through a single threaded lid (shown on the technical drawing on this page): there are no factory side bulkhead outlets, so all fill, vent, and pump-out routing runs through that top lid, and any additional gasketed bulkhead or pass-through must be field-installed. To match gallons to your shift count and pump-out interval, use our Tank Sizing Calculator and the Tank Sizing Guide.
Septic approvals and the mistake to avoid
The most common mistake on a job-shack septic holding tank is treating it like a permitted septic system tank. This is an above-ground holding tank that captures waste for pump-out, and approval scope varies by jurisdiction and across the US/Canada line. Before you specify it, read Norwesco IAPMO and CSA B66 Septic Tank Approvals to understand what the listing does and does not cover for your code. The second mistake is the foundation: at up to 3,753 pounds loaded, a flat low-profile tank needs a properly sized bearing pad - see Concrete Pad Sizing for Above-Ground Polyethylene Tanks. If you reconcile throughput or guard against unauthorized pump-outs, the tank gauge calibration guide covers audit-defensible level records, and the above-ground vs below-ground selection guide helps confirm an above-ground holding tank is the right call for your site.
Freight and ordering
This holding tank ships LTL freight, quoted live to your ZIP code, from the nearest Norwesco plant - Fairfield, TX or Washington Court House, OH. Get your exact freight number with the Freight Cost Estimator, or call 866-418-1777 and we will lock in the closest origin and the right LTL service for your jobsite. Tell us your delivery ZIP and whether you need liftgate or limited-access service, and we will quote it before you buy.
