The Snyder Industries 500 Gallon 1.9SG Double Wall Tank (SII-5780102N52) is a fully self-contained bulk water storage unit: a primary tank nested inside an integral secondary containment shell, molded in white high density linear polyethylene and rated to a 1.9 specific gravity. At 81 inches tall on a 53 x 53 inch footprint, it holds 500 gallons and carries a max rated contents weight of 7,923 pounds, so the built-in containment gives you spill protection without pouring a separate concrete berm.
Will this double wall tank work for your site?
Two weight numbers matter here, and they mean different things. Filled with plain water at about 1.0 specific gravity, 500 gallons weighs roughly 4,170 pounds. The 7,923-pound max rated contents figure is what the 1.9 SG structure is built to carry: a full 500 gallons of a fluid up to 1.9 times the density of water. That headroom is the entire reason to buy the 1.9SG double wall over a standard single-wall water tank; if you ever run heavier contents, this tank is engineered for it. Plumbing runs through an 18-inch vented threaded lid up top and a separate manway that opens 15 inches for entry, cleaning, and inspection. The "vented" detail is not a throwaway spec on a double wall unit; the primary tank has to breathe as it fills and drains. The square 53 x 53 inch footprint sits flat on a properly prepared pad, and the 81-inch height is worth confirming against any doorway or roof clearance before delivery. To pin down the right capacity for your draw-down and refill cycle, run the numbers through our Tank Sizing Calculator or read the Tank Sizing Guide. See the technical drawing on this page for exact fitting placement and dimensions.
Pad and freight: how it ships
Plan the pad around the loaded weight. At the 7,923-pound max contents rating over a 53 x 53 inch footprint (about 19.5 square feet), you are looking at roughly 400 pounds per square foot of bearing load, so the slab has to be sized for it; our concrete pad sizing guide walks through the ACI framework. This 500 gallon double wall tank moves by LTL freight, shipping from the Snyder plant in Marked Tree, Arkansas. Freight is quoted live to your ZIP rather than bundled into the list price, so the delivered total depends on distance, accessorials, and whether you need a liftgate or residential delivery. Get a number before you order with the Freight Cost Estimator, or call 866-418-1777 and we will quote it for you.
The mistake to avoid
The most common error with a double wall tank is treating the containment shell as usable volume. It is not: the 500 gallon rating is the primary tank only, and the outer wall exists solely to catch a leak. Size to 500 gallons of working water and leave the annular space empty. Because this is a Snyder double wall design, freeboard and thermal expansion matter if the contents are denser or warmer than ambient water, walked through in the Snyder double-wall freeboard sizing guide. If this unit will anchor a rural fire-water reserve, the fire-water reservoir design guide covers NFPA 22 sizing and freeze protection.
Ready to move? Pull a live freight quote to your ZIP with the Freight Cost Estimator or call 866-418-1777. For reuse and aggregation setups pairing storage with grey-water or rainwater sources, see our industrial water reuse tank topology guide.
