The Snyder Industries 8700 Gallon ASTM Black Double Wall Tank (SKU 1006400N49) is a large-format polyethylene double wall tank built for bulk water storage where secondary containment is part of the plan. It stands 197 inches tall on a 142 x 142 inch square footprint, so before you commit, confirm you have both the vertical clearance and the pad area to seat it. The black polyethylene wall blocks light transmission, which inhibits algae growth in stored water, and this is an ASTM-standard build rated to a 1.5 specific gravity, the top of the standard polyethylene range, so you have headroom for water and denser-than-water contents without needing a heavier-rated shell.
Will it work for your site?
Filled with water, this tank carries roughly 72,558 lb of contents, and it is rated to a maximum contents weight of 108,837 lb at its 1.5 specific gravity rating. Those are foundation numbers, not footnotes: a double wall tank this size demands a properly engineered, level pad sized for a fully loaded static load. Use the Tank Sizing Calculator and the Tank Sizing Guide to confirm the working volume you actually need, and factor in freeboard for thermal expansion. Our guide on Snyder double-wall freeboard sizing per ASTM D1998 walks through why the nameplate gallons and the volume you can actually use are not the same figure.
Fittings and access
The technical drawing on this page shows the fitting layout: a flange, an 18-inch threaded and vented opening, and a manway with 15-inch access for interior inspection and maintenance. Confirm your bulkhead fittings, flange bolt pattern, and gaskets are sized to the drawing's flange and 18-inch threaded/vented port before you plumb it in — these are interfaces you spec adapters and gaskets against, not pre-supplied hardware. The double wall construction adds an interstitial space between the inner and outer walls for secondary containment; our write-up on cathodic-disbondment testing per ASTM G8, G42 and G80 covers how that interstitial boundary is evaluated. If your application is a fire-water reservoir or rural storage, the rural fire-water reservoir design guide covers NFPA 22 sizing discipline and cold-climate freeze protection.
The mistake to avoid
Don't under-build the foundation or ignore the vapor-saturated headspace. Wall stress at the top of an HDPE tank behaves differently than the liquid-wetted wall below it; our write-up on wall thickness at the vapor-saturated headspace explains where premature failures originate and why liquid-side inspection misses them.
This double wall tank ships LTL freight from Snyder's plant in Lincoln, NE, quoted live to your ZIP. Get a number in seconds with the Freight Cost Estimator, or call 866-418-1777 to talk through delivery, offload, and pad prep before you order.
