The Snyder Industries 12500 Gallon ASTM Black Double Wall Tank (SKU 1031100N49) is a containment-grade black polyethylene tank built for bulk water and fire-water storage where you need a secondary barrier without a second footprint. It holds 12,500 gallons, stands 274 inches tall on a 142 x 142 inch base, and carries a 1.5 specific gravity rating. This is a tank-within-a-tank: the primary storage vessel is nested inside a full outer wall, and the gap between them - the interstitial space - is where a leak in the primary is contained and can be monitored before anything reaches your site.
Will it work for your site?
Confirm the load before you pour the pad. Filled with water this tank weighs about 104,250 lbs; at its full 1.5 SG rating the contents alone can reach 156,375 lbs - roughly 50% heavier than water - and your foundation has to carry that mass across the 142 x 142 inch footprint. The fittings shown on the technical drawing on this page read as a system: a flange, an 18 inch PE threaded and vented fitting to service and vent the primary, and a manway with 15 inch access for interior inspection and cleanout. Review the drawing against your plumbing and vent plan, then use the Tank Sizing Calculator and Tank Sizing Guide to match capacity to your draw and refill cycle.
The mistake to avoid
Do not treat the 1.5 SG rating as a license to skip freeboard math. Double wall polyethylene tanks need proper freeboard for thermal expansion and fill dynamics, so usable volume is not the same as the nameplate 12,500 gallons. Read Snyder Captor double-wall freeboard sizing per ASTM D1998, and because vapor-saturated headspace is where poly walls fail first, review HDPE wall thickness at the vapor-saturated headspace. For cold or remote fire-water sites, our fire-water reservoir design guide covers NFPA 22 sizing and freeze protection.
Freight
This black double wall tank ships LTL freight from the Snyder plant in Lincoln, Nebraska. Because it is an oversized, heavy load, freight is quoted live to your delivery ZIP rather than listed as a flat number. Run your ZIP through the Freight Cost Estimator or call 866-418-1777 for a freight quote and to arrange offload equipment at your site.
