The Snyder Industries 1000 Gallon Double Wall Tank is a self-contained primary-plus-secondary containment package molded in black high density linear polyethylene with a 1.9 specific gravity rating, so the outer wall captures any leak from the inner tank without a separate berm. At 1000 gallons it occupies an 81 x 81 inch square footprint, which lets the entire containment system sit on the same pad space as a single-wall tank of comparable volume - useful when a secondary containment requirement has to be met inside a tight building or on an existing slab.
Will this tank handle your water duty?
Filled with water at 8.34 lb per gallon, this tank carries roughly 8,340 pounds of liquid. The shell itself is rated to hold contents up to 15,846 pounds at its 1.9 specific gravity limit - nearly double the load of plain water. For straight water storage that is generous margin, so the tank will not be working anywhere near its structural ceiling. Before delivery, check the 81 x 81 inch footprint and the tank height against your door and pad clearances; measure the opening, not just the floor space. If you are weighing this capacity against a neighboring size, run your fill volume through the Tank Sizing Calculator and the Tank Sizing Guide so freeboard and working volume line up with how you actually draw the tank down.
Why the 1.9 specific gravity rating matters
The 1.9 specific gravity rating is the spec to understand on this tank, and it is an honest decision point rather than marketing. It means the shell is engineered to carry liquids up to 1.9 times the density of water. If your contents are water today but could shift to a denser ag or industrial liquid later, this tank already covers that range. If you only ever store plain water, a lower-SG double wall tank meets the same duty for less, and you are paying for headroom you will not use. Either way, keep your actual contents at or below the 1.9 specific gravity ceiling, and remember the rating is a density limit, not a license to ignore freeboard. For real working-volume planning on Snyder double-wall tanks, our breakdown of Snyder Captor double-wall freeboard sizing per ASTM D1998 walks through density, thermal expansion, and the volume you can actually use, while our note on HDPE tank wall thickness at the vapor-saturated headspace explains why failures often start above the liquid line where routine inspection misses them.
The mistake to avoid
The most common error with a double wall tank is treating the 1.9 specific gravity rating as a fill-to-the-brim allowance for any heavy liquid. The rating is a maximum density limit, not a working-volume number, and it does not by itself qualify the tank for a particular chemical service. Confirm fitting sizes, locations, and gasket materials from the technical drawing on this page and on your quote rather than assuming them from the listing - the empty interstitial space and outer-wall detail shown there govern how the secondary containment actually works. If this tank is headed for rural fire-protection or freeze-prone duty, the fire-water reservoir design guide covers NFPA 22 sizing and cold-climate protection, and for buried outer-wall installs the cathodic disbondment testing guide covers the interstitial-space methodology.
This 1000 gallon HDPE black double wall tank ships LTL on a freight carrier, quoted live to your delivery ZIP. It molds at two plants - Chowchilla, CA and Lincoln, NE - so a West Coast ZIP and a Midwest ZIP can return very different numbers; the closer plant usually wins on cost. Get an exact figure with the Freight Cost Estimator, or call 866-418-1777 and we will quote it by phone. Have your ZIP and any liftgate or limited-access delivery needs ready when you request the quote.
