The Enduraplas 500 Gallon Green Horizontal Sump Bottom Leg Tank ships with its steel frame and a 1.9 specific gravity rating, which is the reason this tank handles heavy fertilizer blends and concentrated chemicals that thinner-walled tanks cannot. The horizontal leg-tank body sits 49 inches tall, 57 inches wide, and 80 inches long, giving it a 57.0 x 80.0 inch footprint that drops onto a trailer deck or skid without a separate stand. The sump bottom pulls product toward a single low drain point so you empty closer to the last gallon instead of leaving residual in flat-bottom corners.
Will it work for your load?
Capacity is a true 500 gallons of polyethylene with a green tint that shades the contents from UV and lets you read the liquid level. Plan your rigging and axle load around weight, not gallons: filled with plain water this tank carries about 4,170 pounds, and at its full 1.9 SG rating the maximum rated contents weight is 7,923 pounds. That spread is the single most important number on this page. People shopping a 500 gallon horizontal tank or leg tank by capacity alone routinely undersize the trailer, the tie-downs, and the tow vehicle, then find the loaded tank weighs nearly four tons. Size your hauling setup to the 7,923-pound figure if you ever run a dense product, and to 4,170 pounds for water. That 1.9 SG rating is also a selection point, not just a weight warning: it covers every dense chemical in the compatibility list at full fill, where a standard 1.5 SG tank would have to be derated for the heaviest products. Our Tank Sizing Calculator and Tank Sizing Guide help you match the load to your equipment before you buy.
Chemical compatibility
This is an Enduraplas polyethylene tank rated to 1.9 specific gravity. Because the resin code in our data is not confirmed, confirm HDLPE versus XLPE construction for your specific lot before placing any concentrated chemical in service - polyethylene grades resist different chemicals at different temperatures. The compatibility list below is drawn from the OEM chemical-resistance chart and is always concentration- and temperature-specific; verify your exact operating conditions against that chart before committing a load. The tank does not include chemical-rated fittings or gaskets - match your port hardware and seals to your specific chemical per the callouts below, because the most common failure on a chemical leg tank is at the connection, not the wall. For a quick read, the gaskets split three ways: EPDM for the salts, glycols, and most bases; Viton for the strong acids and hypochlorite; and Aflas specifically for peracetic acid.
For the ag and haul buyer, the two highest-probability loads on a North Dakota leg tank are already on the list: DEF (32.5%, 316SS fittings, EPDM gaskets) and Urea Solution (50%, PP/PVC, EPDM) liquid fertilizer. With the correct fitting and gasket materials, this tank is also rated to hold: Acetic Acid (60%, PP/PVC, EPDM), Aluminum Sulfate (50%, PVC, EPDM), Calcium Chloride (40%, PVC, EPDM), Ethylene Glycol (100%, PVC, EPDM), Ferric Chloride (50%, PVC, EPDM), Ferric Sulfate (60%, PVC, EPDM), Ferrous Sulfate (20%, PVC, EPDM), Hydrochloric Acid (37%, PVC, Viton), Hydrofluoric Acid (48%, PP/PVC, Viton), Hydrofluosilicic Acid (26%, PP/PVC, Viton), Hydrogen Peroxide (50%, PVC, Viton), Magnesium Chloride (30%, PVC, EPDM), Peracetic Acid (30%, 316SS, Aflas), Phosphoric Acid (85%, PVC, Viton), Polyaluminum Chloride (PVC, EPDM), Potassium Carbonate (50%, PVC, EPDM), Potassium Hydroxide (saturated, PVC, EPDM), Propylene Glycol (PP/316SS, EPDM), Sodium Bisulfate (PVC/PP, EPDM), Sodium Bisulfite (PVC/PP, EPDM), Sodium Carbonate (30%, PVC, EPDM), Sodium Hypochlorite (under 16.5%, PVC, Viton), Sodium Thiosulfate (40%, PVC, EPDM), Sulfuric Acid (98%, CPVC, Viton), Zinc Orthophosphate (PP/316SS, EPDM), and Ozonated Water (up to 10 PPM, PVC, EPDM). Putting an EPDM gasket on a Viton-only acid, or a plain PVC fitting where 316SS or CPVC is specified, is the mistake that fails at the connection. The sump bottom earns its keep more in chemical service than in water: a full drain-down between dissimilar products prevents cross-contamination and residual reaction in the corners. See our full chemical compatibility reference for the concentration and temperature detail on each.
Freight and ordering
This tank and its frame ship LTL freight from the Enduraplas plant in Neche, ND, quoted live to your ZIP - the listed price is the tank, with freight quoted separately because a four-ton-capable horizontal leg tank moves by the pallet, not by parcel. Get a number in minutes with our Freight Cost Estimator, or call 866-418-1777 and we will quote it for you. If you are spec'ing this for ag use, our guides on applicator and leg tanks for fertilizer, DOT classification for portable utility tanks, and fertilizer-blend tank stratification walk through the regulatory and mixing details that keep a leg tank legal and on-spec. Review the technical drawing on this page for the sump, fitting, and frame layout before you order.
