5000 Gallon Plastic Water Storage Tank - Black (141" x 86"): Complete Buyer's Guide
A 5,000-gallon black water tank from Norwesco built broad and low for commercial-scale storage, seamlessly molded in FDA-grade polyethylene to keep a large reserve clean in open sun.
Specifications at a Glance
Every figure below is pulled straight from the live product record for this exact tank — the same data on the product page, so what you read here and what you buy never disagree.
Standards & Materials
- ASTM D1998 — Standard Specification for Polyethylene Upright Storage Tanks. Governs wall-thickness and hydrostatic design for vertical rotomolded poly tanks of this class.
- FDA 21 CFR 177.1520 — Olefin polymers. The food-contact regulation the FDA-grade resin in this tank is compounded to meet.
- Specific gravity rating 1.1 — the tank is engineered for liquids up to 1.1× the density of water (water is about 8.34 lb/gal). Confirm your fluid’s SG before storage.
Product Overview
Five thousand gallons is commercial-scale water on a single footprint, and this black Norwesco delivers it as a broad, low cylinder — 141 inches across and only 86 inches tall. That deliberately squat proportion keeps a 23-ton full load close to the ground, where it is stable in wind and easy to feed by gravity, and it means the tank can live under a roofline or overhang that a taller 5,000 would never clear. It is the backbone tank for a ranch, a fire-reserve, a packing shed, or a rural system that has to ride out long outages.
The shell is one seamless rotomolding of virgin linear polyethylene, with UV black pigment compounded into the resin so a five-thousand-gallon volume of water stays dark and free of algae no matter how exposed the site. Rated to 1.1 specific gravity, it carries water and compatible liquids to 9.2 pounds per gallon and is FDA-approved for potable and food-grade service.
At this scale the numbers demand respect: 758 pounds empty, but about 46,628 pounds full — over 23 tons — across that 141-inch base, which is why this tank needs an engineered, reinforced slab rather than a gravel pad. A 2-inch NPT outlet and 1.5-inch NPT inlet are factory-fitted and tested, and the larger 22-inch lid (sized up from the 16-inch lid on smaller tanks) gives a worker real access for interior inspection. Norwesco's 3-year warranty applies.
Technical Drawing
Official Norwesco technical drawing — 5000 Gallon Plastic Water Storage Tank - Black (141" x 86")
Key Features and Specifications
- 5,000-gallon capacity — sized for safe potable water storage
- Constructed from virgin linear polyethylene (HDPE) with 1.1 specific gravity rating — handles liquids up to 9.2 lbs/gal
- 86" tall x 141" diameter — compact vertical footprint
- 758 lbs empty, approximately 46,628 lbs when full at rated specific gravity
- 2 NPT outlet fitting — factory installed and leak-tested
- 1.5 NPT inlet fitting included
- 22" lid opening for fill, venting, and interior access
- FDA approved for potable water and food-grade liquid contact
- 3 Year Warranty from Norwesco against manufacturing defects
- UV-resistant black pigmentation provides maximum outdoor durability and inhibits algae growth in stored liquids
- Rated for continuous service up to 120 F / 48 C
- Seamless one-piece rotational molding — no seams, no welds, no leak points
- Manufactured by Norwesco — a leading name in rotomolded polyethylene tanks
- Install on a level, compacted surface. Ensure adequate clearance above for lid access and around the perimeter for plumbing connections and visual inspection
- Ships via dedicated freight carrier due to oversized dimensions — contact us for delivery timeline and site access requirements
Installation and Setup Guide
At 5,000 gallons the installation crosses from a homeowner project into a real engineering exercise. Twenty-three tons of water across a 141-inch circle is a load you design for, not a load you guess at — bring in a structural professional before the first shovel.
Site Preparation
This tank wants a reinforced concrete pad at least six inches thick, engineered by a qualified professional to carry the full 46,628-pound load with margin. The slab has to extend past the 141-inch diameter on every side and finish flat to within a quarter inch across the whole span — on a footprint this wide, even a slight slope concentrates tons of force onto one arc of the wall. Site it where heavy water trucks or a fill line can reach, and where drainage carries runoff away from the slab.
Placement and Connections
Keep three feet of clearance around the perimeter; on a tank this size you need room to walk the whole shell and to swing tools at the fittings. Run the 2-inch outlet to your distribution by the shortest path, and connect both it and the 1.5-inch inlet through flexible couplings — a 23-ton tank moves measurably as it heats, cools, fills, and empties, and rigid pipe will not survive that.
Venting
Venting scales with volume, and on a 5,000-gallon tank it is a safety item, not an afterthought. A fast draw can pull a punishing vacuum and a fast fill can build real pressure; size the lid vent generously to your peak flow so air moves freely both ways and the broad flat top neither sucks down nor domes up.
Maintenance and Long-Term Care
A 5,000-gallon tank rewards a real inspection routine because the consequences of a missed problem scale with the volume. Budget more than a few minutes here — walk the whole shell, and pay attention to the slab.
Quarterly Inspection Checklist
- Full-shell walk: circle the entire 141-inch tank looking for bulging, discoloration, or weeping. The broad low wall carries enormous hoop stress at the base — any distortion in the bottom band is a stop-and-investigate finding.
- Fittings: hand-check the 2-inch outlet and 1.5-inch inlet; never a pipe wrench, a quarter turn past snug at most.
- Slab: inspect the engineered pad for cracking, settling, or any sign one edge is dropping. On 23 tons, a foundation problem grows fast.
- Vent: confirm the large vent is fully open — a blocked vent on this volume can deform the top deck in a single pumping cycle.
Cleaning
Flush annually as a potable tank. Drain it down, sanitize at roughly a quarter cup of unscented bleach per 15 gallons of clean water — which is a meaningful amount of bleach at this scale, so measure to the partial fill you actually use — hold two hours, and rinse clean. The 22-inch lid is wide enough for safe interior access; on a tank this large, use confined-space precautions and never enter alone.
UV and Weather Protection
Black resin is essential at this exposure, holding the wall sound where a white tank would chalk. Even so, in extreme sun inspect the southern and western faces annually. The sheer wall area makes a permanent shade structure worth considering in desert climates, both for service life and to keep the stored water cooler.
Alternatives and Comparisons
At 5,000 gallons your real fork is black potable versus natural-white liquid storage of the same broad shell. This black tank is engineered to keep drinking and process water clean in open sun; the translucent white version forfeits that defense to give you a level you can read through the wall, which only matters for an agricultural liquid you are metering. If 5,000 is more than you need, a 4,200 in a narrower profile fits tighter sites; if it is not enough, the 11,000 is the next real step up and a substantially larger foundation.
Other 5000-Gallon Options
Frequently Asked Questions
How long will the 5000 Gallon Plastic Water Storage Tank - Black (141" x 86") last?
Fifteen to twenty years and often more, given that the tank is set on a proper engineered slab and kept within its 1.1 SG and 120 F ratings. At this scale the foundation is the dominant factor in longevity — a true, reinforced slab is what lets the seamless black shell reach the far end of that range.
What chemicals can I store in this tank?
It is a potable water tank, FDA-cleared for drinking water and food-grade liquids, and within 1.1 specific gravity it also holds light solutions. It is not for fuels, solvents, or anything flammable, and nothing over 9.2 pounds per gallon — at 5,000 gallons an overweight liquid is an enormous overload. Confirm compatibility before filling.
What kind of foundation does a 5000-gallon tank need?
Full it weighs about 46,628 pounds — over 23 tons — so this tank requires an engineered, reinforced concrete slab at least six inches thick, designed by a structural professional for the full load. A gravel pad is not adequate at this scale. The slab must be dead level across the entire 141-inch base.
Does this tank come with a warranty?
Norwesco backs it three years against manufacturing defects — molding flaws, pinholes, factory fitting defects. Overloading, an inadequate foundation, incompatible chemistry, and impact are excluded. Given the cost of a tank this size, keep thorough records and slab engineering documents on file.
Can I install this tank underground?
Absolutely not. This is a large above-ground tank, and burying a 5,000-gallon vertical shell guarantees collapse under soil pressure and voids the warranty. Below-grade storage at this volume requires purpose-engineered underground tankage.
Buying Considerations
Three things stand between you and a successful 5,000-gallon install. First, the foundation: have a structural professional design and pour the reinforced slab before the tank ships. Second, the liquid: water-weight or lighter, at or under 1.1 SG. Third, the freight — a tank this size moves by dedicated carrier on oversized terms, not standard LTL, and the site needs crane or heavy-forklift access to set it. Call us early so we can coordinate the carrier, the unload, and your slab timeline together.
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