100 Gallon Plastic Water Storage Tank: Complete Buyer's Guide
A 100-gallon black water tank from Norwesco in a slim 23-inch column, seamlessly molded in FDA-grade polyethylene with twin 2-inch ports for fast fill and draw.
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
The 100-gallon Norwesco water tank packs a useful reserve into a remarkably small column — 63 inches tall on a 23-inch diameter — so it stands in a closet, a utility corner, or the bed of a truck without dominating the space. At 40 pounds empty it is a one-person carry, and full it tops out near 957 pounds, light enough that a sturdy floor handles it without special pad work.
It is rotomolded as one seamless piece of virgin linear polyethylene with UV black pigment in the resin, keeping stored water dark and algae-free even on a sunny porch. The 1.1 specific gravity rating covers water and light compatible liquids to 9.2 pounds per gallon, and the tank is FDA-approved for potable and food-grade contact.
Plumbing is handled by a 2-inch NPT outlet and a matching 2-inch NPT inlet — an unusually generous pair for a tank this small, giving you fast fill and drain — both factory-fitted and leak-tested. The 8-inch lid sized to the slim shell opens the top for fill and inspection. Norwesco's 3-year warranty applies.
Technical Drawing
Official Norwesco technical drawing — 100 Gallon Plastic Water Storage Tank
Key Features and Specifications
- 100-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
- 63" tall x 23" diameter — compact vertical footprint
- 40 lbs empty, approximately 957 lbs when full at rated specific gravity
- 2" NPT outlet fitting — factory installed and leak-tested
- 2" NPT inlet fitting included
- 8" 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
- Place on a firm, level surface free of rocks or sharp objects that could damage the tank bottom. Ensure adequate ventilation if stored chemicals produce vapors
- Ships via UPS or FedEx ground — typically arrives within 5-7 business days
Installation and Setup Guide
The 100-gallon column is one of the most placement-friendly tanks made — its narrow 23-inch base fits almost anywhere — but that same slim base means it must stand on something genuinely flat so it does not rock.
Site Preparation
A level patch of compacted gravel or, indoors, a flat concrete floor is all this tank requires. The full weight is under half a ton, so you are not engineering a slab; you are simply making sure the small footprint sits flat and supported, with no pebble or seam holding one side high. Clear the spot before you set the tank.
Placement and Connections
A foot of clearance around the tank is plenty for service on a unit this size. The twin 2-inch fittings let you run a real fill line into the top inlet and a real drain off the bottom outlet, so plumb whichever faces your supply most directly. Use short flexible connectors at the fittings to absorb the tank's thermal movement and keep the threads happy.
Venting
With two 2-inch ports this tank can move water quickly, which makes venting matter more than the small size suggests — a fast draw can pull a vacuum on the narrow column. A screened lid vent keeps air flowing both ways and the slim wall from dimpling.
Maintenance and Long-Term Care
There is almost nothing to maintain on a 100-gallon tank, but a quick quarterly look keeps the water clean and the fittings sound.
Quarterly Inspection Checklist
- Visual: scan the narrow shell for any distortion or a damp ring at a fitting — easy to catch on a small tank.
- Fittings: hand-snug both 2-inch ports; a quarter turn past finger-tight, never a wrench.
- Base: confirm the slim tank still stands flat and plumb and has not been knocked askew.
- Vent: verify the lid vent is open and clear.
Cleaning
As a potable tank, sanitize annually. Drain it, add unscented bleach at about a quarter cup per 15 gallons of clean water, hold two hours, and rinse until odor-free. The 8-inch lid is tight, so use a flexible bottle brush or a low-pressure rinse to reach the bottom of the deep narrow shell.
UV and Weather Protection
The black resin protects against sun, but a tank this small often lives outdoors fully exposed; an annual glance at the sunny face for chalking, and a shaded location where possible, keeps it sound for the long haul.
Alternatives and Comparisons
The slim 100-gallon column is about fitting water into tight spaces. If you want the same volume to ride in a vehicle, a low-profile transport tank is steadier on the move; if you need to slip a tank through a standard doorway into a basement, the 100-gallon doorway tank is shaped for exactly that. For more reserve in a similar narrow footprint, the 150- and 175-gallon tanks are the natural next sizes.
Other 100-Gallon Options
Frequently Asked Questions
How long will the 100 Gallon Plastic Water Storage Tank last?
Used within its 1.1 SG and 120 F ratings and protected from constant harsh sun, this tank will run 15 to 20 years. The seamless mold and molded-in black UV barrier do the heavy lifting; keeping it level and shaded does the rest.
What chemicals can I store in this tank?
It is built for potable water and FDA-cleared for drinking water and food-grade liquids, and within 1.1 specific gravity it handles light compatible solutions. No fuels, solvents, or flammables, and nothing heavier than 9.2 pounds per gallon. Verify any chemical on a compatibility chart first.
What kind of foundation does a 100-gallon tank need?
Full of water it weighs only about 957 pounds, so no engineered slab is required — a level patch of compacted gravel or a flat indoor floor carries it easily. The one requirement is that the slim 23-inch base sits flat and fully supported, with no pebble or seam holding one side high.
Does this tank come with a warranty?
Norwesco provides a three-year warranty covering molding flaws, pinholes, and factory fitting defects. Not covered: overloading, incompatible chemicals, or impact. Hang onto your receipt for any claim.
Can I install this tank underground?
No. This is an above-ground tank with walls that cannot resist soil pressure. For buried water storage, use a tank specifically engineered for underground service.
Buying Considerations
Two checks before ordering: a flat, firm spot for the narrow base to stand fully supported, and confirmation your contents are water-weight (at or under 1.1 SG). Freight is simple — this tank ships UPS or FedEx ground and usually arrives within 5 to 7 business days, no freight terminal needed.
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