What Kirkland Water Actually Is

Kirkland Signature water comes in two main varieties, and it’s worth knowing which you’re buying because they’re quite different products.

The purified version is the more common pallet-sized pack. If PFAS is your concern, the purified/RO version is generally the safer bet — see why in our spring vs purified water guide.

Kirkland Water and PFAS: What’s Known

Straight answer: Kirkland has no widely published independent PFAS lab number — it wasn’t part of Consumer Reports’ bottled water testing, so we can’t give it a figure like Spindrift (0.19 ppt) or San Pellegrino (0.31 ppt).

What the evidence suggests: the purified Kirkland version goes through reverse osmosis, and RO is one of the most effective processes for removing PFAS. Across the tested field, purified waters consistently landed lower than spring waters for exactly this reason. That makes a low result likely for the purified version — but “likely” is not a lab result, and untested still means unverified.

Hands-On Taste Notes

Kirkland purified tastes exactly like a good purified water should: clean, neutral, and unremarkable in the best way. There’s no off-taste, no plastic note when it’s fresh and cool, and no mineral character to speak of. Side by side with premium purified brands like Aquafina or Dasani, most people can’t reliably tell them apart — which tells you the premium brands aren’t offering much in the water itself. The spring version has a touch more body and faint mineral note. Neither is exciting, and that’s the point: this is functional hydration water, not a tasting water. Chilled, it’s genuinely pleasant and does the job. Keep the plastic out of hot cars, same as any PET bottle.

Honest take: for daily drinking, the blind-taste gap between Kirkland and water twice the price is essentially zero.

Is Kirkland Water Worth It?

On value, Kirkland is one of the strongest picks in the entire category. You get clean, safe, neutral water at one of the lowest per-bottle costs available, and in blind taste it holds up against brands charging far more. If you’re buying water by the case for a household, this is the sensible default. The only real limitations are that it’s plain (no mineral benefit) and, like all bottled water, it’s still far more expensive and wasteful than a home filter.

Frequently Asked Questions

Does Kirkland water have PFAS?

There’s no published independent PFAS test for Kirkland water. However, the purified version goes through reverse osmosis, which removes most PFAS, and purified waters consistently tested low in the broader field — so a low result is likely for the purified version, though it remains unverified.

Is Kirkland water good quality?

Yes — it’s a clean, safe, neutral-tasting water that holds up against premium brands in blind taste tests. As a US bottled water it meets all regulatory safety standards. Its main limitation is simply that it’s plain, with no mineral character.

Is Kirkland water just tap water?

The purified version starts from a municipal source and is then treated by reverse osmosis, filtration and UV — the same process most purified bottled brands use. So it’s treated municipal water, purified to a clean, neutral standard, not raw tap water.

Is Kirkland water better than Aquafina or Dasani?

In taste and quality they’re very similar — all are purified waters, and most people can’t tell them apart blind. Kirkland’s advantage is price. If you have a Costco membership, it’s typically the better value.

Why is Kirkland water so cheap?

As Costco’s store brand, it skips the marketing and brand premium that name-brand waters carry, and sells in bulk. You’re paying close to the actual cost of clean bottled water, which is why it’s such good value.