Is Cary, NC Water Safe to Drink?

Triangle Waterworks · informational guide

Legally, yes — the Town of Cary's water system meets EPA compliance requirements. But its own testing data, compiled in the Environmental Working Group's (EWG) Tap Water Database, shows 13 contaminants above EWG's health guidelines, including haloacetic acids at 27.5 ppb (458x the 0.06 ppb guideline) and PFAS compounds tied to the Jordan Lake watershed. Cary water won't get you in trouble to drink — but it's carrying more than the legal minimum would suggest.

Does Cary Water Meet EPA Standards? (Yes — and Why That's Not the Whole Story)

Cary's water system is in compliance with the EPA's Safe Drinking Water Act limits. That's a real, meaningful standard — it's what keeps acute contamination and outbreaks out of the tap.

But EPA legal limits and EWG's health guidelines aren't the same yardstick. EWG sets its guidelines using current cancer-risk and developmental-health research, and for several contaminant classes those guidelines sit far below the decades-old legal limits. Cary can be fully compliant and still show levels EWG's scientists would flag as elevated. Both things are true at once — that's not a contradiction, it's just two different bars.

What's Actually in Cary Tap Water?

Cary's EWG profile lists 13 contaminants above health guidelines. The two best-documented, with the clearest numbers:

HAA9 and TTHM are disinfection byproducts — they form when chlorine (necessary for killing bacteria) reacts with organic matter in the source water. PFOA and PFOS are "forever chemicals" tied to the reservoir Cary draws from. All four are measured and reported the same way: real testing numbers compared against EWG's independent health thresholds, not against the (much looser) legal minimum.

Where Does Cary's PFAS Come From?

Cary and Apex both draw drinking water from Jordan Lake. In 2017, Duke University researchers sampled the lake and measured combined PFAS levels above 200 parts per trillion in the source water — well upstream of anything the treatment plant does to it. That's the root of Cary's PFAS numbers, and it's a regional watershed issue, not something specific to Cary's treatment process. We go deeper on the Jordan Lake source-water story, including which other towns share this exposure, in PFAS in Jordan Lake and Cary's water.

What This Means If You Live in Cary

Whether you're in Preston, Amberly, or anywhere else on the Town of Cary system, the water reaching your tap goes through the same treatment plant and carries the same profile — location within town doesn't change your exposure. What does matter locally: Cary water is soft, running roughly 2–5 grains per gallon. If someone's trying to sell you a water softener based on "Cary's hard water," that's not backed by the actual hardness numbers — the real concern here is disinfection byproducts and PFAS, not scale buildup. Whole-home carbon filtration addresses the actual problem; a softener addresses a problem Cary mostly doesn't have.

What Removes These Contaminants?

• Disinfection byproducts (HAA9, TTHM): removed effectively by activated carbon filtration, installed at the point water enters your home.
• PFAS (PFOA, PFOS): requires filtration specifically rated for PFAS removal — not all carbon filters are — or reverse osmosis. NSF/ANSI 53 and P473 certifications matter here; see our NSF certification decoder if you're comparing systems.
• Boiling: does nothing for either category, and can concentrate PFAS as water evaporates rather than remove it.

FAQ

Is Cary water worse than Raleigh water? Cary's HAA9 (27.5 ppb) and TTHM (38.2 ppb) run higher than Raleigh's (19.9 ppb and 21.7 ppb, respectively) — both above EWG guidelines, but Cary's numbers are further above. See our full Raleigh tap water breakdown for the comparison.

Why does Cary have PFAS in its water? Cary draws from Jordan Lake, where Duke University's 2017 sampling found combined PFAS above 200 ppt in the source water itself — before any treatment. It's a watershed-level issue affecting the towns that draw from the lake.

Is Cary water hard? No — roughly 2–5 grains per gallon, which is soft. A water softener isn't the fix for Cary's water-quality concerns.

Can I just boil Cary water to be safe? No. Boiling doesn't remove PFAS or disinfection byproducts, and it can concentrate PFAS as water evaporates. See our full explainer on why boiling doesn't remove PFAS.

Does the Town of Cary tell residents about this? Cary reports what regulators require. The 13-contaminant, above-guideline picture comes from cross-referencing that testing data against EWG's independent Tap Water Database, which most utilities don't proactively surface to residents.

Want to know exactly what's worth filtering in your Cary home? Take the 60-second water quiz — no sales visit required.