Drinking water quality · 2025
What's in Cary, NC tap water
19 contaminants were measured in the Cary, NC water system's 2025 annual report. Each is shown below against its federal limit.
- Reporting year
- 2025
- Contaminants measured
- 19
- Over federal limit
- 0
- Approaching the limit
- 2
- Service area
- NC
PFAS — EPA UCMR5 (2023–2025)
4 PFAS compounds detected in Cary, NC
The EPA finalized the first-ever federal drinking-water limits for six PFAS compounds in April 2024. These numbers come straight from EPA's UCMR5 lab dataset — every U.S. system serving more than 3,300 people tested every PFAS sample at an entry point to its distribution system. PFAS not listed below were either tested and not detected, or not yet sampled.
PFHxA
● Detected (no federal limit)PFPeA
● Detected (no federal limit)PFBS
● Detected (no federal limit)PFBA
● Detected (no federal limit)Where your water comes from · EPA SDWIS
Cary, NC's drinking water comes from surface water, drawn from 1 source.
Source
- JORDAN LAKE
Treatment
- TREATMENT_PLT_CARY/APEX WTP
Distribution
Also buys water from DURHAM, CITY OF, RALEIGH, CITY OF, and 2 more.
Compliance history
Federal Safe Drinking Water Act violation & enforcement records (EPA SDWIS). A violation is a regulatory determination by the state or EPA — separate from the measured levels above.
- Maximum contaminant level exceededHealth-based2 violations on record · most recent May 2023resolved
Source: EPA SDWIS / ECHO. View the full federal record on EPA ECHO ↗
Disinfectants
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| ChloramineA longer-lasting disinfectant made by combining chlorine with ammonia. | 1.33–3.91 mg/LRangeSystem-wide | 4 mg/LMCL | Approaching the limit |
| ChlorineA disinfectant added to drinking water to kill bacteria and viruses. | 0.37–3.29 mg/LRangeSystem-wide | 4 mg/LMCL | Approaching the limit |
Disinfection byproducts
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| TTHMTotal trihalomethanes — a group of four chemicals (including chloroform) formed when chlorine reacts with natural organic matter. | 37 ug/LRunning annual avgSystem-wide | None set | Within the limit |
| BromateA disinfection byproduct formed when bromide-containing water is treated with ozone. | 0–3 ug/LRangeSystem-wide | None set | Within the limit |
| HAA5Haloacetic acids — a group of five disinfection byproducts formed when disinfectants react with organic matter. | 17 ug/LRunning annual avgSystem-wide | None set | Within the limit |
PFAS ("forever chemicals")
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| PFOAPerfluorooctanoic acid, a PFAS 'forever chemical' once used in nonstick and stain-resistant products. | 1.3 ng/LAverageDetection | 4 ng/LMCL | Within the limit |
| Hexafluoropropylene oxide dimer acidHFPO-DA ('GenX chemicals'), a newer-generation PFAS replacement compound. | Not detected ng/LAverageDetection | 10 ng/LMCL | None detected |
| Perfluorohexanesulfonic acidPerfluorohexanesulfonic acid, a PFAS 'forever chemical.' | Not detected ng/LAverageDetection | 10 ng/LMCL | Within the limit |
| PFOSPerfluorooctanesulfonic acid, a PFAS 'forever chemical' once used in firefighting foam and coatings. | Not detected ng/LAverageDetection | 4 ng/LMCL | Within the limit |
| Perfluoroheptanoic acidPerfluoroheptanoic acid, a PFAS 'forever chemical.' | 1.1 ng/LAverageDetection | None set | Detected — no federal limit |
Inorganic chemicals
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| FluorideA mineral often added to drinking water to help prevent tooth decay. | 0.65 mg/LReported levelSystem-wide | 4 mg/LMCL | Within the limit |
Physical & aggregate
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| TurbidityA measure of cloudiness from suspended particles in the water. | 0.1 NTUReported levelSystem-wide | None set | Within the limit |
| TOCTotal organic carbon — a measure of organic material dissolved in the water. | 1.36–1.72RangeSystem-wide | None set | Detected — no federal limit |
Metals
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| CopperA metal that enters water from corroding household plumbing. | 0.096 mg/L90th percentileAt the tap | 1.3 mg/LAction level | Within the limit |
| LeadA toxic metal that leaches into water from old service lines, solder, and plumbing fixtures. | 0.0 mg/L90th percentileAt the tap | 0.015 mg/LAction level | None detected |
People also ask about Cary, NC's water
+Is Cary, NC tap water safe to drink in 2025?
Every one of the 19 contaminants measured in Cary, NC's 2025 Consumer Confidence Report is below its federal limit. "Safe" under the EPA's drinking-water standards is health-based, not aesthetic — but by those standards, no measured contaminant in this report exceeds its enforceable threshold. Individual health concerns (e.g. immunocompromised, infant, pregnancy) may warrant additional filtering regardless of compliance.
+What contaminants are in Cary, NC tap water?
19 contaminants were measured in Cary, NC's 2025 Consumer Confidence Report, spanning pfas ("forever chemicals"), disinfection byproducts, and disinfectants. 9 have an enforceable federal limit; the rest are detected but unregulated. Every measured value, in the utility's own units, is on this page.
+Are any contaminants in Cary, NC tap water approaching the federal limit?
2 contaminants are between 80% and 100% of the federal limit in this report: Chloramine and Chlorine. Approaching means measured but not in violation — a margin that can close quickly if conditions change.
+Where does the data on this page come from?
Every value is transcribed from Cary, NC's 2025 Consumer Confidence Report — the annual drinking-water report every U.S. public water utility is required by federal law to publish. The original source document is archived and viewable on this site. A water-quality report covers an entire service area, not a single address.
+How often is Cary, NC's water quality data updated?
Each U.S. public water utility publishes one Consumer Confidence Report per year, covering the prior calendar year's measurements. This page reflects the 2025 report; a new report will replace it once the utility publishes its next annual update.