Drinking water quality · 2025
· Verified
What's in Cary, NC tap water
18 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
- 18
- 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)near national p90 (12.190000000000003 ng/L across detecting U.S. systems)
PFPeA
● Detected (no federal limit)below national p90 (15.95999999999999 ng/L across detecting U.S. systems)
PFBS
● Detected (no federal limit)below national p90 (13.909999999999979 ng/L across detecting U.S. systems)
PFBA
● Detected (no federal limit)below national p90 (18 ng/L across detecting U.S. systems)
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.
Historical readings · EPA Six-Year Review (2012–2019)
2 contaminants historically over EPA limits in Cary, NC
Every U.S. public water system reports compliance-monitoring data to EPA. The Six-Year Review releases the 2012–2019 window as a single dataset — here's what your system reported, year by year. Values shown are the highest detection per analyte per year, compared to the federal MCL.
| Contaminant | Worst detection | EPA limit | Years (2012–2019) |
|---|---|---|---|
BROMATE worst: 2019 | 0.02 mg/L 2.0× | 0.01 mg/L | '12'13'14'15'16'17'18'19 |
GROSS BETA worst: 2017 | 4.2 mrem/yr 1.1× | 4 mrem/yr | '17 |
TTHM worst: 2017 | 0.077 mg/L 96% | 0.08 mg/L | '12'13'14'15'16'17'18'19 |
HAA5 worst: 2016 | 0.031 mg/L within | 0.06 mg/L | '12'13'14'15'16'17'18'19 |
FLUORIDE worst: 2018 | 0.81 mg/L within | 4 mg/L | '12'13'14'15'16'17'18'19 |
DALAPON worst: 2012 | 0.0016 ug/L within below national p90 | 200 ug/L | '12 |
COPPER worst: 2012 | 0.324 mg/L below national p90 | — | '12'15'18 |
LEAD worst: 2012 | 0.0212 mg/L | — | '12'15'18 |
DBAA worst: 2012 | 0.0058 mg/L | — | '12'13'14'15'16'17'18'19 |
DCAA worst: 2012 | 0.014 mg/L | — | '12'13'14'15'16'17'18'19 |
MBAA worst: 2012 | 0.0021 mg/L | — | '12'13'15'16'17'18 |
TCAA worst: 2012 | 0.0064 mg/L | — | '12'13'14'15'16'17'18'19 |
BROMODICHLOROMETHANE worst: 2012 | 0.025 mg/L | — | '12'13'14'15'16'17'18'19 |
BROMOFORM worst: 2012 | 0.0047 mg/L | — | '12'13'14'15'16'17'18'19 |
CHLOROFORM worst: 2012 | 0.018 mg/L | — | '12'13'14'15'16'17'18'19 |
DIBROMOCHLOROMETHANE worst: 2012 | 0.022 mg/L | — | '12'13'14'15'16'17'18'19 |
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/LMRDL | Approaching the limit |
| ChlorineA disinfectant added to drinking water to kill bacteria and viruses. | 0.37–3.29 mg/LRangeSystem-wide | 4 mg/LMRDL | Approaching the limit |
PFAS ("forever chemicals")
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| PFOAPerfluorooctanoic acid, a PFAS 'forever chemical' once used in nonstick and stain-resistant products. | 1.3AverageDetection | 4MCL | Within the limit |
| Perfluorohexanesulfonic acidPerfluorohexanesulfonic acid, a PFAS 'forever chemical.' | Not detectedAverageDetection | 10MCL | Within the limit |
| PFOSPerfluorooctanesulfonic acid, a PFAS 'forever chemical' once used in firefighting foam and coatings. | Not detectedAverageDetection | 4MCL | Within the limit |
| Perfluoroheptanoic acidPerfluoroheptanoic acid, a PFAS 'forever chemical.' | 1.1AverageDetection | None set | Detected — no federal limit |
Physical & aggregate
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| TOCTotal organic carbon — a measure of organic material dissolved in the water. | 1.36–1.72RangeSystem-wide | None set | Detected — no federal limit |
| TurbidityA measure of cloudiness from suspended particles in the water. | 0.1 NTUReported levelSystem-wide | None set | Detected — no federal limit |
People also ask about Cary, NC's water
+Is Cary, NC tap water safe to drink in 2025?
Every one of the 18 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?
18 contaminants were measured in Cary, NC's 2025 Consumer Confidence Report, spanning pfas ("forever chemicals"), disinfection byproducts, and disinfectants. 11 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.