Hardness
Soft
39.8 PPM · 2.3 GPG
Local water dashboard
Official source aggregationWater quality in Cary, NC 27518
A source-transparent look at local hardness, associated public water systems, EPA compliance history, and the measurements that are—and are not—available for Wake County.
1 reported benchmark flag
- Primary matched system
- Cary, Town Of
- Source water
- Surface water + Groundwater
- County
- Wake County
- Profile updated
At a glance
What the current records say
EPA quarter 2026Q2
Compliance screen
No active flag
0 active health-based records
Lead 90th percentile
0 mg/L
0% of action level
Utility match
10 systems
Serves 227,300 people system-wide
Hardness meter
How hard is the water?
Estimated local hardness
USGS hardness classification scale
39.8 PPM
Soft
0–59Moderate
60–120Hard
121–180Very hard
181+
0–59Moderate
60–120Hard
121–180Very hard
181+
Parts per million
39.8
mg/L as CaCO₃ equivalent
Grains per gallon
2.3
1 GPG ≈ 17.1 PPM
What this means at home
At 39.8 PPM, mineral scale can build up on fixtures and heating elements, reduce soap lather, and leave visible spotting. Hardness is primarily an aesthetic and appliance concern—not itself a tap-water safety rating.
USGS sites used
54
Nearest site
1.4 mi
Observation range
Jan 14, 2016–Jun 9, 2026
Estimate confidence
Moderate
Median of the latest qualifying hardness observation at each nearby monitoring site. Nearest monitoring location: SWIFT CREEK NEAR APEX, NC (Stream).USGS source documentation ↗
Regional context
Is 27518 typical?
These comparisons use other indexed ZIP estimates, not utility tap samples. They help show local context without replacing a household test.
Cary median
40 PPM
About the same4 indexed ZIP readings · Range 39.8–40.5 PPM
North Carolina median
41 PPM
About the same519 indexed ZIP readings · Range 4.7–267.5 PPM
EPA benchmark screen
Contaminant snapshot
Available numerical results from associated SDWIS community water systems, compared with the applicable action level or federal MCL. Federal measured-value coverage is incomplete.
1 pass1 fail
Lead (PB90)
0 mg/L
Reported Dec 31, 2025
Copper (CU90)
3.95 mg/L
Reported Dec 31, 2010
Numerical coverage
2 comparable results
Missing values remain blank; absence is not treated as a pass.
Lead (90th percentile)
Measured in mg/L
Local 0
EPA limit 0.015
Copper (90th percentile)
Measured in mg/L
Local 3.95
EPA limit 1.3
Share of EPA benchmark
100% line = listed limit
2026Q2
- All records
- 20
- Health-based
- 1
- Active health-based
- 0
| Contaminant or rule | System | Status | Period |
|---|---|---|---|
| Consumer Confidence Rule | NC0392160 | Resolved | Jul 1, 2024through Jan 30, 2025 |
| Consumer Confidence Rule | NC0392361 | Resolved | Jul 1, 2024through Dec 10, 2024 |
| Consumer Confidence Rule | NC4392102 | Resolved | Jul 1, 2024through Dec 12, 2024 |
| Consumer Confidence Rule | NC0392381 | Resolved | Jul 1, 2024through Dec 17, 2024 |
| Consumer Confidence Rule | NC4092021 | Resolved | Jul 1, 2024through Dec 5, 2024 |
| Consumer Confidence Rule | NC4392131 | Resolved | Jul 1, 2024through Dec 5, 2024 |
| Consumer Confidence Rule | NC4392229 | Resolved | Jul 1, 2024through Jan 29, 2025 |
| Revised Total Coliform Rule | NC4092021 | Resolved | Jan 11, 2024through Feb 2, 2024 |
| Revised Total Coliform Rule | NC4392131 | Resolved | Jan 11, 2024through Feb 2, 2024 |
| Revised Total Coliform Rule | NC0392160 | Resolved | Dec 11, 2023through Dec 11, 2023 |
| Public Notice | NC0392020 | Resolved | May 10, 2023through Feb 13, 2024 |
| Revised Total Coliform RuleHealth-based | NC0392020 | Resolved | May 1, 2023through May 31, 2023 |
| 2,4,5-TP | NC0392381 | Resolved | Jan 1, 2023through Dec 31, 2025 |
| Dinoseb | NC0392381 | Resolved | Jan 1, 2023through Dec 31, 2025 |
| Pentachlorophenol | NC0392381 | Resolved | Jan 1, 2023through Dec 31, 2025 |
| Picloram | NC0392381 | Resolved | Jan 1, 2023through Dec 31, 2025 |
| Dalapon | NC0392381 | Resolved | Jan 1, 2023through Dec 31, 2025 |
| 2,4-D | NC0392381 | Resolved | Jan 1, 2023through Dec 31, 2025 |
| TTHM | NC4392162 | Resolved | Mar 1, 2021through May 31, 2021 |
| Total Haloacetic Acids (HAA5) | NC4392162 | Resolved | Mar 1, 2021through May 31, 2021 |
No reported violation does not prove that every contaminant was tested or absent; SDWIS measured values are incomplete and lag state records.
Solutions matcher
Your personalized water action plan
Matched to Cary ZIP 27518 using 39.8 PPM nearby hardness and 2 reported measurement benchmarks.
Drinking water protection
Under-Sink Reverse Osmosis System
Copper (90th percentile) has a measured benchmark flag or active health-based SDWIS record in this profile.
A certified multi-stage RO system targets a broader range of dissolved contaminants at the kitchen tap.
Explore under-sink filtrationAffiliate disclosure: we may earn a commission from qualifying purchases, at no added cost to you. Product matching is educational and does not replace certified water testing.
Nearby indexed reports
Compare ZIPs in Cary
Estimates can differ across a city because monitoring locations and associated systems differ.
Frequently asked
Water questions for Cary
Is tap water safe in Cary?+
EPA ECHO shows no active health-based violation for the associated systems in this reporting snapshot. This does not prove every contaminant is absent; federal records can lag and household plumbing can change tap conditions.
How hard is the water?+
Nearby USGS observations produce an estimate of 39.8 PPM, or 2.3 grains per gallon, classified as soft. This is not a household tap measurement.
Do I need a water softener?+
There is no high-hardness trigger in this profile. Confirm with a tap test before buying equipment.