Hardness
Very Hard
255.5 PPM · 14.9 GPG
Local water dashboard
Official source aggregationWater quality in Royal Oak, MI 48067
A source-transparent look at local hardness, associated public water systems, EPA compliance history, and the measurements that are—and are not—available for Oakland County.
No active health-based violation reported
- Primary matched system
- Royal Oak, City Of
- Source water
- Surface water
- County
- Oakland 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
0.004 mg/L
27% of action level
Utility match
1 system
Serves 57,236 people system-wide
Hardness meter
How hard is the water?
Estimated local hardness
USGS hardness classification scale
255.5 PPM
Soft
0–59Moderate
60–120Hard
121–180Very hard
181+
0–59Moderate
60–120Hard
121–180Very hard
181+
Parts per million
255.5
mg/L as CaCO₃ equivalent
Grains per gallon
14.9
1 GPG ≈ 17.1 PPM
What this means at home
At 255.5 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
2
Nearest site
10.3 mi
Observation range
Jan 7, 2016–Jun 9, 2026
Estimate confidence
Low
Median of the latest qualifying hardness observation at each nearby monitoring site. Nearest monitoring location: CLINTON RIVER AT STERLING HEIGHTS, MI (Stream).USGS source documentation ↗
Regional context
Is 48067 typical?
These comparisons use other indexed ZIP estimates, not utility tap samples. They help show local context without replacing a household test.
Royal Oak median
269 PPM
13 PPM lower2 indexed ZIP readings · Range 255.5–283 PPM
Michigan median
283 PPM
27 PPM lower504 indexed ZIP readings · Range 41.3–459.5 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 pass
Lead (PB90)
0.004 mg/L
Reported Dec 31, 2025
Copper (CU90)
Not available
No numerical 90th-percentile result
Numerical coverage
1 comparable result
Missing values remain blank; absence is not treated as a pass.
Lead (90th percentile)
Measured in mg/L
Local 0.004
EPA limit 0.015
Share of EPA benchmark
100% line = listed limit
2026Q2
- All records
- 1
- Health-based
- 0
- Active health-based
- 0
| Contaminant or rule | System | Status | Period |
|---|---|---|---|
| Consumer Confidence Rule | MI0005830 | Resolved | Jul 1, 2021through Sep 20, 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 Royal Oak ZIP 48067 using 255.5 PPM nearby hardness and 1 reported measurement benchmarks.
Scale protection
High-Capacity Whole House Water Softener
255.5 PPM is 2× the high-hardness trigger used by this matcher.
Designed to reduce scale on fixtures, water heaters, glassware, and plumbing throughout the home.
Compare whole-house systemsAffiliate 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 Royal Oak
Estimates can differ across a city because monitoring locations and associated systems differ.
Frequently asked
Water questions for Royal Oak
Is tap water safe in Royal Oak?+
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 255.5 PPM, or 14.9 grains per gallon, classified as very hard. This is not a household tap measurement.
Do I need a water softener?+
At 255.5 PPM, a correctly sized whole-house softener can reduce scale and hard-water spotting. It does not replace contaminant filtration.