Hardness
Hard
166 PPM · 9.7 GPG
Local water dashboard
Official source aggregationA source-transparent look at local hardness, associated public water systems, EPA compliance history, and the measurements that are—and are not—available for Alger County.
At a glance
EPA quarter 2026Q2
Hardness
Hard
166 PPM · 9.7 GPG
Compliance screen
No active flag
0 active health-based records
Lead 90th percentile
Not reported
Check the utility CCR or tap test
Utility match
1 system
Serves 411 people system-wide
Hardness meter
Estimated local hardness
USGS hardness classification scale
166 PPM
Parts per million
166
mg/L as CaCO₃ equivalent
Grains per gallon
9.7
1 GPG ≈ 17.1 PPM
What this means at home
At 166 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
1
Nearest site
20.2 mi
Observation range
Nov 15, 2016–Feb 26, 2024
Estimate confidence
Low
Median of the latest qualifying hardness observation at each nearby monitoring site. Nearest monitoring location: MINERS RIVER NR MUNISING, MI (Stream).USGS source documentation ↗
Regional context
These comparisons use other indexed ZIP estimates, not utility tap samples. They help show local context without replacing a household test.
Grand Marais median
166 PPM
About the same1 indexed ZIP readings · Range 166–166 PPM
Michigan median
283 PPM
117 PPM lower504 indexed ZIP readings · Range 41.3–459.5 PPM
EPA benchmark screen
Available numerical results from associated SDWIS community water systems, compared with the applicable action level or federal MCL. Federal measured-value coverage is incomplete.
Lead (PB90)
Not available
No numerical 90th-percentile result
Copper (CU90)
1.71 mg/L
Reported Dec 31, 1996
Numerical coverage
1 comparable result
Missing values remain blank; absence is not treated as a pass.
Measured in mg/L
Local 1.71
EPA limit 1.3
100% line = listed limit
No violation record was returned for the associated systems in the imported lookback window beginning Jan 1, 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
Matched to Grand Marais ZIP 49839 using 166 PPM nearby hardness and 1 reported measurement benchmarks.
Scale protection
166 PPM is 1× 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 systemsDrinking water protection
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.
Frequently asked
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.
Nearby USGS observations produce an estimate of 166 PPM, or 9.7 grains per gallon, classified as hard. This is not a household tap measurement.
At 166 PPM, a correctly sized whole-house softener can reduce scale and hard-water spotting. It does not replace contaminant filtration.