Hardness
Soft
44.4 PPM · 2.6 GPG
Local water dashboard
Official source aggregationWater quality in Coffman Cove, AK 99918
A source-transparent look at local hardness, associated public water systems, EPA compliance history, and the measurements that are—and are not—available for Prince Of Wales-Hyder Census Area.
1 reported benchmark flag
- Primary matched system
- Coffman Cove
- Source water
- Surface water
- County
- Prince Of Wales-Hyder Census Area
- 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
1 system
Serves 199 people system-wide
Hardness meter
How hard is the water?
Estimated local hardness
USGS hardness classification scale
44.4 PPM
Soft
0–59Moderate
60–120Hard
121–180Very hard
181+
0–59Moderate
60–120Hard
121–180Very hard
181+
Parts per million
44.4
mg/L as CaCO₃ equivalent
Grains per gallon
2.6
1 GPG ≈ 17.1 PPM
What this means at home
At 44.4 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
6
Nearest site
58.8 mi
Observation range
Aug 23, 2017–Jul 22, 2025
Estimate confidence
Low
Median of the latest qualifying hardness observation at each nearby monitoring site. Nearest monitoring location: STIKINE R NR WRANGELL AK (Stream).USGS source documentation ↗
Regional context
Is 99918 typical?
These comparisons use other indexed ZIP estimates, not utility tap samples. They help show local context without replacing a household test.
Coffman Cove median
44 PPM
About the same1 indexed ZIP readings · Range 44.4–44.4 PPM
Alaska median
83 PPM
39 PPM lower18 indexed ZIP readings · Range 36.7–199 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, 2023
Copper (CU90)
Not available
No numerical 90th-percentile result
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
Total Haloacetic Acids (HAA5)
Measured in MG/L
Local 0.078
EPA limit 0.06
Share of EPA benchmark
100% line = listed limit
2026Q2
- All records
- 23
- Health-based
- 9
- Active health-based
- 0
| Contaminant or rule | System | Status | Period |
|---|---|---|---|
| Public Notice | AK2120436 | Resolved | Sep 8, 2025through Oct 30, 2025 |
| Total Haloacetic Acids (HAA5)Health-basedReported 0.078 MG/L · MCL 0.06 | AK2120436 | Resolved | Apr 1, 2025through Jun 30, 2025 |
| Total Haloacetic Acids (HAA5)Health-basedReported 0.077 MG/L · MCL 0.06 | AK2120436 | Resolved | Jan 1, 2025through Mar 31, 2025 |
| Interim Enhanced Surface Water Treatment Rule | AK2120436 | Resolved | Dec 1, 2024through Dec 31, 2024 |
| Surface Water Treatment Rule | AK2120436 | Resolved | Dec 1, 2024through Dec 31, 2024 |
| Total Haloacetic Acids (HAA5)Health-basedReported 0.073 MG/L · MCL 0.06 | AK2120436 | Resolved | Oct 1, 2024through Dec 31, 2024 |
| Consumer Confidence Rule | AK2120436 | Resolved | Jul 1, 2024through Sep 10, 2024 |
| Chlorine | AK2120436 | Resolved | Jun 1, 2024through Jun 30, 2024 |
| Surface Water Treatment Rule | AK2120436 | Resolved | Jun 1, 2024through Jun 30, 2024 |
| Revised Total Coliform Rule | AK2120436 | Resolved | Jun 1, 2024through Jun 30, 2024 |
| CARBON, TOTALHealth-basedReported 0.51 RATIO | AK2120436 | Resolved | Apr 1, 2022through Jun 30, 2022 |
| CARBON, TOTAL | AK2120436 | Resolved | Jan 1, 2022through Mar 1, 2022 |
| CARBON, TOTALHealth-basedReported 0.31 RATIO | AK2120436 | Resolved | Jan 1, 2022through Mar 31, 2022 |
| Revised Total Coliform Rule | AK2120436 | Resolved | Jan 1, 2022through Jan 31, 2022 |
| Revised Total Coliform Rule | AK2120436 | Resolved | Dec 1, 2021through Dec 31, 2021 |
| CARBON, TOTALHealth-basedReported 0.22 RATIO | AK2120436 | Resolved | Oct 1, 2021through Dec 31, 2021 |
| Chlorine | AK2120436 | Resolved | Oct 1, 2021through Dec 31, 2021 |
| Revised Total Coliform Rule | AK2120436 | Resolved | Aug 1, 2021through Aug 31, 2021 |
| Consumer Confidence Rule | AK2120436 | Resolved | Jul 1, 2021through Sep 17, 2021 |
| CARBON, TOTALHealth-basedReported 0.1 RATIO | AK2120436 | Resolved | Jul 1, 2021through Sep 30, 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 Coffman Cove ZIP 99918 using 44.4 PPM nearby hardness and 2 reported measurement benchmarks.
Drinking water protection
Under-Sink Reverse Osmosis System
Total Haloacetic Acids (HAA5) 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
Water questions for Coffman Cove
Is tap water safe in Coffman Cove?+
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 44.4 PPM, or 2.6 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.