Hardness
Moderately Hard
62.8 PPM · 3.7 GPG
Local water dashboard
Official source aggregationWater quality in Castine, ME 04421
A source-transparent look at local hardness, associated public water systems, EPA compliance history, and the measurements that are—and are not—available for Hancock County.
No active health-based violation reported
- Primary matched system
- Castine Water Department
- Source water
- Groundwater influenced by surface water + Groundwater
- County
- Hancock 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
2 systems
Serves 983 people system-wide
Hardness meter
How hard is the water?
Estimated local hardness
USGS hardness classification scale
62.8 PPM
Soft
0–59Moderate
60–120Hard
121–180Very hard
181+
0–59Moderate
60–120Hard
121–180Very hard
181+
Parts per million
62.8
mg/L as CaCO₃ equivalent
Grains per gallon
3.7
1 GPG ≈ 17.1 PPM
What this means at home
At 62.8 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
2
Nearest site
64.2 mi
Observation range
Sep 24, 2019–Oct 11, 2023
Estimate confidence
Low
Median of the latest qualifying hardness observation at each nearby monitoring site. Nearest monitoring location: ME-PEW 692 (Well).USGS source documentation ↗
Regional context
Is 04421 typical?
These comparisons use other indexed ZIP estimates, not utility tap samples. They help show local context without replacing a household test.
Castine median
63 PPM
About the same1 indexed ZIP readings · Range 62.8–62.8 PPM
Maine median
39 PPM
24 PPM higher122 indexed ZIP readings · Range 3.2–94.5 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 mg/L
Reported Dec 31, 2024
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
EPA limit 0.015
Share of EPA benchmark
100% line = listed limit
2026Q2
- All records
- 12
- Health-based
- 1
- Active health-based
- 0
| Contaminant or rule | System | Status | Period |
|---|---|---|---|
| TTHM | ME0002527 | Archived | May 1, 2025through May 31, 2025 |
| Total Haloacetic Acids (HAA5) | ME0002527 | Archived | May 1, 2025through May 31, 2025 |
| Total Haloacetic Acids (HAA5) | ME0002527 | Archived | Apr 1, 2025through Apr 30, 2025 |
| TTHM | ME0002527 | Archived | Apr 1, 2025through Apr 30, 2025 |
| Lead and Copper Rule | ME0002527 | Resolved | Dec 30, 2024through Apr 3, 2025 |
| Revised Total Coliform RuleHealth-based | ME0002527 | Resolved | Sep 1, 2023through Sep 30, 2023 |
| Combined Radium (-226 and -228) | ME0002527 | Resolved | Jan 1, 2023through Jun 30, 2023 |
| Lead and Copper Rule | ME0002527 | Resolved | Oct 1, 2022through Apr 2, 2025 |
| Combined Radium (-226 and -228) | ME0002527 | Resolved | Jan 1, 2022through Jun 30, 2022 |
| Lead and Copper Rule | ME0002527 | Unaddressed | Dec 30, 2021 |
| Combined Radium (-226 and -228) | ME0002527 | Resolved | Jul 1, 2021through Dec 31, 2021 |
| Lead and Copper Rule | ME0002527 | Unaddressed | Oct 1, 2019 |
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 Castine ZIP 04421 using 62.8 PPM nearby hardness and 1 reported measurement benchmarks.
No urgent match
Start with an independent water test
This profile does not trigger a treatment recommendation. Test at the tap before investing in equipment.
Affiliate 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 Castine
Is tap water safe in Castine?+
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 62.8 PPM, or 3.7 grains per gallon, classified as moderately hard. 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.