Hardness
Moderately Hard
70.5 PPM · 4.1 GPG
Local water dashboard
Official source aggregationWater quality in Colchester, CT 06415
A source-transparent look at local hardness, associated public water systems, EPA compliance history, and the measurements that are—and are not—available for New London County.
2 active health-based violations
- Primary matched system
- Colchester Sewer & Water Commission
- Source water
- Groundwater
- County
- New London County
- Profile updated
At a glance
What the current records say
EPA quarter 2026Q2
Compliance screen
Review needed
2 active health-based records
Lead 90th percentile
0 mg/L
0% of action level
Utility match
8 systems
Serves 4,020 people system-wide
Hardness meter
How hard is the water?
Estimated local hardness
USGS hardness classification scale
70.5 PPM
Soft
0–59Moderate
60–120Hard
121–180Very hard
181+
0–59Moderate
60–120Hard
121–180Very hard
181+
Parts per million
70.5
mg/L as CaCO₃ equivalent
Grains per gallon
4.1
1 GPG ≈ 17.1 PPM
What this means at home
At 70.5 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
223
Nearest site
11.9 mi
Observation range
May 11, 2016–Dec 2, 2025
Estimate confidence
Moderate
Median of the latest qualifying hardness observation at each nearby monitoring site. Nearest monitoring location: CT-FR 23 (Well).USGS source documentation ↗
Regional context
Is 06415 typical?
These comparisons use other indexed ZIP estimates, not utility tap samples. They help show local context without replacing a household test.
Colchester median
71 PPM
About the same1 indexed ZIP readings · Range 70.5–70.5 PPM
Connecticut median
53 PPM
18 PPM higher98 indexed ZIP readings · Range 42.8–114 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, 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
EPA limit 0.015
Share of EPA benchmark
100% line = listed limit
2026Q2
- All records
- 66
- Health-based
- 3
- Active health-based
- 2
| Contaminant or rule | System | Status | Period |
|---|---|---|---|
| E. COLI | CT0280011 | Archived | Mar 1, 2026through Mar 31, 2026 |
| Consumer Confidence Rule | CT0280011 | Resolved | Aug 10, 2025through Aug 29, 2025 |
| Consumer Confidence Rule | CT0280011 | Resolved | Jul 1, 2025through Jul 25, 2025 |
| Public Notice | CT0280011 | Resolved | Jun 15, 2025through Aug 29, 2025 |
| Public Notice | CT0280011 | Resolved | Jun 15, 2025through Aug 29, 2025 |
| Lead and Copper Rule | CT0280041 | Resolved | Dec 30, 2024through Dec 31, 2024 |
| Lead and Copper Rule | CT0286011 | Resolved | Dec 30, 2024through Dec 31, 2024 |
| LEAD AND COPPER RULE REVISIONSHealth-based | CT0280041 | Unaddressed | Oct 17, 2024 |
| LEAD AND COPPER RULE REVISIONS | CT0280041 | Unaddressed | Oct 17, 2024 |
| LEAD AND COPPER RULE REVISIONS | CT0286011 | Unaddressed | Oct 17, 2024 |
| LEAD AND COPPER RULE REVISIONSHealth-based | CT0286011 | Unaddressed | Oct 17, 2024 |
| Consumer Confidence Rule | CT0280031 | Resolved | Jul 1, 2024through Jul 2, 2024 |
| Public Notice | CT0280011 | Resolved | May 25, 2024through Aug 29, 2025 |
| E. COLI | CT0280011 | Resolved | Mar 1, 2024through Mar 31, 2024 |
| E. COLI | CT0280011 | Resolved | Jan 1, 2024through Jan 31, 2024 |
| Total Haloacetic Acids (HAA5) | CT0280011 | Resolved | Jan 1, 2024through Dec 31, 2024 |
| TTHM | CT0280011 | Resolved | Jan 1, 2024through Dec 31, 2024 |
| Consumer Confidence Rule | CT0280011 | Resolved | Jul 1, 2023through Jul 17, 2023 |
| Nitrate | CT0280041 | Resolved | Jan 1, 2023through Dec 31, 2023 |
| Nitrite | CT0280041 | Resolved | Jan 1, 2023through Dec 31, 2023 |
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 Colchester ZIP 06415 using 70.5 PPM nearby hardness and 1 reported measurement benchmarks.
Drinking water protection
Under-Sink Reverse Osmosis System
LEAD AND COPPER RULE REVISIONS 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 Colchester
Is tap water safe in Colchester?+
EPA ECHO reports 2 active health-based violations among the associated community water systems. Review the affected utility's current notice and Consumer Confidence Report.
How hard is the water?+
Nearby USGS observations produce an estimate of 70.5 PPM, or 4.1 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.