Hardness
Moderately Hard
65.3 PPM · 3.8 GPG
Local water dashboard
Official source aggregationWater quality in Sudbury, MA 01776
A source-transparent look at local hardness, associated public water systems, EPA compliance history, and the measurements that are—and are not—available for Middlesex County.
1 active health-based violation
- Primary matched system
- Sudbury Water District
- Source water
- Groundwater
- County
- Middlesex County
- Profile updated
At a glance
What the current records say
EPA quarter 2026Q2
Compliance screen
Review needed
1 active health-based record
Lead 90th percentile
0.0035 mg/L
23% of action level
Utility match
1 system
Serves 18,416 people system-wide
Hardness meter
How hard is the water?
Estimated local hardness
USGS hardness classification scale
65.3 PPM
Soft
0–59Moderate
60–120Hard
121–180Very hard
181+
0–59Moderate
60–120Hard
121–180Very hard
181+
Parts per million
65.3
mg/L as CaCO₃ equivalent
Grains per gallon
3.8
1 GPG ≈ 17.1 PPM
What this means at home
At 65.3 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
181
Nearest site
3.6 mi
Observation range
Jan 13, 2016–Sep 25, 2023
Estimate confidence
Moderate
Median of the latest qualifying hardness observation at each nearby monitoring site. Nearest monitoring location: MA-WKW 95 (Well).USGS source documentation ↗
Regional context
Is 01776 typical?
These comparisons use other indexed ZIP estimates, not utility tap samples. They help show local context without replacing a household test.
Sudbury median
65 PPM
About the same1 indexed ZIP readings · Range 65.3–65.3 PPM
Massachusetts median
49 PPM
16 PPM higher328 indexed ZIP readings · Range 24.3–128 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)
0.0035 mg/L
Reported Jun 30, 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 0.0035
EPA limit 0.015
Share of EPA benchmark
100% line = listed limit
2026Q2
- All records
- 4
- Health-based
- 1
- Active health-based
- 1
| Contaminant or rule | System | Status | Period |
|---|---|---|---|
| Revised Total Coliform RuleHealth-based | MA3288000 | Addressed | Aug 1, 2025 |
| Lead and Copper Rule | MA3288000 | Addressed | Jun 1, 2022 |
| ENTEROCOCCI | MA3288000 | Unaddressed | Jun 1, 2019 |
| Lead and Copper Rule | MA3288000 | Addressed | Jun 1, 2018 |
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 Sudbury ZIP 01776 using 65.3 PPM nearby hardness and 1 reported measurement benchmarks.
Drinking water protection
Under-Sink Reverse Osmosis System
Revised Total Coliform Rule 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 Sudbury
Is tap water safe in Sudbury?+
EPA ECHO reports 1 active health-based violation 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 65.3 PPM, or 3.8 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.