County water report

Norfolk County Water Report

Drinking-water compliance, watershed health, monitoring records, and river conditions for Norfolk County, Massachusetts.

Water grade

Water score

63.8

State rank

#10

of 14

Health violations

EPA SDWIS, 5-year lookback

Watershed impaired

Not reported

EPA ATTAINS coverage varies by state

Monitoring sites

24,294 recent measurements

Live streamflow

43%

CHARLES RIVER AT WELLESLEY, MA

Water at a glance

Key Water Indicators for Norfolk County

EPA SDWIS

Safety Grade

Score: 63.8 / 100

EPA SDWIS

Active Violations

5-year health-based lookback

EPA ATTAINS

Watershed Health

Not reported

Coverage varies by state

USGS NWIS

Streamflow Snapshot

43% of mean

CHARLES RIVER AT WELLESLEY, MA

EPA WQP

Monitoring Sites

24,294 recent readings

Source: EPA SDWIS · Safe Drinking Water Information System

Drinking Water Compliance

Compliance grade

Based on EPA SDWIS compliance history.

Water score

Higher scores indicate cleaner recent compliance records.

63.8/100

Health violations

Health-based violations

Violations per 100K served

4.3

Population-normalized SDWIS rate

Data center water stress

Norfolk County has 1 facility in the DCWSI dataset.

ByCounty's DCWSI ranks this county #1177 nationally by combining its water score with mapped data center density.

DCWSI

38.3

0-100 index

Facility count

0.0 density percentile

Discharge estimate

Not reported

EPA CWA fields where available

Water vs median

+13.8

Compared with US county median

Mapped facilities

BAKER HUGHES
FOXBORO
EPA ECHO

See the Norfolk County data-center report Review methodology

Data Center Water Budget Calculator

Estimate daily water use for a hypothetical facility in Norfolk County.

Facility size: 100 MW

1 MW1,000 MW

Cooling type

Utilization: 70%

40%100%

799K gallons/dayHigh Impact

Your facility would use 36.7% of this county's industrial water baseline. Verify water rights and long-term drought projections before committing.

36.7% of county industrial baseline1.38 Mgal/day remaining headroom

Based on USGS 2020 water-use data and EPA-standard cooling intensity constants. Not a substitute for site-specific water rights analysis.

Editorial analysis

Understanding Norfolk County’s Water

Drinking Water Quality Overview

EPA SDWIS

Norfolk County earns a B grade for drinking water quality, scoring 63.8 out of 100. Over the past five years, EPA SDWIS records 33 health-based violations — a pattern that public water utilities are required to disclose and correct.

River & Streamflow Status

USGS NWIS

USGS NWIS gauge data (as of 2026-05-14T14:35:00.000-04:00) puts CHARLES RIVER at 125.0 cfs — well below its long-term average at 43% of mean — low-flow conditions worth noting for water-dependent ecosystems. Streamflow is a leading indicator of drought stress, sediment load, and dilution capacity: low flows concentrate pollutants and warm water temperatures, stressing aquatic life and, in surface-water-dependent systems, the source water quality for treatment plants.

Monitoring Network

EPA WQP

EPA's Water Quality Portal (WQP) aggregates monitoring data from federal, state, and tribal agencies. Norfolk County has extensive coverage with 82 active monitoring sites with 24,294 recent measurements on record. Predominant monitoring categories include physical and microbiological. More monitoring sites generally indicate greater scientific attention to local water conditions — and provide the baseline data that regulators use to set future impairment listings.

Editorial advisory

What the data suggests for Norfolk County

Water Verdict

Norfolk County, Massachusetts receives a fair water quality assessment with a grade of B and a score of 63.8 out of 100. The water supply meets baseline federal standards, but there may be periods of elevated contaminant levels or infrastructure concerns worth monitoring. The county's primary USGS gauge drains roughly 211 square miles of upstream watershed, giving local source waters a regional footprint. At the most recent USGS reading, local streamflow was below its historical mean at 42.6% — worth watching in drier seasons.

Violation Context

EPA SDWIS records for Norfolk County, Massachusetts show 33 health-based violations, indicating multiple instances where federal contaminant limits or treatment requirements were not met. At 4.3 violations per 100,000 people served, this rate is moderate and suggests recurring water quality challenges. This compliance record sits alongside an unusually deep monitoring archive: 24,294 water-quality results have been logged across the county in the EPA Water Quality Portal over the past five years.

Consumer Guidance

Tap water in Norfolk County meets baseline safety standards, though the compliance record shows some violations worth watching. Norfolk County's drinking-water compliance score is 63.8 out of 100. The violation rate for Norfolk County is 4.3 per 100,000 people served. Running tap water for 30 seconds before drinking can reduce any localized lead exposure from household plumbing. Requesting your utility's most recent Consumer Confidence Report is the fastest way to identify which specific contaminants were flagged. With 82 active water-quality monitoring sites in Norfolk County, data coverage is strong. A pipeline streamflow snapshot from the CHARLES RIVER gauge is also available on this page.

Regional Context

Norfolk County has poorer water quality than the average county in Massachusetts. Its water score is 5.3 points lower than the state average, suggesting more challenges with contamination control or infrastructure than neighboring counties.

Advisory text summarizes county-level public records and is not a replacement for your utility's current Consumer Confidence Report or direct local notices.

Contaminants & Resources

Key issues flagged in Norfolk County's water environment

Official EPA Resources for Norfolk County

EPA How's My Waterway

Interactive watershed health data for Norfolk County

EPA ECHO: Drinking Water Systems

Search water utilities and violation records for Norfolk County

Consumer Confidence Reports (MA)

Annual water quality reports from utilities in Massachusetts

Past 5 years

Water Quality Monitoring

Monitoring Sites

Active in the past 5 years

Measurements Recorded

24K

24,294 total readings

Most Measured

Physical
Microbiological
Nutrient

Categories measured most frequently

Data from the EPA Water Quality Portal (WQP), aggregating monitoring records from federal, state, and tribal sources. Each measurement represents a single sample analyzed for a specific characteristic (e.g., E. coli, pH, dissolved oxygen, nitrogen).

Live USGS Streamgage

River & Stream Conditions

Current Discharge

125cfs

May 14, 6:35 PM UTC

vs Long-Term Average

43%

Well below typical

Primary Streamgage

CHARLES RIVER AT WELLESLEY, MA

USGS site: 01104200
Drainage area: 211 sq mi
Long-term mean: 293 cfs

One representative streamgage (the one with the largest drainage area in the county). Many counties have multiple gauges; this view summarizes the primary one. The long-term mean is the full-record annual average; the percent-of-typical value compares the latest reading against that average.

Free tool

Estimate Your Water Costs

Water Cost Estimate

Household size

3 people · ~225 gal/day

Filter type

Annual Total

$558

Monthly

$47

Water Bill

$558/yr

Filter Cost

$0/yr

Safety Grade for Norfolk County:C — Moderate

Some violations or watershed impairment detected.

Estimates use the national average residential water rate ($0.0068/gal, EPA/AWWA 2023) and EPA WaterSense per-person consumption baseline (75 gal/person/day). Actual bills vary by utility, usage tier, and local infrastructure fees. For informational purposes only.

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Frequently Asked Questions

What is the water quality in Norfolk County, Massachusetts?

Norfolk County, Massachusetts has a drinking-water quality grade of B with a score of 63.8/100, based on EPA SDWIS compliance data. The county has 33 health-based drinking water violations over the past 5 years. Watershed health, monitoring records, and streamflow snapshots are reported separately on this page.

Are there any water violations in Norfolk County?

Norfolk County has 33 health-based drinking water violations recorded by the EPA over the past 5 years. Health-based violations indicate instances where contaminant levels exceeded EPA Maximum Contaminant Levels (MCLs). Violations may have been resolved — check with your local water utility for current status.

How much water-quality monitoring happens in Norfolk County?

EPA's Water Quality Portal records 24,294 measurements from 82 monitoring sites in Norfolk County over the past five years. The most frequently measured characteristic groups are Physical, Microbiological, Nutrient. Each measurement is a single sample analyzed for one characteristic (E. coli, pH, dissolved oxygen, etc.). High monitoring density means more scientific evidence behind any reported signal — it does not by itself indicate water quality.

What's happening with rivers in Norfolk County right now?

Norfolk County's primary USGS streamgage on the CHARLES RIVER has a pipeline snapshot of 125 cubic feet per second — 43% of the long-term mean of 293.11 cfs. This is well below typical — often a signal of drought stress on source water. For the latest gauge feed, visit waterdata.usgs.gov.

How does Norfolk County water compare to the Massachusetts average?

Norfolk County's SDWIS water quality score of 63.8/100 is lower than the Massachusetts state average of 69.1. The average water quality grade across Massachusetts is C, based on data from 14 counties with available SDWIS data.

Is tap water safe to drink in Norfolk County?

Based on EPA SDWIS data, Norfolk County has a water quality grade of B (63.8/100). This indicates good to excellent water quality with strong SDWIS compliance. The grade speaks to the public water system, not the watershed — for watershed-level concerns, see the Watershed Health zone. For the most up-to-date information, contact your local water utility or review your Consumer Confidence Report (CCR).

Why does Norfolk County have so many water violations?

Norfolk County has 33 health-based drinking water violations on record from the EPA SDWIS database. A higher violation count can result from aging infrastructure, underfunded water utilities, agricultural runoff contamination, or industrial pollution. Counties with more water systems may also see more violations simply due to scale. Residents concerned about water quality should consider independent water testing and home filtration systems.

How does Norfolk County rank for water quality in Massachusetts?

Norfolk County ranks #10 out of 14 counties in Massachusetts by SDWIS water quality score (1 = best). With a score of 63.8/100, it falls in the middle third of counties statewide. The ranking reflects EPA SDWIS compliance only — not watershed impairment, monitoring density, or streamflow, which are tracked separately on this page.

Counties with Similar Water Quality

Worcester County

Massachusetts

63.5

Water score

Plymouth County

Massachusetts

64.5

Water score

Hampden County

Massachusetts

66.4

Water score

Data Sources

Drinking-water compliance data from the EPA Safe Drinking Water Information System (SDWIS) via the ECHO enforcement database. Scores reflect compliance history and health-based violation counts.

Water-quality monitoring counts from the EPA Water Quality Portal (WQP), federated USGS, EPA, and state agency sampling records over a rolling 5-year window.

Live streamflow from the USGS National Water Information System (NWIS), continuous discharge measurements from the largest-drainage gauge in each county, compared against the full-record long-term annual mean.

Disclaimer: This data is informational only. It is not health, legal, or professional advice. For concerns about your specific water supply, contact your local water utility.

By Evan Brooks, Data EditorUpdated May 14, 2026Reviewed by Evan Brooks, Data Editor

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