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Federal water data

County water report

Plymouth County Water Report

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

Water grade

B

Water score

64.5

State rank

#9

of 14

Health violations

21

EPA SDWIS, 5-year lookback

Watershed impaired

Not reported

EPA ATTAINS coverage varies by state

Monitoring sites

400

24,969 recent measurements

Live streamflow

49%

TAUNTON RIVER NEAR BRIDGEWATER, MA

Water at a glance

Key Water Indicators for Plymouth County

EPA SDWIS

Safety Grade

B

Score: 64.5 / 100

EPA SDWIS

Active Violations

21

5-year health-based lookback

EPA ATTAINS

Watershed Health

Not reported

Coverage varies by state

USGS NWIS

Streamflow Snapshot

49% of mean

TAUNTON RIVER NEAR BRIDGEWATER, MA

EPA WQP

Monitoring Sites

400

24,969 recent readings

Source: EPA SDWIS · Safe Drinking Water Information System

Drinking Water Compliance

Compliance grade

B

Based on EPA SDWIS compliance history.

Water score

Higher scores indicate cleaner recent compliance records.

64.5/100

Health violations

21

Health-based violations

Violations per 100K served

3.8

Population-normalized SDWIS rate

Editorial analysis

Understanding Plymouth County’s Water

Drinking Water Quality Overview

EPA SDWIS

Plymouth County earns a B grade for drinking water quality, scoring 64.5 out of 100. Over the past five years, EPA SDWIS records 21 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 2026-05-14T14:45:00.000-04:00) puts TAUNTON RIVER at 244.0 cfs — well below its long-term average at 49% 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. Plymouth County has extensive coverage with 400 active monitoring sites with 24,969 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 Plymouth County

Water Verdict

Plymouth County receives a fair water quality assessment with a grade of B and a score of 64.5 out of 100. The water supply meets baseline federal standards, but there may be periods of elevated contaminant levels or infrastructure concerns worth monitoring.

Violation Context

Plymouth County has recorded 21 health-based violations, indicating multiple instances where federal contaminant limits or treatment requirements were not met. At 3.8 violations per 100,000 people served, this rate is moderate and suggests recurring water quality challenges.

Consumer Guidance

Tap water in Plymouth County meets baseline safety standards, though the compliance record shows some violations worth watching. Plymouth County's drinking-water compliance score is 64.5 out of 100. The violation rate for Plymouth County is 3.8 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 400 active water-quality monitoring sites in Plymouth County, data coverage is strong. A pipeline streamflow snapshot from the TAUNTON RIVER gauge is also available on this page.

Regional Context

Plymouth County has water quality close to the average county in Massachusetts. Its water score is within 4.6 points of the state average, meaning its overall water system performance is broadly representative of Massachusetts as a whole.

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 Plymouth County's water environment

Official EPA Resources for Plymouth County

EPA How's My Waterway

Interactive watershed health data for Plymouth County

EPA ECHO: Drinking Water Systems

Search water utilities and violation records for Plymouth County

Consumer Confidence Reports (MA)

Annual water quality reports from utilities in Massachusetts

Past 5 years

Water Quality Monitoring

Monitoring Sites

400

Active in the past 5 years

Measurements Recorded

25K

24,969 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

244cfs

May 14, 6:45 PM UTC

vs Long-Term Average

49%

Well below typical

Primary Streamgage

TAUNTON RIVER NEAR BRIDGEWATER, MA

USGS site
01108000
Drainage area
261 sq mi
Long-term mean
497 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.

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Water Cost Estimate

3

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Annual Total

$558

Monthly

$47

Water Bill

$558/yr

Filter Cost

$0/yr

Safety Grade for Plymouth 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 Plymouth County, Massachusetts?
Plymouth County, Massachusetts has a drinking-water quality grade of B with a score of 64.5/100, based on EPA SDWIS compliance data. The county has 21 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 Plymouth County?
Plymouth County has 21 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 Plymouth County?
EPA's Water Quality Portal records 24,969 measurements from 400 monitoring sites in Plymouth 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 Plymouth County right now?
Plymouth County's primary USGS streamgage on the TAUNTON RIVER has a pipeline snapshot of 244 cubic feet per second — 49% of the long-term mean of 497.19 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 Plymouth County water compare to the Massachusetts average?
Plymouth County's SDWIS water quality score of 64.5/100 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 Plymouth County?
Based on EPA SDWIS data, Plymouth County has a water quality grade of B (64.5/100). 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 Plymouth County have so many water violations?
Plymouth County has 21 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 Plymouth County rank for water quality in Massachusetts?
Plymouth County ranks #9 out of 14 counties in Massachusetts by SDWIS water quality score (1 = best). With a score of 64.5/100, 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

Norfolk County

Massachusetts

B

63.8

Water score

Worcester County

Massachusetts

B

63.5

Water score

Hampden County

Massachusetts

B

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 Reviewed by Evan Brooks, Data Editor

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