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County water report

Carroll County Water Report

Drinking-water compliance, watershed health, monitoring records, and river conditions for Carroll County, New Hampshire.

Water grade

F

Water score

7.5

State rank

#10

of 10

Health violations

177

EPA SDWIS, 5-year lookback

Watershed impaired

Not reported

EPA ATTAINS coverage varies by state

Monitoring sites

173

21,252 recent measurements

Live streamflow

92%

Saco River near Conway, NH

Water at a glance

Key Water Indicators for Carroll County

EPA SDWIS

Safety Grade

F

Score: 7.5 / 100

EPA SDWIS

Active Violations

177

5-year health-based lookback

EPA ATTAINS

Watershed Health

Not reported

Coverage varies by state

USGS NWIS

Streamflow Snapshot

92% of mean

Saco River near Conway, NH

EPA WQP

Monitoring Sites

173

21,252 recent readings

Source: EPA SDWIS · Safe Drinking Water Information System

Drinking Water Compliance

Compliance grade

F

Based on EPA SDWIS compliance history.

Water score

Higher scores indicate cleaner recent compliance records.

7.5/100

Health violations

177

Health-based violations

Violations per 100K served

465.2

Population-normalized SDWIS rate

Editorial analysis

Understanding Carroll County’s Water

Drinking Water Quality Overview

EPA SDWIS

Carroll County's water systems carry a failing grade, scoring 7.5 out of 100. Over the past five years, EPA SDWIS records 177 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 Saco River at 901.0 cfs — near its historical average at 92% of mean flow. 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. Carroll County has extensive coverage with 173 active monitoring sites with 21,252 recent measurements on record. Predominant monitoring categories include physical and nutrient. 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 Carroll County

Water Verdict

Carroll County, New Hampshire receives a poor water quality assessment with a grade of F and a score of 7.5 out of 100. The water supply has documented quality issues. Residents are strongly encouraged to use filtered or bottled water for drinking and to stay informed about utility improvement plans. The county's primary USGS gauge drains roughly 385 square miles of upstream watershed, giving local source waters a regional footprint. At the most recent USGS reading, local streamflow was tracking near its historical mean (92.2%).

Violation Context

EPA SDWIS records for Carroll County, New Hampshire show 177 health-based violations, indicating multiple instances where federal contaminant limits or treatment requirements were not met. At 465.2 violations per 100,000 people served, this rate is high and signals significant water quality management issues. This compliance record sits alongside an unusually deep monitoring archive: 21,252 water-quality results have been logged across the county in the EPA Water Quality Portal over the past five years.

Consumer Guidance

Carroll County has a Grade F compliance record with 177 health-based violations — among the highest levels in the country. Carroll County's drinking-water compliance score is 7.5 out of 100. Residents are strongly advised to use a certified NSF 58 reverse-osmosis filter or bottled water for all drinking and cooking until violations are corrected. Contacting the New Hampshire Department of Environmental Quality or Health can expedite utility compliance action. With 173 active water-quality monitoring sites in Carroll County, data coverage is strong. A pipeline streamflow snapshot from the Saco River gauge is also available on this page.

Regional Context

Carroll County has poorer water quality than the average county in New Hampshire. Its water score is 25.7 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 Carroll County's water environment

Official EPA Resources for Carroll County

EPA How's My Waterway

Interactive watershed health data for Carroll County

EPA ECHO: Drinking Water Systems

Search water utilities and violation records for Carroll County

Consumer Confidence Reports (NH)

Annual water quality reports from utilities in New Hampshire

Past 5 years

Water Quality Monitoring

Monitoring Sites

173

Active in the past 5 years

Measurements Recorded

21K

21,252 total readings

Most Measured

  • Physical
  • Nutrient
  • Microbiological

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

901cfs

May 14, 6:45 PM UTC

vs Long-Term Average

92%

Near typical

Primary Streamgage

Saco River near Conway, NH

USGS site
01064500
Drainage area
385 sq mi
Long-term mean
977 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

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Annual Total

$558

Monthly

$47

Water Bill

$558/yr

Filter Cost

$0/yr

Safety Grade for Carroll County:F — Failing

High violation count or severe watershed conditions.

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 Carroll County, New Hampshire?
Carroll County, New Hampshire has a drinking-water quality grade of F with a score of 7.5/100, based on EPA SDWIS compliance data. The county has 177 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 Carroll County?
Carroll County has 177 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 Carroll County?
EPA's Water Quality Portal records 21,252 measurements from 173 monitoring sites in Carroll County over the past five years. The most frequently measured characteristic groups are Physical, Nutrient, Microbiological. 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 Carroll County right now?
Carroll County's primary USGS streamgage on the Saco River has a pipeline snapshot of 901 cubic feet per second — 92% of the long-term mean of 976.8 cfs. Flow is within typical range for this gauge. For the latest gauge feed, visit waterdata.usgs.gov.
How does Carroll County water compare to the New Hampshire average?
Carroll County's SDWIS water quality score of 7.5/100 is lower than the New Hampshire state average of 33.2. The average water quality grade across New Hampshire is F, based on data from 10 counties with available SDWIS data.
Is tap water safe to drink in Carroll County?
Based on EPA SDWIS data, Carroll County has a water quality grade of F (7.5/100). This indicates below-average compliance with significant violations. Residents may want to consider home water filtration or independent testing. 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 Carroll County have so many water violations?
Carroll County has 177 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 Carroll County rank for water quality in New Hampshire?
Carroll County ranks #10 out of 10 counties in New Hampshire by SDWIS water quality score (1 = best). With a score of 7.5/100, it falls in the bottom 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

Belknap County

New Hampshire

F

13.5

Water score

Merrimack County

New Hampshire

F

20.5

Water score

Rockingham County

New Hampshire

F

26.4

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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