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County water report

Cheshire County Water Report

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

Water grade

C

Water score

51.2

State rank

#2

of 10

Health violations

7

EPA SDWIS, 5-year lookback

Watershed impaired

50.0%

2 water bodies assessed

Monitoring sites

313

22,992 recent measurements

Live streamflow

122%

CONNECTICUT RIVER AT NORTH WALPOLE, NH

Water at a glance

Key Water Indicators for Cheshire County

EPA SDWIS

Safety Grade

C

Score: 51.2 / 100

EPA SDWIS

Active Violations

7

5-year health-based lookback

EPA ATTAINS

Watershed Health

50% impaired

2 bodies assessed

USGS NWIS

Streamflow Snapshot

122% of mean

CONNECTICUT RIVER AT NORTH WALPOLE, NH

EPA WQP

Monitoring Sites

313

22,992 recent readings

Source: EPA SDWIS · Safe Drinking Water Information System

Drinking Water Compliance

Compliance grade

C

Based on EPA SDWIS compliance history.

Water score

Higher scores indicate cleaner recent compliance records.

51.2/100

Health violations

7

Health-based violations

Violations per 100K served

14.5

Population-normalized SDWIS rate

Editorial analysis

Understanding Cheshire County’s Water

Drinking Water Quality Overview

EPA SDWIS

Cheshire County's drinking water earned a C grade, scoring 51.2 out of 100. Over the past five years, EPA SDWIS records 7 health-based violations — a pattern that public water utilities are required to disclose and correct.

Watershed Conditions

EPA ATTAINS

Under the Clean Water Act §303(d), EPA ATTAINS tracks whether waterways meet quality standards for drinking, recreation, and aquatic life (reporting cycle: 2022). A substantial 50.0% of assessed waterways are impaired (1 of 2 water bodies) across Cheshire County's watersheds. The leading impairment causes are mercury - fish consumption advisory and ph. Impairment does not mean tap water is unsafe — it measures ambient waterway conditions upstream of treatment, not finished drinking water.

River & Streamflow Status

USGS NWIS

USGS NWIS gauge data (as of 2026-05-14T14:30:00.000-04:00) puts CONNECTICUT RIVER at 12.2k cfs — flowing above its historical average at 122% of mean. 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. Cheshire County has extensive coverage with 313 active monitoring sites with 22,992 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 Cheshire County

Water Verdict

Cheshire County receives a below-average water quality assessment with a grade of C and a score of 51.2 out of 100. Residents should review their utility's Consumer Confidence Report and may want to consider additional water filtration for drinking.

Violation Context

Cheshire County has recorded 7 health-based violations, indicating multiple instances where federal contaminant limits or treatment requirements were not met. At 14.5 violations per 100,000 people served, this rate is high and signals significant water quality management issues.

Consumer Guidance

Tap water in Cheshire County meets baseline standards but the compliance record shows room for improvement, with a Grade C rating. Cheshire County's drinking-water compliance score is 51.2 out of 100. The violation rate for Cheshire County is 14.5 per 100,000 people served. Residents who are immunocompromised, pregnant, or have young children may benefit from using an NSF 53-certified filter. Contacting your local utility for the current Consumer Confidence Report will confirm which specific violations were recorded and whether they have been resolved. Mercury - Fish Consumption Advisory is the leading impairment cause in Cheshire County's watershed. With 313 active water-quality monitoring sites in Cheshire County, data coverage is strong. A pipeline streamflow snapshot from the CONNECTICUT RIVER gauge is also available on this page.

Regional Context

Cheshire County has better water quality than the average county in New Hampshire. Its water score is 18 points higher than the state average, indicating stronger water system performance relative to 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 Cheshire County's water environment

Watershed Impairment Causes (EPA ATTAINS)

  • 1

    Mercury - Fish Consumption Advisory

    Impairment cause per EPA Clean Water Act §303(d) assessment

  • 2

    pH imbalance

    Impairment cause per EPA Clean Water Act §303(d) assessment

Source: EPA ATTAINS · Reporting cycle 2022

Official EPA Resources for Cheshire County

EPA How's My Waterway

Interactive watershed health data for Cheshire County

EPA ECHO: Drinking Water Systems

Search water utilities and violation records for Cheshire County

Consumer Confidence Reports (NH)

Annual water quality reports from utilities in New Hampshire

Clean Water Act §303(d)

Watershed Health

Impaired Water Bodies

50.0%

1 of 2 assessed

Moderate concern

Top Impairment Causes

  • 1

    MERCURY - FISH CONSUMPTION ADVISORY

  • 2

    PH

Source: EPA ATTAINS · Reporting cycle 2022

Impairment is determined under the Clean Water Act §303(d): a water body is impaired when it fails to meet state-defined quality standards for designated uses (drinking, recreation, aquatic life). Assessment coverage varies by state; counties without assessed water bodies are not shown.

Past 5 years

Water Quality Monitoring

Monitoring Sites

313

Active in the past 5 years

Measurements Recorded

23K

22,992 total readings

Most Measured

  • Physical
  • Nutrient
  • Inorganics, Major, Non-metals

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

12.2Kcfs

May 14, 6:30 PM UTC

vs Long-Term Average

122%

Above typical

Primary Streamgage

CONNECTICUT RIVER AT NORTH WALPOLE, NH

USGS site
01154500
Drainage area
5,493 sq mi
Long-term mean
9,976 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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Estimate Your Water Costs

Water Cost Estimate

3

3 people  ·  ~225 gal/day

Annual Total

$558

Monthly

$47

Water Bill

$558/yr

Filter Cost

$0/yr

Safety Grade for Cheshire County:D — Poor

Elevated violations or significant watershed impairment.

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 Cheshire County, New Hampshire?
Cheshire County, New Hampshire has a drinking-water quality grade of C with a score of 51.2/100, based on EPA SDWIS compliance data. The county has 7 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 Cheshire County?
Cheshire County has 7 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 healthy are the watersheds in Cheshire County?
EPA ATTAINS assessments under Clean Water Act §303(d) indicate 50.0% of Cheshire County's 2 assessed water bodies are classified as impaired (1 impaired). The top reported causes are MERCURY - FISH CONSUMPTION ADVISORY, PH. Impairment means the water body fails to meet state quality standards for at least one designated use — drinking water source, recreation, aquatic life, or fish consumption. Note: watershed impairment doesn't always translate to tap-water issues; treatment plants can remove most regulated contaminants.
How much water-quality monitoring happens in Cheshire County?
EPA's Water Quality Portal records 22,992 measurements from 313 monitoring sites in Cheshire County over the past five years. The most frequently measured characteristic groups are Physical, Nutrient, Inorganics, Major, Non-metals. 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 Cheshire County right now?
Cheshire County's primary USGS streamgage on the CONNECTICUT RIVER has a pipeline snapshot of 12,200 cubic feet per second — 122% of the long-term mean of 9,975.93 cfs. Flow is within typical range for this gauge. For the latest gauge feed, visit waterdata.usgs.gov.
How does Cheshire County water compare to the New Hampshire average?
Cheshire County's SDWIS water quality score of 51.2/100 is higher 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 Cheshire County?
Based on EPA SDWIS data, Cheshire County has a water quality grade of C (51.2/100). This indicates moderate compliance. Some violations have been recorded but overall standards are maintained. 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 Cheshire County have so many water violations?
Cheshire County has 7 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 Cheshire County rank for water quality in New Hampshire?
Cheshire County ranks #2 out of 10 counties in New Hampshire by SDWIS water quality score (1 = best). With a score of 51.2/100, it falls in the top 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

Coos County

New Hampshire

D

49.9

Water score

Sullivan County

New Hampshire

C

57.8

Water score

Hillsborough County

New Hampshire

D

41.5

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.

Watershed health and impaired-waterway data from the EPA ATTAINS Clean Water Act §303(d) assessments, state-reported and EPA-finalized.

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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