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County water report

Lewis County Water Report

Drinking-water compliance, watershed health, monitoring records, and river conditions for Lewis County, Missouri.

Water grade

F

Water score

36.2

State rank

#73

of 115

Health violations

3

EPA SDWIS, 5-year lookback

Watershed impaired

Not reported

EPA ATTAINS coverage varies by state

Monitoring sites

13

3,078 recent measurements

Live streamflow

11%

North Fabius River near Ewing, MO

Water at a glance

Key Water Indicators for Lewis County

EPA SDWIS

Safety Grade

F

Score: 36.2 / 100

EPA SDWIS

Active Violations

3

5-year health-based lookback

EPA ATTAINS

Watershed Health

Not reported

Coverage varies by state

USGS NWIS

Streamflow Snapshot

11% of mean

North Fabius River near Ewing, MO

EPA WQP

Monitoring Sites

13

3,078 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.

36.2/100

Health violations

3

Health-based violations

Violations per 100K served

42.8

Population-normalized SDWIS rate

Editorial analysis

Understanding Lewis County’s Water

Drinking Water Quality Overview

EPA SDWIS

Lewis County's water systems carry a failing grade, scoring 36.2 out of 100. Over the past five years, EPA SDWIS records 3 health-based violations — a small cluster that warrants attention.

River & Streamflow Status

USGS NWIS

USGS NWIS gauge data (as of 2026-05-14T13:30:00.000-05:00) puts North Fabius River at 41.7 cfs — well below its long-term average at 11% 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. Lewis County has moderate coverage with 13 active monitoring sites with 3,078 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 Lewis County

Water Verdict

Lewis County, Missouri receives a poor water quality assessment with a grade of F and a score of 36.2 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 471 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 11.0% — worth watching in drier seasons.

Violation Context

EPA SDWIS records for Lewis County, Missouri show 3 health-based violations, indicating multiple instances where federal contaminant limits or treatment requirements were not met. At 42.8 violations per 100,000 people served, this rate is high and signals significant water quality management issues. For independent context, 3,078 water-quality monitoring results have been recorded across the county in the EPA Water Quality Portal over the past five years.

Consumer Guidance

Drinking-water compliance in Lewis County is rated Grade F, reflecting significant health-based violations in the recent reporting period. Lewis County's drinking-water compliance score is 36.2 out of 100. The violation rate for Lewis County is 42.8 per 100,000 people served. An NSF 53 or NSF 58-certified filter is recommended for drinking and cooking water. Check the Consumer Confidence Report from your utility to identify the specific contaminants and required corrective actions — utilities are legally required to notify customers of violations. With 13 active water-quality monitoring sites in Lewis County, data coverage is strong. A pipeline streamflow snapshot from the North Fabius River gauge is also available on this page.

Regional Context

Lewis County has poorer water quality than the average county in Missouri. Its water score is 12.6 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 Lewis County's water environment

Official EPA Resources for Lewis County

EPA How's My Waterway

Interactive watershed health data for Lewis County

EPA ECHO: Drinking Water Systems

Search water utilities and violation records for Lewis County

Consumer Confidence Reports (MO)

Annual water quality reports from utilities in Missouri

Past 5 years

Water Quality Monitoring

Monitoring Sites

13

Active in the past 5 years

Measurements Recorded

3.1K

3,078 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

41.7cfs

May 14, 6:30 PM UTC

vs Long-Term Average

11%

Well below typical

Primary Streamgage

North Fabius River near Ewing, MO

USGS site
05497150
Drainage area
471 sq mi
Long-term mean
378 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

3 people  ·  ~225 gal/day

Annual Total

$558

Monthly

$47

Water Bill

$558/yr

Filter Cost

$0/yr

Safety Grade for Lewis 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 Lewis County, Missouri?
Lewis County, Missouri has a drinking-water quality grade of F with a score of 36.2/100, based on EPA SDWIS compliance data. The county has 3 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 Lewis County?
Lewis County has 3 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 Lewis County?
EPA's Water Quality Portal records 3,078 measurements from 13 monitoring sites in Lewis 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 Lewis County right now?
Lewis County's primary USGS streamgage on the North Fabius River has a pipeline snapshot of 41.7 cubic feet per second — 11% of the long-term mean of 377.66 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 Lewis County water compare to the Missouri average?
Lewis County's SDWIS water quality score of 36.2/100 is lower than the Missouri state average of 48.8. The average water quality grade across Missouri is D, based on data from 115 counties with available SDWIS data.
Is tap water safe to drink in Lewis County?
Based on EPA SDWIS data, Lewis County has a water quality grade of F (36.2/100). 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).
Does Lewis County have clean drinking water?
Lewis County has 3 health-based drinking water violations according to EPA records. With a water quality score of 36.2/100 and grade F, the county's drinking water has had some compliance issues but continues to be monitored. Note: drinking-water compliance speaks to the public water system, not necessarily to the watershed itself — check the Watershed Health zone for ATTAINS §303(d) data.
How does Lewis County rank for water quality in Missouri?
Lewis County ranks #73 out of 115 counties in Missouri by SDWIS water quality score (1 = best). With a score of 36.2/100, 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

Gasconade County

Missouri

F

36.9

Water score

Stone County

Missouri

F

35.4

Water score

Cass County

Missouri

F

37.1

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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