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Federal water data

County water report

Montgomery County Water Report

Drinking-water compliance, watershed health, monitoring records, and river conditions for Montgomery County, Illinois.

Water grade

C

Water score

58.3

State rank

#36

of 102

Health violations

2

EPA SDWIS, 5-year lookback

Watershed impaired

45.3%

563 water bodies assessed

Monitoring sites

13

3,183 recent measurements

Live streamflow

30%

EAST FORK SHOAL CREEK NEAR COFFEEN, IL

Water at a glance

Key Water Indicators for Montgomery County

EPA SDWIS

Safety Grade

C

Score: 58.3 / 100

EPA SDWIS

Active Violations

2

5-year health-based lookback

EPA ATTAINS

Watershed Health

45% impaired

563 bodies assessed

USGS NWIS

Streamflow Snapshot

30% of mean

EAST FORK SHOAL CREEK NEAR COFFEEN, IL

EPA WQP

Monitoring Sites

13

3,183 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.

58.3/100

Health violations

2

Health-based violations

Violations per 100K served

7.8

Population-normalized SDWIS rate

Editorial analysis

Understanding Montgomery County’s Water

Drinking Water Quality Overview

EPA SDWIS

Montgomery County's drinking water earned a C grade, scoring 58.3 out of 100. Over the past five years, EPA SDWIS records 2 health-based violations — a small cluster that warrants attention.

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 45.3% of assessed waterways are impaired (255 of 563 water bodies) across Montgomery County's watersheds. The leading impairment causes are phosphorus, total and total suspended solids (tss). 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 2026-05-14T13:00:00.000-06:00) puts EAST FORK SHOAL CREEK at 13.8 cfs — well below its long-term average at 30% 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. Montgomery County has moderate coverage with 13 active monitoring sites with 3,183 recent measurements on record. Predominant monitoring categories include physical and inorganics, minor, metals. 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 Montgomery County

Water Verdict

Montgomery County receives a fair water quality assessment with a grade of C and a score of 58.3 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

Montgomery County has recorded 2 health-based violations, indicating multiple instances where federal contaminant limits or treatment requirements were not met. At 7.8 violations per 100,000 people served, this rate is moderate and suggests recurring water quality challenges.

Consumer Guidance

Tap water in Montgomery County meets baseline standards but the compliance record shows room for improvement, with a Grade C rating. Montgomery County's drinking-water compliance score is 58.3 out of 100. The violation rate for Montgomery County is 7.8 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. Phosphorus, Total is the leading impairment cause in Montgomery County's watershed. With 13 active water-quality monitoring sites in Montgomery County, data coverage is strong. A pipeline streamflow snapshot from the EAST FORK SHOAL CREEK gauge is also available on this page.

Regional Context

Montgomery County has better water quality than the average county in Illinois. Its water score is 10.5 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 Montgomery County's water environment

Watershed Impairment Causes (EPA ATTAINS)

  • 1

    Phosphorus (excess nutrients)

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

  • 2

    Total Suspended Solids (Tss)

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

  • 3

    Low dissolved oxygen

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

Source: EPA ATTAINS · Reporting cycle 2022

Official EPA Resources for Montgomery County

EPA How's My Waterway

Interactive watershed health data for Montgomery County

EPA ECHO: Drinking Water Systems

Search water utilities and violation records for Montgomery County

Consumer Confidence Reports (IL)

Annual water quality reports from utilities in Illinois

Clean Water Act §303(d)

Watershed Health

Impaired Water Bodies

45.3%

255 of 563 assessed

Moderate concern

Top Impairment Causes

  • 1

    PHOSPHORUS, TOTAL

  • 2

    TOTAL SUSPENDED SOLIDS (TSS)

  • 3

    DISSOLVED OXYGEN

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

13

Active in the past 5 years

Measurements Recorded

3.2K

3,183 total readings

Most Measured

  • Physical
  • Inorganics, Minor, Metals
  • Organics, Pesticide

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

13.8cfs

May 14, 7:00 PM UTC

vs Long-Term Average

30%

Well below typical

Primary Streamgage

EAST FORK SHOAL CREEK NEAR COFFEEN, IL

USGS site
05593900
Drainage area
55.5 sq mi
Long-term mean
46.3 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

3

3 people  ·  ~225 gal/day

Annual Total

$558

Monthly

$47

Water Bill

$558/yr

Filter Cost

$0/yr

Safety Grade for Montgomery 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 Montgomery County, Illinois?
Montgomery County, Illinois has a drinking-water quality grade of C with a score of 58.3/100, based on EPA SDWIS compliance data. The county has 2 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 Montgomery County?
Montgomery County has 2 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 Montgomery County?
EPA ATTAINS assessments under Clean Water Act §303(d) indicate 45.3% of Montgomery County's 563 assessed water bodies are classified as impaired (255 impaired). The top reported causes are PHOSPHORUS, TOTAL, TOTAL SUSPENDED SOLIDS (TSS), DISSOLVED OXYGEN. 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 Montgomery County?
EPA's Water Quality Portal records 3,183 measurements from 13 monitoring sites in Montgomery County over the past five years. The most frequently measured characteristic groups are Physical, Inorganics, Minor, Metals, Organics, Pesticide. 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 Montgomery County right now?
Montgomery County's primary USGS streamgage on the EAST FORK SHOAL CREEK has a pipeline snapshot of 13.8 cubic feet per second — 30% of the long-term mean of 46.28 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 Montgomery County water compare to the Illinois average?
Montgomery County's SDWIS water quality score of 58.3/100 is higher than the Illinois state average of 47.8. The average water quality grade across Illinois is D, based on data from 102 counties with available SDWIS data.
Is tap water safe to drink in Montgomery County?
Based on EPA SDWIS data, Montgomery County has a water quality grade of C (58.3/100). 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).
Does Montgomery County have clean drinking water?
Montgomery County has 2 health-based drinking water violations according to EPA records. With a water quality score of 58.3/100 and grade C, 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 Montgomery County rank for water quality in Illinois?
Montgomery County ranks #36 out of 102 counties in Illinois by SDWIS water quality score (1 = best). With a score of 58.3/100, 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

Lawrence County

Illinois

C

58.3

Water score

Monroe County

Illinois

C

58.7

Water score

White County

Illinois

C

59.0

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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