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County water report

Linn County Water Report

Drinking-water compliance, watershed health, monitoring records, and river conditions for Linn County, Iowa.

Water grade

B

Water score

69.0

State rank

#71

of 99

Health violations

3

EPA SDWIS, 5-year lookback

Watershed impaired

Not reported

EPA ATTAINS coverage varies by state

Monitoring sites

27

32,404 recent measurements

Live streamflow

62%

Cedar River below Indian Creek at Cedar Rapids, IA

Water at a glance

Key Water Indicators for Linn County

EPA SDWIS

Safety Grade

B

Score: 69.0 / 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

62% of mean

Cedar River below Indian Creek at Cedar Rapids, IA

EPA WQP

Monitoring Sites

27

32,404 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.

69.0/100

Health violations

3

Health-based violations

Violations per 100K served

1.4

Population-normalized SDWIS rate

Editorial analysis

Understanding Linn County’s Water

Drinking Water Quality Overview

EPA SDWIS

Linn County earns a B grade for drinking water quality, scoring 69.0 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 Cedar River below Indian Creek at 4.2k cfs — running somewhat below its historical average at 62% 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. Linn County has moderate coverage with 27 active monitoring sites with 32,404 recent measurements on record. Predominant monitoring categories include organics, pesticide and physical. 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 Linn County

Water Verdict

Linn County, Iowa receives a fair water quality assessment with a grade of B and a score of 69.0 out of 100. The water supply meets baseline federal standards, but there may be periods of elevated contaminant levels or infrastructure concerns worth monitoring. The county's primary USGS gauge drains roughly 6,830 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 61.8% — worth watching in drier seasons.

Violation Context

EPA SDWIS records for Linn County, Iowa show 3 health-based violations, indicating multiple instances where federal contaminant limits or treatment requirements were not met. At 1.4 violations per 100,000 people served, this rate is relatively low compared to many U.S. counties. This compliance record sits alongside an unusually deep monitoring archive: 32,404 water-quality results have been logged across the county in the EPA Water Quality Portal over the past five years.

Consumer Guidance

Tap water in Linn County scores well above average for drinking-water safety. Linn County's drinking-water compliance score is 69.0 out of 100. With 3 recorded health violations, the water supply is generally reliable. The violation rate for Linn County is 1.4 per 100,000 people served. Households with infants, pregnant individuals, or immunocompromised members may want to use an NSF 53-certified pitcher filter as a low-cost precaution. With 27 active water-quality monitoring sites in Linn County, data coverage is strong. A pipeline streamflow snapshot from the Cedar River below Indian Creek gauge is also available on this page.

Regional Context

Linn County has water quality close to the average county in Iowa. Its water score is within 2.7 points of the state average, meaning its overall water system performance is broadly representative of Iowa 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 Linn County's water environment

Official EPA Resources for Linn County

EPA How's My Waterway

Interactive watershed health data for Linn County

EPA ECHO: Drinking Water Systems

Search water utilities and violation records for Linn County

Consumer Confidence Reports (IA)

Annual water quality reports from utilities in Iowa

Past 5 years

Water Quality Monitoring

Monitoring Sites

27

Active in the past 5 years

Measurements Recorded

32K

32,404 total readings

Most Measured

  • Organics, Pesticide
  • Physical
  • 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

4,160cfs

May 14, 6:30 PM UTC

vs Long-Term Average

62%

Below typical

Primary Streamgage

Cedar River below Indian Creek at Cedar Rapids, IA

USGS site
05464730
Drainage area
6,830 sq mi
Long-term mean
6,736 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 Linn 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 Linn County, Iowa?
Linn County, Iowa has a drinking-water quality grade of B with a score of 69.0/100, 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 Linn County?
Linn 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 Linn County?
EPA's Water Quality Portal records 32,404 measurements from 27 monitoring sites in Linn County over the past five years. The most frequently measured characteristic groups are Organics, Pesticide, Physical, 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 Linn County right now?
Linn County's primary USGS streamgage on the Cedar River below Indian Creek has a pipeline snapshot of 4,160 cubic feet per second — 62% of the long-term mean of 6,736 cfs. Flow is within typical range for this gauge. For the latest gauge feed, visit waterdata.usgs.gov.
How does Linn County water compare to the Iowa average?
Linn County's SDWIS water quality score of 69.0/100 is lower than the Iowa state average of 71.7. The average water quality grade across Iowa is C, based on data from 99 counties with available SDWIS data.
Is tap water safe to drink in Linn County?
Based on EPA SDWIS data, Linn County has a water quality grade of B (69.0/100). 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).
Does Linn County have clean drinking water?
Linn County has 3 health-based drinking water violations according to EPA records. With a water quality score of 69.0/100 and grade B, 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 Linn County rank for water quality in Iowa?
Linn County ranks #71 out of 99 counties in Iowa by SDWIS water quality score (1 = best). With a score of 69.0/100, 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

Polk County

Iowa

A

69.8

Water score

Scott County

Iowa

B

68.2

Water score

Woodbury County

Iowa

B

67.8

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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