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Federal water data

County water report

Riley County Water Report

Drinking-water compliance, watershed health, monitoring records, and river conditions for Riley County, Kansas.

Water grade

B

Water score

65.6

State rank

#37

of 105

Health violations

2

EPA SDWIS, 5-year lookback

Watershed impaired

Not reported

EPA ATTAINS coverage varies by state

Monitoring sites

4

1,574 recent measurements

Live streamflow

26%

BIG BLUE R NR MANHATTAN, KS

Water at a glance

Key Water Indicators for Riley County

EPA SDWIS

Safety Grade

B

Score: 65.6 / 100

EPA SDWIS

Active Violations

2

5-year health-based lookback

EPA ATTAINS

Watershed Health

Not reported

Coverage varies by state

USGS NWIS

Streamflow Snapshot

26% of mean

BIG BLUE R NR MANHATTAN, KS

EPA WQP

Monitoring Sites

4

1,574 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.

65.6/100

Health violations

2

Health-based violations

Violations per 100K served

3.2

Population-normalized SDWIS rate

Editorial analysis

Understanding Riley County’s Water

Drinking Water Quality Overview

EPA SDWIS

Riley County earns a B grade for drinking water quality, scoring 65.6 out of 100. Over the past five years, EPA SDWIS records 2 health-based violations — a small cluster that warrants attention.

River & Streamflow Status

USGS NWIS

USGS NWIS gauge data (as of 2026-05-14T13:00:00.000-05:00) puts BIG BLUE R at 585.0 cfs — well below its long-term average at 26% 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. Riley County has limited coverage with 4 active monitoring sites with 1,574 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 Riley County

Water Verdict

Riley County, Kansas receives a fair water quality assessment with a grade of B and a score of 65.6 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 9,640 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 26.1% — worth watching in drier seasons.

Violation Context

EPA SDWIS records for Riley County, Kansas show 2 health-based violations, indicating multiple instances where federal contaminant limits or treatment requirements were not met. At 3.2 violations per 100,000 people served, this rate is moderate and suggests recurring water quality challenges. For independent context, 1,574 water-quality monitoring results have been recorded across the county in the EPA Water Quality Portal over the past five years.

Consumer Guidance

Tap water in Riley County scores well above average for drinking-water safety. Riley County's drinking-water compliance score is 65.6 out of 100. With 2 recorded health violations, the water supply is generally reliable. The violation rate for Riley County is 3.2 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. There are 4 active water-quality monitoring sites in Riley County. A pipeline streamflow snapshot from the BIG BLUE R gauge is also available on this page.

Regional Context

Riley County has better water quality than the average county in Kansas. Its water score is 23 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 Riley County's water environment

Official EPA Resources for Riley County

EPA How's My Waterway

Interactive watershed health data for Riley County

EPA ECHO: Drinking Water Systems

Search water utilities and violation records for Riley County

Consumer Confidence Reports (KS)

Annual water quality reports from utilities in Kansas

Past 5 years

Water Quality Monitoring

Monitoring Sites

4

Active in the past 5 years

Measurements Recorded

1.6K

1,574 total readings

Most Measured

  • Physical
  • Nutrient
  • 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

585cfs

May 14, 6:00 PM UTC

vs Long-Term Average

26%

Well below typical

Primary Streamgage

BIG BLUE R NR MANHATTAN, KS

USGS site
06887000
Drainage area
9,640 sq mi
Long-term mean
2,239 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 Riley 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 Riley County, Kansas?
Riley County, Kansas has a drinking-water quality grade of B with a score of 65.6/100, 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 Riley County?
Riley 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 much water-quality monitoring happens in Riley County?
EPA's Water Quality Portal records 1,574 measurements from 4 monitoring sites in Riley County over the past five years. The most frequently measured characteristic groups are Physical, Nutrient, 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 Riley County right now?
Riley County's primary USGS streamgage on the BIG BLUE R has a pipeline snapshot of 585 cubic feet per second — 26% of the long-term mean of 2,238.93 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 Riley County water compare to the Kansas average?
Riley County's SDWIS water quality score of 65.6/100 is higher than the Kansas state average of 42.6. The average water quality grade across Kansas is D, based on data from 105 counties with available SDWIS data.
Is tap water safe to drink in Riley County?
Based on EPA SDWIS data, Riley County has a water quality grade of B (65.6/100). 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 Riley County have clean drinking water?
Riley County has 2 health-based drinking water violations according to EPA records. With a water quality score of 65.6/100 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 Riley County rank for water quality in Kansas?
Riley County ranks #37 out of 105 counties in Kansas by SDWIS water quality score (1 = best). With a score of 65.6/100, 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

Saline County

Kansas

B

67.8

Water score

Neosho County

Kansas

C

60.8

Water score

Johnson County

Kansas

A

71.3

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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