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County water report

Fall River County Water Report

Drinking-water compliance, watershed health, monitoring records, and river conditions for Fall River County, South Dakota.

Water grade

F

Water score

21.4

State rank

#53

of 63

Health violations

7

EPA SDWIS, 5-year lookback

Watershed impaired

Not reported

EPA ATTAINS coverage varies by state

Monitoring sites

8

883 recent measurements

Live streamflow

1%

CHEYENNE RIVER BELOW ANGOSTURA DAM,SD

Water at a glance

Key Water Indicators for Fall River County

EPA SDWIS

Safety Grade

F

Score: 21.4 / 100

EPA SDWIS

Active Violations

7

5-year health-based lookback

EPA ATTAINS

Watershed Health

Not reported

Coverage varies by state

USGS NWIS

Streamflow Snapshot

1% of mean

CHEYENNE RIVER BELOW ANGOSTURA DAM,SD

EPA WQP

Monitoring Sites

8

883 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.

21.4/100

Health violations

7

Health-based violations

Violations per 100K served

116.9

Population-normalized SDWIS rate

Editorial analysis

Understanding Fall River County’s Water

Drinking Water Quality Overview

EPA SDWIS

Fall River County's water systems carry a failing grade, scoring 21.4 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.

River & Streamflow Status

USGS NWIS

USGS NWIS gauge data (as of 2026-05-14T12:15:00.000-06:00) puts CHEYENNE RIVER BELOW ANGOSTURA DAM,SD at 0.6 cfs — well below its long-term average at 1% 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. Fall River County has limited coverage with 8 active monitoring sites with 883 recent measurements on record. Predominant monitoring categories include physical and inorganics, major, non-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 Fall River County

Water Verdict

Fall River County receives a poor water quality assessment with a grade of F and a score of 21.4 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.

Violation Context

Fall River County has recorded 7 health-based violations, indicating multiple instances where federal contaminant limits or treatment requirements were not met. At 116.9 violations per 100,000 people served, this rate is high and signals significant water quality management issues.

Consumer Guidance

Drinking-water compliance in Fall River County is rated Grade F, reflecting significant health-based violations in the recent reporting period. Fall River County's drinking-water compliance score is 21.4 out of 100. 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. There are 8 active water-quality monitoring sites in Fall River County. A pipeline streamflow snapshot from the CHEYENNE RIVER BELOW ANGOSTURA DAM,SD gauge is also available on this page.

Regional Context

Fall River County has poorer water quality than the average county in South Dakota. Its water score is 35.4 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 Fall River County's water environment

Official EPA Resources for Fall River County

EPA How's My Waterway

Interactive watershed health data for Fall River County

EPA ECHO: Drinking Water Systems

Search water utilities and violation records for Fall River County

Consumer Confidence Reports (SD)

Annual water quality reports from utilities in South Dakota

Past 5 years

Water Quality Monitoring

Monitoring Sites

8

Active in the past 5 years

Measurements Recorded

883

883 total readings

Most Measured

  • Physical
  • Inorganics, Major, Non-metals
  • 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

0.59cfs

May 14, 6:15 PM UTC

vs Long-Term Average

1%

Well below typical

Primary Streamgage

CHEYENNE RIVER BELOW ANGOSTURA DAM,SD

USGS site
06401500
Drainage area
9,097 sq mi
Long-term mean
61.5 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 Fall River 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 Fall River County, South Dakota?
Fall River County, South Dakota has a drinking-water quality grade of F with a score of 21.4/100, 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 Fall River County?
Fall River 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 much water-quality monitoring happens in Fall River County?
EPA's Water Quality Portal records 883 measurements from 8 monitoring sites in Fall River County over the past five years. The most frequently measured characteristic groups are Physical, Inorganics, Major, Non-metals, 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 Fall River County right now?
Fall River County's primary USGS streamgage on the CHEYENNE RIVER BELOW ANGOSTURA DAM,SD has a pipeline snapshot of 0.59 cubic feet per second — 1% of the long-term mean of 61.47 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 Fall River County water compare to the South Dakota average?
Fall River County's SDWIS water quality score of 21.4/100 is lower than the South Dakota state average of 56.8. The average water quality grade across South Dakota is D, based on data from 63 counties with available SDWIS data.
Is tap water safe to drink in Fall River County?
Based on EPA SDWIS data, Fall River County has a water quality grade of F (21.4/100). 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).
Why does Fall River County have so many water violations?
Fall River 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 Fall River County rank for water quality in South Dakota?
Fall River County ranks #53 out of 63 counties in South Dakota by SDWIS water quality score (1 = best). With a score of 21.4/100, 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

Brule County

South Dakota

F

21.0

Water score

Miner County

South Dakota

F

22.5

Water score

Deuel County

South Dakota

F

19.4

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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