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Federal water data

County water report

Butte County Water Report

Drinking-water compliance, watershed health, monitoring records, and river conditions for Butte County, California.

Water grade

C

Water score

57.2

State rank

#16

of 58

Health violations

17

EPA SDWIS, 5-year lookback

Watershed impaired

38.6%

70 water bodies assessed

Monitoring sites

54

10,345 recent measurements

Live streamflow

No gauge

FEATHER R A OROVILLE CA

Water at a glance

Key Water Indicators for Butte County

EPA SDWIS

Safety Grade

C

Score: 57.2 / 100

EPA SDWIS

Active Violations

17

5-year health-based lookback

EPA ATTAINS

Watershed Health

39% impaired

70 bodies assessed

USGS NWIS

Streamflow Snapshot

No gauge

FEATHER R A OROVILLE CA

EPA WQP

Monitoring Sites

54

10,345 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.

57.2/100

Health violations

17

Health-based violations

Violations per 100K served

8.6

Population-normalized SDWIS rate

Editorial analysis

Understanding Butte County’s Water

Drinking Water Quality Overview

EPA SDWIS

Butte County's drinking water earned a C grade, scoring 57.2 out of 100. Over the past five years, EPA SDWIS records 17 health-based violations — a pattern that public water utilities are required to disclose and correct.

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 38.6% of assessed waterways are impaired (27 of 70 water bodies) across Butte County's watersheds. The leading impairment causes are toxicity and mercury. Impairment does not mean tap water is unsafe — it measures ambient waterway conditions upstream of treatment, not finished drinking water.

Monitoring Network

EPA WQP

EPA's Water Quality Portal (WQP) aggregates monitoring data from federal, state, and tribal agencies. Butte County has extensive coverage with 54 active monitoring sites with 10,345 recent measurements on record. Predominant monitoring categories include organics, pesticide and organics, other. 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 Butte County

Water Verdict

Butte County, California receives a fair water quality assessment with a grade of C and a score of 57.2 out of 100. The water supply meets baseline federal standards, but there may be periods of elevated contaminant levels or infrastructure concerns worth monitoring. Separately, EPA ATTAINS assessments cover 70 water bodies in the county's watershed, with 38.6% listed as impaired under the Clean Water Act — a source-water measure that is tracked independently of tap-water compliance.

Violation Context

EPA SDWIS records for Butte County, California show 17 health-based violations, indicating multiple instances where federal contaminant limits or treatment requirements were not met. At 8.6 violations per 100,000 people served, this rate is high and signals significant water quality management issues. This compliance record sits alongside an unusually deep monitoring archive: 10,345 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 Butte County meets baseline standards but the compliance record shows room for improvement, with a Grade C rating. Butte County's drinking-water compliance score is 57.2 out of 100. The violation rate for Butte County is 8.6 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. Toxicity is the leading impairment cause in Butte County's watershed. With 54 active water-quality monitoring sites in Butte County, data coverage is strong. A pipeline streamflow snapshot from the FEATHER R A OROVILLE CA gauge is also available on this page.

Regional Context

Butte County has better water quality than the average county in California. Its water score is 12.6 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 Butte County's water environment

Watershed Impairment Causes (EPA ATTAINS)

  • 1

    Toxicity

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

  • 2

    Mercury

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

  • 3

    Polychlorinated Biphenyls (Pcbs)

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

Source: EPA ATTAINS · Reporting cycle 2022

Official EPA Resources for Butte County

EPA How's My Waterway

Interactive watershed health data for Butte County

EPA ECHO: Drinking Water Systems

Search water utilities and violation records for Butte County

Consumer Confidence Reports (CA)

Annual water quality reports from utilities in California

Clean Water Act §303(d)

Watershed Health

Impaired Water Bodies

38.6%

27 of 70 assessed

Moderate concern

Top Impairment Causes

  • 1

    TOXICITY

  • 2

    MERCURY

  • 3

    POLYCHLORINATED BIPHENYLS (PCBS)

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

54

Active in the past 5 years

Measurements Recorded

10K

10,345 total readings

Most Measured

  • Organics, Pesticide
  • Organics, Other
  • PFAS,Perfluorinated Alkyl Substance

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).

Free tool

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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 Butte 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 Butte County, California?
Butte County, California has a drinking-water quality grade of C with a score of 57.2/100, based on EPA SDWIS compliance data. The county has 17 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 Butte County?
Butte County has 17 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 Butte County?
EPA ATTAINS assessments under Clean Water Act §303(d) indicate 38.6% of Butte County's 70 assessed water bodies are classified as impaired (27 impaired). The top reported causes are TOXICITY, MERCURY, POLYCHLORINATED BIPHENYLS (PCBS). 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 Butte County?
EPA's Water Quality Portal records 10,345 measurements from 54 monitoring sites in Butte County over the past five years. The most frequently measured characteristic groups are Organics, Pesticide, Organics, Other, PFAS,Perfluorinated Alkyl Substance. 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.
How does Butte County water compare to the California average?
Butte County's SDWIS water quality score of 57.2/100 is higher than the California state average of 44.6. The average water quality grade across California is D, based on data from 58 counties with available SDWIS data.
Is tap water safe to drink in Butte County?
Based on EPA SDWIS data, Butte County has a water quality grade of C (57.2/100). 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).
Why does Butte County have so many water violations?
Butte County has 17 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 Butte County rank for water quality in California?
Butte County ranks #16 out of 58 counties in California by SDWIS water quality score (1 = best). With a score of 57.2/100, it falls in the top 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

El Dorado County

California

C

57.1

Water score

Nevada County

California

C

58.7

Water score

Santa Barbara County

California

C

58.9

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.

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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