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Federal water data

County water report

El Dorado County Water Report

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

Water grade

C

Water score

57.1

State rank

#17

of 58

Health violations

23

EPA SDWIS, 5-year lookback

Watershed impaired

16.2%

142 water bodies assessed

Monitoring sites

44

15,780 recent measurements

Live streamflow

No gauge

SF AMERICAN R NR PLACERVILLE CA

Water at a glance

Key Water Indicators for El Dorado County

EPA SDWIS

Safety Grade

C

Score: 57.1 / 100

EPA SDWIS

Active Violations

23

5-year health-based lookback

EPA ATTAINS

Watershed Health

16% impaired

142 bodies assessed

USGS NWIS

Streamflow Snapshot

No gauge

SF AMERICAN R NR PLACERVILLE CA

EPA WQP

Monitoring Sites

44

15,780 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.

57.1/100

Health violations

23

Health-based violations

Violations per 100K served

8.8

Population-normalized SDWIS rate

Editorial analysis

Understanding El Dorado County’s Water

Drinking Water Quality Overview

EPA SDWIS

El Dorado County's drinking water earned a C grade, scoring 57.1 out of 100. Over the past five years, EPA SDWIS records 23 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 notable 16.2% of assessed waterways carry an impairment designation (23 of 142 water bodies) across El Dorado County's watersheds. The leading impairment causes are phosphorus and iron. 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. El Dorado County has moderate coverage with 44 active monitoring sites with 15,780 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 El Dorado County

Water Verdict

El Dorado County receives a fair water quality assessment with a grade of C and a score of 57.1 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

El Dorado County has recorded 23 health-based violations, indicating multiple instances where federal contaminant limits or treatment requirements were not met. At 8.8 violations per 100,000 people served, this rate is high and signals significant water quality management issues.

Consumer Guidance

Tap water in El Dorado County meets baseline standards but the compliance record shows room for improvement, with a Grade C rating. El Dorado County's drinking-water compliance score is 57.1 out of 100. The violation rate for El Dorado County is 8.8 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 is the leading impairment cause in El Dorado County's watershed. With 44 active water-quality monitoring sites in El Dorado County, data coverage is strong. A pipeline streamflow snapshot from the SF AMERICAN R gauge is also available on this page.

Regional Context

El Dorado County has better water quality than the average county in California. Its water score is 12.5 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 El Dorado County's water environment

Watershed Impairment Causes (EPA ATTAINS)

  • 1

    Phosphorus (excess nutrients)

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

  • 2

    Iron

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

  • 3

    Mercury

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

Source: EPA ATTAINS · Reporting cycle 2022

Official EPA Resources for El Dorado County

EPA How's My Waterway

Interactive watershed health data for El Dorado County

EPA ECHO: Drinking Water Systems

Search water utilities and violation records for El Dorado County

Consumer Confidence Reports (CA)

Annual water quality reports from utilities in California

Clean Water Act §303(d)

Watershed Health

Impaired Water Bodies

16.2%

23 of 142 assessed

Some impairment

Top Impairment Causes

  • 1

    PHOSPHORUS

  • 2

    IRON

  • 3

    MERCURY

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

44

Active in the past 5 years

Measurements Recorded

16K

15,780 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).

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 El Dorado 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 El Dorado County, California?
El Dorado County, California has a drinking-water quality grade of C with a score of 57.1/100, based on EPA SDWIS compliance data. The county has 23 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 El Dorado County?
El Dorado County has 23 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 El Dorado County?
EPA ATTAINS assessments under Clean Water Act §303(d) indicate 16.2% of El Dorado County's 142 assessed water bodies are classified as impaired (23 impaired). The top reported causes are PHOSPHORUS, IRON, MERCURY. 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 El Dorado County?
EPA's Water Quality Portal records 15,780 measurements from 44 monitoring sites in El Dorado 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.
How does El Dorado County water compare to the California average?
El Dorado County's SDWIS water quality score of 57.1/100 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 El Dorado County?
Based on EPA SDWIS data, El Dorado County has a water quality grade of C (57.1/100). 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 El Dorado County have so many water violations?
El Dorado County has 23 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 El Dorado County rank for water quality in California?
El Dorado County ranks #17 out of 58 counties in California by SDWIS water quality score (1 = best). With a score of 57.1/100, 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

Butte County

California

C

57.2

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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