waterbycounty
Federal water data

County water report

San Bernardino County Water Report

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

Water grade

C

Water score

52.3

State rank

#22

of 58

Health violations

327

EPA SDWIS, 5-year lookback

Watershed impaired

28.8%

125 water bodies assessed

Monitoring sites

232

28,118 recent measurements

Live streamflow

54%

AMARGOSA RV ABV CHINA RANCH WASH NR TECOPA, CA

Water at a glance

Key Water Indicators for San Bernardino County

EPA SDWIS

Safety Grade

C

Score: 52.3 / 100

EPA SDWIS

Active Violations

327

5-year health-based lookback

EPA ATTAINS

Watershed Health

29% impaired

125 bodies assessed

USGS NWIS

Streamflow Snapshot

54% of mean

AMARGOSA RV ABV CHINA RANCH WASH NR TECOPA, CA

EPA WQP

Monitoring Sites

232

28,118 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.

52.3/100

Health violations

327

Health-based violations

Violations per 100K served

13.2

Population-normalized SDWIS rate

Editorial analysis

Understanding San Bernardino County’s Water

Drinking Water Quality Overview

EPA SDWIS

San Bernardino County's drinking water earned a C grade, scoring 52.3 out of 100. Over the past five years, EPA SDWIS records 327 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 28.8% of assessed waterways carry an impairment designation (36 of 125 water bodies) across San Bernardino County's watersheds. The leading impairment causes are pathogens and nutrients. Impairment does not mean tap water is unsafe — it measures ambient waterway conditions upstream of treatment, not finished drinking water.

River & Streamflow Status

USGS NWIS

USGS NWIS gauge data (as of 2026-05-14T11:30:00.000-07:00) puts AMARGOSA RV ABV CHINA RANCH WASH at 1.8 cfs — well below its long-term average at 54% 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. San Bernardino County has extensive coverage with 232 active monitoring sites with 28,118 recent measurements on record. Predominant monitoring categories include organics, other 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 San Bernardino County

Water Verdict

San Bernardino County receives a below-average water quality assessment with a grade of C and a score of 52.3 out of 100. Residents should review their utility's Consumer Confidence Report and may want to consider additional water filtration for drinking.

Violation Context

San Bernardino County has recorded 327 health-based violations, indicating multiple instances where federal contaminant limits or treatment requirements were not met. At 13.2 violations per 100,000 people served, this rate is high and signals significant water quality management issues.

Consumer Guidance

Tap water in San Bernardino County meets baseline standards but the compliance record shows room for improvement, with a Grade C rating. San Bernardino County's drinking-water compliance score is 52.3 out of 100. The violation rate for San Bernardino County is 13.2 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. Pathogens is the leading impairment cause in San Bernardino County's watershed. With 232 active water-quality monitoring sites in San Bernardino County, data coverage is strong. A pipeline streamflow snapshot from the AMARGOSA RV ABV CHINA RANCH WASH gauge is also available on this page.

Regional Context

San Bernardino County has better water quality than the average county in California. Its water score is 7.7 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 San Bernardino County's water environment

Watershed Impairment Causes (EPA ATTAINS)

  • 1

    Pathogens

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

  • 2

    Nutrient pollution

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

  • 3

    Total Dissolved Solids (Tds)

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

Source: EPA ATTAINS · Reporting cycle 2022

Official EPA Resources for San Bernardino County

EPA How's My Waterway

Interactive watershed health data for San Bernardino County

EPA ECHO: Drinking Water Systems

Search water utilities and violation records for San Bernardino County

Consumer Confidence Reports (CA)

Annual water quality reports from utilities in California

Clean Water Act §303(d)

Watershed Health

Impaired Water Bodies

28.8%

36 of 125 assessed

Some impairment

Top Impairment Causes

  • 1

    PATHOGENS

  • 2

    NUTRIENTS

  • 3

    TOTAL DISSOLVED SOLIDS (TDS)

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

232

Active in the past 5 years

Measurements Recorded

28K

28,118 total readings

Most Measured

  • Organics, Other
  • 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

1.77cfs

May 14, 6:30 PM UTC

vs Long-Term Average

54%

Well below typical

Primary Streamgage

AMARGOSA RV ABV CHINA RANCH WASH NR TECOPA, CA

USGS site
10251330
Drainage area
3,241 sq mi
Long-term mean
3.26 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 San Bernardino 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.

Try the full calculator →

Improve your water quality at home

Berkey filters remove 99.9%+ of contaminants from tap water.

Shop Berkey →

Sponsored

Test your tap water

Tap Score provides professional mail-in water testing.

Get Tested →

Frequently Asked Questions

What is the water quality in San Bernardino County, California?
San Bernardino County, California has a drinking-water quality grade of C with a score of 52.3/100, based on EPA SDWIS compliance data. The county has 327 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 San Bernardino County?
San Bernardino County has 327 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 San Bernardino County?
EPA ATTAINS assessments under Clean Water Act §303(d) indicate 28.8% of San Bernardino County's 125 assessed water bodies are classified as impaired (36 impaired). The top reported causes are PATHOGENS, NUTRIENTS, TOTAL DISSOLVED SOLIDS (TDS). 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 San Bernardino County?
EPA's Water Quality Portal records 28,118 measurements from 232 monitoring sites in San Bernardino County over the past five years. The most frequently measured characteristic groups are Organics, Other, 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 San Bernardino County right now?
San Bernardino County's primary USGS streamgage on the AMARGOSA RV ABV CHINA RANCH WASH has a pipeline snapshot of 1.77 cubic feet per second — 54% of the long-term mean of 3.26 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 San Bernardino County water compare to the California average?
San Bernardino County's SDWIS water quality score of 52.3/100 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 San Bernardino County?
Based on EPA SDWIS data, San Bernardino County has a water quality grade of C (52.3/100). 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 San Bernardino County have so many water violations?
San Bernardino County has 327 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 San Bernardino County rank for water quality in California?
San Bernardino County ranks #22 out of 58 counties in California by SDWIS water quality score (1 = best). With a score of 52.3/100, 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

Fresno County

California

C

52.5

Water score

Santa Cruz County

California

D

50.6

Water score

Lassen County

California

C

54.6

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.

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

Explore more data for San Bernardino County

Property TaxCost of LivingCrime RateIncomeHealthSchoolsDisaster RiskWeatherCounty Score