San Bernardino, California Water Quality Report

Comprehensive water safety analysis • Updated February 2026

San Bernardino's water quality score of 45/100 falls below average, with 1 contaminants at concerning levels.

There are currently 1 unresolved EPA violation(s) for San Bernardino's water system.

Water Safety Overview

Caution Advised. We recommend using a certified water filter. Score: 45/100.

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10
Total Tested
0
Above EPA Limit
1
Elevated
9
Safe Levels

Contaminants at Elevated Levels

Above 50% of EPA limits

ContaminantLevel DetectedEPA Limit% of LimitStatus
Copper
0.704 mg/L
1.30 mg/L
54.1%
Warning

All Detected Contaminants

10 contaminants tested • EPA SDWIS data

ContaminantLevel DetectedEPA Limit% of LimitStatus
Copper
0.704 mg/L
1.30 mg/L
54.1%
Warning
Nitrite
0.431 mg/L
1.00 mg/L
43.1%
Safe
Total Trihalomethanes
30.97 ug/L
80.00 ug/L
38.7%
Safe
Chromium
0.034 mg/L
0.100 mg/L
34.2%
Safe
Haloacetic Acids
20.16 ug/L
60.00 ug/L
33.6%
Safe
Fluoride
1.15 mg/L
4.00 mg/L
28.6%
Safe
Lead
0.0042 mg/L
0.015 mg/L
28.3%
Safe
Mercury
0.0005 mg/L
0.0020 mg/L
24.8%
Safe
Arsenic
0.0025 mg/L
0.010 mg/L
24.7%
Safe
Nitrate
1.86 mg/L
10.00 mg/L
18.6%
Safe

Detailed Water Quality Analysis for San Bernardino

In-depth assessment of your municipal water supply

The water quality in San Bernardino, California has been comprehensively evaluated using data from the EPA's Safe Drinking Water Information System (SDWIS) and local water utility reports. Our analysis examines 10 distinct contaminants across multiple categories including inorganic chemicals, disinfection byproducts, microorganisms, and radionuclides. With an overall quality score of 45 out of 100 (Grade: F), San Bernardino's water supply requires attention due to elevated contaminant levels.

Water Source and Treatment

San Bernardino's primary water system, SAN BERNARDINO WATER SYSTEM, serves approximately 221,094 residents. The water is sourced from a combination of surface and groundwater sources. Groundwater is generally naturally filtered through soil and rock layers, though it may contain elevated levels of minerals and naturally occurring contaminants like arsenic or radon.

Contaminant Profile Overview

Of the 10 contaminants analyzed in San Bernardino's water supply, 9 (90%) are present at safe levels below 50% of EPA Maximum Contaminant Levels (MCLs). 1 contaminant is detected at elevated levels between 50-100% of MCLs, warranting monitoring. No contaminants currently exceed EPA safety limits. The most common categories of concern in municipal water supplies include disinfection byproducts formed during the chlorination process, heavy metals like lead that can leach from aging infrastructure, and naturally occurring contaminants like arsenic or radium that vary by geographic region.

Regulatory Compliance Status

San Bernardino's water system has a compliance history with 6 documented EPA violations. Currently, 1 violation remains unresolved and under active remediation. Violations can range from monitoring and reporting failures to actual exceedances of contaminant limits. Water utilities are required by law to notify customers of any violations that may affect health and to take corrective action to return to compliance.

Infrastructure Considerations

Water quality at the tap can differ from quality at the treatment plant due to distribution system conditions. Homes built before 1986 may have lead service lines or lead solder in plumbing that can contribute to lead exposure. Older galvanized pipes can harbor bacteria and release metals. Running cold water for 30 seconds to 2 minutes before drinking or cooking helps flush stagnant water from pipes. Residents in older homes should consider testing their water directly at the tap to assess any additional contamination from household plumbing, as EPA monitoring typically occurs at distribution points rather than individual residences.

Health Implications of San Bernardino Water Quality

Understanding potential health effects for residents

Vulnerable Populations

Certain groups face elevated health risks from water contaminants and should take extra precautions. Pregnant women are particularly vulnerable as contaminants like lead and nitrates can affect fetal development, potentially causing developmental delays and birth defects. Infants and young children are at heightened risk because their developing bodies absorb contaminants more readily and are more susceptible to their effects; lead exposure in children can cause irreversible cognitive impairment and behavioral problems. Elderly individuals and those with compromised immune systems (including cancer patients, organ transplant recipients, and HIV/AIDS patients) are more susceptible to waterborne pathogens and may experience severe illness from microorganisms that healthy adults can tolerate. Individuals with kidney disease should be aware of fluoride and other mineral levels, as impaired kidney function affects the body's ability to filter these substances.

Lead Health Effects

Lead has been detected in San Bernardino's water supply. There is no safe level of lead exposure. In children, lead can cause developmental delays, learning difficulties, irritability, weight loss, hearing loss, and seizures. In adults, lead exposure contributes to cardiovascular problems, decreased kidney function, and reproductive issues. Pregnant women exposed to lead can transfer it to their developing fetus, increasing risk of premature birth and reduced growth. Use an NSF 53 certified filter and run cold water before drinking to reduce exposure.

Arsenic Health Effects

Arsenic has been detected in San Bernardino's water supply. Long-term arsenic exposure, even at levels near EPA limits, is associated with increased risk of skin, lung, bladder, kidney, and liver cancers. Arsenic exposure can also cause cardiovascular disease, diabetes, and neurological effects. Skin changes like thickening and pigmentation may indicate chronic exposure. Reverse osmosis filtration is highly effective at removing arsenic from drinking water.

Nitrate Health Effects

Elevated nitrate levels in San Bernardino's water pose particular risk to infants under six months. Nitrates can cause methemoglobinemia ("blue baby syndrome"), a condition where the blood cannot carry sufficient oxygen. Symptoms include bluish skin color, shortness of breath, and in severe cases, death. Formula-fed infants are at greatest risk. Pregnant women should also limit nitrate exposure. Boiling water does NOT remove nitrates—it actually concentrates them. Reverse osmosis or distillation systems effectively remove nitrates.

General Recommendations

Based on San Bernardino's water quality profile, residents should consider the following protective measures: Installing a point-of-use water filter is strongly recommended given the current water quality score. Always use cold water for drinking and cooking, as hot water can contain higher levels of metals from pipes. Have your home tested if it was built before 1986 to check for lead plumbing. Review your annual Consumer Confidence Report (water quality report) from your utility to stay informed about local water quality trends. Pregnant women, families with young children, and immunocompromised individuals should consult healthcare providers about water safety precautions specific to their situation.

Recommended Water Filters for San Bernardino

Based on detected contaminants

Reverse Osmosis System

Best for San Bernardino. Removes 95-99% of contaminants including heavy metals, PFAS, and nitrates.

  • ✓ Removes lead
  • ✓ Removes arsenic
  • ✓ Removes nitrates
  • ✓ Removes total dissolved solids

Activated Carbon Filter

Good for San Bernardino. Removes chlorine, improves taste, and filters many organic compounds.

  • ✓ Removes chlorine and chloramine
  • ✓ Improves taste and odor
  • ✓ Filters pesticides and VOCs

NSF 53 Lead Certification Required

Lead detected in San Bernardino. Ensure any filter is NSF/ANSI 53 certified for lead removal.

EPA Compliance History

Past violations for San Bernardino's water system

other

Nitrate - 2/3/2025

reporting

Arsenic - 2/4/2022

Resolved

monitoring

Nitrite - 2/4/2021

Resolved

MCL

Mercury - 2/3/2025

Resolved

other

Total Trihalomethanes - 2/3/2025

Resolved

Showing 5 of 6 violations

Water System Information

SAN BERNARDINO WATER SYSTEM

PWS ID:
CA652925
Population Served:
221,094
Water Source:
mixed
F45/100

San Bernardino Water Quality Score

Based on EPA contaminant data and compliance records

41
Contaminants
46
Compliance
56
Infrastructure

Areas of Concern

  • Aging infrastructure may affect water quality
  • Recent compliance violations

Positive Findings

  • Water quality needs improvement

Protect Your Family's Water

San Bernardino's water contains Copper at 54% of the EPA limit. A quality water filter can reduce this contaminant.

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