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Not health advice. Contact your local water utility for concerns.
Data from EPA Water Quality Reports. For official information, contact your water utility or health department.
Water quality data for 24 cities serving 2,816,161 residents
Orange County in California has an average water quality score of 80/100 (Grade B+) based on analysis of 24 municipal water systems. The county's water systems serve approximately 2,816,161 residents.
Overall, Orange County demonstrates good water quality standards. 15 of 24 cities exceed the county average, with Anaheim leading with a score of 98/100.
24 cities ranked by water quality score
| Rank | City | Score | Grade | Population |
|---|---|---|---|---|
| 1 | Anaheim Top concern: Fluoride (17.6% of limit) | 98 | A+ | 348,053 |
| 2 | San Clemente Top concern: Total Trihalomethanes (16.1% of limit) | 97 | A+ | 69,091 |
| 3 | Yorba Linda Top concern: Copper (16.1% of limit) | 95 | A+ | 71,222 |
| 4 | Laguna Hills Top concern: Fluoride (18.8% of limit) | 95 | A+ | 33,380 |
| 5 | Costa Mesa Top concern: Chromium (13.5% of limit) | 91 | A | 115,133 |
| 6 | Cypress Top concern: Total Trihalomethanes (20.2% of limit) | 91 | A | 44,701 |
| 7 | Fullerton Top concern: Total Trihalomethanes (22.4% of limit) | 85 | A- | 147,284 |
| 8 | Buena Park Top concern: Total Trihalomethanes (42.9% of limit) | 85 | A- | 81,383 |
| 9 | Fountain Valley Top concern: Lead (39.4% of limit) | 85 | A- | 52,876 |
| 10 | Westminster Top concern: Lead (18.7% of limit) | 84 | B+ | 91,850 |
| 11 | Placentia Top concern: Total Trihalomethanes (22.4% of limit) | 84 | B+ | 57,150 |
| 12 | Rancho Santa Margarita Top concern: Total Trihalomethanes (38.1% of limit) | 84 | B+ | 45,678 |
| 13 | Irvine Top concern: Lead (39% of limit) | 81 | B+ | 307,203 |
| 14 | La Habra Top concern: Haloacetic Acids (38.1% of limit) | 81 | B+ | 67,723 |
| 15 | Laguna Niguel Top concern: Fluoride (19% of limit) | 81 | B+ | 64,992 |
| 16 | Aliso Viejo Top concern: Haloacetic Acids (25.3% of limit) | 79 | B | 53,305 |
| 17 | Newport Beach Top concern: Lead (37.6% of limit) | 77 | B | 81,997 |
| 18 | Tustin Top concern: Nitrate (27.5% of limit) | 70 | B- | 76,425 |
| 19 | Huntington Beach Top concern: Nitrite (28.8% of limit) | 69 | C+ | 198,012 |
| 20 | Santa Ana Top concern: Haloacetic Acids (67.5% of limit) | 68 | C+ | 310,209 |
| 21 | Lake Forest Top concern: Lead (55% of limit) | 68 | C+ | 86,093 |
| 22 | Orange Top concern: Copper (35.1% of limit) | 66 | C+ | 135,695 |
| 23 | Mission Viejo Top concern: Haloacetic Acids (52.2% of limit) | 56 | C- | 99,786 |
| 24 | Garden Grove Top concern: Total Trihalomethanes (67.5% of limit) | 54 | D | 176,920 |
Top detected contaminants across county water systems
| Contaminant | Avg Level | Max Level | EPA Limit | % of Limit | Cities |
|---|---|---|---|---|---|
| Lead | 0.004 mg/L | 0.009 mg/L | 0.015 mg/L | 23.4% | 20 |
| Haloacetic Acids | 13.037 ug/L | 40.511 ug/L | 60 ug/L | 21.7% | 20 |
| Total Trihalomethanes | 17.065 ug/L | 53.975 ug/L | 80 ug/L | 21.3% | 20 |
| Fluoride | 0.823 mg/L | 1.491 mg/L | 4 mg/L | 20.6% | 23 |
| Copper | 0.248 mg/L | 0.678 mg/L | 1.3 mg/L | 19.1% | 22 |
| Arsenic | 0.002 mg/L | 0.004 mg/L | 0.01 mg/L | 16.7% | 23 |
| Nitrite | 0.167 mg/L | 0.476 mg/L | 1 mg/L | 16.7% | 22 |
| Mercury | 0 mg/L | 0.001 mg/L | 0.002 mg/L | 16.5% | 20 |
Recent violations across county water systems
Showing 10 of 20 recent violations
Water quality in Orange County, California reflects the region's unique combination of water sources, treatment infrastructure, and environmental factors. Our comprehensive analysis examines 24 municipal water systems serving a combined population of over 2,816,161 residents.
The county shows strong water quality performance, with scores ranging from 54/100 in Garden Grove to 98/100 in Anaheim. This 44-point spread indicates significant variation in water quality across the county, suggesting different water sources or treatment approaches.
The most prevalent contaminants detected across Orange County water systems include Lead, Haloacetic Acids, Total Trihalomethanes. All monitored contaminants remain within acceptable levels relative to EPA Maximum Contaminant Levels (MCLs).
Orange County's water quality is generally good. Residents can feel confident in their tap water quality, though those with specific health concerns or sensitivity to certain contaminants may still benefit from filtration. Regular review of your city's annual Consumer Confidence Report is recommended.
Orange County has an average water quality score of 80/100 (Grade B+) based on analysis of 24 municipal water systems serving 2,816,161 residents.
Anaheim has the highest water quality score in Orange County at 98/100. View the detailed report for Anaheim.
Most cities in Orange County have water that meets EPA standards. However, a water filter can provide additional protection and improve taste. The need depends on your specific city and any personal health considerations.
Click on any city in the rankings table above to view its detailed water quality report, including contaminant levels, EPA compliance history, and filter recommendations.