States › California › Los Angeles County

Los Angeles County, CA Water Quality

Water quality data for 74 public water systems serving Los Angeles County, California — based on EPA SDWIS enforcement records, lead testing results, and health-based violation history.

📅 2026 Report 🔄 Data updated 2026 Q2 📍 74 water systems · 142 cities
✅
Excellent — All Systems Performing Well

Water quality across the county is outstanding with minimal violations and very low lead levels.

A

Los Angeles County Earns a A

Los Angeles County: 142 communities across 74 water systems. 98.6% have no open violations.

  • Median lead where detected: 1.80 ppb
  • 27 communities with a lead detection, 93 reporting none detected
  • 31 communities with PFAS above the federal limit
  • 9 with significant inspection deficiencies
  • 98.6% of communities have no open violations
1.8 ppb
Median Lead Level
County-wide, 90th percentile
74
Water Systems
Active CWS & NTNCWS
98%
Violation-Free
No active violations on record
How we grade counties: MyWaterIQ uses EPA SDWIS enforcement data — actual MCL violations and lead test results — not the aspirational MCLG targets used by some sites. A grade reflects real compliance history, not theoretical risk. Learn more →

Cities by Water Quality

⭐ Best Performing
  • Long Beach
    0.97 ppb
    No federal limits exceeded on record
    A
  • Pasadena
    Not detected
    No federal limits exceeded on record
    A
  • Palmdale
    Not detected
    No federal limits exceeded on record
    A
  • Burbank
    Not detected
    No federal limits exceeded on record
    A
  • Torrance
    Not detected
    No federal limits exceeded on record
    A
⚠ Needs Attention
  • Glendale
    Not detected
    PFAS above the limit at 3 of 5 sampling points
    D
  • Downey
    Not detected
    PFAS above the limit at 5 of 5 sampling points
    C
  • Monterey Park
    Not detected
    1 violation currently open
    C
  • Green Valley
    Not detected
    1 violation currently open
    C
  • East Los Angeles
    Not detected
    PFAS above the limit at 1 of 10 sampling points
    C
County Lead Level — Median 1.8 ppb
Based on most recent 90th percentile lead tests across all reporting systems
0 ppb5 ppb10 ppb15 ppb
County median: 1.8 ppb — 12% of the federal action level
Systems by Lead Level
Under 5 ppb
25
5 – 10 ppb
2
No Data
115

All Cities in Los Angeles County

Los Angeles 3.90 ppb B
Long Beach 0.97 ppb A
Glendale Not detected D
Pasadena Not detected A
Palmdale Not detected A
East Los Angeles Not detected C
Downey Not detected C
Burbank Not detected A
Torrance Not detected A
Lancaster Not reported B
Santa Monica 1.40 ppb A
Carson 1.80 ppb A
Inglewood Not detected A
South Gate Not detected C
Alhambra Not detected A
West Covina Not detected A
Compton Not detected C
Redondo Beach 1.40 ppb A
Pomona Not reported B
El Monte Not detected B
Florence-Graham Not detected A
Lakewood Not detected B
Gardena Not detected A
Norwalk 1.90 ppb C
Lynwood Not detected C
Monterey Park Not detected C
Arcadia 1.90 ppb C
Azusa Not detected A
Cerritos Not detected A
Whittier Not detected B
Bellflower Not detected C
Paramount Not detected A
Huntington Park Not detected C
Hawthorne Not detected A
Santa Clarita Not detected C
Rancho Palos Verdes 1.60 ppb A
Baldwin Park Not detected A
La Mirada Not detected C
Monrovia Not detected B
Manhattan Beach 5.40 ppb A
Westmont Not detected A
Lawndale Not detected A
West Hollywood 3.90 ppb B
Diamond Bar Not reported B
Bell Gardens Not detected C
Hacienda Heights Not detected B
South Pasadena Not detected A
Bell Not detected C
Montebello 4.20 ppb C
Covina Not detected B
Rowland Heights Not reported B
Pico Rivera Not detected C
San Gabriel Not detected A
West Whittier-Los Nietos Not detected B
Glendora Not reported B
Valinda Not detected A
West Carson 1.80 ppb A
Culver City 3.90 ppb B
Duarte 1.00 ppb A
Altadena Not reported B
Calabasas Not detected A
Lennox Not detected A
Agoura Hills Not detected A
Hermosa Beach 1.40 ppb A
Lomita Not detected B
South El Monte Not detected B
Rosemead Not detected A
La Puente Not detected A
South Whittier Not detected C
El Segundo Not detected B
Vincent Not detected A
Santa Fe Springs Not detected C
Walnut Park Not detected A
Cudahy Not detected C
Walnut Not reported B
San Dimas Not reported B
West Rancho Dominguez Not detected A
Hawaiian Gardens Not detected C
West Puente Valley Not detected B
Beverly Hills 3.90 ppb B
East Rancho Dominguez 0.85 ppb C
Palos Verdes Estates 1.60 ppb A
Claremont Not reported B
Artesia Not detected C
Temple City Not detected A
Commerce Not detected B
Maywood Not detected A
San Fernando 3.90 ppb B
Signal Hill 6.60 ppb B
San Marino Not detected A
Sierra Madre Not detected A
La Verne Not reported B
Malibu Not detected B
La Cañada Flintridge Not reported B
Del Aire Not detected A
Citrus Not detected A
La Crescenta-Montrose Not detected C
South San Jose Hills Not reported B
Willowbrook Not detected A
West Athens Not detected A
Alondra Park Not detected A
Rolling Hills Estates 1.60 ppb A
East San Gabriel Not detected A
Topanga Not detected B
Lake Los Angeles Not reported B
Avocado Heights Not detected A
East Whittier Not detected C
Quartz Hill Not reported B
Westlake Village Not detected A
View Park-Windsor Hills 3.90 ppb B
La Habra Heights Not detected C
Sun Village Not reported B
Mayflower Village Not detected C
South San Gabriel Not detected B
Acton Not reported B
South Monrovia Island 1.00 ppb A
Charter Oak Not reported B
Stevenson Ranch Not detected C
North El Monte Not detected C
Castaic Not detected C
Ladera Heights 3.90 ppb B
East Pasadena Not detected A
Rose Hills Not detected B
Marina del Rey 3.90 ppb B
Agua Dulce Not reported B
Pepperdine University Not detected B
Rolling Hills 1.60 ppb A
Hidden Hills Not detected A
San Pasqual Not detected A
Desert View Highlands Not reported B
Littlerock Not detected A
Irwindale Not detected A
Green Valley Not detected C
Bradbury 1.00 ppb A
Leona Valley Not reported B
Elizabeth Lake Not reported B
Val Verde Not detected A
Hasley Canyon Not detected A
Lake Hughes Not reported B
Industry Not detected B
Vernon Not detected A
Avalon Not detected A
Showing 142 cities
No active violations Active violations

About Los Angeles County Drinking Water

Los Angeles County is served by 74 water systems covering 142 communities. 99% have no open violations.

Of the communities reporting lead results, 27 recorded a detection, with a median of 1.80 ppb — 12% of the federal action level. 93 reported none detected, which means below the laboratory limit rather than an absence of lead.

31 of 142 communities have PFAS above the limits EPA set in 2024, measured as a running annual average at each sampling point. State inspectors recorded significant deficiencies at 9 of them.

Frequently Asked Questions

Is Los Angeles County tap water safe to drink?▼
99% of communities have no open violation. 31 of 142 have PFAS above the federal limit, which is the main open concern.
What is the lead level in Los Angeles County?▼
Among communities with a detection the median is 1.80 ppb, 12% of the 15 ppb action level. 93 reported none detected and 22 reported no result.
How many water systems serve Los Angeles County?▼
74 community water systems serve 142 communities here.
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