WaterVerge

Is Westlake Village, CA Tap Water Safe to Drink?

Graded F, with 51 unresolved violations on record. See what was cited — and what it means for your tap. What to do next ↓

14K residents served 3 water systems PWSID: CA5610043
Overall Score
44.4 / 100
Violations
51 active
Last Updated
May 2026
Source
Purchased surface water
#645 of 694 in California Top 91% nationally
Private
High data confidence
Reviewed by WaterVerge Editorial Team · Last updated May 2026
FGRADE
Water Quality Grade
44.4/100
waterverge.com
F 44.4/100

Westlake Village, CA — Water Quality Report

Westlake Village's drinking water received a grade of F (44.4 out of 100), indicating failing water quality. The city's 3 water systems serve approximately 14,424 residents using purchased surface water.

Lead levels were measured at 0.0 ppb (90th percentile), well within EPA limits. UCMR 5 testing detected 1 PFAS compound in the water supply.

The system has 230 violations on record, including 8 health-based violations. 51 remain unresolved.

Data last updated: May 2026 · Source: EPA SDWIS, UCMR 5
Analysis

What to know about Westlake Village's water

Westlake Village ranks #645 out of 694 cities in California for water quality, placing it among the lowest-rated in the state.

The city draws from surface water sources, which are more susceptible to seasonal runoff and agricultural contamination, requiring extensive multi-barrier treatment including coagulation, filtration, and disinfection.

PFAS compounds were detected in testing, though levels remain within current EPA limits. Residents seeking extra precaution may consider an activated carbon or reverse osmosis filter.

Hexavalent chromium (chromium-6) was detected at 0.68 µg/L in UCMR 3 testing. While below California's 10 µg/L limit and with no federal MCL set, residents sensitive to this contaminant may consider reverse osmosis filtration.

The system has seen 18 violations in the past five years, suggesting a pattern of compliance challenges that residents should monitor closely.

Quality Breakdown

Water quality score

See methodology →
44.4 out of 100 Grade F
A: 90-100
B: 74-89
C: 60-73
F: <50
How is this calculated?
Violations
1.1/45
F
Historical violation record including health-based and monitoring violations.
Lead & Copper
20/20
A
Lead at 0.0 ppb (90th percentile).
Contaminants
14.2/20
C
1 PFAS compound detected.
Compliance
5/10
D
Monitoring and reporting compliance with EPA regulations.
Source Risk
4/5
B
Water source: Purchased surface water.
Water Safety

Is Westlake Village, CA water safe to drink?

Concerns Identified

Westlake Village's drinking water has significant quality concerns based on EPA testing data. With a grade of F (44.4/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 3 water systems serve approximately 14,424 residents using surface water (rivers, lakes, or reservoirs).

51
Active Violations
0.0 ppb
Lead (90th %ile)
1 compound
PFAS Detected
10 events
Disaster History

Recent water quality updates for Westlake Village

A timeline of significant water quality events, violations, and data updates.

PFAS
1 PFAS "forever chemical" compound detected

Detected at levels within current EPA limits. PFAS persist indefinitely in the environment.

Update
Water quality data updated

Latest EPA compliance and testing data incorporated into Westlake Village's water quality assessment. Grade: F (44.4/100).

Violation
1 drinking water violation recorded

Contaminants: Revised Total Coliform Rule.

Violation
1 drinking water violation recorded

Contaminants: Revised Total Coliform Rule.

Violation
1 drinking water violation recorded

Contaminants: Revised Total Coliform Rule.

Disaster
SEVERE WINTER STORMS, FLOODING, LANDSLIDES, AND MUDSLIDES

Federal disaster declaration (FEMA DR-3592). Flood event — may have impacted local water infrastructure.

Key contaminant findings

Based on the most recent EPA sampling data for Westlake Village's water supply.

Lead Within Limits
Detected: 0.0 ppb Limit: 15 ppb (EPA Action Level)

Well within EPA limits.

PFAS (1 compound) Elevated
Detected: Highest: lithium at 9.8000 µg/L Limit: 0.004 µg/L (EPA MCL)

Detected but within current EPA limits. PFAS do not break down in the environment and can accumulate in the body over time. An activated carbon filter can reduce exposure.

Violation history

Westlake Village's water system has 230 total violations on record, including 8 health-based violations. 51 remain unresolved. 18 violations were issued in the last 5 years.

MONMROtherTTRPTMCL
Most recent violations:
Oct 2025 Revised Total Coliform Rule Resolved
Sep 2025 Revised Total Coliform Rule Resolved
Aug 2025 Revised Total Coliform Rule Resolved
Jul 2025 Nitrate Resolved
Jul 2025 Revised Total Coliform Rule Resolved

Flood & environmental risk

Los Angeles County has experienced 10 federally declared disasters since 1980. Flooding and severe storms can overwhelm water treatment plants, cause sewage overflows, and introduce agricultural runoff, bacteria, and sediment into drinking water supplies.

SEVERE WINTER STORMS, FLOODING, LANDSLIDES, AND MUDSLIDES
Flood FEMA DR-3592
SEVERE WINTER STORMS, FLOODING, LANDSLIDES, AND MUDSLIDES
Flood FEMA DR-4683
SEVERE WINTER STORMS, FLOODING, AND MUDSLIDES
Flood FEMA DR-3591

Where does Westlake Village's water come from?

Westlake Village's drinking water comes from surface water (rivers, lakes, or reservoirs), supplied by 3 water systems serving approximately 14,424 people. Surface water sources are more susceptible to contamination from runoff, industrial discharge, and algal blooms, requiring extensive treatment.

What Westlake Village residents can do

Install a water filter

Recommended: Activated carbon or reverse osmosis filter. This addresses the specific contaminants found in Westlake Village's water.

Request your utility's CCR

Your water utility is required to publish an annual Consumer Confidence Report (CCR) with detailed testing results. Ask for the latest copy or check your utility's website.

Monitor alerts during storms

Westlake Village's area has a history of flooding. After severe weather, watch for boil water advisories from your local utility.

Data: EPA SDWIS, UCMR 5 (PFAS), FEMA, NOAA. Last updated May 2026.

Contaminant Alerts

Top contaminants to know

View all ↓
Lead (90th percentile)
Inorganic / Heavy Metal
Safe
0.0 ppb
EPA Action Level: 15 ppb · 0% of limit
Safe Level
lithium
PFAS / Forever Chemical
Near MCL
9.8000 µg/L
EPA MCL: 0.004 µg/L · +20% over limit
Detected
HAA5 (Disinfection Byproducts)
Disinfection Byproduct
Safe
5.9 µg/L
EPA MCL: 60 µg/L · 10% of limit
Within LimitUCMR 4 DataHAA6Br: 7.3 µg/LHAA9: 9.7 µg/L
Chromium-6 (Hexavalent Chromium)
Inorganic
Detected
0.68 µg/L
CA MCL (no federal MCL): 10 µg/L · 7% of limit
DetectedUCMR 3 Data
Strontium
Inorganic
Detected
620.0 µg/L
EPA Health Ref Level: 1,500 µg/L · 41% of limit
DetectedUCMR 3 Data
Manganese
Inorganic
Detected
1.4 µg/L
EPA Secondary MCL: 50 µg/L · 3% of limit
DetectedUCMR 4 Data
Vanadium
Inorganic
Detected
6.10 µg/L
EPA Short-term HA: 21 µg/L · 29% of limit
DetectedUCMR 3 Data
Chlorate
Disinfection Byproduct
Detected
84.0 µg/L
EPA Lifetime HA: 210 µg/L · 40% of limit
DetectedUCMR 3 Data
Molybdenum
Inorganic
Detected
6.60 µg/L
EPA Lifetime HA: 40 µg/L · 16% of limit
DetectedUCMR 3 Data
Lithium
Inorganic
Detected
9.8 µg/L
State screening level: 60 µg/L · 16% of limit
DetectedNo federal MCLUCMR 5 Data (2023–2025)
PFAS Testing

Forever chemicals overview

National PFAS report →
30
Compounds tested
1
Detected
0
Exceed EPA MCL
Compliance Record

Violation summary

230
Total violations
8
Health-based
51
Active / unresolved
Oct 2025
Most recent violation
Compliance Record

Violations & advisories

230 Total
51 Active
8 Health-based
179 Resolved
Violations by category
Volatile Organic Chemicals
63
Synthetic Organic Chemicals
40
Public Notice Rule and Revised PN Rule
30
Stage 1 Disinfectants and Disinfection Byproducts Rule
24
Inorganic Chemicals
19
Jul 2025 Active
Consumer Confidence Rule
Other Violation 0
Dec 2024 Active
Lead and Copper Rule
Monitoring & Reporting
Monitoring & Reporting 0
Oct 2024 Active
LEAD AND COPPER RULE REVISIONS
Treatment Technique
Health-Based Health 0
Oct 2024 Active
LEAD AND COPPER RULE REVISIONS
Reporting
Reporting 0
Jul 2024 Active
Consumer Confidence Rule
Other Violation 0
Jul 2023 Active
Consumer Confidence Rule
Other Violation 0
Oct 2022 Active
Public Notice
Other Violation 0
Jul 2022 Active
Consumer Confidence Rule
Other Violation 0
Dec 2021 Active
Public Notice
Other Violation 0
Oct 2021 Active
Public Notice
Other Violation 0
Sep 2021 Active
Public Notice
Other Violation 0
Dec 2018 Active
Lead and Copper Rule
Monitoring & Reporting
Monitoring & Reporting 0
Aug 2017 Active
Public Notice
Other Violation 0
Aug 2017 Active
Public Notice
Other Violation 0
Aug 2017 Active
Public Notice
Other Violation 0
May 2017 Active
Public Notice
Other Violation 0
Dec 2016 Active
Public Notice
Other Violation 0
Dec 2016 Active
Public Notice
Other Violation 0
Dec 2016 Active
Public Notice
Other Violation 0
Dec 2016 Active
Public Notice
Other Violation 0
Showing 20 of 230 violations
Industrial pollution

Top industrial polluters within 10 miles of Westlake Village

Industrial polluters nearby

Reported releases to surface water by facilities near Westlake Village, ranked by pounds discharged annually.

FacilityTop chemicalTo surface water (lbs/yr)Distance
BAXALTA US INC
Chemicals · BAXALTA US INC
THOUSAND OAKS, CA91320
8.0 mi
SKYWORKS SOLUTIONS INC.
Computers and Electronic Products · SKYWORKS SOLUTIONS INC
NEWBURY PARK, CA91320
7.2 mi
KAVLICO/SENSATA
Computers and Electronic Products · SENSATA TECHNOLOGIES INC
NEWBURY PARK, CA91320
7.6 mi
PSI BEARINGS
Machinery · REGAL REXNORD CORP
SIMI VALLEY, CA93065
9.6 mi

Source: EPA Toxic Release Inventory (TRI) 2023

Environmental Risk

Flood & disaster history

10
Declared disasters
Mar 2023
Most recent
Flood
Most common type

Los Angeles County has experienced 10 federally declared disasters since 1980. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.

Mar 2023
SEVERE WINTER STORMS, FLOODING, LANDSLIDES, AND MUDSLIDES
Flood FEMA #3592
Jan 2023
SEVERE WINTER STORMS, FLOODING, LANDSLIDES, AND MUDSLIDES
Flood FEMA #4683
Jan 2023
SEVERE WINTER STORMS, FLOODING, AND MUDSLIDES
Flood FEMA #3591
Mar 2017
SEVERE WINTER STORMS, FLOODING, AND MUDSLIDES
Flood FEMA #4305
Sep 2005
HURRICANE KATRINA EVACUATION
Hurricane FEMA #3248
Feb 1993
SEVERE WINTER STORM, MUD & LAND SLIDES, & FLOODING
Flood FEMA #979

Recommended water filters

Based on contaminants detected in Westlake Village's water supply, we recommend the following filter types.

🧪
For PFAS
Reverse Osmosis or Activated Carbon Block
1 PFAS compound detected

Full contaminants report

Contaminant Detected Level EPA Limit Unit Category Status
Lead (90th percentile) 0.0 15 ppb Inorganic Safe
11Cl-PF3OUdS ND HI µg/L PFAS Not Detected
4:2 FTS ND HI µg/L PFAS Not Detected
6:2 FTS ND HI µg/L PFAS Not Detected
8:2 FTS ND HI µg/L PFAS Not Detected
9Cl-PF3ONS ND HI µg/L PFAS Not Detected
ADONA ND HI µg/L PFAS Not Detected
HFPO-DA ND 0.01 µg/L PFAS Not Detected
lithium 9.800 HI µg/L PFAS Detected
NEtFOSAA ND HI µg/L PFAS Not Detected
NFDHA ND HI µg/L PFAS Not Detected
NMeFOSAA ND HI µg/L PFAS Not Detected
PFBA ND HI µg/L PFAS Not Detected
PFBS ND HI µg/L PFAS Not Detected
PFDA ND HI µg/L PFAS Not Detected
PFDoA ND HI µg/L PFAS Not Detected
PFEESA ND HI µg/L PFAS Not Detected
PFHpA ND HI µg/L PFAS Not Detected
PFHpS ND HI µg/L PFAS Not Detected
PFHxA ND HI µg/L PFAS Not Detected
PFHxS ND HI µg/L PFAS Not Detected
PFMBA ND HI µg/L PFAS Not Detected
PFMPA ND HI µg/L PFAS Not Detected
PFNA ND HI µg/L PFAS Not Detected
PFOA ND 0.004 µg/L PFAS Not Detected
PFOS ND 0.004 µg/L PFAS Not Detected
PFPeA ND HI µg/L PFAS Not Detected
PFPeS ND HI µg/L PFAS Not Detected
PFTA ND HI µg/L PFAS Not Detected
PFTrDA ND HI µg/L PFAS Not Detected
PFUnA ND HI µg/L PFAS Not Detected
Data source: EPA SDWIS, UCMR 5, local utility CCR.

Lead level trend (90th percentile)

EPA action level: 15 ppb
Lead has decreased by 2.5 ppb from 1992 (2.5 ppb) to 2025 (0.0 ppb).
Contaminant Rankings

See how Westlake Village compares by contaminant

Explore where Westlake Village ranks among all California cities for specific contaminants.

Infrastructure

Water source & infrastructure

Primary Source
Purchased Surface Water
Operator
Private
Population Served
14,424
Water Systems
3
Source breakdown
Groundwater
2
Purchased Surface Water
1
Water Source

Where Westlake Village's water comes from

Purchased Surface Water

Westlake Village's drinking water comes primarily from surface water sources such as rivers, lakes, or reservoirs.

Surface water systems require multi-stage treatment including coagulation, sedimentation, filtration, and disinfection to meet EPA Safe Drinking Water Act standards.

These sources can be impacted by seasonal changes, stormwater runoff, upstream agriculture, and industrial discharge.

The system is operated by private ownership and serves approximately 14,424 people through 3 water systems.

Infrastructure

Water systems serving Westlake Village

System Name PWSID Population Source
TRIUNFO WATER & SANITATION DISTRICT CA5610043 13,898 SWP
PEARLAND ACRES MHP TX0200353 501 GW
DEL SUR GARDENS TRAILER PARK CA1900304 25 GW
Regional Comparison

How Westlake Village compares

Full California rankings →

Westlake Village's score of 44.4/100 is below the average of 57/100 among major California cities. It outscores 5 of 10 nearby cities.

Westlake Village (this city)
44.4
Oakland
77.9
San Diego
39.7
Sacramento
31.2
California avg
57
City Profile

About Westlake Village, CA

Wikipedia →

Westlake Village is a city in Los Angeles County, California, on its western border with Ventura County. Upon its incorporation in 1981, Westlake Village became the 82nd municipality of Los Angeles County. The population of the city was 8,029 at the 2020 census.

Economic Profile
$188,681
Median Income
$1,225,398
Median Home Value
$3,501/mo
Median Rent
2.9%
Unemployment
Community
51.2
Median Age
592
People / sq mi
68.8%
College Educated
80.4%
Homeownership
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Frequently asked questions

Is Westlake Village, CA tap water safe to drink?

Westlake Village's water quality earned a grade of F (44.4/100). Significant issues have been found. A water filter is strongly recommended. The city ranks #645 out of 694 cities tested in California.

What contaminants are in Westlake Village's water?

Lead was measured at 0.0 ppb (90th percentile). 1 PFAS compound was detected. 230 violations are on record.

How is Westlake Village's water quality grade calculated?

The grade is based on four factors: violation history (40%), lead and copper levels (25%), PFAS contamination (25%), and regulatory compliance (10%). The score is also adjusted based on how complete the available data is. See our methodology page for full details.

Do I need a water filter in Westlake Village?

PFAS compounds have been detected. A filter with activated carbon can help reduce exposure.

Where does Westlake Village's water come from?

Westlake Village's water is sourced from Purchased surface water. The city has 3 water systems serving approximately 14,424 residents.

What health violations has Westlake Village's water system had?

Westlake Village has 8 health-based violations on record. The most recent violation was recorded in October 2025. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 51 violations remain unresolved.

How does Westlake Village's water compare to other cities?

Westlake Village ranks #645 out of 694 cities in California (better than 7% of state cities) and #14380 out of 15744 cities nationally (9th percentile). The grade of F reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.