WaterVerge

Is Sierra Madre, CA Tap Water Safe to Drink?

Graded A, with 1 unresolved violation on record. See what was cited — and what it means for your tap. What to do next ↓

11K residents served 1 water system PWSID: CA1910148
Overall Score
93.8 / 100
Violations
1 active
Last Updated
May 2026
Source
Purchased surface water
#60 of 694 in California Top 5% nationally
Local Government
High data confidence
Reviewed by WaterVerge Editorial Team · Last updated May 2026
AGRADE
Water Quality Grade
93.8/100
waterverge.com
A 93.8/100

Sierra Madre, CA — Water Quality Report

Sierra Madre's drinking water received a grade of A (93.8 out of 100), indicating excellent water quality. The city's 1 water system serves approximately 11,000 residents using purchased surface water.

Lead levels were measured at 0.0 ppb (90th percentile), well within EPA limits. PFAS testing under UCMR 5 found no detectable forever chemicals.

The system has 6 violations on record, including 5 health-based violations. 1 remains unresolved.

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

What to know about Sierra Madre's water

Sierra Madre ranks #60 out of 694 cities in California for water quality, placing it one of the best 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.

Hexavalent chromium (chromium-6) was detected at 1.50 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.

Quality Breakdown

Water quality score

See methodology →
93.8 out of 100 Grade A
A: 90-100
B: 74-89
C: 60-73
F: <50
How is this calculated?
Violations
44/45
A
Historical violation record including health-based and monitoring violations.
Lead & Copper
20/20
A
Lead at 0.0 ppb (90th percentile).
Contaminants
17.8/20
B
No PFAS compounds detected.
Compliance
8/10
B
Monitoring and reporting compliance with EPA regulations.
Source Risk
4/5
B
Water source: Purchased surface water.
Water Safety

Is Sierra Madre, CA water safe to drink?

Use Caution

Sierra Madre's tap water meets most EPA standards but has areas that warrant attention. With a grade of A (93.8/100), some contaminant levels or compliance issues suggest that residents may benefit from additional filtration. The city's 1 water system serves approximately 11,000 residents using surface water (rivers, lakes, or reservoirs).

1
Active Violations
0.0 ppb
Lead (90th %ile)
None
PFAS Detected
10 events
Disaster History

Recent water quality updates for Sierra Madre

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

Update
Water quality data updated

Latest EPA compliance and testing data incorporated into Sierra Madre's water quality assessment. Grade: A (93.8/100).

Disaster
SEVERE WINTER STORMS, FLOODING, LANDSLIDES, AND MUDSLIDES

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

Disaster
SEVERE WINTER STORMS, FLOODING, LANDSLIDES, AND MUDSLIDES

Federal disaster declaration (FEMA DR-4683). Flood event — may have impacted local water infrastructure.

Violation
1 drinking water violation recorded

1 health-based. Contaminants: Coliform (TCR).

Violation
1 drinking water violation recorded

1 health-based. Contaminants: Fluoride.

Violation
1 drinking water violation recorded

1 health-based. Contaminants: Coliform (TCR).

Key contaminant findings

Based on the most recent EPA sampling data for Sierra Madre's water supply.

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

Well within EPA limits.

Violation history

Sierra Madre's water system has 6 total violations on record, including 5 health-based violations. 1 remain unresolved.

MCL
Most recent violations:
Dec 2007 Coliform (TCR) Resolved
Jan 1993 Fluoride Resolved
Nov 1992 Coliform (TCR) Resolved
Sep 1992 Coliform (TCR) Resolved
Mar 1992 Coliform (TCR) 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. Local water sources include San Gabriel R Bl Santa Fe Dam Nr Baldwin Pk, San Gabriel R Ab Whittier Narrows Dam, Arroyo Seco Nr Pasadena, Rio Hondo Ab Whittier Narrows Dam, Rio Hondo Bl Whittier Narrows Dam.

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 Sierra Madre's water come from?

Sierra Madre's drinking water comes from surface water (rivers, lakes, or reservoirs), supplied by 1 water system serving approximately 11,000 people. Surface water sources are more susceptible to contamination from runoff, industrial discharge, and algal blooms, requiring extensive treatment. Nearby water bodies include San Gabriel R Bl Santa Fe Dam Nr Baldwin Pk (river), San Gabriel R Ab Whittier Narrows Dam (river), Arroyo Seco Nr Pasadena (river), Rio Hondo Ab Whittier Narrows Dam (river), Rio Hondo Bl Whittier Narrows Dam (river).

What Sierra Madre residents can do

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

Sierra Madre'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
HAA5 (Disinfection Byproducts)
Disinfection Byproduct
Safe
1.5 µg/L
EPA MCL: 60 µg/L · 3% of limit
Within LimitUCMR 4 DataHAA6Br: 1.9 µg/LHAA9: 2.5 µg/L
Chromium-6 (Hexavalent Chromium)
Inorganic
Detected
1.50 µg/L
CA MCL (no federal MCL): 10 µg/L · 15% of limit
DetectedUCMR 3 Data
Strontium
Inorganic
Elevated
960.0 µg/L
EPA Health Ref Level: 1,500 µg/L · 64% of limit
DetectedUCMR 3 Data
Vanadium
Inorganic
Detected
9.70 µg/L
EPA Short-term HA: 21 µg/L · 46% of limit
DetectedUCMR 3 Data
Chlorate
Disinfection Byproduct
Elevated
130.0 µg/L
EPA Lifetime HA: 210 µg/L · 62% of limit
DetectedUCMR 3 Data
Molybdenum
Inorganic
Detected
4.30 µg/L
EPA Lifetime HA: 40 µg/L · 11% of limit
DetectedUCMR 3 Data
PFAS Testing

Forever chemicals overview

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

Violation summary

6
Total violations
5
Health-based
1
Active / unresolved
Dec 2007
Most recent violation
Compliance Record

Violations & advisories

6 Total
1 Active
5 Health-based
5 Resolved
Violations by category
Total Coliform Rule
4
Inorganic Chemicals
1
Active
Compliance Violation
Monitoring 0
Dec 2007 Resolved
Coliform (TCR)
Max Contaminant Level
Health-Based Health Resolved Dec 2007
Jan 1993 Resolved
Fluoride
Max Contaminant Level
Health-Based Health Resolved Mar 1993
Nov 1992 Resolved
Coliform (TCR)
Max Contaminant Level
Health-Based Health Resolved Nov 1992
Sep 1992 Resolved
Coliform (TCR)
Max Contaminant Level
Health-Based Health Resolved Sep 1992
Mar 1992 Resolved
Coliform (TCR)
Max Contaminant Level
Health-Based Health Resolved Mar 1992
Industrial pollution

Top industrial polluters within 10 miles of Sierra Madre

Industrial polluters nearby

Reported releases to surface water by facilities near Sierra Madre, ranked by pounds discharged annually.

Total reported releases to surface water: 9 lbs

FacilityTop chemicalTo surface water (lbs/yr)Distance
SOLVENTUM ORTHODONTICS CORP
Miscellaneous Manufacturing · SOLVENTUM US LLC
MONROVIA, CA91016
Chromium84.5 mi
CONCORDE/INTERSPACE BATTERY CORP
Electrical Equipment · CONCORDE BATTERY CORP
WEST COVINA, CA91790
Lead And Lead Compounds18.1 mi
CUSTOM ALLOY SALES INC.
Primary Metals · CUSTOM ALLOY SALES INC
CITY OF INDUSTRY, CA91746
Copper08.6 mi
INWESCO INC
Fabricated Metals · CRH AMERICAS INC
AZUSA, CA91702
Chromium07.7 mi
GRIFOLS BIOLOGICALS
Chemicals · GRIFOLS SHARED SERVICES NORTH AMERICA INC
LOS ANGELES, CA90032
9.1 mi

Source: EPA Toxic Release Inventory (TRI) 2023

Site context

Superfund sites within 10 miles of Sierra Madre

Superfund sites nearby

Federally tracked hazardous-waste sites on the EPA National Priorities List. Proximity does not necessarily indicate tap-water contamination — the connection depends on hydrology and treatment.

Source: EPA Superfund National Priorities List

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

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 ND HI µg/L PFAS Not 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 11.0 ppb from 1992 (11.0 ppb) to 2023 (0.0 ppb).
Contaminant Rankings

See how Sierra Madre compares by contaminant

Explore where Sierra Madre ranks among all California cities for specific contaminants.

Infrastructure

Water source & infrastructure

Primary Source
Purchased Surface Water
Operator
Local Government
Population Served
11,000
Water Systems
1
Water Source

Where Sierra Madre's water comes from

Purchased Surface Water

Sierra Madre'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 local government ownership and serves approximately 11,000 people through 1 water system.

Local Hydrology

Water bodies near Sierra Madre

Sierra Madre is located near 5 notable water bodies. As a surface water system, these water bodies may directly influence the city's drinking water supply.

San Gabriel R Bl Santa Fe Dam Nr Baldwin Pk
river
San Gabriel R Ab Whittier Narrows Dam
river
Arroyo Seco Nr Pasadena
river
Rio Hondo Ab Whittier Narrows Dam
river
Rio Hondo Bl Whittier Narrows Dam
river
Infrastructure

Water systems serving Sierra Madre

System Name PWSID Population Source
SIERRA MADRE-CITY, WATER DEPT. CA1910148 11,000 SWP
Regional Comparison

How Sierra Madre compares

Full California rankings →

Sierra Madre's score of 93.8/100 is above the average of 57/100 among major California cities. It outscores 10 of 10 nearby cities.

Sierra Madre (this city)
93.8
Oakland
77.9
San Diego
39.7
Sacramento
31.2
California avg
57
City Profile

About Sierra Madre, CA

Economic Profile
$128,056
Median Income
$1,132,000
Median Home Value
$1,994/mo
Median Rent
3.2%
Unemployment
Community
46.6
Median Age
1,459
People / sq mi
64.7%
College Educated
56.2%
Homeownership
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Frequently asked questions

Is Sierra Madre, CA tap water safe to drink?

Sierra Madre's water quality earned a grade of A (93.8/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #60 out of 694 cities tested in California.

What contaminants are in Sierra Madre's water?

Lead was measured at 0.0 ppb (90th percentile). No PFAS compounds were detected. 6 violations are on record.

How is Sierra Madre'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 Sierra Madre?

Based on current data, basic filtration should suffice for additional peace of mind.

Where does Sierra Madre's water come from?

Sierra Madre's water is sourced from Purchased surface water. The city has 1 water system serving approximately 11,000 residents.

What health violations has Sierra Madre's water system had?

Sierra Madre has 5 health-based violations on record. The most recent violation was recorded in December 2007. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 1 violation remains unresolved.

How does Sierra Madre's water compare to other cities?

Sierra Madre ranks #60 out of 694 cities in California (better than 91% of state cities) and #706 out of 15744 cities nationally (96th percentile). The grade of A reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.