Water Quality Report · Updated May 12, 2026

DOWNEY - CITY, WATER DEPT.

Serving 110,556 residents in DOWNEY, California .

National rank 4th percentile
California rank 15th percentile
Data confidence Medium
Quick answer

DOWNEY - CITY, WATER DEPT. delivers tap water graded F (48/100) by TapWaterSafety.org. The utility serves approximately 110,556 residents in DOWNEY, California using groundwater. The most significant water quality concerns are: PFAS contamination; Perfluorohexane sulfonate (PFHXS) significantly above health guideline; Arsenic significantly above health guideline. For questions, the utility can be reached at 562-904-7110.

Data sources for this grade: utilities.csv EWG Tap Water Database ⓘ How did we get this rating?
110,556
People served
1
City served
28
Contaminants detected
12
Above health guidelines
0
EPA violations (5 yr)

Is DOWNEY tap water safe to drink?

DOWNEY - CITY, WATER DEPT. delivers tap water that earns a grade of F (48/100) from TapWaterSafety.org — a poor rating, with significant contamination concerns and/or recent violations.

The utility serves 110,556 residents in DOWNEY, drawing from groundwater.

Public testing data identifies 12 contaminants in this water above EWG's health-based guidelines, including: Perfluorooctanoic acid (PFOA), Perfluorooctane sulfonate (PFOS), Perfluorohexane sulfonate (PFHXS), Arsenic, Perfluorononanoic acid (PFNA), Nitrate, Nitrate and nitrite, Chromium (hexavalent), Tetrachloroethylene (perchloroethylene), 1,4-Dioxane, Perfluorodecanoic acid (PFDA), Uranium. For most residents, a properly certified home filter at the kitchen tap is the most cost-effective way to reduce exposure to whatever's in your water. See our filter recommendations below, matched specifically to this utility's contaminant profile.

Top concerns in this water

Based on the most recent EPA and EWG data, these are the most significant water quality issues for DOWNEY - CITY, WATER DEPT..

PFAS contamination

Severe concern

Perfluorononanoic acid (PFNA), Perfluorooctane sulfonate (PFOS) detected. PFAS are persistent chemicals linked to cancer and immune effects with no known safe exposure threshold.

Perfluorohexane sulfonate (PFHXS) significantly above health guideline

Moderate concern

Perfluorohexane sulfonate (PFHXS) detected at 5.87 ppt, 5873x above the EWG health guideline of 0.001 ppt.

Arsenic significantly above health guideline

Moderate concern

Arsenic detected at 1.43 ppb, 357x above the EWG health guideline of 0.004 ppb.

Contact DOWNEY - CITY, WATER DEPT.

Reach the utility directly for service issues, water quality concerns, or to request your Consumer Confidence Report.

Recommended water filters for DOWNEY

Filters matched to the specific contaminants in this water supply.

Reverse Osmosis or NSF P473 certified carbon

$80-$750

Activated carbon and RO are the only technologies proven to remove PFAS at certified levels.

AquaTru Countertop Reverse Osmosis
$449-$599 NSF 42, 53, 58, 401, P473
Editorial pick · affiliate link coming soon
Aquasana OptimH2O Reverse Osmosis + Claryum
$429-$549 NSF 42, 53, 58, 401, P473
Editorial pick · affiliate link coming soon
Waterdrop G3P800 Tankless RO
$600-$750 NSF 58, 372
View on retailer →
Waterdrop N1 Countertop RO
$249-$329 NSF 58, 372
View on retailer →
Clearly Filtered Pitcher Filter
$80-$95 NSF 42, 53, 401, P473
Editorial pick · affiliate link coming soon

Reverse Osmosis

$249-$750

Arsenic is most effectively removed by reverse osmosis. Some specialized adsorptive filters also work.

AquaTru Countertop Reverse Osmosis
$449-$599 NSF 42, 53, 58, 401, P473
Editorial pick · affiliate link coming soon
Aquasana OptimH2O Reverse Osmosis + Claryum
$429-$549 NSF 42, 53, 58, 401, P473
Editorial pick · affiliate link coming soon
Waterdrop G3P800 Tankless RO
$600-$750 NSF 58, 372
View on retailer →
Waterdrop N1 Countertop RO
$249-$329 NSF 58, 372
View on retailer →

Disclosure: TapWaterSafety earns a commission from purchases made through these links. This does not influence our scoring methodology or filter selection.

Score breakdown

This utility's overall score of 48/100 breaks down across five weighted components. Read the full methodology →

Health Guideline Performance
10 / 40
Legal Compliance
20 / 20
High-Risk Contaminants
0 / 20
Compliance History
10 / 10
Source Water Vulnerability
8 / 10

Contaminants detected — international standards comparison

Every contaminant detected, compared side-by-side against US EPA legal limits, the EU Drinking Water Directive (2020/2184), WHO Guidelines, and California's Public Health Goal (the strictest US benchmark). Why we show multiple standards →

Contaminant Detected EWG
US health-based
EPA
US legal
EU DWD
Europe
WHO
global
CA PHG
strictest US
Tested
sample year
Status
Perfluorooctanoic acid (PFOA)
PFAS
12.1 ppt 0.09 4.0 100 100 0.007 EPA violation
Perfluorooctane sulfonate (PFOS)
PFAS
29.9 ppt 0.3 4.0 100 100 1 EPA violation
Perfluorohexane sulfonate (PFHXS)
PFAS
5.87 ppt 0.001 10.0 5873× over
Arsenic
Heavy metal
1.43 ppb 0.004 10.0 10 10 0.004 357× over
Perfluorononanoic acid (PFNA)
PFAS
2.07 ppt 0.006 10.0 345× over
Nitrate
Inorganic
3.16 ppm 0.14 10.0 11.3 11.3 10 23× over
Nitrate and nitrite
Inorganic
3.18 ppm 0.14 10.0 11.3 11.3 10 23× over
Chromium (hexavalent)
Heavy metal
0.276 ppb 0.02 14× over
Tetrachloroethylene (perchloroethylene)
Volatile organic compound
0.541 ppb 0.06 5.0 9.0× over
1,4-Dioxane
Semi-volatile organic compound
1.64 ppb 0.35 50 1 4.7× over
Perfluorodecanoic acid (PFDA)
PFAS
0.025 ppt 0.006 4.2× over
Uranium
Radiological
1.51 pCi/L 0.43 20.0 30 30 0.43 3.5× over
Trichloroethylene
Volatile organic compound
0.177 ppb 0.4 5.0 10 20 1.7 Below guideline
Manganese
Heavy metal
12.9 ppb 100.0 50 80 Below guideline
Vanadium
Other
2.6 ppb 21.0 Below guideline
Chlorate
Disinfection byproduct
23.5 ppb 210.0 Below guideline
Barium
Heavy metal
65.4 ppb 700.0 2000.0 1300 2000 Below guideline
Molybdenum
Other
2.05 ppb 40.0 Below guideline
Perfluoropentanoic Acid (PFPeA)
PFAS
9.66 ppt 1000.0 Below guideline
Perfluorohexanoic Acid (PFHxA)
PFAS
8.07 ppt 1000.0 Below guideline
Perfluorobutanoic Acid (PFBA)
PFAS
6.27 ppt 1000.0 Below guideline
Aluminum
Heavy metal
2.83 ppb 600.0 200 600 Below guideline
Perfluorobutane sulfonate (PFBS)
PFAS
6.03 ppt 2000.0 Below guideline
Perfluoroheptanoic acid (PFHPA)
PFAS
2.58 ppt 1000.0 Below guideline
1,1-Dichloroethane
Volatile organic compound
0.00349 ppb 3.0 Below guideline
Strontium
Radiological
0.496 ppb 1500.0 Below guideline
Chlorodifluoromethane
Other
0.0227 ppb Below guideline
Fluoride
Inorganic
0.301 ppm 4.0 1.5 1.5 Below guideline

All values in the unit of the detected level. Red cells indicate the detected level exceeds that standard. Some contaminants have limits in some jurisdictions but not others (shown as —). The "Tested" column shows the year each contaminant sample was collected.

Sources: US EPA, EU Drinking Water Directive 2020/2184, WHO Guidelines (4th ed.), California OEHHA PHGs, EWG Tap Water Database.

DOWNEY - CITY, WATER DEPT. service area

This water system serves 1 community in Los Angeles County, California. Click any city for its dedicated tap water quality page.

About this water system

Public Water System ID
CA1910034
Owner type
Local government
Source water
Groundwater
Service connections
23,459
Service area
DOWNEY, Los Angeles County, California