Tap Water Quality Report

Tap water quality in DOWNEY, California

Served by 3 public water systems. 247,649 residents.

Average score 53/100
Utilities 3
Population 247,649
Quick answer

Tap water in DOWNEY, California receives a grade of F (53/100) from TapWaterSafety.org. It's served by 3 public water systems, primarily LIBERTY UTILITIES (AV RANCHOS) CORP.. The most significant water quality concerns are: Arsenic significantly above health guideline; Haloacetic acids (HAA5) significantly above health guideline; Chromium (hexavalent) significantly above health guideline; PFAS contamination; Perfluorohexane sulfonate (PFHXS) significantly above health guideline. Data sources: EPA SDWIS, EPA ECHO, EWG Tap Water Database.

Data sources for this grade: utilities.csv EWG Tap Water Database ⓘ How did we get this rating?

What's in DOWNEY's tap water

Top water quality concerns identified by the EPA and Environmental Working Group across the utilities serving DOWNEY.

Arsenic significantly above health guideline

Moderate concern

Arsenic detected at 1.01 ppb, 251x above the EWG health guideline of 0.004 ppb.

Haloacetic acids (HAA5) significantly above health guideline

Moderate concern

Haloacetic acids (HAA5) detected at 24.4 ppb, 244x above the EWG health guideline of 0.1 ppb.

Chromium (hexavalent) significantly above health guideline

Moderate concern

Chromium (hexavalent) detected at 2.46 ppb, 123x above the EWG health guideline of 0.02 ppb.

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.

Recommended filters for DOWNEY

Filters matched to the specific contaminants in DOWNEY's water supply.

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.

All contaminants detected in DOWNEY's tap water

Every contaminant identified, compared side-by-side against US EPA legal limits, the EU Drinking Water Directive (2020/2184), WHO Guidelines, and California's Public Health Goal. 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
39.7 ppt 0.3 4.0 100 100 1 EPA violation
Perfluorohexane sulfonate (PFHXS)
PFAS
7.52 ppt 0.001 10.0 7518× over
Haloacetic acids (HAA5)
Disinfection byproduct
36.2 ppb 0.1 60.0 60 362× 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
Total trihalomethanes (TTHMs)
Disinfection byproduct
28.8 ppb 0.15 80.0 100 192× over
Bromodichloromethane
Disinfection byproduct
8.61 ppb 0.06 143× over
Chromium (hexavalent)
Heavy metal
2.46 ppb 0.02 123× over
Dibromochloromethane
Disinfection byproduct
8.38 ppb 0.1 84× over
Dibromoacetic acid
Disinfection byproduct
1.73 ppb 0.03 58× over
Haloacetic acids (HAA9)
Disinfection byproduct
3.46 ppb 0.06 58× over
Arsenic*
Heavy metal
0.16 ppb 0.004 10.0 10 10 0.004 40× over
Trichloroacetic acid
Disinfection byproduct
3.36 ppb 0.1 34× over
Chloroform
Disinfection byproduct
9.49 ppb 0.4 24× over
Dichloroacetic acid
Disinfection byproduct
4.79 ppb 0.2 24× 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
Radium, combined (-226 and -228)
Radiological
0.62 pCi/L 0.05 5.0 12× over
Bromoform
Disinfection byproduct
5.43 ppb 0.5 11× over
Tetrachloroethylene (perchloroethylene)
Volatile organic compound
0.541 ppb 0.06 5.0 9.0× over
1,4-Dioxane
Semi-volatile organic compound
2.0 ppb 0.35 50 1 5.7× over
Uranium
Radiological
2.08 pCi/L 0.43 20.0 30 30 0.43 4.8× over
Perfluorodecanoic acid (PFDA)
PFAS
0.025 ppt 0.006 4.2× over
Vanadium
Other
13.9 ppb 21.0 Below guideline
Trichloroethylene
Volatile organic compound
0.177 ppb 0.4 5.0 10 20 1.7 Below guideline
Chlorate
Disinfection byproduct
56.3 ppb 210.0 Below guideline
Aluminum*
Heavy metal
77.5 ppb 600.0 200 600 Below guideline
Manganese
Heavy metal
12.9 ppb 100.0 50 80 Below guideline
Barium
Heavy metal
65.4 ppb 700.0 2000.0 1300 2000 Below guideline
Molybdenum
Other
3.48 ppb 40.0 Below guideline
Aluminum
Heavy metal
13.6 ppb 600.0 200 600 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
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
Cobalt
Other
0.0542 ppb 70.0 Below guideline
Strontium
Radiological
0.703 ppb 1500.0 Below guideline
Chlorodifluoromethane
Other
0.0425 ppb Below guideline
Fluoride
Inorganic
0.442 ppm 4.0 1.5 1.5 Below guideline
cis-1,2-Dichloroethylene
Volatile organic compound
0.276 ppb 70.0 Below guideline
Lithium
Other
35.5 ppb Below guideline
Germanium
Other
0.0326 ppb 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, California OEHHA PHGs, EWG Tap Water Database.

Treatment plant contact info

For service issues, water quality concerns, or to request a Consumer Confidence Report from LIBERTY UTILITIES (AV RANCHOS) CORP..

Treatment Plant

FacilityWELL 30 (HILLTOP WELL) - TREATED

ZIP codes served

DOWNEY's public water systems serve the following ZIP codes: