Drinking water quality · 2023

· Verified May 23, 2026

What's in Los Angeles LADWP, CA tap water

33 contaminants were measured in the Los Angeles LADWP, CA water system's 2023 annual report. Each is shown below against its federal limit.

See it on the mapFull source report ↗

Reporting year: 2023
Contaminants measured: 33
Over federal limit: 0
Approaching the limit: 0
Service area: CA
Source: Utility CCR

All within federal limits. Every measured contaminant in this report is below its federal threshold.

PFAS — EPA UCMR5 (2023–2025)

1 PFAS compound detected in Los Angeles LADWP, CA

About this data

The EPA finalized the first-ever federal drinking-water limits for six PFAS compounds in April 2024. These numbers come straight from EPA's UCMR5 lab dataset — every U.S. system serving more than 3,300 people tested every PFAS sample at an entry point to its distribution system. PFAS not listed below were either tested and not detected, or not yet sampled.

Lithium

● Detected (no federal limit)

Measured 100 mg/LSample year 2023Samples 4 detect / 4

above national p90 (76.59999999999991 mg/L across detecting U.S. systems)

Source:EPA UCMR5· 2023 · 4 samples · 4 detected↗

PWSID CA1910067 · Source: EPA UCMR5. Limits per EPA's April 2024 PFAS National Primary Drinking Water Regulation. PFAS values reported in nanograms per liter (ng/L) — note that 1 ng/L = 1 part per trillion.

Where your water comes from · EPA SDWIS

Los Angeles LADWP, CA's drinking water comes from ground water, drawn from 54 sources.

Source

54ground water

RINALDI TOLUCA · 15
NORTH HOLLYWOOD · 11
TUJUNGA · 9
MANHATTAN · 5
+ 11 more

Treatment

27treatment plants

NORTH HOLLYWOOD WEST WELLHEAD TREATMENT
TOYONIN BLEND
RIVER SUPPY CONDUIT BCL - TREATED
+ 24 more

Distribution

99storage units

Also buys water from BURBANK-CITY, WATER DEPT., METROPOLITAN WATER DIST. OF SO. CAL..

Source: EPA SDWIS facilities inventory. Methodology.

Historical readings · EPA Six-Year Review (2012–2019)

11 contaminants historically over EPA limits in Los Angeles LADWP, CA

About this data

Every U.S. public water system reports compliance-monitoring data to EPA. The Six-Year Review releases the 2012–2019 window as a single dataset — here's what your system reported, year by year. Values shown are the highest detection per analyte per year, compared to the federal MCL.

Contaminant	Worst detection	EPA limit	Years (2012–2019)
TCE worst: 2015	0.246 mg/L 49.2×	0.005 mg/L	'12'13'15'16'17'18'19
NITRATE NITRITE worst: 2013	480 mg/L 48.0×	10 mg/L	'13'16'17'18'19
PCE worst: 2018	0.0673 mg/L 13.5×	0.005 mg/L	'12'13'14'15'16'17'18'19
GROSS BETA worst: 2017	14 mrem/yr 3.5×	4 mrem/yr	'12'13'14'15'16'17'18'19
CHROMIUM worst: 2015	0.348 mg/L 3.5× 34.8× the national p90	0.1 mg/L	'12'13'14'15'16'17'18'19
TTHM worst: 2012	0.214 mg/L 2.7×	0.08 mg/L	'12'13'14'15'16'17'18'19
DICHLOROETHYLENE 11 worst: 2012	0.0159 mg/L 2.3× above national p90	0.007 mg/L	'12'13'14'15'16'17'18'19
ARSENIC worst: 2016	0.0202 mg/L 2.0× above national p90	0.01 mg/L	'12'13'14'15'16'17'18'19
HAA5 worst: 2012	0.085 mg/L 1.4×	0.06 mg/L	'12'13'14'15'16'17'18'19
NITRATE worst: 2015	14.1 mg/L 1.4×	10 mg/L	'12'13'14'15'16'17'18'19
BROMATE worst: 2013	0.0119 mg/L 1.2×	0.01 mg/L	'12'13'15'19
CARBON TETRACHLORIDE worst: 2012	0.00296 mg/L within near national p90	0.005 mg/L	'12'13'14'15'16'17'18'19
SELENIUM worst: 2016	0.0224 mg/L within	0.05 mg/L	'12'13'14'15'16'17'18'19
FLUORIDE worst: 2018	1.56 mg/L within	4 mg/L	'12'13'14'15'16'17'18'19
RADIUM 226 228 worst: 2018	1.26 pCi/L within below national p90	5 pCi/L	'18
CADMIUM worst: 2015	0.0012 mg/L within below national p90	0.005 mg/L	'15
DICHLOROETHANE 12 worst: 2016	0.000603 mg/L within below national p90	0.005 mg/L	'13'15'16'19
BARIUM worst: 2012	0.218 mg/L within near national p90	2 mg/L	'12'13'14'15'16'17'18'19
CIS DICHLOROETHYLENE 12 worst: 2013	0.00746 mg/L within near national p90	0.07 mg/L	'12'13'14'15'16'17'18'19
TRICHLOROETHANE 111 worst: 2012	0.00213 mg/L within below national p90	0.2 mg/L	'12'13'14'15'16
URANIUM worst: 2016	0.0309 ug/L within above national p90	30 ug/L	'12'13'14'15'16'17'18'19
TOLUENE worst: 2019	0.000522 mg/L within	1 mg/L	'19
XYLENES TOTAL worst: 2014	0.00189 mg/L within	10 mg/L	'14
NITRITE worst: 2019	0.0000284 mg/L within	1 mg/L	'19
COPPER worst: 2014	0.167 mg/L below national p90	—	'14'15'16'18'19
LEAD worst: 2014	0.0421 mg/L	—	'14'15'19

PWSID CA1910067 · Source: EPA Six-Year Review 4 (2012–2019). Values are the highest detection in each calendar year; non-detect years are omitted. Year tags above show every year with a detection.

Disinfectants

Contaminant	Measured	Federal limit	Status
ChlorineA disinfectant added to drinking water to kill bacteria and viruses.	1.9 mg/LAverageSystem-wide	4 mg/LMCL	Within the limit

Radionuclides

Contaminant	Measured	Federal limit	Status
Gross AlphaGross alpha particle activity — a combined measure of alpha-emitting radioactive substances.	4 pCi/LAverageNorthern Combined Wells	15 pCi/LMCL	Within the limit
+By source (6)— MWD Diemer Plant, Northern Combined Wells, Southern Combined Wells +3 more MWD Diemer PlantPlant avgNot detected pCi/Lrange0–5 pCi/L33% of limit Northern Combined WellsPlant avg4 pCi/Lrange3.5–4.3 pCi/L29% of limit Southern Combined WellsPlant avg3.5 pCi/Lrange3.5–3.6 pCi/L24% of limit Los Angeles Aqueduct Filtration PlantPlant avg3.1 pCi/Lrange3.1 pCi/L21% of limit MWD Weymouth PlantPlant avgNot detected pCi/LrangeNot detected pCi/L0% of limit MWD Jensen PlantPlant avgNot detected pCi/LrangeNot detected pCi/L0% of limit

Metals

Contaminant	Measured	Federal limit	Status
AluminumA common element sometimes used as a treatment coagulant.	93 ug/LAverageMWD Weymouth Plant	1000 ug/LMCL	Within the limit
+By source (6)— MWD Weymouth Plant, MWD Diemer Plant, MWD Jensen Plant +3 more MWD Weymouth PlantPlant avg93 ug/Lrange0–150 ug/L15% of limit MWD Diemer PlantPlant avgNot detected ug/Lrange0–110 ug/L11% of limit MWD Jensen PlantPlant avg62 ug/Lrange52–91 ug/L9% of limit Southern Combined WellsPlant avgNot detected ug/LrangeNot detected ug/L0% of limit Los Angeles Aqueduct Filtration PlantPlant avgNot detected ug/LrangeNot detected ug/L0% of limit Northern Combined WellsPlant avgNot detected ug/LrangeNot detected ug/L0% of limit
Chromium, TotalTotal chromium — the sum of all chromium forms, from natural deposits and industrial discharge.	0.2 ug/LAverageSouthern Combined Wells	10 ug/LMCL	Within the limit
+By source (6)— Southern Combined Wells, Northern Combined Wells, MWD Jensen Plant +3 more Southern Combined WellsPlant avg0.2 ug/Lrange0–0.4 ug/L4% of limit Northern Combined WellsPlant avg0.1 ug/Lrange0–0.3 ug/L3% of limit MWD Jensen PlantPlant avgNot detected ug/LrangeNot detected ug/L0% of limit MWD Weymouth PlantPlant avgNot detected ug/LrangeNot detected ug/L0% of limit Los Angeles Aqueduct Filtration PlantPlant avgNot detected ug/LrangeNot detected ug/L0% of limit MWD Diemer PlantPlant avgNot detected ug/LrangeNot detected ug/L0% of limit
BoronA naturally occurring element from rock and soil.	450AverageLos Angeles Aqueduct Filtration Plant	None set	Detected — no federal limit
+By source (6)— Los Angeles Aqueduct Filtration Plant, Southern Combined Wells, Northern Combined Wells +3 more Los Angeles Aqueduct Filtration PlantPlant avg450range373–507 Southern Combined WellsPlant avg398range320–501 Northern Combined WellsPlant avg448range326–501 MWD Jensen PlantPlant avg170range170 MWD Weymouth PlantPlant avg140range140 MWD Diemer PlantPlant avg140range140
CalciumA naturally occurring mineral that contributes to water hardness.	68 mg/LAverageMWD Weymouth Plant	None set	Detected — no federal limit
+By source (6)— MWD Diemer Plant, MWD Weymouth Plant, Southern Combined Wells +3 more MWD Diemer PlantPlant avg68 mg/Lrange58–78 mg/L MWD Weymouth PlantPlant avg68 mg/Lrange59–76 mg/L Southern Combined WellsPlant avg41 mg/Lrange30–53 mg/L Northern Combined WellsPlant avg33 mg/Lrange27–49 mg/L MWD Jensen PlantPlant avg38 mg/Lrange38–39 mg/L Los Angeles Aqueduct Filtration PlantPlant avg31 mg/Lrange30–32 mg/L
MagnesiumA naturally occurring mineral that contributes to water hardness.	26 mg/LAverageMWD Weymouth Plant	None set	Detected — no federal limit
+By source (6)— MWD Weymouth Plant, MWD Diemer Plant, Southern Combined Wells +3 more MWD Weymouth PlantPlant avg26 mg/Lrange23–29 mg/L MWD Diemer PlantPlant avg26 mg/Lrange22–29 mg/L Southern Combined WellsPlant avg11.1 mg/Lrange8.3–15 mg/L MWD Jensen PlantPlant avg14 mg/Lrange13–14 mg/L Northern Combined WellsPlant avg8.3 mg/Lrange6.3–12.9 mg/L Los Angeles Aqueduct Filtration PlantPlant avg8.3 mg/Lrange7.6–9.2 mg/L
PotassiumA naturally occurring mineral from rock and soil.	5 mg/LAverageMWD Weymouth Plant	None set	Detected — no federal limit
+By source (6)— MWD Weymouth Plant, MWD Diemer Plant, Los Angeles Aqueduct Filtration Plant +3 more MWD Weymouth PlantPlant avg5 mg/Lrange4.6–5.4 mg/L MWD Diemer PlantPlant avg4.9 mg/Lrange4.4–5.4 mg/L Los Angeles Aqueduct Filtration PlantPlant avg4.5 mg/Lrange3.8–5.3 mg/L Southern Combined WellsPlant avg4.4 mg/Lrange3.8–5.2 mg/L Northern Combined WellsPlant avg4.6 mg/Lrange3.8–5.2 mg/L MWD Jensen PlantPlant avg2.6 mg/Lrange2.6 mg/L
SilicaA naturally occurring compound from sand and rock.	19.2 mg/LAverageSouthern Combined Wells	None set	Detected — no federal limit
+By source (3)— Southern Combined Wells, Los Angeles Aqueduct Filtration Plant, Northern Combined Wells Southern Combined WellsPlant avg19.2 mg/Lrange14.4–21.6 mg/L Los Angeles Aqueduct Filtration PlantPlant avg17.7 mg/Lrange14.1–20.7 mg/L Northern Combined WellsPlant avg18.7 mg/Lrange14.4–19.8 mg/L
SodiumA naturally occurring salt component.	105 mg/LAverageMWD Weymouth Plant	None set	Detected — no federal limit
+By source (6)— MWD Weymouth Plant, MWD Diemer Plant, Southern Combined Wells +3 more MWD Weymouth PlantPlant avg105 mg/Lrange93–117 mg/L MWD Diemer PlantPlant avg103 mg/Lrange90–116 mg/L Southern Combined WellsPlant avg46.5 mg/Lrange39.7–57.3 mg/L Northern Combined WellsPlant avg43.2 mg/Lrange34.6–48.5 mg/L Los Angeles Aqueduct Filtration PlantPlant avg42.6 mg/Lrange37.3–47.5 mg/L MWD Jensen PlantPlant avg46 mg/Lrange46 mg/L

VOCs & pesticides

Contaminant	Measured	Federal limit	Status
Dichloromethane	Not detected ug/LAverageLos Angeles Aqueduct Filtration Plant	5 ug/LMCL	Within the limit
+By source (6)— Los Angeles Aqueduct Filtration Plant, MWD Weymouth Plant, Southern Combined Wells +3 more Los Angeles Aqueduct Filtration PlantPlant avgNot detected ug/Lrange0–1.3 ug/L26% of limit MWD Weymouth PlantPlant avgNot detected ug/LrangeNot detected ug/L0% of limit Southern Combined WellsPlant avgNot detected ug/LrangeNot detected ug/L0% of limit Northern Combined WellsPlant avgNot detected ug/LrangeNot detected ug/L0% of limit MWD Jensen PlantPlant avgNot detected ug/LrangeNot detected ug/L0% of limit MWD Diemer PlantPlant avgNot detected ug/LrangeNot detected ug/L0% of limit

Disinfection byproducts

Contaminant	Measured	Federal limit	Status
ChlorateA byproduct that can form during disinfection, especially when hypochlorite solutions degrade.	366AverageSouthern Combined Wells	None set	Detected — no federal limit
+By source (4)— Southern Combined Wells, MWD Weymouth Plant, MWD Diemer Plant +1 more Southern Combined WellsPlant avg366range21–820 MWD Weymouth PlantPlant avg80range80 MWD Diemer PlantPlant avg77range77 MWD Jensen PlantPlant avg71range71
N-Nitrosodi-n-butylamine	2.5 ng/LAverageMWD Diemer Plant	None set	Detected — no federal limit
+By source (3)— MWD Diemer Plant, MWD Weymouth Plant, MWD Jensen Plant MWD Diemer PlantPlant avg2.5 ng/Lrange2.5 ng/L MWD Weymouth PlantPlant avgNot detected ng/LrangeNot detected ng/L MWD Jensen PlantPlant avgNot detected ng/LrangeNot detected ng/L

Inorganic chemicals

Contaminant	Measured	Federal limit	Status
BromideA naturally occurring salt found in source water.	Not detectedAverageNorthern Combined Wells	None set	Detected — no federal limit
+By source (3)— Los Angeles Aqueduct Filtration Plant, Northern Combined Wells, Southern Combined Wells Los Angeles Aqueduct Filtration PlantPlant avgNot detectedrange0–0.1 Northern Combined WellsPlant avgNot detectedrange0–0.1 Southern Combined WellsPlant avgNot detectedrange0–0.1

Microbial

Contaminant	Measured	Federal limit	Status
Total ColiformA group of bacteria used as an indicator of overall water-system sanitation.	0–0.6 %RangeSystem-wide	None set	Detected — no federal limit

Physical & aggregate

Contaminant	Measured	Federal limit	Status
AlkalinityA measure of the water's capacity to neutralize acids.	119 mg/LAverageSouthern Combined Wells	None set	Detected — no federal limit
+By source (6)— Southern Combined Wells, MWD Weymouth Plant, Los Angeles Aqueduct Filtration Plant +3 more Southern Combined WellsPlant avg119 mg/Lrange107–132 mg/L MWD Weymouth PlantPlant avg118 mg/Lrange109–127 mg/L Los Angeles Aqueduct Filtration PlantPlant avg112 mg/Lrange100–124 mg/L MWD Diemer PlantPlant avg114 mg/Lrange105–123 mg/L Northern Combined WellsPlant avg110 mg/Lrange92–119 mg/L MWD Jensen PlantPlant avg98 mg/Lrange94–101 mg/L
Bicarbonate	119 mg/LAverageSouthern Combined Wells	None set	Detected — no federal limit
+By source (3)— Southern Combined Wells, Los Angeles Aqueduct Filtration Plant, Northern Combined Wells Southern Combined WellsPlant avg119 mg/Lrange107–132 mg/L Los Angeles Aqueduct Filtration PlantPlant avg112 mg/Lrange100–124 mg/L Northern Combined WellsPlant avg110 mg/Lrange92–119 mg/L
HardnessA measure of dissolved calcium and magnesium minerals.	272 mg/LAverageMWD Weymouth Plant	None set	Detected — no federal limit
+By source (6)— MWD Diemer Plant, MWD Weymouth Plant, Southern Combined Wells +3 more MWD Diemer PlantPlant avg270 mg/Lrange235–305 mg/L MWD Weymouth PlantPlant avg272 mg/Lrange241–303 mg/L Southern Combined WellsPlant avg142 mg/Lrange112–195 mg/L Northern Combined WellsPlant avg122 mg/Lrange106–174 mg/L MWD Jensen PlantPlant avg148 mg/Lrange143–153 mg/L Los Angeles Aqueduct Filtration PlantPlant avg112 mg/Lrange109–113 mg/L
pHA measure of how acidic or basic the water is.	8.3AverageMWD Jensen Plant	None set	Detected — no federal limit
+By source (6)— Southern Combined Wells, Northern Combined Wells, Los Angeles Aqueduct Filtration Plant +3 more Southern Combined WellsPlant avg8range7.1–9 Northern Combined WellsPlant avg7.9range6.9–9 Los Angeles Aqueduct Filtration PlantPlant avg7.7range7.2–8.5 MWD Jensen PlantPlant avg8.3range8.2–8.3 MWD Weymouth PlantPlant avg8.2range8.2 MWD Diemer PlantPlant avg8.2range8.2
TemperatureThe measured temperature of the water sample.	18.4AverageSouthern Combined Wells	None set	Detected — no federal limit
+By source (3)— Northern Combined Wells, Southern Combined Wells, Los Angeles Aqueduct Filtration Plant Northern Combined WellsPlant avg18range8.5–29.9 Southern Combined WellsPlant avg18.4range10.7–29.9 Los Angeles Aqueduct Filtration PlantPlant avg17.1range8.1–27.5
TOCTotal organic carbon — a measure of organic material dissolved in the water.	2.4 mg/LAverageMWD Jensen Plant	None set	Detected — no federal limit
+By source (6)— MWD Weymouth Plant, MWD Jensen Plant, MWD Diemer Plant +3 more MWD Weymouth PlantPlant avg2.4 mg/Lrange2.1–2.6 mg/L MWD Jensen PlantPlant avg2.4 mg/Lrange2–2.5 mg/L MWD Diemer PlantPlant avg2.4 mg/Lrange2–2.5 mg/L Northern Combined WellsPlant avg1.9 mg/Lrange1.5–2.4 mg/L Southern Combined WellsPlant avg1.7 mg/Lrange1.5–2.1 mg/L Los Angeles Aqueduct Filtration PlantPlant avg1.8 mg/Lrange1.7–2 mg/L

Source: Los Angeles LADWP, CA's 2023 Consumer Confidence Report — the annual drinking-water report every U.S. utility is required to publish. The numbers on this page are the utility's own. A water-quality report covers an entire service area, not a single address.