Drinking water quality · 2023

What's in Los Angeles LADWP, CA tap water

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

Browse the mapFull source report ↗

Reporting year: 2023
Contaminants measured: 35
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.

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.

Compliance history

Federal Safe Drinking Water Act violation & enforcement records (EPA SDWIS). A violation is a regulatory determination by the state or EPA — separate from the measured levels above.

Treatment technique violationHealth-based
4 violations on record · most recent Jan 2018
resolved
Maximum contaminant level exceededHealth-based
1 violation on record · most recent Jun 2014
resolved

Source: EPA SDWIS / ECHO. View the full federal record on EPA ECHO ↗

Other

Contaminant	Measured	Federal limit	Status
Chlorine Total	1.9 mg/LAverageSystem-wide	4 mg/LMCL	Within the limit
Nitrate Nitrite	0.6 mg/LAverageSouthern Combined Wells	10 mg/LMCL	Within the limit
+By source (6)— Southern Combined Wells, Northern Combined Wells, MWD Jensen Plant +3 more Southern Combined WellsPlant avg0.6 mg/Lrange0–1.1 mg/L11% of limit Northern Combined WellsPlant avgNot detected mg/Lrange0–0.7 mg/L7% of limit MWD Jensen PlantPlant avg0.5 mg/Lrange0.5 mg/L5% of limit Los Angeles Aqueduct Filtration PlantPlant avgNot detected mg/LrangeNot detected mg/L0% of limit MWD Weymouth PlantPlant avgNot detected mg/LrangeNot detected mg/L0% of limit MWD Diemer PlantPlant avgNot detected mg/LrangeNot detected mg/L0% of limit
Chromium	0.2 ug/LAverageSouthern Combined Wells	None set	Within the limit
+By source (6)— Southern Combined Wells, Northern Combined Wells, Los Angeles Aqueduct Filtration Plant +3 more Southern Combined WellsPlant avg0.2 ug/Lrange0–0.4 ug/L0% of limit Northern Combined WellsPlant avg0.1 ug/Lrange0–0.3 ug/L0% of limit Los Angeles Aqueduct Filtration PlantPlant avgNot detected ug/LrangeNot detected ug/L0% of limit MWD Weymouth PlantPlant avgNot detected ug/LrangeNot detected ug/L0% of limit MWD Diemer PlantPlant avgNot detected ug/LrangeNot detected ug/L0% of limit MWD Jensen PlantPlant avgNot detected ug/LrangeNot detected ug/L0% of limit

Disinfection byproducts

Contaminant	Measured	Federal limit	Status
TTHMTotal trihalomethanes — a group of four chemicals (including chloroform) formed when chlorine reacts with natural organic matter.	34.4 ug/LAverageSystem-wide	None set	Within the limit
BromateA disinfection byproduct formed when bromide-containing water is treated with ozone.	3.1 ug/LAverageMWD Jensen Plant	None set	Within the limit
+By source (6)— MWD Weymouth Plant, MWD Jensen Plant, Los Angeles Aqueduct Filtration Plant +3 more MWD Weymouth PlantPlant avg2 ug/Lrange0–9.2 ug/L92% of limit MWD Jensen PlantPlant avg3.1 ug/Lrange0–5.4 ug/L54% of limit Los Angeles Aqueduct Filtration PlantPlant avgNot detected ug/Lrange0–2 ug/L20% of limit MWD Diemer PlantPlant avgNot detected ug/Lrange0–1.6 ug/L16% of limit Southern Combined WellsPlant avgNot detected ug/Lrange0–1.4 ug/L14% of limit Northern Combined WellsPlant avgNot detected ug/LrangeNot detected ug/L0% of limit
HAA5Haloacetic acids — a group of five disinfection byproducts formed when disinfectants react with organic matter.	14.9 ug/LAverageSystem-wide	None set	Within the limit
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

Metals

Contaminant	Measured	Federal limit	Status
ArsenicA naturally occurring element that also enters water from industry and agriculture.	3.5 ug/LAverageLos Angeles Aqueduct Filtration Plant	None set	Within the limit
+By source (6)— Northern Combined Wells, Los Angeles Aqueduct Filtration Plant, Southern Combined Wells +3 more Northern Combined WellsPlant avg3.5 ug/Lrange0–8.4 ug/L84% of limit Los Angeles Aqueduct Filtration PlantPlant avg3.5 ug/Lrange0–6.3 ug/L63% of limit Southern Combined WellsPlant avg2.7 ug/Lrange0–4.5 ug/L45% of limit MWD Weymouth PlantPlant avgNot detected ug/LrangeNot detected ug/L0% of limit MWD Diemer PlantPlant avgNot detected ug/LrangeNot detected ug/L0% of limit MWD Jensen PlantPlant avgNot detected ug/LrangeNot detected ug/L0% of limit
LeadA toxic metal that leaches into water from old service lines, solder, and plumbing fixtures.	0.0039 mg/L90th percentileAt the tap	0.015 mg/LAction level	Within the limit
CopperA metal that enters water from corroding household plumbing.	90 ug/LAverageSystem-wide	None set	Within the limit
BariumA metal from erosion of natural deposits and industrial discharge.	124 ug/LAverageMWD Weymouth Plant	None set	Within the limit
+By source (6)— MWD Weymouth Plant, MWD Diemer Plant, Southern Combined Wells +3 more MWD Weymouth PlantPlant avg124 ug/Lrange124 ug/L6% of limit MWD Diemer PlantPlant avg124 ug/Lrange124 ug/L6% of limit Southern Combined WellsPlant avgNot detected ug/LrangeNot detected ug/L0% of limit MWD Jensen PlantPlant 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
AluminumA common element sometimes used as a treatment coagulant.	93 ug/LAverageMWD Weymouth Plant	None set	Detected — no federal limit
+By source (6)— MWD Weymouth Plant, MWD Diemer Plant, MWD Jensen Plant +3 more MWD Weymouth PlantPlant avg93 ug/Lrange0–150 ug/L MWD Diemer PlantPlant avgNot detected ug/Lrange0–110 ug/L MWD Jensen PlantPlant avg62 ug/Lrange52–91 ug/L Los Angeles Aqueduct Filtration PlantPlant avgNot detected ug/LrangeNot detected ug/L Northern Combined WellsPlant avgNot detected ug/LrangeNot detected ug/L Southern Combined WellsPlant avgNot detected ug/LrangeNot detected ug/L
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, Northern Combined Wells, Southern Combined Wells +3 more Los Angeles Aqueduct Filtration PlantPlant avg450range373–507 Northern Combined WellsPlant avg448range326–501 Southern Combined WellsPlant avg398range320–501 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
LithiumA naturally occurring element found in some groundwater.	88AverageSan Fernando Valley Los Angeles Aqueduct Filtration plant	None set	Detected — no federal limit
+By source (5)— San Fernando Valley Los Angeles Aqueduct Filtration plant, Western LA Los Angeles Aqueduct Filtration plant, San Fernando Valley Northern Combined Wells +2 more San Fernando Valley Los Angeles Aqueduct Filtration plantPlant avg88range80–94 Western LA Los Angeles Aqueduct Filtration plantPlant avg88range80–94 San Fernando Valley Northern Combined WellsPlant avg69range63–76 Central LA Southern Combined WellsPlant avg69range63–76 Harbor/Eastern LA Distribution System Sampling LocationsZone avg38range10–57
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

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
Gross Beta Particle ActivityGross beta particle activity — a combined measure of beta-emitting radioactive substances.	4.8 pCi/LAverageSouthern Combined Wells	None set	Detected — no federal limit
+By source (6)— Southern Combined Wells, Northern Combined Wells, MWD Weymouth Plant +3 more Southern Combined WellsPlant avg4.8 pCi/Lrange0–6.3 pCi/L Northern Combined WellsPlant avg4.3 pCi/Lrange0–5.6 pCi/L MWD Weymouth PlantPlant avgNot detected pCi/Lrange0–5 pCi/L MWD Diemer PlantPlant avg4 pCi/Lrange0–5 pCi/L Los Angeles Aqueduct Filtration PlantPlant avg4 pCi/Lrange0–4.9 pCi/L MWD Jensen PlantPlant avgNot detected pCi/LrangeNot detected pCi/L
UraniumA naturally occurring radioactive metal from erosion of natural deposits.	7 pCi/LAverageNorthern Combined Wells	20 pCi/LMCL	Detected — no federal limit
+By source (6)— Northern Combined Wells, Southern Combined Wells, Los Angeles Aqueduct Filtration Plant +3 more Northern Combined WellsPlant avg7 pCi/Lrange4.8–8.5 pCi/L Southern Combined WellsPlant avg7 pCi/Lrange4.8–8.5 pCi/L Los Angeles Aqueduct Filtration PlantPlant avg4.3 pCi/Lrange2.9–5.9 pCi/L MWD Weymouth PlantPlant avgNot detected pCi/Lrange0–3 pCi/L MWD Diemer PlantPlant avg1 pCi/Lrange0–3 pCi/L MWD Jensen PlantPlant avg2 pCi/Lrange2–3 pCi/L

Inorganic chemicals

Contaminant	Measured	Federal limit	Status
FluorideA mineral often added to drinking water to help prevent tooth decay.	0.8 mg/LAverageSouthern Combined Wells	4 mg/LMCL	Within the limit
+By source (6)— Los Angeles Aqueduct Filtration Plant, MWD Weymouth Plant, MWD Diemer Plant +3 more Los Angeles Aqueduct Filtration PlantPlant avg0.8 mg/Lrange0.7–0.9 mg/L23% of limit MWD Weymouth PlantPlant avg0.7 mg/Lrange0.3–0.8 mg/L20% of limit MWD Diemer PlantPlant avg0.7 mg/Lrange0.6–0.8 mg/L20% of limit MWD Jensen PlantPlant avg0.7 mg/Lrange0.6–0.8 mg/L20% of limit Northern Combined WellsPlant avg0.7 mg/Lrange0.7–0.8 mg/L20% of limit Southern Combined WellsPlant avg0.8 mg/Lrange0.7–0.8 mg/L20% of limit
NitrateA compound from fertilizer runoff, septic systems, and erosion of natural deposits.	0.5 mg/LAverageMWD Jensen Plant	10 mg/LMCL	Within the limit
+By source (6)— Southern Combined Wells, Northern Combined Wells, MWD Jensen Plant +3 more Southern Combined WellsPlant avg0.5 mg/Lrange0–2.4 mg/L24% of limit Northern Combined WellsPlant avg0.5 mg/Lrange0–1.8 mg/L18% of limit MWD Jensen PlantPlant avg0.5 mg/Lrange0.5 mg/L5% of limit Los Angeles Aqueduct Filtration PlantPlant avgNot detected mg/Lrange0–0.5 mg/L5% of limit MWD Weymouth PlantPlant avgNot detected mg/LrangeNot detected mg/L0% of limit MWD Diemer PlantPlant avgNot detected mg/LrangeNot detected mg/L0% of limit
Ammonia	0.6 mg/LAverageLos Angeles Aqueduct Filtration Plant	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 avg0.6 mg/Lrange0.6 mg/L Northern Combined WellsPlant avg0.5 mg/Lrange0.4–0.5 mg/L Southern Combined WellsPlant avg0.5 mg/Lrange0.4–0.5 mg/L
BromideA naturally occurring salt found in source water.	Not detectedAverageSouthern 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 avgNot detectedrange0–0.1 Los Angeles Aqueduct Filtration PlantPlant avgNot detectedrange0–0.1 Northern Combined WellsPlant avgNot detectedrange0–0.1

VOCs & pesticides

Contaminant	Measured	Federal limit	Status
Dichloromethane	Not detected ug/LAverageLos Angeles Aqueduct Filtration Plant	None set	Within the limit
+By source (6)— Los Angeles Aqueduct Filtration Plant, Northern Combined Wells, Southern Combined Wells +3 more Los Angeles Aqueduct Filtration PlantPlant avgNot detected ug/Lrange0–1.3 ug/L26% of limit Northern Combined WellsPlant avgNot detected ug/LrangeNot detected ug/L0% of limit Southern Combined WellsPlant avgNot detected ug/LrangeNot detected ug/L0% of limit MWD Weymouth PlantPlant avgNot detected ug/LrangeNot detected ug/L0% of limit MWD Diemer PlantPlant avgNot detected ug/LrangeNot detected ug/L0% of limit MWD Jensen PlantPlant avgNot detected ug/LrangeNot detected ug/L0% of limit

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)— Northern Combined Wells, Southern Combined Wells, Los Angeles Aqueduct Filtration Plant +3 more Northern Combined WellsPlant avg7.9range6.9–9 Southern Combined WellsPlant avg8range7.1–9 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 Weymouth Plant	None set	Detected — no federal limit
+By source (6)— MWD Weymouth Plant, MWD Diemer Plant, MWD Jensen Plant +3 more MWD Weymouth PlantPlant avg2.4 mg/Lrange2.1–2.6 mg/L MWD Diemer PlantPlant avg2.4 mg/Lrange2–2.5 mg/L MWD Jensen 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.