What's in Chula Vista Otay, CA tap water

18 contaminants were measured in the Chula Vista Otay, CA water system's 2024 annual report. Each is shown below against its federal limit — 1 sit at or above that limit.

See it on the mapFull source report ↗

Reporting year: 2024
Contaminants measured: 18
Over federal limit: 1
Approaching the limit: 1
Worst contaminant: Lithium
Service area: CA
Source: Utility CCR

At or above the federal limit

Lithium
Metals · Reported level
0–28.9 ug/L
limit 9 ug/L · 3.2× the limit

Approaching the limit (≥ 80%)

Bromate
Disinfection byproducts
0–8.5 ug/L
85% of the limit

Where your water comes from · EPA SDWIS

Chula Vista Otay, CA's drinking water comes from ground water, drawn from 1 source.

Source

1ground water

WELL

Treatment

1treatment plant

WELL #1 PFAS TREATMENT PLANT

Distribution

0storage units

Source: EPA SDWIS facilities inventory. Methodology.

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

9 historically-detected contaminants in Chula Vista Otay, 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)
NITRATE worst: 2014	3.84 mg/L within	10 mg/L	'12'13'14'15'18'19
NITRATE NITRITE worst: 2018	2.9 mg/L within	10 mg/L	'18
CHROMIUM worst: 2014	0.013 mg/L within above national p90	0.1 mg/L	'14'18
ARSENIC worst: 2014	0.00079 mg/L within below national p90	0.01 mg/L	'14
FLUORIDE worst: 2018	0.21 mg/L within	4 mg/L	'14'18
BARIUM worst: 2014	0.028 mg/L within below national p90	2 mg/L	'14'18
SELENIUM worst: 2018	0.00066 mg/L within	0.05 mg/L	'18
COPPER worst: 2019	0.0032 mg/L below national p90	—	'19
LEAD worst: 2014	0.0011 mg/L	—	'14

PWSID CA4400763 · 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.

Metals

Contaminant	Measured	Federal limit	Status
LithiumA naturally occurring element found in some groundwater.	0–28.9 ug/LReported levelSystem-wide	9 ug/LMCL	At or above the limit
AluminumA common element sometimes used as a treatment coagulant.	64–230 ug/LReported levelHelix Plant	1000 ug/LMCL	Within the limit
+By source (4)— Helix Plant, Skinner Plant, Twin Oaks Plant +1 more Helix PlantPlant 23% of limit Skinner PlantPlant 16% of limit Twin Oaks PlantPlant 16% of limit Carlsbad Desal PlantPlant 0% of limit
ManganeseA naturally occurring metal from soil and rock.	0–9.2 ug/LReported levelSystem-wide	50 ug/LMCL	Within the limit

Disinfection byproducts

Contaminant	Measured	Federal limit	Status
BromateA disinfection byproduct formed when bromide-containing water is treated with ozone.	0–8.5 ug/LReported levelTwin Oaks Plant	10 ug/LMCL	Approaching the limit
+By source (3)— Twin Oaks Plant, Skinner Plant, Helix Plant Twin Oaks PlantPlant 85% of limit Skinner PlantPlant 60% of limit Helix PlantPlant 0% of limit
HAA5Haloacetic acids — a group of five disinfection byproducts formed when disinfectants react with organic matter.	3.2–24.4 ug/LAverageSystem-wide	None set	Detected — no federal limit
TTHMTotal trihalomethanes — a group of four chemicals (including chloroform) formed when chlorine reacts with natural organic matter.	10.5–60.6 ug/LAverageSystem-wide	None set	Detected — no federal limit

Radionuclides

Contaminant	Measured	Federal limit	Status
Gross AlphaGross alpha particle activity — a combined measure of alpha-emitting radioactive substances.	0–4 pCi/LReported levelSkinner Plant	15 pCi/LMCL	Within the limit
+By source (4)— Skinner Plant, Helix Plant, Twin Oaks Plant +1 more Skinner PlantPlant 27% of limit Helix PlantPlant 27% of limit Twin Oaks PlantPlant 0% of limit Carlsbad Desal PlantPlant 0% of limit
UraniumA naturally occurring radioactive metal from erosion of natural deposits.	2–3 pCi/LReported levelTwin Oaks Plant	20 pCi/LMCL	Within the limit
+By source (4)— Twin Oaks Plant, Skinner Plant, Helix Plant +1 more Twin Oaks PlantPlant 15% of limit Skinner PlantPlant 15% of limit Helix PlantPlant 15% of limit Carlsbad Desal PlantPlant 0% of limit
Gross Beta Particle ActivityGross beta particle activity — a combined measure of beta-emitting radioactive substances.	0–5 pCi/LReported levelSkinner Plant	50 pCi/LMCL	Within the limit
+By source (4)— Skinner Plant, Twin Oaks Plant, Helix Plant +1 more Skinner PlantPlant 10% of limit Twin Oaks PlantPlant 8% of limit Helix PlantPlant 0% of limit Carlsbad Desal PlantPlant 0% of limit

Physical & aggregate

Contaminant	Measured	Federal limit	Status
TurbidityA measure of cloudiness from suspended particles in the water.	0.3 %AverageSystem-wide	95 %MCL	Within the limit

Microbial

Contaminant	Measured	Federal limit	Status
Escherichia coli (E. coli)Escherichia coli — bacteria found in the gut of humans and animals.	0AverageSystem-wide	0MCL	None detected
Total ColiformA group of bacteria used as an indicator of overall water-system sanitation.	0 %AverageSystem-wide	5 %MCL	None detected

Disinfectants

Contaminant	Measured	Federal limit	Status
ChlorineA disinfectant added to drinking water to kill bacteria and viruses.	0.2–3.6 mg/LAverageSystem-wide	None set	Detected — no federal limit

Source: Chula Vista Otay, CA's 2024 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.