City of Corona Water Quality (California) – 2025 Report Results

We read 18 results from City of Corona’s 2025 water quality report. No results over a legal limit; 5 above a health goal or guideline.

Serves about 168,575 people · Water system ID CA3310037 · Read the district’s 2025 report (opens in a new tab)

Open this district in the water lookupCompare with your own test results, see the district map and get matched filters.

Results from the 2025 report

Each number is copied from the district’s report and links to the page it’s printed on. Where the report lists several plants, wells or purchased water, the highest is shown.

Contaminant	Result	Health goal	Legal limit	What it means
Arsenichighest measured · range ND to 2 · Treated system water · 2025 report	2 ppb	0.004 ppb	10 ppb	Above the health goal500x the health goal
Bromatehighest running annual average · range ND to 5.6 · Metropolitan Mills plant connection · 2025 report	3 ppb	0.1 ppb	10 ppb	Above the health goal30x the health goal
Chromium-6average · range ND to 0.59 · Treated system water · 2025 report	0.2 ppb	0.02 ppb	10 ppb	Above the health goal10x the health goal
Lead90th percentile of 53 homes tested, 3 over the action level · sampled 2023 · Customer taps (53 sites) · 2025 report	5 ppb	0.2 ppb	15 ppb (action level)	Above the health goal25x the health goal
Perchloratehighest measured · range ND to 2.8 · Treated system water · 2025 report	2.8 ppb	1 ppb	6 ppb	Above the health goal2.8x the health goal
Chloraminehighest running annual average · range 1.03 to 2.82 · Distribution system · 2025 report	1.98 ppm	None set	4 ppm	Below the legal limit
Chlorideaverage · range 17 to 110 · Treated system water · 2025 report	66 ppm	—	250 ppm guideline	Within the guideline
Copper90th percentile of 53 homes tested, 0 over the action level · sampled 2023 · Customer taps (53 sites) · 2025 report	0.17 ppm	0.3 ppm	1.3 ppm (action level)	Below the health goal
Disinfection byproducts (HAA5)highest running annual average · range ND to 11 · Distribution system · 2025 report	9.9 ppb	None set	60 ppb	Below the legal limit
Disinfection byproducts (TTHM)highest running annual average · range 6.5 to 63 · Distribution system · 2025 report	38.8 ppb	None set	80 ppb	Below the legal limit
Fluorideaverage · range ND to 0.73 · Treated system water · 2025 report	0.23 ppm	1 ppm	2 ppm	Below the health goal
Nitrate (as N)average · range ND to 6 · Treated system water · 2025 report	2.3 ppm	10 ppm	10 ppm	Below the health goal
Sulfateaverage · range 3.2 to 220 · Treated system water · 2025 report	109 ppm	—	250 ppm guideline	Within the guideline
Total coliform bacteriahighest month · Distribution system · 2025 report	Not detected	0 % positive	5 % positive	Not detected
Total dissolved solidsaverage · range 46 to 650 · Treated system water · 2025 report	385 ppm	—	500 ppm guideline	Within the guideline
Turbidity (cloudiness)average · range 0.1 to 0.3 · Treated system water, highest of 3 sources · 2025 report	0.17 NTU	None set	1 NTU	Below the legal limit
Boronaverage · range 0.07 to 0.28 · Treated system water · 2025 report	0.21 ppm	None set	None	No health limit
Hardnessaverage · range 0.42 to 17 · Treated system water · 2025 report	8.54 gpg (146 ppm)	—	—	Hard

Utility results describe the whole system, measured where water enters the pipes, not your tap. Your home’s plumbing can add lead or copper.

EPA testing for PFAS and lithium

EPA’s own nationwide testing (UCMR 5) found these in City of Corona’s water between Sep 2023 and Sep 2024. These are EPA lab results, separate from the district’s report. Anything not listed was not detected.

PFHxS3.3 pptFound in 1 of 54 samples · highest resultNo federal limit in force for this one
Lithium55.1 ppbFound in 24 of 54 samples · highest resultAbove EPA’s health reference level of 10 ppb (a guide, not a legal limit)

Source: EPA UCMR 5 occurrence data. The highest single result is shown; one high sample doesn’t mean every glass is that high.

What you can do

Nothing here is an emergency notice: if the district has a violation, it must tell customers directly. If you’d like to lower these at your tap, these are the treatments that remove them, and the catalog shows the models certified for each. Ranking is by certified removal; commissions never change the order.