Compliance record
Formal violations the EPA has on file for this supplier. A health-based violation means a contaminant limit or a required treatment was breached; the rest are monitoring or reporting failures — still violations, but not a measured health risk.
5
health-based violations
13
violations on file
0
still open
| Violation | Type | Status | Period |
|---|---|---|---|
| MCL | Health-based | Resolved | 1994-07-01 → 1994-07-31 |
| MCL | Health-based | Resolved | 1994-07-01 → 1994-07-31 |
| MCL | Health-based | Resolved | 1994-07-01 → 1994-07-31 |
| MCL | Health-based | Resolved | 1994-07-01 → 1994-07-31 |
| MCL | Health-based | Archived | 1984-09-01 → 1984-09-30 |
| MR | Monitoring | Resolved | 1994-07-01 → 1994-07-31 |
| MR | Monitoring | Resolved | 1994-07-01 → 1994-07-31 |
| MR | Monitoring | Resolved | 1994-07-01 → 1994-07-31 |
| MR | Monitoring | Resolved | 1994-07-01 → 1994-07-31 |
| MR | Monitoring | Resolved | 1994-07-01 → 1994-07-31 |
Other contaminants detected
Each bar shows the measured level as a share of the EPA limit: green is
well under, amber is close to it, red is over. For lead and copper the
limit applies to exactly the 90th-percentile figure shown, so red there
means a real exceedance. For everything else the limit applies to a
running annual average while the figure is the 95th percentile of this
system's samples — over 100% is worth reading, but is not by itself a
violation. Where a single sample came in higher than that percentile, it
is noted under the bar. Formal violations are listed separately.
| Contaminant | Level vs EPA limit | Detection rate | Source | Period |
|---|---|---|---|---|
| Nitrate | 9718 µg/L 97% of the EPA limit 10000 µg/L
worst single sample: 11074 µg/L | 1218/1218 | SYR4 | 2012–2019 |
| Arsenic | 22.75 µg/L 228% of the EPA limit, at the 95th percentile of samples — 10 µg/L
worst single sample: 56 µg/L | 326/597 | SYR4 | 2012–2019 |
| TTHM | 66 µg/L 83% of the EPA limit 80 µg/L
worst single sample: 140 µg/L | 192/207 | SYR4 | 2012–2019 |
| Dibromochloromethane | 25.2 µg/L No EPA limit set
worst single sample: 50 µg/L | 177/213 | SYR4 | 2012–2019 |
| Bromodichloromethane | 20 µg/L No EPA limit set
worst single sample: 44 µg/L | 176/213 | SYR4 | 2012–2019 |
| Chloroform | 14 µg/L No EPA limit set
worst single sample: 29 µg/L | 174/211 | SYR4 | 2012–2019 |
| Bromoform | 19 µg/L No EPA limit set
worst single sample: 35 µg/L | 171/213 | SYR4 | 2012–2019 |
| Total Haloacetic Acids (HAA5) | 16.65 µg/L 28% of the EPA limit 60 µg/L
worst single sample: 23 µg/L | 148/202 | SYR4 | 2012–2019 |
| Dibromoacetic Acid | 6.46 µg/L No EPA limit set
worst single sample: 9.5 µg/L | 129/202 | SYR4 | 2012–2019 |
| Dichloroacetic Acid | 9.445 µg/L No EPA limit set
worst single sample: 11 µg/L | 82/202 | SYR4 | 2012–2019 |
| Trichloroacetic Acid | 3.715 µg/L No EPA limit set
worst single sample: 6.7 µg/L | 60/202 | SYR4 | 2012–2019 |
| Monochloroacetic Acid | 9.48 µg/L No EPA limit set
worst single sample: 16 µg/L | 45/202 | SYR4 | 2012–2019 |
| Monobromoacetic Acid | 3.105 µg/L No EPA limit set
worst single sample: 4.2 µg/L | 38/202 | SYR4 | 2012–2019 |
| Lead | 0.0 mg/L 0% of the EPA limit 0.0150 mg/L | 33/33 | LCR | 2024 |
| Fluoride | 605 µg/L 15% of the EPA limit 4000 µg/L
worst single sample: 800 µg/L | 14/15 | SYR4 | 2012–2019 |
| Chromium | 9.98 µg/L 10% of the EPA limit 100 µg/L
worst single sample: 11 µg/L | 7/15 | SYR4 | 2012–2019 |
| Nitrate-Nitrite | 9700 µg/L 97% of the EPA limit 10000 µg/L
worst single sample: 9800 µg/L | 5/5 | SYR4 | 2017 |
| Selenium | 10.54 µg/L 21% of the EPA limit 50 µg/L
worst single sample: 11 µg/L | 5/15 | SYR4 | 2012–2019 |
| Trichloroethylene | 7.37 µg/L 147% of the EPA limit, at the 95th percentile of samples — 5 µg/L
worst single sample: 7.8 µg/L | 3/14 | SYR4 | 2012–2019 |
| 1,1-Dichloroethylene | 2.0315 µg/L 29% of the EPA limit 7 µg/L
worst single sample: 2.1 µg/L | 2/14 | SYR4 | 2012–2019 |
| Barium | 53.15 µg/L 2.7% of the EPA limit 2000 µg/L
worst single sample: 54 µg/L | 2/15 | SYR4 | 2012–2019 |
| Tetrachloroethylene | 0.5675 µg/L 11% of the EPA limit 5 µg/L
worst single sample: 0.5700 µg/L | 2/14 | SYR4 | 2012–2019 |
| Copper | 79 µg/L 6.1% of the EPA limit 1300 µg/L | 1/15 | SYR4 | 2012–2019 |
| Lead | 6.5 µg/L 43% of the EPA limit 15 µg/L | 1/15 | SYR4 | 2012–2019 |
86 contaminants tested, none detected
1,1,1-Trichloroethane1,1,2-Trichloroethane1,2,4-Trichlorobenzene1,2-DIBROMO-3-CHLOROPROPANE1,2-Dichloroethane1,2-Dichloropropane11Cl-PF3OUdS2,3,7,8-TCDD2,4,5-TP2,4-D4:2 Fts6:2 Fts8:2 Fts9Cl-PF3ONSAdonaAntimony, TotalAsbestosAtrazineBhc-GammaBenzeneBenzo(A)PyreneBeryllium, TotalChlorobenzeneCyanideCadmiumCarbofuranCarbon TetrachlorideChlordaneDichloromethaneDalaponDi(2-ethylhexyl) AdipateDi(2-ethylhexyl) PhthalateDinosebDiquatEthylene DibromideEndothallEndrinEthylbenzeneGlyphosateHexachlorobenzeneHfpo-DaHeptachlorHeptachlor EpoxideHexachlorocyclopentadieneLassoMercuryMethoxychlorNetfosaaNfdhaNmefosaaNitriteOxamylPfbaPFBSPfdaPfdoaPfeesaPfhpaPfhpsPfhxaPFHXSPfmbaPfmpaPFNAPFOAPFOSPfpeaPfpesPftaPftrdaPfunaPentachlorophenolPicloramSimazineStyreneThallium, TotalTolueneTotal Polychlorinated Biphenyls (PCB)ToxapheneVinyl ChlorideXylenes, Totalcis-1,2-DichloroethyleneLithiumO-DichlorobenzeneP-Dichlorobenzenetrans-1,2-Dichloroethylene
Utility contact
Frequently asked questions about Chino Hills, City of
Is Chino Hills, City of tap water safe to drink?
EPA monitoring detected 24 contaminants in Chino Hills, City of's water. A detection isn't the same as a violation — most levels are within federal limits. See each level and source above, and the utility's annual Consumer Confidence Report for its official compliance status.
What contaminants were detected in Chino Hills, City of's water?
EPA monitoring detected Nitrate, Arsenic, TTHM, Dibromochloromethane, Bromodichloromethane, and others. The full list with the level and data source for each is above.
How many people does Chino Hills, City of serve?
Chino Hills, City of reports serving 76,414 people in California, per its EPA record.
Has Chino Hills, City of had any water quality violations?
The EPA has 13 violations on file for Chino Hills, City of, of which 5 are health-based (a contaminant limit or required treatment was breached) and 0 remain open. The rest are monitoring or reporting failures.
Where does this data come from?
Every figure is official EPA drinking-water monitoring — the Lead & Copper Rule, the UCMR-5 nationwide testing program, and the EPA Six-Year Review — not our own testing. Each number is labelled with its source and period.