Compliance record
PFAS detected
PFAS are industrial “forever chemicals”. These are the EPA's latest
nationwide test results (2023–2025).
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 | 17402 µg/L 174% of the EPA limit, at the 95th percentile of samples — 10000 µg/L
worst single sample: 24000 µg/L | 2170/2248 | SYR4 | 2012–2019 |
| Lead | 0.0 mg/L 0% of the EPA limit 0.0150 mg/L | 46/46 | LCR | 2023 |
| Fluoride | 226 µg/L 5.7% of the EPA limit 4000 µg/L
worst single sample: 250 µg/L | 9/16 | SYR4 | 2012–2019 |
| Nitrate-Nitrite | 705000 µg/L 7050% of the EPA limit, at the 95th percentile of samples — 10000 µg/L
worst single sample: 720000 µg/L | 7/9 | SYR4 | 2012–2019 |
| Barium | 138.5 µg/L 6.9% of the EPA limit 2000 µg/L
worst single sample: 140 µg/L | 4/16 | SYR4 | 2012–2019 |
| Dibromochloromethane | 1.48 µg/L No EPA limit set
worst single sample: 1.5 µg/L | 2/6 | SYR4 | 2013–2019 |
| TTHM | 2.795 µg/L 3.5% of the EPA limit 80 µg/L
worst single sample: 2.8 µg/L | 2/6 | SYR4 | 2013–2019 |
| Bromoform | 1.3 µg/L No EPA limit set | 1/6 | SYR4 | 2013–2019 |
| Chromium | 15 µg/L 15% of the EPA limit 100 µg/L | 1/16 | SYR4 | 2012–2019 |
| Combined Radium (-226 And -228) | 0.6200 pCi/L 12% of the EPA limit 5 pCi/L | 1/1 | SYR4 | 2018 |
| Dichloromethane | 0.5000 µg/L 10% of the EPA limit 5 µg/L | 1/21 | SYR4 | 2014–2019 |
| Monochloroacetic Acid | 4.6 µg/L No EPA limit set | 1/5 | SYR4 | 2013–2019 |
| Total Haloacetic Acids (HAA5) | 4.6 µg/L 7.7% of the EPA limit 60 µg/L | 1/5 | SYR4 | 2013–2019 |
| Lithium | 9.6 µg/L No EPA limit set | 1/8 | UCMR-5 | 2023 |
95 contaminants tested, none detected
1,1,1-Trichloroethane1,1,2-Trichloroethane1,1-Dichloroethylene1,2,4-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, TotalArsenicAsbestosAtrazineBhc-GammaBenzeneBenzo(A)PyreneBeryllium, TotalBromodichloromethaneChlorobenzeneCopperCyanideCadmiumCarbofuranCarbon TetrachlorideChlordaneChloroformCombined UraniumDalaponDi(2-ethylhexyl) AdipateDi(2-ethylhexyl) PhthalateDibromoacetic AcidDichloroacetic AcidDinosebDiquatEthylene DibromideEndothallEndrinEthylbenzeneGlyphosateGross Beta Particle ActivityHexachlorobenzeneHfpo-DaHeptachlorHeptachlor EpoxideHexachlorocyclopentadieneLassoLeadMercuryMethoxychlorMonobromoacetic AcidNetfosaaNfdhaNmefosaaNitriteOxamylPfbaPfdaPfdoaPfeesaPfhpaPfhpsPfmbaPfmpaPFNAPFOAPFOSPfpesPftaPftrdaPfunaPentachlorophenolPicloramSeleniumSimazineStyreneTetrachloroethyleneThallium, TotalTolueneTotal Polychlorinated Biphenyls (PCB)ToxapheneTrichloroacetic AcidTrichloroethyleneVinyl ChlorideXylenes, Totalcis-1,2-DichloroethyleneO-DichlorobenzeneP-Dichlorobenzenetrans-1,2-Dichloroethylene
Utility contact
Frequently asked questions about Golden State Water Company - Los Osos
Is Golden State Water Company - Los Osos tap water safe to drink?
EPA monitoring detected 18 contaminants in Golden State Water Company - Los Osos'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 Golden State Water Company - Los Osos's water?
EPA monitoring detected Nitrate, Lead, Fluoride, Nitrate-Nitrite, Barium, and others. The full list with the level and data source for each is above.
How many people does Golden State Water Company - Los Osos serve?
Golden State Water Company - Los Osos reports serving 5,924 people in California, per its EPA record.
Has Golden State Water Company - Los Osos had any water quality violations?
The EPA has no formal drinking-water violations on file for Golden State Water Company - Los Osos.
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.