Is Oswego Tap Water Safe? Quality Report

Water source: Ground water
Ownership: Local government
Counties served: Kendall

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.

169

health-based violations

258

violations on file

still open

Violation	Type	Status	Period
MCL	Health-based	Resolved	2017-01-01 → 2017-03-31
MCL	Health-based	Resolved	2017-01-01 → 2017-03-31
MCL	Health-based	Resolved	2017-01-01 → 2017-03-31
MCL	Health-based	Resolved	2017-01-01 → 2017-03-31
MCL	Health-based	Resolved	2017-01-01 → 2017-03-31
MCL	Health-based	Resolved	2017-01-01 → 2017-03-31
MCL	Health-based	Resolved	2006-04-01 → 2006-06-30
MCL	Health-based	Resolved	2006-04-01 → 2006-06-30
MCL	Health-based	Resolved	2006-04-01 → 2006-06-30
MCL	Health-based	Resolved	2006-04-01 → 2006-06-30

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
Combined Radium (-226 And -228)	6.6895 pCi/L 134% of the EPA limit, at the 95th percentile of samples — 5 pCi/L worst single sample: 9 pCi/L	54/60	SYR4	2012–2019
Copper	1043.5 µg/L 80% of the EPA limit 1300 µg/L worst single sample: 1220 µg/L	40/40	SYR4	2014–2017
Barium	79.9 µg/L 4% of the EPA limit 2000 µg/L worst single sample: 92.1 µg/L	22/22	SYR4	2012–2018
Fluoride	1206 µg/L 30% of the EPA limit 4000 µg/L worst single sample: 1260 µg/L	22/22	SYR4	2012–2018
Lead	0.0 mg/L 0% of the EPA limit 0.0150 mg/L	17/17	LCR	2025
Nitrate	190 µg/L 1.9% of the EPA limit 10000 µg/L	16/128	SYR4	2012–2019
Lithium	114 µg/L No EPA limit set	16/16	UCMR-5	2025
Nitrate-Nitrite	140.2 µg/L 1.4% of the EPA limit 10000 µg/L worst single sample: 190 µg/L	13/38	SYR4	2012–2016
Lead	11.81 µg/L 79% of the EPA limit 15 µg/L worst single sample: 12.8 µg/L	3/40	SYR4	2014–2017
Total Haloacetic Acids (HAA5)	2.2131 µg/L 3.7% of the EPA limit 60 µg/L worst single sample: 2.42 µg/L	3/27	SYR4	2012–2019
Xylenes, Total	1.898 µg/L 0% of the EPA limit 10000 µg/L worst single sample: 2.02 µg/L	3/17	SYR4	2012–2015
Dichloromethane	0.7895 µg/L 16% of the EPA limit 5 µg/L worst single sample: 0.8000 µg/L	2/19	SYR4	2012–2015
Dichloroacetic Acid	2.31475 µg/L No EPA limit set worst single sample: 2.42 µg/L	2/27	SYR4	2012–2019
Nitrite	64.65 µg/L 6.5% of the EPA limit 1000 µg/L worst single sample: 67 µg/L	2/80	SYR4	2012–2019
Mercury	0.1830 µg/L 9.2% of the EPA limit 2 µg/L	1/22	SYR4	2012–2018

93 contaminants tested, none detected

1,1,1-Trichloroethane1,1,2-Trichloroethane1,1-Dichloroethylene1,2,4-Trichlorobenzene1,2-DIBROMO-3-CHLOROPROPANE1,2-Dichloroethane1,2-Dichloropropane11Cl-PF3OUdS2,4,5-TP2,4-D4:2 Fts6:2 Fts8:2 Fts9Cl-PF3ONSAdonaAntimony, TotalArsenicAtrazineBhc-GammaBenzeneBenzo(A)PyreneBeryllium, TotalBromodichloromethaneBromoformChlorobenzeneCyanideCadmiumCarbofuranCarbon TetrachlorideChlordaneChloroformChromiumDalaponDi(2-ethylhexyl) AdipateDi(2-ethylhexyl) PhthalateDibromoacetic AcidDibromochloromethaneDinosebDiquatEthylene DibromideEndothallEndrinEthylbenzeneHexachlorobenzeneHfpo-DaHeptachlorHeptachlor EpoxideHexachlorocyclopentadieneLassoMethoxychlorMonobromoacetic AcidMonochloroacetic AcidNetfosaaNfdhaNmefosaaOxamylPfbaPFBSPfdaPfdoaPfeesaPfhpaPfhpsPfhxaPFHXSPfmbaPfmpaPFNAPFOAPFOSPfpeaPfpesPftaPftrdaPfunaPentachlorophenolPicloramSeleniumSimazineStyreneTTHMTetrachloroethyleneThallium, TotalTolueneTotal Polychlorinated Biphenyls (PCB)ToxapheneTrichloroacetic AcidTrichloroethyleneVinyl Chloridecis-1,2-DichloroethyleneO-DichlorobenzeneP-Dichlorobenzenetrans-1,2-Dichloroethylene

Utility contact

Contact: CASSIDY, CURTIS
Phone: 630-551-2189
Email: [email protected]

Frequently asked questions about Oswego

Is Oswego tap water safe to drink?

EPA monitoring detected 15 contaminants in Oswego'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 Oswego's water?

EPA monitoring detected Combined Radium (-226 And -228), Copper, Barium, Fluoride, Lead, and others. The full list with the level and data source for each is above.

How many people does Oswego serve?

Oswego reports serving 38,169 people in Illinois, per its EPA record.

Has Oswego had any water quality violations?

The EPA has 258 violations on file for Oswego, of which 169 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.