Is Challis City of Tap Water Safe? Quality Report

Water source: Surface water
Ownership: Local government
Counties served: Custer

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.

health-based violations

187

violations on file

still open

Violation	Type	Status	Period
MCL	Health-based	Archived	1995-08-01 → 1995-08-31
MCL	Health-based	Archived	1991-10-01 → 1991-10-31
MCL	Health-based	Archived	1991-09-01 → 1991-09-30
MR	Monitoring	Unaddressed	2026-01-01
MR	Monitoring	Unaddressed	2026-01-01
MR	Monitoring	Resolved	2024-09-01 → 2024-09-30
MR	Monitoring	Resolved	2024-09-01 → 2024-09-30
MR	Monitoring	Resolved	2024-09-01 → 2024-09-30
MON	Monitoring	Resolved	2024-07-01 → 2024-07-31
MON	Monitoring	Resolved	2024-07-01 → 2024-07-31

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	2917.5 µg/L 29% of the EPA limit 10000 µg/L worst single sample: 2960 µg/L	38/56	SYR4	2012–2019
Lead	0.0050 mg/L 33% of the EPA limit 0.0150 mg/L	16/16	LCR	2025
Combined Radium (-226 And -228)	2.29 pCi/L 46% of the EPA limit 5 pCi/L worst single sample: 2.5 pCi/L	8/8	SYR4	2016–2018
Combined Uranium	7.156 µg/L 24% of the EPA limit 30 µg/L worst single sample: 7.78 µg/L	7/10	SYR4	2013–2019
Arsenic	1.964 µg/L 20% of the EPA limit 10 µg/L worst single sample: 2 µg/L	4/14	SYR4	2012–2019
Gross Alpha, Excl. Radon And U	3.2 pCi/L 21% of the EPA limit 15 pCi/L	4/6	SYR4	2017–2019
Nitrate-Nitrite	1937.5 µg/L 19% of the EPA limit 10000 µg/L worst single sample: 2200 µg/L	4/4	SYR4	2017–2019
TTHM	18.985 µg/L 24% of the EPA limit 80 µg/L worst single sample: 19.3 µg/L	4/4	SYR4	2012–2015
Total Haloacetic Acids (HAA5)	21.625 µg/L 36% of the EPA limit 60 µg/L worst single sample: 22.3 µg/L	4/4	SYR4	2012–2015
Barium	65.34 µg/L 3.3% of the EPA limit 2000 µg/L worst single sample: 70 µg/L	3/3	SYR4	2013–2017
Chromium	1.9745 µg/L 2% of the EPA limit 100 µg/L worst single sample: 2 µg/L	2/3	SYR4	2013–2017
Antimony, Total	1 µg/L 17% of the EPA limit 6 µg/L	1/3	SYR4	2013–2017
Fluoride	350 µg/L 8.8% of the EPA limit 4000 µg/L	1/5	SYR4	2013–2019

57 contaminants tested, none detected

1,1,1-Trichloroethane1,1,2-Trichloroethane1,1-Dichloroethylene1,2,4-Trichlorobenzene1,2-DIBROMO-3-CHLOROPROPANE1,2-Dichloroethane1,2-Dichloropropane2,4,5-TP2,4-DAtrazineBhc-GammaBenzeneBenzo(A)PyreneBeryllium, TotalChlorobenzeneCyanideCadmiumCarbofuranCarbon TetrachlorideChlordaneDichloromethaneDalaponDi(2-ethylhexyl) AdipateDi(2-ethylhexyl) PhthalateDinosebDiquatEthylene DibromideEndothallEndrinEthylbenzeneGlyphosateHexachlorobenzeneHeptachlorHeptachlor EpoxideHexachlorocyclopentadieneLassoMercuryMethoxychlorNitriteOxamylPentachlorophenolPicloramSeleniumSimazineStyreneTetrachloroethyleneThallium, TotalTolueneTotal Polychlorinated Biphenyls (PCB)ToxapheneTrichloroethyleneVinyl ChlorideXylenes, Totalcis-1,2-DichloroethyleneO-DichlorobenzeneP-Dichlorobenzenetrans-1,2-Dichloroethylene

Utility contact

Contact: ELY, JESSICA
Phone: 208-879-6553
Email: [email protected]

Frequently asked questions about Challis City of

Is Challis City of tap water safe to drink?

EPA monitoring detected 13 contaminants in Challis 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 Challis City of's water?

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

How many people does Challis City of serve?

Challis City of reports serving 900 people in Idaho, per its EPA record.

Has Challis City of had any water quality violations?

The EPA has 187 violations on file for Challis City of, of which 3 are health-based (a contaminant limit or required treatment was breached) and 2 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.