Is Black Rock Wsc Tap Water Safe? Quality Report

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

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

violations on file

still open

Violation	Type	Status	Period
Other	Monitoring	Resolved	2025-07-01
Other	Monitoring	Resolved	2025-07-01
MON	Monitoring	Resolved	2023-09-01 → 2023-09-30
MON	Monitoring	Resolved	2023-09-01 → 2023-09-30
MON	Monitoring	Resolved	2023-09-01 → 2023-09-30
MON	Monitoring	Resolved	2023-09-01 → 2023-09-30
MR	Monitoring	Resolved	2021-01-01
MR	Monitoring	Resolved	2021-01-01
MR	Monitoring	Resolved	2021-01-01
MR	Monitoring	Archived	2021-01-01 → 2023-12-31

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	117 µg/L 1.2% of the EPA limit 10000 µg/L worst single sample: 772 µg/L	44/48	SYR4	2012–2019
Copper	96.625 µg/L 7.4% of the EPA limit 1300 µg/L worst single sample: 132.2 µg/L	26/26	SYR4	2012–2018
Dibromochloromethane	2.312 µg/L No EPA limit set worst single sample: 2.63 µg/L	13/24	SYR4	2013–2019
Bromoform	2.1 µg/L No EPA limit set worst single sample: 2.3 µg/L	11/24	SYR4	2013–2019
Barium	21.6 µg/L 1.1% of the EPA limit 2000 µg/L worst single sample: 22 µg/L	9/9	SYR4	2012–2019
Nitrate-Nitrite	53.8 µg/L 0.5% of the EPA limit 10000 µg/L worst single sample: 60 µg/L	9/9	SYR4	2012–2019
Fluoride	622.35 µg/L 16% of the EPA limit 4000 µg/L worst single sample: 678 µg/L	8/8	SYR4	2012–2018
TTHM	5.6305 µg/L 7% of the EPA limit 80 µg/L worst single sample: 5.97 µg/L	8/8	SYR4	2013–2019
Lead	0.0 mg/L 0% of the EPA limit 0.0150 mg/L	7/7	LCR	2025
Chromium	4.075 µg/L 4.1% of the EPA limit 100 µg/L worst single sample: 4.4 µg/L	6/9	SYR4	2012–2019
Lead	11.23 µg/L 75% of the EPA limit 15 µg/L worst single sample: 12.7 µg/L	4/26	SYR4	2012–2018
Bromodichloromethane	1.181 µg/L No EPA limit set worst single sample: 1.19 µg/L	3/24	SYR4	2013–2019
Arsenic	0.3125 µg/L 3.1% of the EPA limit 10 µg/L worst single sample: 0.3170 µg/L	2/9	SYR4	2012–2019
Cyanide	9.657 µg/L 4.8% of the EPA limit 200 µg/L worst single sample: 9.86 µg/L	2/6	SYR4	2014–2017
Combined Radium (-226 And -228)	1.5 pCi/L 30% of the EPA limit 5 pCi/L	2/2	SYR4	2016
Thallium, Total	0.0118 µg/L 0.6% of the EPA limit 2 µg/L worst single sample: 0.0120 µg/L	2/9	SYR4	2012–2019
Dibromoacetic Acid	2.3 µg/L No EPA limit set	1/8	SYR4	2013–2019
Total Haloacetic Acids (HAA5)	2.3 µg/L 3.8% of the EPA limit 60 µg/L	1/8	SYR4	2013–2019

61 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-DAntimony, TotalAsbestosAtrazineBhc-GammaBenzeneBenzo(A)PyreneBeryllium, TotalChlorobenzeneCadmiumCarbofuranCarbon TetrachlorideChlordaneChloroformCombined UraniumDichloromethaneDalaponDi(2-ethylhexyl) AdipateDi(2-ethylhexyl) PhthalateDichloroacetic AcidDinosebEthylene DibromideEndrinEthylbenzeneGross Alpha, Excl. Radon And UGross Beta Particle ActivityHexachlorobenzeneHeptachlorHeptachlor EpoxideHexachlorocyclopentadieneLassoMercuryMethoxychlorMonobromoacetic AcidMonochloroacetic AcidNitriteOxamylPentachlorophenolPicloramSeleniumSimazineStyreneTetrachloroethyleneTolueneToxapheneTrichloroacetic AcidTrichloroethyleneVinyl ChlorideXylenes, Totalcis-1,2-DichloroethyleneO-DichlorobenzeneP-Dichlorobenzenetrans-1,2-Dichloroethylene

Utility contact

Contact: DUNFEE, DAN
Phone: 940-365-0963

Frequently asked questions about Black Rock Wsc

Is Black Rock Wsc tap water safe to drink?

EPA monitoring detected 18 contaminants in Black Rock Wsc'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 Black Rock Wsc's water?

EPA monitoring detected Nitrate, Copper, Dibromochloromethane, Bromoform, Barium, and others. The full list with the level and data source for each is above.

How many people does Black Rock Wsc serve?

Black Rock Wsc reports serving 1,764 people in Texas, per its EPA record.

Has Black Rock Wsc had any water quality violations?

The EPA has 59 violations on file for Black Rock Wsc, of which 0 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.