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Tap water quality report

City of Patterson Water

EPA monitoring tested this supplier for 112 contaminants and detected 29. A detection doesn't automatically mean the water is unsafe — the level and EPA source for each is below.

112
contaminants tested
29
detected
8,456
people served
53
health-based violations
Louisiana rankingsLead in LouisianaPFAS in Louisiana
Water source
Surface water
Ownership
Local government
Counties served
St. Mary Parish

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.

53
health-based violations
60
violations on file
0
still open
ViolationTypeStatusPeriod
MCL Health-based Archived 2026-01-01 → 2026-03-31
MCL Health-based Archived 2026-01-01 → 2026-03-31
MCL Health-based Archived 2026-01-01 → 2026-03-31
MCL Health-based Archived 2026-01-01 → 2026-03-31
MCL Health-based Archived 2025-10-01 → 2025-12-31
MCL Health-based Archived 2025-10-01 → 2025-12-31
MCL Health-based Archived 2025-10-01 → 2025-12-31
MCL Health-based Archived 2025-10-01 → 2025-12-31
MCL Health-based Archived 2025-07-01 → 2025-09-30
MCL Health-based Archived 2025-07-01 → 2025-09-30

PFAS detected

PFAS are industrial “forever chemicals”. These are the EPA's latest nationwide test results (2023–2025).
ContaminantMaxDetection ratePeriod
Pfba 0.0061 µg/L 2/4 2024
Pfpea 0.0032 µg/L 1/4 2024

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 single worst sample on record — over 100% is worth reading, but is not by itself a violation. Formal violations are listed separately.
ContaminantLevel vs EPA limitDetection rateSourcePeriod
Bromodichloromethane
22 µg/L
No EPA limit set
 64/64 SYR4 2012–2019
Chloroform
91 µg/L
No EPA limit set
 64/64 SYR4 2012–2019
Dibromochloromethane
7.9 µg/L
No EPA limit set
 64/64 SYR4 2012–2019
TTHM
117.3 µg/L 147%
of the EPA limit, in the worst sample — 80 µg/L
 61/61 SYR4 2012–2019
Total Haloacetic Acids (HAA5)
48.2 µg/L 80%
of the EPA limit 60 µg/L
 60/61 SYR4 2012–2019
Dichloroacetic Acid
26 µg/L
No EPA limit set
 59/61 SYR4 2012–2019
Trichloroacetic Acid
21.8 µg/L
No EPA limit set
 58/61 SYR4 2012–2019
Dibromoacetic Acid
2.2 µg/L
No EPA limit set
 39/61 SYR4 2012–2019
Copper
3500 µg/L 269%
of the EPA limit, in the worst sample — 1300 µg/L
 24/47 SYR4 2014–2019
Monochloroacetic Acid
2.9 µg/L
No EPA limit set
 22/61 SYR4 2012–2019
Nitrate-Nitrite
1000 µg/L 10%
of the EPA limit 10000 µg/L
 18/20 SYR4 2012–2019
Lead
15 µg/L 100%
of the EPA limit 15 µg/L
 14/47 SYR4 2014–2019
Lead
0.0 mg/L 0%
of the EPA limit 0.0150 mg/L
 12/12 LCR 2023
Fluoride
160 µg/L 4%
of the EPA limit 4000 µg/L
 10/10 SYR4 2012–2019
Monobromoacetic Acid
1.5 µg/L
No EPA limit set
 8/61 SYR4 2012–2019
Barium
82 µg/L 4.1%
of the EPA limit 2000 µg/L
 7/10 SYR4 2012–2019
Atrazine
0.5700 µg/L 19%
of the EPA limit 3 µg/L
 6/18 SYR4 2012–2019
Gross Beta Particle Activity
4.27 pCi/L
No EPA limit set
 6/10 SYR4 2012–2019
Dalapon
38.27 µg/L 19%
of the EPA limit 200 µg/L
 5/15 SYR4 2012–2019
Di(2-ethylhexyl) Phthalate
1.22 µg/L 20%
of the EPA limit 6 µg/L
 4/17 SYR4 2012–2019
Arsenic
1.4 µg/L 14%
of the EPA limit 10 µg/L
 3/10 SYR4 2012–2019
Combined Radium (-226 And -228)
0.5390 pCi/L 11%
of the EPA limit 5 pCi/L
 3/7 SYR4 2015–2019
Combined Uranium
1.3 µg/L 4.3%
of the EPA limit 30 µg/L
 2/7 SYR4 2012–2019
Bromoform
0.5800 µg/L
No EPA limit set
 1/64 SYR4 2012–2019
Carbon Tetrachloride
0.8100 µg/L 16%
of the EPA limit 5 µg/L
 1/10 SYR4 2012–2019
Selenium
0.5100 µg/L 1%
of the EPA limit 50 µg/L
 1/10 SYR4 2012–2019
Xylenes, Total
0.6600 µg/L 0%
of the EPA limit 10000 µg/L
 1/10 SYR4 2012–2019
83 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, TotalAsbestosBhc-GammaBenzeneBenzo(A)PyreneBeryllium, TotalChlorobenzeneCyanideCadmiumCarbofuranChlordaneChromiumDichloromethaneDi(2-ethylhexyl) AdipateDinosebDiquatEthylene DibromideEndothallEndrinEthylbenzeneGlyphosateGross Alpha, Excl. Radon And UHexachlorobenzeneHfpo-DaHeptachlorHeptachlor EpoxideHexachlorocyclopentadieneLassoMercuryMethoxychlorNetfosaaNfdhaNmefosaaOxamylPFBSPfdaPfdoaPfeesaPfhpaPfhpsPfhxaPFHXSPfmbaPfmpaPFNAPFOAPFOSPfpesPftaPftrdaPfunaPentachlorophenolPicloramSimazineStyreneTetrachloroethyleneThallium, TotalTolueneTotal Polychlorinated Biphenyls (PCB)ToxapheneTrichloroethyleneVinyl Chloridecis-1,2-DichloroethyleneLithiumO-DichlorobenzeneP-Dichlorobenzenetrans-1,2-Dichloroethylene

Utility contact

Contact
GROGAN, RODNEY
Phone
985-395-5205
Email
rgrogan@cityofpattersonla.gov

Frequently asked questions about City of Patterson Water

Is City of Patterson Water tap water safe to drink?

EPA monitoring detected 29 contaminants in City of Patterson Water'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 City of Patterson Water's water?

EPA monitoring detected Bromodichloromethane, Chloroform, Dibromochloromethane, TTHM, Total Haloacetic Acids (HAA5), and others. The full list with the level and data source for each is above.

How many people does City of Patterson Water serve?

City of Patterson Water reports serving 8,456 people in Louisiana, per its EPA record.

Has City of Patterson Water had any water quality violations?

The EPA has 60 violations on file for City of Patterson Water, of which 53 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.