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Clean Water Act discharge permit · NPDES TX0021547

CITY OF MERCEDES WWTP, Mercedes, TX: NPDES TX0021547 discharge permit, effluent exceedances, inspections, penalties

CITY OF MERCEDES WWTP, held by MERCEDES, CITY OF, holds NPDES permit TX0021547, which discharges to Unnamed Drain Ditch, Arroyo Anacuit. EPA’s file records it issued January 14, 2016 and expiring June 1, 2020. The status and dates are as EPA’s permit file stood when Velarion loaded it (September 15, 2026); EPA’s free Detailed Facility Report on ECHO carries the permit’s current standing.

Identity

Facility as filedCITY OF MERCEDES WWTP
Permittee as filedMERCEDES, CITY OF
NPDES IDTX0021547
Permit statusAdministratively continued (past its expiration date and still in force until reissued)
Permit typeIndividual permit
Discharger classMajor discharger
Facility typePublicly owned treatment works
ProgramPublicly owned treatment works
IssuedJanuary 14, 2016
Expiration dateJune 1, 2020
AddressMercedes, TX 78570
Receiving waterUNNAMED DRAIN DITCH, ARROYO ANACUIT
SubwatershedLa Feria Main Canal-Arroyo Colorado (HUC 121102080600)

Cited to the EPA ICIS-NPDES permit file (ECHO download).

Effluent limits and exceedances

An effluent exceedance is a discharge monitoring report value over the permit’s numeric limit (EPA’s violation code E90). A violation of any kind also counts a report not filed. Each row is EPA’s own count for that pollutant.

Pollutant or measureLimitsViolations, any kindEffluent exceedancesLatest exceedanceLargest exceedance, as filed
Nitrogen, ammonia total [as N]37821May 31, 2023353% over the limit
E. coli24414March 31, 202599,999% over the limit
Solids, total suspended3625July 31, 2021755% over the limit
Flow, in conduit or thru treatment plant4864March 31, 20253,235% over the limit
BOD, carbonaceous [5 day, 20 C]3573April 30, 2022109% over the limit
Chlorine, total residual0351January 31, 20101% over the limit
Oxygen, dissolved [DO]1201June 30, 201920% over the limit
Polychlorinated biphenyls [PCBs]161July 31, 2013308% over the limit
pH3440
NOEC Lethal Static Renewal 7 Day Chronic Ceriodaphnia dubia2380
Low Flow Pass/Fail Survival Test Static Renewal 7 Day Chronic Ceriodaphnia dubia2360
NOEC Sub-Lethal Static Renewal 7 Day Chronic Ceriodaphnia dubia2360
Pass/Fail Sub-Lethal Static Renewal 7 Day Chronic Ceriodaphnia dubia2360
LOEC Lethal Survival Static Renewal 7 Day Chronic Ceriodaphnia dubia2360
LOEC Sub-Lethal Reproduction Static Renewal 7 Day Chronic Ceriodaphnia dubia2360
Low Flow Pass/Fail Survival Test Static Renewal 7 Day Chronic Pimephales promelas2340
NOEC Lethal Static Renewal 7 Day Chronic Pimephales promelas2340
NOEC Sub-Lethal Static Renewal 7 Day Chronic Pimephales promelas2340
Pass/Fail Sub-Lethal Static Renewal 7 Day Chronic Pinephales promelas2340
LOEC Lethal Survival Static Renewal 7 Day Chronic Pimephales promelas2320
LOEC Sub-Lethal Reproduction Static Renewal 7 Day Chronic Pimephales promelas2320
Arsenic, dry weight5200
Chromium, sludge, total, dry weight [as Cr]5200
Whole effluent toxicity8160
Selenium, dry weight3120
Copper, dry weight3120
Cadmium, dry weight3120
Molybdenum, sludge, total, dry weight [as Mo]3120
Zinc, sludge, total, dry weight [as Zn]3120
Lead, sludge, total, dry weight [as Pb]3120
Nickel, sludge, total, dry weight [as Ni]3120
Mercury, sludge, total, dry weight [as Hg]3120
LC50 Pass/Fail Static 24Hr Acute D. Pulex1100
LC50 Pass/Fail Static 24Hr Acute Pimephales promelas1100
Description of pathogen option used290
Nickel, total [as Ni]280
Level of pathogen requirements achieved280
Vector attraction reduction alternative used280
Toxicity characteristic leaching procedure160
Ann. amt sludge disposed by other method150
Annual amt of sludge incinerated150
Annual sludge production, total150
Annual amount of sludge land applied150
Annual amt. sludge disposed surface unit150
Annual amt sludge disposed in landfill150
Annual amt sludge transported interstate150
Compliance w/part 258 sludge requirement150
Salmonella150
Pollutant table from 503.13150
Fecal coliform140
Unit w/liner/leachate collection system140
Boundary areas140
Whole effluent toxicity - retest #1320
Whole effluent toxicity - retest #2320
Annual whole sludge application rate100

Cited to the EPA ICIS-NPDES limits and effluent violations files (ECHO download); up to 60 rows shown, most exceedances first.

Inspections, violations and enforcement

DateWhat EPA recordedAgency
November 9, 2022Permit Violations - Violation Specified in CommentST6
July 15, 2021Permit Violations - Violation Specified in CommentST6
July 6, 2021Permit Violations - Violation Specified in CommentST6
March 11, 2020Permit Violations - Violation Specified in CommentST6
April 12, 2018Permit Violations - Violation Specified in CommentST6

Velarion’s copy of EPA’s ICIS-NPDES files does not include the inspections, formal enforcement actions and informal enforcement actions files, so this page shows none of them. EPA’s free Detailed Facility Report on ECHO lists this permit’s inspections, enforcement actions and penalties.

Cited to the EPA ICIS-NPDES violation, inspection and enforcement files (ECHO download); up to 50 rows of each shown, newest first.

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EPA publishes a free Detailed Facility Report for every permit on ECHO: its compliance status quarter by quarter, its inspections, and its enforcement actions and penalties. EPA also sends free notices of new inspections and enforcement actions through ECHO Notify; enter NPDES ID TX0021547 there.

Nearby on the register

Figures from EPA’s ICIS-NPDES download, loaded September 15, 2026.