Clean Water Act discharge permit · NPDES TX0021547
CITY OF MERCEDES WWTP, Mercedes, TX: NPDES TX0021547 discharge permit, effluent exceedances, inspections, penalties
- Administratively continuedPermit status
- MajorDischarger class
- 54Pollutants under a numeric limit
- 8Pollutants with an effluent exceedance
- 1Inspections on file
- 0Formal enforcement actions
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.
Identity
| Facility as filed | CITY OF MERCEDES WWTP |
|---|---|
| Permittee as filed | MERCEDES, CITY OF |
| NPDES ID | TX0021547 |
| Permit status | Administratively continued (past its expiration date and still in force until reissued) |
| Permit type | Individual permit |
| Discharger class | Major discharger |
| Facility type | Publicly owned treatment works |
| Program | Publicly owned treatment works |
| Issued | January 14, 2016 |
| Expiration date | June 1, 2020 |
| Address | Mercedes, TX 78570 |
| Receiving water | UNNAMED DRAIN DITCH, ARROYO ANACUIT |
| Subwatershed | La Feria Main Canal-Arroyo Colorado (HUC 121102080600) |
Effluent limits and exceedances
- 55Pollutants on file
- 54Under a numeric limit
- 54With a violation of any kind
- 8With an effluent exceedance
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 measure | Limits | Violations, any kind | Effluent exceedances | Latest exceedance | Largest exceedance, as filed |
|---|---|---|---|---|---|
| Nitrogen, ammonia total [as N] | 3 | 78 | 21 | May 31, 2023 | 353% over the limit |
| E. coli | 2 | 44 | 14 | March 31, 2025 | 99,999% over the limit |
| Solids, total suspended | 3 | 62 | 5 | July 31, 2021 | 755% over the limit |
| Flow, in conduit or thru treatment plant | 4 | 86 | 4 | March 31, 2025 | 3,235% over the limit |
| BOD, carbonaceous [5 day, 20 C] | 3 | 57 | 3 | April 30, 2022 | 109% over the limit |
| Chlorine, total residual | 0 | 35 | 1 | January 31, 2010 | 1% over the limit |
| Oxygen, dissolved [DO] | 1 | 20 | 1 | June 30, 2019 | 20% over the limit |
| Polychlorinated biphenyls [PCBs] | 1 | 6 | 1 | July 31, 2013 | 308% over the limit |
| pH | 3 | 44 | 0 | ||
| NOEC Lethal Static Renewal 7 Day Chronic Ceriodaphnia dubia | 2 | 38 | 0 | ||
| Low Flow Pass/Fail Survival Test Static Renewal 7 Day Chronic Ceriodaphnia dubia | 2 | 36 | 0 | ||
| NOEC Sub-Lethal Static Renewal 7 Day Chronic Ceriodaphnia dubia | 2 | 36 | 0 | ||
| Pass/Fail Sub-Lethal Static Renewal 7 Day Chronic Ceriodaphnia dubia | 2 | 36 | 0 | ||
| LOEC Lethal Survival Static Renewal 7 Day Chronic Ceriodaphnia dubia | 2 | 36 | 0 | ||
| LOEC Sub-Lethal Reproduction Static Renewal 7 Day Chronic Ceriodaphnia dubia | 2 | 36 | 0 | ||
| Low Flow Pass/Fail Survival Test Static Renewal 7 Day Chronic Pimephales promelas | 2 | 34 | 0 | ||
| NOEC Lethal Static Renewal 7 Day Chronic Pimephales promelas | 2 | 34 | 0 | ||
| NOEC Sub-Lethal Static Renewal 7 Day Chronic Pimephales promelas | 2 | 34 | 0 | ||
| Pass/Fail Sub-Lethal Static Renewal 7 Day Chronic Pinephales promelas | 2 | 34 | 0 | ||
| LOEC Lethal Survival Static Renewal 7 Day Chronic Pimephales promelas | 2 | 32 | 0 | ||
| LOEC Sub-Lethal Reproduction Static Renewal 7 Day Chronic Pimephales promelas | 2 | 32 | 0 | ||
| Arsenic, dry weight | 5 | 20 | 0 | ||
| Chromium, sludge, total, dry weight [as Cr] | 5 | 20 | 0 | ||
| Whole effluent toxicity | 8 | 16 | 0 | ||
| Selenium, dry weight | 3 | 12 | 0 | ||
| Copper, dry weight | 3 | 12 | 0 | ||
| Cadmium, dry weight | 3 | 12 | 0 | ||
| Molybdenum, sludge, total, dry weight [as Mo] | 3 | 12 | 0 | ||
| Zinc, sludge, total, dry weight [as Zn] | 3 | 12 | 0 | ||
| Lead, sludge, total, dry weight [as Pb] | 3 | 12 | 0 | ||
| Nickel, sludge, total, dry weight [as Ni] | 3 | 12 | 0 | ||
| Mercury, sludge, total, dry weight [as Hg] | 3 | 12 | 0 | ||
| LC50 Pass/Fail Static 24Hr Acute D. Pulex | 1 | 10 | 0 | ||
| LC50 Pass/Fail Static 24Hr Acute Pimephales promelas | 1 | 10 | 0 | ||
| Description of pathogen option used | 2 | 9 | 0 | ||
| Nickel, total [as Ni] | 2 | 8 | 0 | ||
| Level of pathogen requirements achieved | 2 | 8 | 0 | ||
| Vector attraction reduction alternative used | 2 | 8 | 0 | ||
| Toxicity characteristic leaching procedure | 1 | 6 | 0 | ||
| Ann. amt sludge disposed by other method | 1 | 5 | 0 | ||
| Annual amt of sludge incinerated | 1 | 5 | 0 | ||
| Annual sludge production, total | 1 | 5 | 0 | ||
| Annual amount of sludge land applied | 1 | 5 | 0 | ||
| Annual amt. sludge disposed surface unit | 1 | 5 | 0 | ||
| Annual amt sludge disposed in landfill | 1 | 5 | 0 | ||
| Annual amt sludge transported interstate | 1 | 5 | 0 | ||
| Compliance w/part 258 sludge requirement | 1 | 5 | 0 | ||
| Salmonella | 1 | 5 | 0 | ||
| Pollutant table from 503.13 | 1 | 5 | 0 | ||
| Fecal coliform | 1 | 4 | 0 | ||
| Unit w/liner/leachate collection system | 1 | 4 | 0 | ||
| Boundary areas | 1 | 4 | 0 | ||
| Whole effluent toxicity - retest #1 | 3 | 2 | 0 | ||
| Whole effluent toxicity - retest #2 | 3 | 2 | 0 | ||
| Annual whole sludge application rate | 1 | 0 | 0 |
Inspections, violations and enforcement
- 5Single-event violations
| Date | What EPA recorded | Agency |
|---|---|---|
| November 9, 2022 | Permit Violations - Violation Specified in Comment | ST6 |
| July 15, 2021 | Permit Violations - Violation Specified in Comment | ST6 |
| July 6, 2021 | Permit Violations - Violation Specified in Comment | ST6 |
| March 11, 2020 | Permit Violations - Violation Specified in Comment | ST6 |
| April 12, 2018 | Permit Violations - Violation Specified in Comment | ST6 |
Inspections
| Date | What EPA recorded | Agency |
|---|---|---|
| January 28, 2026 | Evaluation | E |
Formal enforcement and penalties
0 formal actions, 0 of them with a penalty assessed. Federal and state penalties are separate figures from separate authorities and are shown as each was filed, never added together.
Informal enforcement
| Date | What EPA recorded | Agency |
|---|---|---|
| September 3, 2026 | Letter of Violation/ Warning Letter | State |
| August 6, 2026 | Phone Call/ EMAIL | State |
| July 9, 2026 | Phone Call/ EMAIL | State |
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Figures from EPA’s ICIS-NPDES download, loaded September 15, 2026.