Clean Water Act discharge permit · NPDES TX0055166
CNP UD WWTP, Houston, TX: NPDES TX0055166 discharge permit, effluent exceedances, inspections, penalties
- Administratively continuedPermit status
- MajorDischarger class
- 23Pollutants under a numeric limit
- 5Pollutants with an effluent exceedance
CNP UD WWTP, held by CNP UTILITY DISTRICT, holds NPDES permit TX0055166, which discharges to Cypress Creek. EPA’s file records it issued November 29, 2021 and expiring November 29, 2024. The status and dates are as EPA’s permit file stood when Velarion loaded it (October 14, 2026); EPA’s free Detailed Facility Report on ECHO carries the permit’s current standing.
Identity
| Facility as filed | CNP UD WWTP |
|---|---|
| Permittee as filed | CNP UTILITY DISTRICT |
| NPDES ID | TX0055166 |
| 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 | November 29, 2021 |
| Expiration date | November 29, 2024 |
| Address | Houston, TX 77090 |
| Receiving water | Cypress Creek |
| Subwatershed | Turkey Creek-Cypress Creek (HUC 120401020107) |
| SIC | 4952 – Sewerage Systems |
Cited to the EPA ICIS-NPDES permit file (ECHO download) and EPA’s NAICS/SIC and component files, the same download.
Effluent limits and exceedances
- 24Pollutants on file
- 23Under a numeric limit
- 8With a violation of any kind
- 5With 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 |
|---|---|---|---|---|---|
| E. coli | 2 | 18 | 18 | July 31, 2026 | 1,200% over the limit |
| Oxygen, dissolved [DO] | 1 | 10 | 10 | June 30, 2026 | 13% over the limit |
| Coliform, fecal general | 0 | 7 | 5 | November 30, 2010 | 6,151% over the limit |
| Nitrogen, ammonia total [as N] | 3 | 2 | 2 | September 30, 2017 | 10% over the limit |
| Solids, total suspended | 3 | 1 | 1 | October 31, 2005 | 67% over the limit |
| NOEC Sub-Lethal Static Renewal 7 Day Chronic Ceriodaphnia dubia | 2 | 3 | 0 | ||
| LOEC Sub-Lethal Reproduction Static Renewal 7 Day Chronic Ceriodaphnia dubia | 2 | 2 | 0 | ||
| Flow, in conduit or thru treatment plant | 4 | 1 | 0 | ||
| Whole effluent toxicity - retest #1 | 3 | 0 | 0 | ||
| Whole effluent toxicity - retest #2 | 3 | 0 | 0 | ||
| BOD, carbonaceous [5 day, 20 C] | 3 | 0 | 0 | ||
| pH | 2 | 0 | 0 | ||
| Low Flow Pass/Fail Survival Test Static Renewal 7 Day Chronic Ceriodaphnia dubia | 2 | 0 | 0 | ||
| Low Flow Pass/Fail Survival Test Static Renewal 7 Day Chronic Pimephales promelas | 2 | 0 | 0 | ||
| NOEC Lethal Static Renewal 7 Day Chronic Ceriodaphnia dubia | 2 | 0 | 0 | ||
| NOEC Lethal Static Renewal 7 Day Chronic Pimephales promelas | 2 | 0 | 0 | ||
| NOEC Sub-Lethal Static Renewal 7 Day Chronic Pimephales promelas | 2 | 0 | 0 | ||
| Pass/Fail Sub-Lethal Static Renewal 7 Day Chronic Ceriodaphnia dubia | 2 | 0 | 0 | ||
| Pass/Fail Sub-Lethal Static Renewal 7 Day Chronic Pinephales promelas | 2 | 0 | 0 | ||
| LOEC Lethal Survival Static Renewal 7 Day Chronic Ceriodaphnia dubia | 2 | 0 | 0 | ||
| LOEC Lethal Survival Static Renewal 7 Day Chronic Pimephales promelas | 2 | 0 | 0 | ||
| LOEC Sub-Lethal Reproduction Static Renewal 7 Day Chronic Pimephales promelas | 2 | 0 | 0 | ||
| LC50 Pass/Fail Static 24Hr Acute D. Pulex | 1 | 0 | 0 | ||
| LC50 Pass/Fail Static 24Hr Acute Pimephales promelas | 1 | 0 | 0 |
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
- 3Single-event violations
| Date | What EPA recorded | Agency |
|---|---|---|
| September 4, 2025 | Permit Violations - Violation Specified in Comment | ST6 |
| January 30, 2024 | Permit Violations - Violation Specified in Comment | ST6 |
| December 13, 2021 | Permit Violations - Violation Specified in Comment | ST6 |
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.
Watch this permit
One permit holder, $99/month. Watch the register for one permit holder and the places and receiving waters tied to its permits. Choose “One permit holder” and enter this permit’s NPDES ID, TX0055166.
Start the watch
- One permit holder — $99/month
- One watershed — $2,990/year
- One state — $4,990/year
- The whole register — $18,000/year
How we handle your data → Privacy
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 TX0055166 there.
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Figures from EPA’s ICIS-NPDES download, loaded October 14, 2026.