Clean Water Act discharge permit · NPDES TX0071111
CITY OF MASON WWTP, Mason, TX: NPDES TX0071111 discharge permit, effluent exceedances, inspections, penalties
- Administratively continuedPermit status
- MinorDischarger class
- 37Pollutants under a numeric limit
- 7Pollutants with an effluent exceedance
CITY OF MASON WWTP, held by MASON, CITY OF, holds NPDES permit TX0071111, which discharges to Comanche Ck;Llano River. EPA’s file records it issued January 13, 2017 and expiring December 1, 2019. 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 | CITY OF MASON WWTP |
|---|---|
| Permittee as filed | MASON, CITY OF |
| NPDES ID | TX0071111 |
| Permit status | Administratively continued (past its expiration date and still in force until reissued) |
| Permit type | Individual permit |
| Discharger class | Minor discharger |
| Facility type | Publicly owned treatment works |
| Program | Publicly owned treatment works |
| Issued | January 13, 2017 |
| Expiration date | December 1, 2019 |
| Address | Mason, TX 76856 |
| Receiving water | COMANCHE CK;LLANO RIVER |
| Subwatershed | Lower Comanche Creek (HUC 120902040504) |
| 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
- 38Pollutants on file
- 37Under a numeric limit
- 37With a violation of any kind
- 7With 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 | 110 | 42 | February 28, 2026 | 325% over the limit |
| E. coli | 2 | 53 | 32 | November 30, 2025 | 1,621% over the limit |
| BOD, carbonaceous [5 day, 20 C] | 3 | 87 | 14 | July 31, 2026 | 87% over the limit |
| pH | 3 | 70 | 3 | April 30, 2016 | |
| Flow, in conduit or thru treatment plant | 2 | 59 | 2 | July 31, 2025 | 70% over the limit |
| Oxygen, dissolved [DO] | 1 | 34 | 2 | July 31, 2025 | 21% over the limit |
| BOD, 5-day, 20 deg. C | 0 | 23 | 2 | March 31, 2005 | 13% over the limit |
| Solids, total suspended | 2 | 61 | 0 | ||
| Arsenic, dry weight | 5 | 20 | 0 | ||
| Chromium, sludge, total, dry weight [as Cr] | 5 | 20 | 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 | ||
| Nickel, total [as Ni] | 2 | 8 | 0 | ||
| Level of pathogen requirements achieved | 2 | 8 | 0 | ||
| Description of pathogen option used | 2 | 8 | 0 | ||
| Vector attraction reduction alternative used | 2 | 8 | 0 | ||
| Polychlorinated biphenyls [PCBs] | 1 | 5 | 0 | ||
| Fecal coliform | 1 | 4 | 0 | ||
| Toxicity characteristic leaching procedure | 1 | 4 | 0 | ||
| Ann. amt sludge disposed by other method | 1 | 4 | 0 | ||
| Annual amt of sludge incinerated | 1 | 4 | 0 | ||
| Annual sludge production, total | 1 | 4 | 0 | ||
| Annual amount of sludge land applied | 1 | 4 | 0 | ||
| Annual amt. sludge disposed surface unit | 1 | 4 | 0 | ||
| Annual amt sludge disposed in landfill | 1 | 4 | 0 | ||
| Annual amt sludge transported interstate | 1 | 4 | 0 | ||
| Unit w/liner/leachate collection system | 1 | 4 | 0 | ||
| Compliance w/part 258 sludge requirement | 1 | 4 | 0 | ||
| Boundary areas | 1 | 4 | 0 | ||
| Salmonella | 1 | 4 | 0 | ||
| Pollutant table from 503.13 | 1 | 4 | 0 | ||
| Annual whole sludge application rate | 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
- 2Single-event violations
| Date | What EPA recorded | Agency |
|---|---|---|
| July 20, 2020 | Permit Violations - Violation Specified in Comment | ST6 |
| October 24, 2017 | 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.
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Figures from EPA’s ICIS-NPDES download, loaded October 14, 2026.