Clean Water Act discharge permit · NPDES TN0024945
MOUNTAIN CITY WWTP, Mountain City, TN: NPDES TN0024945 discharge permit, effluent exceedances, inspections, penalties
- Administratively continuedPermit status
- MajorDischarger class
- 17Pollutants under a numeric limit
- 18Pollutants with an effluent exceedance
MOUNTAIN CITY WWTP, held by Town of Mountain City, holds NPDES permit TN0024945, which discharges to Watauga. EPA’s file records it issued April 9, 2021 and expiring July 31, 2026. 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 filed | MOUNTAIN CITY WWTP |
|---|---|
| Permittee as filed | Town of Mountain City |
| NPDES ID | TN0024945 |
| 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 | April 9, 2021 |
| Expiration date | July 31, 2026 |
| Issuing agency | TDEC - DWR |
| Address | Mountain City, TN 37683 |
| Receiving water | Watauga |
| Receiving water impaired | 303(D) Listed |
| Subwatershed | Town Creek (HUC 060101030101) |
Cited to the EPA ICIS-NPDES permit file (ECHO download).
Effluent limits and exceedances
- 22Pollutants on file
- 17Under a numeric limit
- 22With a violation of any kind
- 18With 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 |
|---|---|---|---|---|---|
| Solids, total suspended | 7 | 70 | 69 | May 31, 2025 | 771% over the limit |
| Nitrogen, ammonia total [as N] | 22 | 53 | 52 | February 28, 2025 | 400% over the limit |
| E. coli, MTEC-MF | 0 | 42 | 42 | February 29, 2016 | 99,999% over the limit |
| BOD, carbonaceous [5 day, 20 C] | 12 | 41 | 40 | October 31, 2025 | 99,999% over the limit |
| Solids, suspended percent removal | 2 | 37 | 37 | February 28, 2026 | 99,999% over the limit |
| Chlorine, total residual | 1 | 21 | 21 | March 31, 2019 | 3,075% over the limit |
| Carbonaceous oxygen demand, % removal | 0 | 17 | 17 | January 31, 2021 | 99,999% over the limit |
| Mercury, total [as Hg] | 0 | 15 | 15 | May 31, 2012 | 400% over the limit |
| E. coli | 2 | 11 | 11 | December 31, 2024 | 99,999% over the limit |
| Coliform, fecal MF, MFC broth, 44.5 C | 0 | 10 | 10 | August 31, 2004 | 99,999% over the limit |
| BOD, carbonaceous, percent removal | 2 | 9 | 9 | October 31, 2025 | 99,999% over the limit |
| Oxygen, dissolved [DO] | 1 | 9 | 9 | December 31, 2024 | 35% over the limit |
| Solids, settleable | 1 | 9 | 9 | December 31, 2024 | 99,999% over the limit |
| IC25 Static Renewal 7 Day Chronic Ceriodaphnia dubia | 2 | 26 | 4 | May 31, 2019 | 87% over the limit |
| SSO, Dry Weather | 1 | 4 | 4 | May 31, 2025 | 2,147,483,650% over the limit |
| IC25 Static Renewal 7 Day Chronic Chrpimephales | 2 | 23 | 3 | November 30, 2022 | 89% over the limit |
| SSO, Wet Weather | 1 | 3 | 3 | February 28, 2026 | 2,147,483,650% over the limit |
| pH | 2 | 2 | 2 | November 30, 2020 | |
| Phosphorus, total [as P] | 5 | 9 | 0 | ||
| Nitrogen, total [as N] | 5 | 8 | 0 | ||
| Copper, total [as Cu] | 0 | 6 | 0 | ||
| Flow, in conduit or thru treatment plant | 4 | 4 | 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
- 0Single-event violations
EPA’s single-event violation file, as loaded, holds no violation for NPDES TN0024945.
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
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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 TN0024945 there.
Nearby on the register
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Figures from EPA’s ICIS-NPDES download, loaded September 15, 2026.