Clean Water Act discharge permit · NPDES TN0020079
MARYVILLE STP, Maryville, TN: NPDES TN0020079 discharge permit, effluent exceedances, inspections, penalties
- Administratively continuedPermit status
- MajorDischarger class
- 21Pollutants under a numeric limit
- 17Pollutants with an effluent exceedance
MARYVILLE STP, held by City of Maryville, holds NPDES permit TN0020079, which discharges to Ft. Loudoun/Little River. EPA’s file records it issued August 14, 2020 and expiring December 31, 2022. The status and dates are as EPA’s permit file stood when Velarion loaded it (September 14, 2026); EPA’s free Detailed Facility Report on ECHO carries the permit’s current standing.
Identity
| Facility as filed | MARYVILLE STP |
|---|---|
| Permittee as filed | City of Maryville |
| NPDES ID | TN0020079 |
| 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 | August 14, 2020 |
| Expiration date | December 31, 2022 |
| Issuing agency | TDEC - DWR |
| Address | Maryville, TN 37801 |
| Receiving water | Ft. Loudoun/Little River |
| Receiving water impaired | 303(D) Listed |
| Subwatershed | Little River-Roddy Branch (HUC 060102010110) |
Cited to the EPA ICIS-NPDES permit file (ECHO download).
Effluent limits and exceedances
- 30Pollutants on file
- 21Under a numeric limit
- 26With a violation of any kind
- 17With 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] | 12 | 64 | 45 | May 31, 2026 | 1,013% over the limit |
| Solids, total suspended | 21 | 74 | 36 | March 31, 2023 | 696% over the limit |
| E. coli | 4 | 46 | 34 | July 31, 2026 | 99,999% over the limit |
| E. coli, MTEC-MF | 0 | 22 | 16 | November 30, 2005 | 418% over the limit |
| Chlorine, total residual | 4 | 23 | 15 | August 31, 2023 | 833% over the limit |
| Solids, settleable | 2 | 21 | 12 | January 31, 2024 | 9,900% over the limit |
| Duration | 0 | 13 | 12 | July 31, 2013 | 688% over the limit |
| BOD, carbonaceous [5 day, 20 C] | 21 | 48 | 9 | June 30, 2012 | 387% over the limit |
| Solids, suspended percent removal | 4 | 22 | 8 | March 31, 2023 | 99,999% over the limit |
| Oxygen, dissolved [DO] | 2 | 17 | 7 | March 31, 2023 | 42% over the limit |
| Coliform, fecal MF, MFC broth, 44.5 C | 0 | 7 | 7 | January 31, 2010 | 99,999% over the limit |
| SSO, Wet Weather | 3 | 7 | 4 | February 28, 2025 | 2,147,483,650% over the limit |
| Carbonaceous oxygen demand, % removal | 0 | 6 | 4 | September 30, 2010 | 67% over the limit |
| SSO, Dry Weather | 3 | 6 | 3 | July 31, 2023 | 2,147,483,650% over the limit |
| Number of Events | 0 | 4 | 3 | December 31, 2013 | 600% over the limit |
| BOD, carbonaceous, percent removal | 4 | 14 | 2 | April 30, 2026 | 99,999% over the limit |
| Dilution factor | 0 | 3 | 2 | May 31, 2013 | 100% over the limit |
| Nitrogen, total [as N] | 9 | 34 | 0 | ||
| Phosphorus, total [as P] | 9 | 34 | 0 | ||
| pH | 4 | 18 | 0 | ||
| Flow, in conduit or thru treatment plant | 8 | 17 | 0 | ||
| IC25 Static Renewal 7 Day Chronic Ceriodaphnia dubia | 2 | 7 | 0 | ||
| IC25 Static Renewal 7 Day Chronic Chrpimephales | 2 | 7 | 0 | ||
| Overflows | 0 | 2 | 0 | ||
| Number of Extension Lines in Operation | 0 | 1 | 0 | ||
| Bypass valve | 0 | 1 | 0 | ||
| Di[2-ethylhexyl] phthalate [DEHP] | 2 | 0 | 0 | ||
| Release [Sewer], Dry Weather | 2 | 0 | 0 | ||
| Release [Sewer], Wet Weather | 2 | 0 | 0 | ||
| Bypass of Treatment Facility | 2 | 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
- 1Single-event violations
| Date | What EPA recorded | Agency |
|---|---|---|
| November 29, 2023 | Pretreatment - Failure to Conduct Inspections | 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 September 14, 2026.