Clean Water Act discharge permit · NPDES NC0021121
MOUNT AIRY WWTP, Mount Airy, NC: NPDES NC0021121 discharge permit, effluent exceedances, inspections, penalties
- EffectivePermit status
- MajorDischarger class
- 14Pollutants under a numeric limit
- 5Pollutants with an effluent exceedance
MOUNT AIRY WWTP, held by City of Mount Airy, holds NPDES permit NC0021121. EPA’s file records it issued September 28, 2020 and expiring February 28, 2025. 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 | MOUNT AIRY WWTP |
|---|---|
| Permittee as filed | City of Mount Airy |
| NPDES ID | NC0021121 |
| Permit status | Effective |
| Permit type | Individual permit |
| Discharger class | Major discharger |
| Facility type | Publicly owned treatment works |
| Program | Publicly owned treatment works |
| Issued | September 28, 2020 |
| Expiration date | February 28, 2025 |
| Address | Mount Airy, NC 27030 |
| Subwatershed | Little Yadkin River (HUC 030401011005) |
Cited to the EPA ICIS-NPDES permit file (ECHO download).
Effluent limits and exceedances
- 17Pollutants on file
- 14Under a numeric limit
- 17With 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 |
|---|---|---|---|---|---|
| Copper, total [as Cu] | 3 | 19 | 14 | January 31, 2025 | 95% over the limit |
| Mercury, total [as Hg] | 0 | 5 | 5 | April 30, 2009 | 71% over the limit |
| Coliform, fecal MF, MFC broth, 44.5 C | 2 | 23 | 4 | April 30, 2015 | 228% over the limit |
| Cyanide, total [as CN] | 0 | 3 | 3 | June 30, 2005 | 441% over the limit |
| Pass/Fail Static Renewal 7 Day Chronic Ceriodaphnia dubia | 0 | 1 | 1 | April 30, 2008 | |
| Oxygen, dissolved [DO] | 2 | 59 | 0 | ||
| BOD, 5-day, 20 deg. C | 3 | 43 | 0 | ||
| Solids, total suspended | 3 | 43 | 0 | ||
| Zinc, total [as Zn] | 2 | 32 | 0 | ||
| Nitrogen, ammonia total [as N] | 4 | 24 | 0 | ||
| pH | 2 | 4 | 0 | ||
| Flow, in conduit or thru treatment plant | 1 | 3 | 0 | ||
| Temperature, water deg. centigrade | 1 | 2 | 0 | ||
| Conductivity | 1 | 2 | 0 | ||
| Nitrogen, total [as N] | 1 | 2 | 0 | ||
| Phosphorus, total [as P] | 1 | 2 | 0 | ||
| Chlorine, total residual | 1 | 2 | 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 NC0021121.
Velarion’s copy of EPA’s ICIS-NPDES files does not yet 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, NC0021121.
Start the watch
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- One watershed — $2,990/year
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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 NC0021121 there.
Nearby on the register
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- Every permit record in North Carolina, A to Z
Figures from EPA’s ICIS-NPDES download, loaded September 14, 2026.