Clean Water Act discharge permit · NPDES MAG590031
AYER W W T P, Ayer, MA: NPDES MAG590031 discharge permit, effluent exceedances, inspections, penalties
- EffectivePermit status
- MinorDischarger class
- 69Pollutants under a numeric limit
- 6Pollutants with an effluent exceedance
AYER W W T P, held by AYER WWTF, holds NPDES permit MAG590031, which discharges to Merrimack River Watershed - Nashua River. EPA’s file records it issued September 28, 2022 and expiring October 31, 2027. 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 | AYER W W T P |
|---|---|
| Permittee as filed | AYER WWTF |
| NPDES ID | MAG590031 |
| Permit status | Effective |
| Permit type | Coverage under a general permit |
| Discharger class | Minor discharger |
| Facility type | Publicly owned treatment works |
| Program | Publicly owned treatment works |
| Issued | September 28, 2022 |
| Expiration date | October 31, 2027 |
| Address | Ayer, MA 01432 |
| Receiving water | MERRIMACK RIVER WATERSHED - NASHUA RIVER |
| Receiving water impaired | 303(D) Listed |
| Subwatershed | Mulpus Brook-Nashua River (HUC 010700040205) |
Cited to the EPA ICIS-NPDES permit file (ECHO download).
Effluent limits and exceedances
- 69Pollutants on file
- 69Under a numeric limit
- 24With a violation of any kind
- 6With 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; the 60 with the most exceedances of 69 are shown.
| Pollutant or measure | Limits | Violations, any kind | Effluent exceedances | Latest exceedance | Largest exceedance, as filed |
|---|---|---|---|---|---|
| Copper, total recoverable | 2 | 56 | 54 | June 30, 2026 | 221% over the limit |
| Phosphorus, total [as P] | 3 | 7 | 5 | June 30, 2026 | 115% over the limit |
| E. coli | 2 | 6 | 4 | March 31, 2026 | 1,856% over the limit |
| Aluminum, total recoverable | 1 | 4 | 3 | July 31, 2026 | 41% over the limit |
| Lead, total recoverable | 1 | 2 | 1 | July 31, 2026 | 50% over the limit |
| NOEC Static Renewal 7Day Chronic Ceriodaphnia dubia | 1 | 2 | 1 | September 30, 2024 | 25% over the limit |
| BOD, 5-day, 20 deg. C | 6 | 6 | 0 | ||
| Solids, total suspended | 6 | 6 | 0 | ||
| Nitrogen, total [as N] | 3 | 3 | 0 | ||
| Flow, in conduit or thru treatment plant | 3 | 3 | 0 | ||
| Nitrogen, Kjeldahl, total [as N] | 4 | 2 | 0 | ||
| Nitrite + Nitrate total [as N] | 4 | 2 | 0 | ||
| pH | 3 | 2 | 0 | ||
| Chlorine, total residual | 2 | 2 | 0 | ||
| Nitrogen, ammonia total [as N] | 2 | 1 | 0 | ||
| Carbon, tot organic [TOC] | 2 | 1 | 0 | ||
| Hardness, total [as CaCO3] | 2 | 1 | 0 | ||
| Copper, total [as Cu] | 2 | 1 | 0 | ||
| Nickel, total [as Ni] | 2 | 1 | 0 | ||
| Zinc, total [as Zn] | 2 | 1 | 0 | ||
| Aluminum, total [as Al] | 2 | 1 | 0 | ||
| Oxygen, dissolved [DO] | 1 | 1 | 0 | ||
| BOD, 5-day, percent removal | 1 | 1 | 0 | ||
| Solids, suspended percent removal | 1 | 1 | 0 | ||
| Perfluorooctanoic acid (PFOA) | 3 | 0 | 0 | ||
| Perfluorobutanoic acid (PFBA) | 3 | 0 | 0 | ||
| Perfluorooctanesulfonamide (PFOSA) | 3 | 0 | 0 | ||
| Perfluoropentanoic acid (PFPeA) | 3 | 0 | 0 | ||
| Perfluorohexanoic acid (PFHxA) | 3 | 0 | 0 | ||
| Perfluoroheptanoic acid (PFHpA) | 3 | 0 | 0 | ||
| Perfluorononanoic acid (PFNA) | 3 | 0 | 0 | ||
| Perfluorodecanoic acid (PFDA) | 3 | 0 | 0 | ||
| Perfluoroundecanoic acid (PFUnA) | 3 | 0 | 0 | ||
| Perfluorododecanoic acid (PFDoA) | 3 | 0 | 0 | ||
| Perfluorotridecanoic acid (PFTrDA) | 3 | 0 | 0 | ||
| Perfluorotetradecanoic acid (PFTeDA) | 3 | 0 | 0 | ||
| N-ethyl perfluorooctanesulfonamidoethanol (NEtFOSE) | 3 | 0 | 0 | ||
| N-methyl perfluorooctanesulfonamidoethanol (NMeFOSE) | 3 | 0 | 0 | ||
| N-ethyl perfluorooctanesulfonamidoacetic acid (NEtFOSAA) | 3 | 0 | 0 | ||
| N-methyl perfluorooctanesulfonamidoacetic acid (NMeFOSAA) | 3 | 0 | 0 | ||
| Perfluorobutanesulfonic acid (PFBS) | 3 | 0 | 0 | ||
| Perfluorodecanesulfonic acid (PFDS) | 3 | 0 | 0 | ||
| Perfluoroheptanesulfonic acid (PFHpS) | 3 | 0 | 0 | ||
| Perfluorohexanesulfonic acid (PFHxS) | 3 | 0 | 0 | ||
| Perfluorooctanesulfonic acid (PFOS) | 3 | 0 | 0 | ||
| 1H,1H,2H,2H-Perfluorohexane sulfonic acid (4:2 FTS) | 3 | 0 | 0 | ||
| 1H,1H,2H,2H-Perfluorooctane sulfonic acid (6:2 FTS) | 3 | 0 | 0 | ||
| 1H,1H, 2H, 2H-Perfluorodecane sulfonic acid (8:2 FTS) | 3 | 0 | 0 | ||
| Perfluoropentanesulfonic acid (PFPeS) | 3 | 0 | 0 | ||
| Perfluorononanesulfonic acid (PFNS) | 3 | 0 | 0 | ||
| Hexafluoropropylene oxide dimer acid (HFPO-DA) | 3 | 0 | 0 | ||
| Nonafluoro-3,6-dioxaheptanoic acid (NFDHA) | 3 | 0 | 0 | ||
| Perfluoro(2-ethoxyethane)sulfonic acid (PFEESA) | 3 | 0 | 0 | ||
| Perfluorododecanesulfonic acid (PFDoS) | 3 | 0 | 0 | ||
| 4,8-Dioxa-3H-perfluorononanoic acid (ADONA) | 3 | 0 | 0 | ||
| N-methyl perfluorooctanesulfonamide (NMeFOSA) | 3 | 0 | 0 | ||
| N-ethyl perfluorooctanesulfonamide (NEtFOSA) | 3 | 0 | 0 | ||
| 3-Perfluoropropyl propanoic acid (3:3 FTCA) | 3 | 0 | 0 | ||
| Perfluoro-3-methoxypropanoic acid (PFMPA) | 3 | 0 | 0 | ||
| 9-Chlorohexadecafluoro-3-oxanonane-1-sulfonic acid (9Cl-PF3ONS) | 3 | 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
- 0Single-event violations
EPA’s single-event violation file, as loaded, holds no violation for NPDES MAG590031.
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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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 MAG590031 there.
Nearby on the register
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- Every permit record in Massachusetts, A to Z
Figures from EPA’s ICIS-NPDES download, loaded September 15, 2026.