Clean Water Act discharge permit · NPDES CA0104400
IMPERIAL WPCP, Imperial, CA: NPDES CA0104400 discharge permit, effluent exceedances, inspections, penalties
- Administratively continuedPermit status
- MajorDischarger class
- 150Pollutants under a numeric limit
- 12Pollutants with an effluent exceedance
IMPERIAL WPCP, held by Imperial, City of, holds NPDES permit CA0104400, which discharges to Dolson Drain. EPA’s file records it issued September 16, 2010 and expiring September 30, 2015. 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 | IMPERIAL WPCP |
|---|---|
| Permittee as filed | Imperial, City of |
| NPDES ID | CA0104400 |
| 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 | September 16, 2010 |
| Expiration date | September 30, 2015 |
| Address | Imperial, CA 92251 |
| Receiving water | Dolson Drain |
| Receiving water impaired | 303(D) Listed |
| 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
- 154Pollutants on file
- 150Under a numeric limit
- 154With a violation of any kind
- 12With 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 154 are shown.
| Pollutant or measure | Limits | Violations, any kind | Effluent exceedances | Latest exceedance | Largest exceedance, as filed |
|---|---|---|---|---|---|
| Copper, total recoverable | 8 | 77 | 31 | April 30, 2025 | 512% over the limit |
| E. coli | 2 | 58 | 10 | June 30, 2024 | 99,999% over the limit |
| Coliform, fecal - % samples exceeding limit | 0 | 10 | 8 | March 31, 2021 | 1,000% over the limit |
| Solids, total suspended | 6 | 169 | 6 | February 28, 2013 | 165% over the limit |
| Solids, suspended percent removal | 1 | 32 | 6 | October 31, 2014 | 27% over the limit |
| Thallium, total recoverable | 1 | 70 | 4 | July 31, 2010 | 669% over the limit |
| Oil and grease | 2 | 27 | 3 | August 31, 2016 | 84% over the limit |
| Coliform, fecal general | 2 | 23 | 3 | July 31, 2015 | 99,999% over the limit |
| Selenium, total recoverable | 1 | 71 | 2 | July 31, 2010 | 4,900% over the limit |
| pH | 2 | 54 | 2 | February 29, 2016 | |
| Toxic Units Static Renewal 96Hr Acute Ceriodaphnia dubia | 2 | 12 | 2 | March 31, 2006 | 9,900% over the limit |
| TU Static Renewal 96Hr Acute Pimphales promelas | 2 | 11 | 1 | March 31, 2006 | 9,900% over the limit |
| BOD, 5-day, 20 deg. C | 6 | 163 | 0 | ||
| Silver total recoverable | 4 | 41 | 0 | ||
| Zinc, total recoverable | 4 | 41 | 0 | ||
| Flow, in conduit or thru treatment plant | 2 | 37 | 0 | ||
| Solids, total dissolved | 1 | 32 | 0 | ||
| Temperature, water deg. fahrenheit | 1 | 26 | 0 | ||
| BOD, 5-day, percent removal | 1 | 26 | 0 | ||
| Nitrogen, total [as N] | 1 | 25 | 0 | ||
| Nitrogen, ammonia total [as N] | 1 | 25 | 0 | ||
| Nitrogen, nitrite total [as N] | 1 | 25 | 0 | ||
| Nitrogen, nitrate total [as N] | 1 | 25 | 0 | ||
| Phosphate, ortho [as P] | 1 | 25 | 0 | ||
| Hardness, total [as CaCO3] | 1 | 24 | 0 | ||
| Phosphate, total, color method [as P] | 1 | 24 | 0 | ||
| TU Static Renewal 7-Day Chronic Ceriodaphnia dubia | 2 | 16 | 0 | ||
| TU Static Renewal 7-Day Chronic Pimphales promelas | 2 | 16 | 0 | ||
| Oxygen, dissolved [DO] | 1 | 12 | 0 | ||
| Cyanide, total [as CN] | 1 | 8 | 0 | ||
| Arsenic, total recoverable | 1 | 8 | 0 | ||
| Beryllium, total recoverable [as Be] | 1 | 8 | 0 | ||
| Chromium, hexavalent [as Cr] | 1 | 8 | 0 | ||
| Nickel, total recoverable | 1 | 8 | 0 | ||
| Cadmium, total recoverable | 1 | 8 | 0 | ||
| Lead, total recoverable | 1 | 8 | 0 | ||
| Antimony, total recoverable | 1 | 8 | 0 | ||
| 2-Methyl-4,6-dinitrophenol | 1 | 8 | 0 | ||
| Dichlorobromomethane | 1 | 8 | 0 | ||
| Carbon tetrachloride | 1 | 8 | 0 | ||
| 1,2-Dichloroethane | 1 | 8 | 0 | ||
| Bromoform | 1 | 8 | 0 | ||
| Dibromochloromethane | 1 | 8 | 0 | ||
| Chloroform | 1 | 8 | 0 | ||
| Toluene | 1 | 8 | 0 | ||
| Benzene | 1 | 8 | 0 | ||
| .delta.-BHC | 1 | 8 | 0 | ||
| Acenaphthylene | 1 | 8 | 0 | ||
| Acenaphthene | 1 | 8 | 0 | ||
| Acrolein | 1 | 8 | 0 | ||
| Acrylonitrile | 1 | 8 | 0 | ||
| Anthracene | 1 | 8 | 0 | ||
| Benzo[b]fluoranthene | 1 | 8 | 0 | ||
| Benzo[k]fluoranthene | 1 | 8 | 0 | ||
| Benzo[a]pyrene | 1 | 8 | 0 | ||
| Bis[2-chloroethyl] ether | 1 | 8 | 0 | ||
| Bis[2-chloroethoxy]methane | 1 | 8 | 0 | ||
| Bis[2-chloroisopropyl] ether | 1 | 8 | 0 | ||
| Butyl benzyl phthalate | 1 | 8 | 0 | ||
| Chlorobenzene | 1 | 8 | 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 CA0104400.
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.