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Clean Water Act discharge permit · NPDES AZ0110426

USDOI NPS - GRAND CANYON NP - NORTH RIM WWTP, Grand Canyon, AZ: NPDES AZ0110426 discharge permit, effluent exceedances, inspections, penalties

USDOI NPS - GRAND CANYON NP - NORTH RIM WWTP, held by Grand Canyon National Park, holds NPDES permit AZ0110426. EPA’s file records it issued January 26, 2018 and expiring January 25, 2023. 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 filedUSDOI NPS - GRAND CANYON NP - NORTH RIM WWTP
Permittee as filedGrand Canyon National Park
NPDES IDAZ0110426
Permit statusEffective
Permit typeIndividual permit
Discharger classMinor discharger
Facility typeFederal facility
ProgramPublicly owned treatment works
IssuedJanuary 26, 2018
Expiration dateJanuary 25, 2023
AddressGrand Canyon, AZ 86023
SubwatershedThe Transept (HUC 150100010606)

Cited to the EPA ICIS-NPDES permit file (ECHO download).

Effluent limits and exceedances

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 125 are shown.

Pollutant or measureLimitsViolations, any kindEffluent exceedancesLatest exceedanceLargest exceedance, as filed
Copper, total recoverable54444December 31, 20242,718% over the limit
Silver total recoverable51919December 31, 20084,650% over the limit
Chlorine, total residual52416September 30, 201162,780% over the limit
Oil & Grease31111December 31, 2012244% over the limit
Nitrogen, ammonia total [as N]3139May 31, 2024360% over the limit
BOD, 5-day, 20 deg. C7166August 31, 2019160% over the limit
pH495June 30, 2021
TU Static 4 Day Chronic Raphidocelis subcapitata (formerly Selenastrum capricornutum)244December 31, 2021500% over the limit
Cyanide, total [as CN]533December 31, 2024128% over the limit
TU Static Renewal 7-Day Chronic Ceriodaphnia dubia233December 31, 2021700% over the limit
Zinc, total recoverable122December 31, 201224% over the limit
Solids, total dissolved731December 31, 202321% over the limit
E. coli031June 30, 200659% over the limit
Selenium, total recoverable511December 31, 200722% over the limit
Mercury, total recoverable511September 30, 200925% over the limit
Sulfide, total [as S]211June 30, 201020% over the limit
Cyanide, total recoverable011December 31, 201126% over the limit
Solids, total suspended760
E. coli, colony forming units [CFU]360
Flow, in conduit or thru treatment plant220
BOD, 5-day, percent removal110
Solids, suspended percent removal110
Hardness, total [as CaCO3]300
Iron, total recoverable300
Hydrogen sulfide200
TU Static Renewal 7-Day Chronic Pimphales promelas200
Temperature, water deg. centigrade100
Oxygen, dissolved [DO]100
Nitrogen, Kjeldahl, total [as N]100
Nitrite + Nitrate total [as N]100
Phosphorus, total [as P]100
Arsenic, total recoverable100
Thallium, total recoverable100
Beryllium, total recoverable [as Be]100
Nickel, total recoverable100
Cadmium, total recoverable100
Lead, total recoverable100
Chromium, total recoverable100
Chromium, hexavalent dissolved [as Cr]100
Antimony, total recoverable100
2-Methyl-4,6-dinitrophenol100
Dichlorobromomethane100
Carbon tetrachloride100
1,2-Dichloroethane100
Bromoform100
Dibromochloromethane100
Chloroform100
Toluene100
Benzene100
Acenaphthylene100
Acenaphthene100
Acrolein100
Acrylonitrile100
Anthracene100
Benzo[b]fluoranthene100
Benzo[k]fluoranthene100
Benzo[a]pyrene100
Bis[2-chloroethyl] ether100
Bis[2-chloroethoxy]methane100
Bis[2-chloroisopropyl] ether100

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

EPA’s single-event violation file, as loaded, holds no violation for NPDES AZ0110426.

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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How we handle your data → Privacy

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 AZ0110426 there.

Nearby on the register

Figures from EPA’s ICIS-NPDES download, loaded September 14, 2026.