Clean Water Act discharge permit · NPDES GU0020222
AGAT STP, Agat, GU: NPDES GU0020222 discharge permit, effluent exceedances, inspections, penalties
- EffectivePermit status
- MajorDischarger class
- 19Pollutants under a numeric limit
- 17Pollutants with an effluent exceedance
- 0Inspections on file
- 0Formal enforcement actions
AGAT STP, held by GUAM WATERWORKS AUTHORITY, holds NPDES permit GU0020222, which discharges to Tipalao Bay Philippine Sea. EPA’s file records it issued November 28, 2017 and expiring December 31, 2022.
AGAT STP, Agat, Guam: Individual permit GU0020222, held by GUAM WATERWORKS AUTHORITY; Publicly owned treatment works; Effective; issued November 28, 2017, term to December 31, 2022; discharges to TIPALAO BAY PHILIPPINE SEA.
- Copper, total recoverable: 1 limit, 602 violations of any kind, 442 effluent exceedances, latest November 30, 2017, largest 371,329% over the limit.
- Solids, total suspended: 8 limits, 519 violations of any kind, 357 effluent exceedances, latest May 31, 2022, largest 3,555% over the limit.
- Enterococci: 2 limits, 342 violations of any kind, 296 effluent exceedances, latest December 31, 2019, largest 4,244,111% over the limit.
- Coliform, fecal general: 0 limits, 332 violations of any kind, 286 effluent exceedances, latest May 31, 2017, largest 1,209,700% over the limit.
- Aluminum, total recoverable: 1 limit, 380 violations of any kind, 230 effluent exceedances, latest March 31, 2017, largest 10,780% over the limit.
- BOD, 5-day, 20 deg. C: 8 limits, 330 violations of any kind, 158 effluent exceedances, latest April 30, 2017, largest 391% over the limit.
- BOD, 5-day, percent removal: 1 limit, 177 violations of any kind, 143 effluent exceedances, latest February 29, 2020, largest 560% over the limit.
- Solids, suspended percent removal: 1 limit, 173 violations of any kind, 143 effluent exceedances, latest December 31, 2025, largest 2,093% over the limit.
- Flow, in conduit or thru treatment plant: 4 limits, 183 violations of any kind, 106 effluent exceedances, latest April 30, 2026, largest 227% over the limit.
- Zinc, total recoverable: 2 limits, 239 violations of any kind, 83 effluent exceedances, latest March 31, 2020, largest 1,082% over the limit.
- Oil and grease: 0 limits, 154 violations of any kind, 30 effluent exceedances, latest July 31, 2015, largest 1,490% over the limit.
- Nickel, total recoverable: 2 limits, 168 violations of any kind, 8 effluent exceedances, latest March 31, 2013, largest 412% over the limit.
- Oil & grease, total recoverable: 2 limits, 27 violations of any kind, 7 effluent exceedances, latest August 31, 2023, largest 254% over the limit.
- Chlordane [tech mix. and metabolites]: 0 limits, 186 violations of any kind, 6 effluent exceedances, latest February 28, 2014, largest 339% over the limit.
- Dieldrin: 2 limits, 122 violations of any kind, 5 effluent exceedances, latest December 31, 2025, largest 14,186% over the limit.
- pH: 2 limits, 46 violations of any kind, 2 effluent exceedances, latest October 31, 2017.
- Chlordane: 2 limits, 2 violations of any kind, 2 effluent exceedances, latest December 31, 2022, largest 4,355% over the limit.
- Ammonia & ammonium- total: 0 limits, 192 violations of any kind, 0 effluent exceedances.
- Chlorine, total residual: 0 limits, 148 violations of any kind, 0 effluent exceedances.
- 4,4'-DDE: 0 limits, 123 violations of any kind, 0 effluent exceedances.
- 4,4'-DDD: 0 limits, 121 violations of any kind, 0 effluent exceedances.
- Static 20Min Chronic Dendraster excentricus: 0 limits, 98 violations of any kind, 0 effluent exceedances.
- Arsenic, total recoverable: 0 limits, 80 violations of any kind, 0 effluent exceedances.
- TU Static 20Min Chronic Strongyl. purpuratus: 0 limits, 62 violations of any kind, 0 effluent exceedances.
- Chromium, trivalent dissolved, as Cr: 0 limits, 57 violations of any kind, 0 effluent exceedances.
- Silver total recoverable: 0 limits, 56 violations of any kind, 0 effluent exceedances.
- Cadmium, total recoverable: 0 limits, 56 violations of any kind, 0 effluent exceedances.
- Mercury, dissolved [as Hg]: 0 limits, 56 violations of any kind, 0 effluent exceedances.
- Arsenic, dissolved [as As]: 0 limits, 53 violations of any kind, 0 effluent exceedances.
- Cadmium, dissolved [as Cd]: 0 limits, 53 violations of any kind, 0 effluent exceedances.
- Lead, dissolved [as Pb]: 0 limits, 53 violations of any kind, 0 effluent exceedances.
- Silver, dissolved [as Ag]: 0 limits, 53 violations of any kind, 0 effluent exceedances.
- Chromium, hexavalent dissolved [as Cr]: 0 limits, 53 violations of any kind, 0 effluent exceedances.
- Chromium, trivalent total recoverable: 0 limits, 48 violations of any kind, 0 effluent exceedances.
- Chromium, hexavalent tot recoverable: 0 limits, 48 violations of any kind, 0 effluent exceedances.
- Mercury, total recoverable: 0 limits, 45 violations of any kind, 0 effluent exceedances.
- Lead, total recoverable: 0 limits, 44 violations of any kind, 0 effluent exceedances.
- Phosphate, ortho [as PO4]: 2 limits, 22 violations of any kind, 0 effluent exceedances.
- Nitrite + Nitrate total [as N]: 0 limits, 22 violations of any kind, 0 effluent exceedances.
- Cyanide, total [as CN]: 0 limits, 12 violations of any kind, 0 effluent exceedances.
- Selenium, total recoverable: 0 limits, 12 violations of any kind, 0 effluent exceedances.
- Thallium, total recoverable: 0 limits, 12 violations of any kind, 0 effluent exceedances.
- Beryllium, total recoverable [as Be]: 0 limits, 12 violations of any kind, 0 effluent exceedances.
- Zinc, dissolved [as Zn]: 0 limits, 12 violations of any kind, 0 effluent exceedances.
- Antimony, total recoverable: 0 limits, 12 violations of any kind, 0 effluent exceedances.
- Chromium, total recoverable: 0 limits, 8 violations of any kind, 0 effluent exceedances.
- .delta.-BHC: 0 limits, 8 violations of any kind, 0 effluent exceedances.
- Endosulfan sulfate: 0 limits, 8 violations of any kind, 0 effluent exceedances.
- .beta.-Endosulfan: 0 limits, 8 violations of any kind, 0 effluent exceedances.
- .alpha.-Endosulfan: 0 limits, 8 violations of any kind, 0 effluent exceedances.
- Endrin aldehyde: 0 limits, 8 violations of any kind, 0 effluent exceedances.
- PCB-1016: 0 limits, 8 violations of any kind, 0 effluent exceedances.
- 4,4'-DDT: 0 limits, 8 violations of any kind, 0 effluent exceedances.
- Aldrin: 0 limits, 8 violations of any kind, 0 effluent exceedances.
- .alpha.-BHC: 0 limits, 8 violations of any kind, 0 effluent exceedances.
- .beta.-BHC: 0 limits, 8 violations of any kind, 0 effluent exceedances.
- .gamma.-BHC: 0 limits, 8 violations of any kind, 0 effluent exceedances.
- Endrin: 0 limits, 8 violations of any kind, 0 effluent exceedances.
- Toxaphene: 0 limits, 8 violations of any kind, 0 effluent exceedances.
- Heptachlor: 0 limits, 8 violations of any kind, 0 effluent exceedances.
Guam holds 6 Publicly owned treatment works coverages of this permit type in EPA’s file; 5 were issued before GU0020222. GUAM WATERWORKS AUTHORITY holds 8 permits in Guam.
Other permits held by GUAM WATERWORKS AUTHORITY
- AGANA SEWERAGE TREATMENT PLANT, Hagatna: GU0020087, issued April 10, 2013
- BAZA GARDENS WWTF, Yona: GU0020095, issued November 24, 2008
- NORTHERN DISTRICT STP, Dededo: GU0020141, issued April 10, 2013
- UNKNOWN, Agat: GU0020265
- UMATAC-MERIZO STP, Merizo: GU0020273, issued August 19, 2015
- UGUM SURFACE WATER TREATMENT PLANT, Talofofo: GU0020371, issued July 8, 2016
- GUAM WATERWORKS AUTHORITY, Hagatna: GUL020222, issued January 1, 2021
Coverages issued nearest GU0020222
- November 24, 2008: BAZA GARDENS WWTF, Yona, GU0020095, held by GUAM WATERWORKS AUTHORITY
- April 10, 2013: AGANA SEWERAGE TREATMENT PLANT, Hagatna, GU0020087, held by GUAM WATERWORKS AUTHORITY
- April 10, 2013: NORTHERN DISTRICT STP, Dededo, GU0020141, held by GUAM WATERWORKS AUTHORITY
- August 19, 2015: UMATAC-MERIZO STP, Merizo, GU0020273, held by GUAM WATERWORKS AUTHORITY
- July 8, 2016: UGUM SURFACE WATER TREATMENT PLANT, Talofofo, GU0020371, held by GUAM WATERWORKS AUTHORITY
AGAT STP among its neighbors
Its county holds 82, 4 of them major permits; GU0020222 is a major permit.
Other permits in the county
- ACHO LATTE, Dededo: GUR10006Z, minor permit, permit term to February 16, 2027
- AGANA SEWERAGE TREATMENT PLANT, Hagatna: GU0020087, major permit, discharging to PACIFIC OCEAN, permit term to May 31, 2018
- APRA HARBOR WWTP, Apra Harbor Naval Base: GU0110019, major permit, discharging to TIPALAO BAY PHILIPPINE SEA, permit term to April 30, 2022
- APRA HARBOR WWTP, Agat: GUL110019, minor permit, permit term to December 31, 2025
- APRA MEDICAL/DENTAL CLINIC, Naval Base: GUR100013, minor permit, permit term to February 15, 2022
- BAZA GARDENS WWTF, Yona: GU0020095, minor permit, discharging to TOGCHA RIVER, permit term to November 30, 2013
- BEQ J-031 & J-033, Yigo: GUR10002B, minor permit, permit term to February 15, 2022
- BUENA VISTA ENVIRONMENTAL, Piti: GUU001014, not classed
- CABRAS MARINE CORPORATION, Piti: GU0020397, minor permit, permit term to January 30, 2018
- CABRAS POWER PLANT, Piti: GU0020001, minor permit, discharging to INNER APRA HARBOR, permit term to January 31, 2018
Identity
| Facility as filed | AGAT STP |
|---|---|
| Permittee as filed | GUAM WATERWORKS AUTHORITY |
| NPDES ID | GU0020222 |
| Permit status | Effective |
| Permit type | Individual permit |
| Discharger class | Major discharger |
| Facility type | Publicly owned treatment works |
| Program | Publicly owned treatment works |
| Issued | November 28, 2017 |
| Expiration date | December 31, 2022 |
| Address | Agat, GU 96928 |
| Receiving water | TIPALAO BAY PHILIPPINE SEA |
| Program components on file | POTW, Pretreatment |
| SIC | 4952 – Sewerage Systems |
Effluent limits and exceedances
- 159Pollutants on file
- 19Under a numeric limit
- 156With 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; the 60 with the most exceedances of 159 are shown.
| Pollutant or measure | Limits | Violations, any kind | Effluent exceedances | Latest exceedance | Largest exceedance, as filed |
|---|---|---|---|---|---|
| Copper, total recoverable | 1 | 602 | 442 | November 30, 2017 | 371,329% over the limit |
| Solids, total suspended | 8 | 519 | 357 | May 31, 2022 | 3,555% over the limit |
| Enterococci | 2 | 342 | 296 | December 31, 2019 | 4,244,111% over the limit |
| Coliform, fecal general | 0 | 332 | 286 | May 31, 2017 | 1,209,700% over the limit |
| Aluminum, total recoverable | 1 | 380 | 230 | March 31, 2017 | 10,780% over the limit |
| BOD, 5-day, 20 deg. C | 8 | 330 | 158 | April 30, 2017 | 391% over the limit |
| BOD, 5-day, percent removal | 1 | 177 | 143 | February 29, 2020 | 560% over the limit |
| Solids, suspended percent removal | 1 | 173 | 143 | December 31, 2025 | 2,093% over the limit |
| Flow, in conduit or thru treatment plant | 4 | 183 | 106 | April 30, 2026 | 227% over the limit |
| Zinc, total recoverable | 2 | 239 | 83 | March 31, 2020 | 1,082% over the limit |
| Oil and grease | 0 | 154 | 30 | July 31, 2015 | 1,490% over the limit |
| Nickel, total recoverable | 2 | 168 | 8 | March 31, 2013 | 412% over the limit |
| Oil & grease, total recoverable | 2 | 27 | 7 | August 31, 2023 | 254% over the limit |
| Chlordane [tech mix. and metabolites] | 0 | 186 | 6 | February 28, 2014 | 339% over the limit |
| Dieldrin | 2 | 122 | 5 | December 31, 2025 | 14,186% over the limit |
| pH | 2 | 46 | 2 | October 31, 2017 | |
| Chlordane | 2 | 2 | 2 | December 31, 2022 | 4,355% over the limit |
| Ammonia & ammonium- total | 0 | 192 | 0 | ||
| Chlorine, total residual | 0 | 148 | 0 | ||
| 4,4'-DDE | 0 | 123 | 0 | ||
| 4,4'-DDD | 0 | 121 | 0 | ||
| Static 20Min Chronic Dendraster excentricus | 0 | 98 | 0 | ||
| Arsenic, total recoverable | 0 | 80 | 0 | ||
| TU Static 20Min Chronic Strongyl. purpuratus | 0 | 62 | 0 | ||
| Chromium, trivalent dissolved, as Cr | 0 | 57 | 0 | ||
| Silver total recoverable | 0 | 56 | 0 | ||
| Cadmium, total recoverable | 0 | 56 | 0 | ||
| Mercury, dissolved [as Hg] | 0 | 56 | 0 | ||
| Arsenic, dissolved [as As] | 0 | 53 | 0 | ||
| Cadmium, dissolved [as Cd] | 0 | 53 | 0 | ||
| Lead, dissolved [as Pb] | 0 | 53 | 0 | ||
| Silver, dissolved [as Ag] | 0 | 53 | 0 | ||
| Chromium, hexavalent dissolved [as Cr] | 0 | 53 | 0 | ||
| Chromium, trivalent total recoverable | 0 | 48 | 0 | ||
| Chromium, hexavalent tot recoverable | 0 | 48 | 0 | ||
| Mercury, total recoverable | 0 | 45 | 0 | ||
| Lead, total recoverable | 0 | 44 | 0 | ||
| Phosphate, ortho [as PO4] | 2 | 22 | 0 | ||
| Nitrite + Nitrate total [as N] | 0 | 22 | 0 | ||
| Cyanide, total [as CN] | 0 | 12 | 0 | ||
| Selenium, total recoverable | 0 | 12 | 0 | ||
| Thallium, total recoverable | 0 | 12 | 0 | ||
| Beryllium, total recoverable [as Be] | 0 | 12 | 0 | ||
| Zinc, dissolved [as Zn] | 0 | 12 | 0 | ||
| Antimony, total recoverable | 0 | 12 | 0 | ||
| Chromium, total recoverable | 0 | 8 | 0 | ||
| .delta.-BHC | 0 | 8 | 0 | ||
| Endosulfan sulfate | 0 | 8 | 0 | ||
| .beta.-Endosulfan | 0 | 8 | 0 | ||
| .alpha.-Endosulfan | 0 | 8 | 0 | ||
| Endrin aldehyde | 0 | 8 | 0 | ||
| PCB-1016 | 0 | 8 | 0 | ||
| 4,4'-DDT | 0 | 8 | 0 | ||
| Aldrin | 0 | 8 | 0 | ||
| .alpha.-BHC | 0 | 8 | 0 | ||
| .beta.-BHC | 0 | 8 | 0 | ||
| .gamma.-BHC | 0 | 8 | 0 | ||
| Endrin | 0 | 8 | 0 | ||
| Toxaphene | 0 | 8 | 0 | ||
| Heptachlor | 0 | 8 | 0 |
Inspections, violations and enforcement
- 0Single-event violations
EPA’s single-event violation file, as loaded, holds no violation for NPDES GU0020222.
Inspections
EPA’s inspection file holds no inspection for NPDES GU0020222.
Formal enforcement and penalties
0 formal actions, 0 of them with a penalty assessed. Federal and state penalties are separate figures from separate authorities and are shown as each was filed, never added together.
Informal enforcement
EPA’s informal enforcement file holds no action for NPDES GU0020222.
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Figures from EPA’s ICIS-NPDES download, loaded October 14, 2026.