Hoquiam STP
Hoquiam, WA · Grays Harbor County · Publicly Owned Treatment Works
- Average flow
- —
- Design flow
- —
- NPDES permit
- WA0020915
- Effective
- Permit expires
- October 2030
- Population served
- 9,902
- CWNS 2022
Hoquiam STP is a publicly owned wastewater treatment works in Hoquiam, Grays Harbor County, Washington, serving about 9,902 residents. Treatment on site includes clarifiers, uncovered lagoons, carrousels / oxidation ditches. It discharges under NPDES permit WA0020915 (effective), which expires in October 2030, with 0 recorded violations in the last three years.
Treatment technology
Treatment structures identified at this facility. Exact unit counts are available in Klarifi.
Clarifiers
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Uncovered lagoons
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Carrousels / oxidation ditches
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Compliance snapshot (last 3 years)
- Total violations
- 0
- Effluent violations
- 0
Based on NPDES Discharge Monitoring Reports. Full violation history, parameters and discharge data available in the Klarifi platform.
Key contacts
2 verified contacts for Hoquiam STP, with validated emails and direct phone numbers.
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Names, validated emails and direct phone numbers for decision-makers at Hoquiam STP, plus the full compliance history and discharge data.
Nearby wastewater treatment plants in Washington
Montesano · 15 mi away
0.24 MGD
Pacific Beach · 21 mi away
0.09 MGD
Moclips · 23 mi away
0.01 MGD
Littlerock · 37 mi away
0.04 MGD
Rochester · 44 mi away
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Olympia · 48 mi away
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Ilwaco · 48 mi away
0.15 MGD
Shelton · 52 mi away
0.000000013 MGD
Hoquiam STP: frequently asked questions
Sources and methodology
Flow, permit and violation figures come from the EPA's ICIS-NPDES discharge monitoring records. Population served comes from the Clean Watersheds Needs Survey 2022. Treatment structures are identified by Klarifi's review of aerial imagery, and capital improvement projects are extracted from published municipal budget documents. Violations are counted over the last three years of monitoring reports.
Data refreshed September 11, 2026; facility record last updated April 13, 2025.