Concrete STP
46051 Lagoon Ave, Concrete, WA 98237 · Skagit County · Publicly Owned Treatment Works
- Average flow
- 0.09 MGD
- Design flow
- 0.2 MGD
- NPDES permit
- WA0020851
- Administratively continued
- Permit expires
- April 2023
- Population served
- 734
- CWNS 2022
Concrete STP is a publicly owned wastewater treatment works in Concrete, Skagit County, Washington treating an average of 0.09 million gallons per day against a permitted design capacity of 0.2 MGD, serving about 734 residents. It discharges under NPDES permit WA0020851 (administratively continued), which expires in April 2023, with 5 recorded violations in the last three years.
Treatment technology
Treatment structures and unit processes at Concrete STP.
Treatment structure data not yet analyzed for this facility.
Compliance snapshot (last 3 years)
- Total violations
- 5
- Effluent violations
- 0
Based on NPDES Discharge Monitoring Reports. Full violation history, parameters and discharge data available in the Klarifi platform.
Key contacts
Decision-makers at Concrete STP.
No verified contacts on file yet
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Nearby wastewater treatment plants in Washington
Sedro-Woolley · 23 mi away
0.96 MGD
Mount Vernon · 25 mi away
0.19 MGD
Burlington · 26 mi away
1.56 MGD
Granite Falls · 33 mi away
0.41 MGD
Bellingham · 34 mi away
0.0032 MGD
Stanwood · 35 mi away
0.67 MGD
Mount Vernon · 35 mi away
0.28 MGD
Bellingham · 37 mi away
15.62 MGD
Concrete 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 October 26, 2026; facility record last updated November 8, 2025.
Wastewater terms: POTW · MGD · NPDES permit · Inflow and infiltration · Equalization tank · Centrate · all terms