Lewis County Water And Sewer District 6 STP
149 Lakeside Dr, Mossyrock, WA 98564 · Lewis County · Publicly Owned Treatment Works
- Average flow
- 0.02 MGD
- Design flow
- —
- NPDES permit
- WA0037141
- Administratively continued
- Permit expires
- October 2016
- Population served
- 400
- CWNS 2022
Lewis County Water And Sewer District 6 STP is a publicly owned wastewater treatment works in Mossyrock, Lewis County, Washington treating an average of 0.02 million gallons per day, serving about 400 residents. It discharges under NPDES permit WA0037141 (administratively continued), which expires in October 2016, with 3 recorded violations in the last three years.
Treatment technology
Treatment structures and unit processes at Lewis County Water And Sewer District 6 STP.
Treatment structure data not yet analyzed for this facility.
Compliance snapshot (last 3 years)
- Total violations
- 3
- Effluent violations
- 3
Based on NPDES Discharge Monitoring Reports. Full violation history, parameters and discharge data available in the Klarifi platform.
Key contacts
Decision-makers at Lewis County Water And Sewer District 6 STP.
No verified contacts on file yet
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Nearby wastewater treatment plants in Washington
Chehalis · 9 mi away
0.07 MGD
Toledo · 12 mi away
0.002 MGD
Toledo · 14 mi away
0.1 MGD
Toutle · 14 mi away
0.06 MGD
Winlock · 18 mi away
0.54 MGD
Castle Rock · 23 mi away
0.37 MGD
Ryderwood · 24 mi away
0.1 MGD
Eatonville · 29 mi away
0.24 MGD
Lewis County Water And Sewer District 6 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 October 6, 2025.
Wastewater terms: POTW · MGD · NPDES permit · Inflow and infiltration · Lift station · Sludge dewatering · all terms