Southern Marin WWTP
Mill Valley, CA · Marin County · Publicly Owned Treatment Works
- Average flow
- —
- Design flow
- 24.7 MGD
- NPDES permit
- CA0037711
- Effective
- Permit expires
- December 2028
- Population served
- 30,981
- CWNS 2022
Southern Marin WWTP is a publicly owned wastewater treatment works in Mill Valley, Marin County, California, serving about 30,981 residents. Treatment on site includes clarifiers, uncovered lagoons, biogas silos, biogas balloons. It discharges under NPDES permit CA0037711 (effective), which expires in December 2028, with 8 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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Biogas silos
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Biogas balloons
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Compliance snapshot (last 3 years)
- Total violations
- 8
- Effluent violations
- 8
Based on NPDES Discharge Monitoring Reports. Full violation history, parameters and discharge data available in the Klarifi platform.
Key contacts
1 verified contact for Southern Marin WWTP, with validated emails and direct phone numbers.
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Names, validated emails and direct phone numbers for decision-makers at Southern Marin WWTP, plus the full compliance history and discharge data.
Nearby wastewater treatment plants in California
Tiburon · 4 mi away
0.000000011 MGD
Sausalito · 5 mi away
—
San Francisco · 13 mi away
45.87 MGD
Oakland · 14 mi away
—
Novato · 14 mi away
—
Pinole · 15 mi away
—
Rodeo · 18 mi away
—
Pacifica · 19 mi away
1.91 MGD
Southern Marin WWTP: 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 May 10, 2025.