Ironhouse Sd WWTP
450 Walnut Meadows, Oakley, CA 94561 · Contra Costa County · Publicly Owned Treatment Works
- Average flow
- 2.81 MGD
- Design flow
- 4.3 MGD
- NPDES permit
- CA0085260
- Effective
- Permit expires
- July 2029
- Population served
- 39,600
- CWNS 2022
Ironhouse Sd WWTP is a publicly owned wastewater treatment works in Oakley, Contra Costa County, California treating an average of 2.81 million gallons per day against a permitted design capacity of 4.3 MGD, serving about 39,600 residents. It discharges under NPDES permit CA0085260 (effective), which expires in July 2029, with 9 recorded violations in the last three years. EPA has recorded 1 formal enforcement action naming the plant, the latest in September 2025.
Treatment technology
Treatment structures and unit processes at Ironhouse Sd WWTP.
Treatment structure data not yet analyzed for this facility.
Compliance snapshot (last 3 years)
- Total violations
- 9
- Effluent violations
- 9
Based on NPDES Discharge Monitoring Reports. Full violation history, parameters and discharge data available in the Klarifi platform.
EPA enforcement history
Federal civil enforcement cases, compliance inspections and informal actions recorded for Ironhouse Sd WWTP in EPA's ICIS system.
- Formal actions
- 1
- 1 since FY2020
- Penalties assessed
- $1,500
- all cases
- EPA inspections
- 0
- none on record
Latest case · Sep 2025
Ironhouse SD Biosolids ESA CWA 309G2E AO For Class I Penalties - Biosolids Expedited Settlement Prog
Administrative order · CWA, NPDES Permit Violations · Final Order With Penalty · Penalty $1,500
EPA's description of the case:
“Facility did not meet VAR requirements when biosolids were land applied.”
Source: EPA ECHO, civil enforcement case 07-2025-0102.
Full case history with a free Klarifi account
Every action against Ironhouse Sd WWTP with dates, milestones, violation types and EPA's complete case summaries, plus inspections and informal actions.
Key contacts
2 verified contacts for Ironhouse Sd WWTP, with validated emails and direct phone numbers.
Unlock 2 verified contacts
Names, validated emails and direct phone numbers for decision-makers at Ironhouse Sd WWTP, plus the full compliance history and discharge data.
Nearby wastewater treatment plants in California
Brentwood · 3 mi away
2.88 MGD
Antioch · 8 mi away
—
Discovery Bay · 9 mi away
1.08 MGD
Rio Vista · 10 mi away
0.51 MGD
Rio Vista · 13 mi away
0.33 MGD
Mountain House · 18 mi away
1.42 MGD
Lodi · 18 mi away
—
Martinez · 20 mi away
—
Ironhouse Sd 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 October 26, 2026; facility record last updated August 19, 2026.
Wastewater terms: POTW · MGD · NPDES permit · Inflow and infiltration · Biosolids · Filter press · all terms