Hull City Of STP
Hull, IA 51239 · Sioux County · Publicly Owned Treatment Works
- Average flow
- 0.21 MGD
- Design flow
- 0.9 MGD
- NPDES permit
- IA0020991
- Effective
- Permit expires
- May 2030
- Population served
- 2,049
- CWNS 2022
Hull City Of STP is a publicly owned wastewater treatment works in Hull, Sioux County, Iowa treating an average of 0.21 million gallons per day against a permitted design capacity of 0.9 MGD, serving about 2,049 residents. It discharges under NPDES permit IA0020991 (effective), which expires in May 2030, with 1 recorded violation in the last three years. EPA has recorded 2 formal enforcement actions naming the plant, the latest in February 2015.
Treatment technology
2 treatment structures and unit processes identified at Hull City Of STP.
Available with a free Klarifi account
See the full treatment train at Hull City Of STP: structures, unit processes and planned upgrades, with exact unit counts.
Compliance snapshot (last 3 years)
- Total violations
- 1
- Effluent violations
- 1
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 Hull City Of STP in EPA's ICIS system.
- Formal actions
- 2
- 0 since FY2020
- Compliance actions
- $2.6M
- required by EPA orders
- EPA inspections
- 0
- none on record
Latest case · Feb 2015
CITY OF HULL
Administrative order · CWA, NPDES Permit Violations · Final Order No Penalty · Compliance actions $2.5M
Source: EPA ECHO, civil enforcement case 07-2012-0010.
Full case history with a free Klarifi account
Every action against Hull City Of STP with dates, milestones, violation types and EPA's complete case summaries, plus inspections and informal actions.
Key contacts
2 verified contacts for Hull City Of STP, with validated emails and direct phone numbers.
Unlock 2 verified contacts
Names, validated emails and direct phone numbers for decision-makers at Hull City Of STP, plus the full compliance history and discharge data.
Nearby wastewater treatment plants in Iowa
Boyden · 5 mi away
0.15 MGD
Doon · 7 mi away
—
Sioux Center · 9 mi away
0.97 MGD
George · 10 mi away
0.08 MGD
Alvord · 13 mi away
—
Sheldon · 13 mi away
0.9 MGD
Orange City · 14 mi away
0.85 MGD
Hospers · 15 mi away
0.24 MGD
Hull City Of 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 September 11, 2026.
Wastewater terms: POTW · MGD · NPDES permit · Inflow and infiltration · Anaerobic digester · Lift station · all terms