MSD Coldwater WWTP
13798 Old Halls Ferry Rd, Florissant, MO 63034 · St Louis County · Publicly Owned Treatment Works
- Average flow
- 22.75 MGD
- Design flow
- —
- NPDES permit
- MO0025160
- Effective
- Permit expires
- August 2031
- Population served
- 160,833
- CWNS 2022
MSD Coldwater WWTP is a publicly owned wastewater treatment works in Florissant, St Louis County, Missouri treating an average of 22.75 million gallons per day, serving about 160,833 residents. It discharges under NPDES permit MO0025160 (effective), which expires in August 2031, with 1 recorded violation in the last three years. EPA has recorded 1 formal enforcement action naming the plant, the latest in April 2003.
Treatment technology
8 treatment structures and unit processes identified at MSD Coldwater WWTP.
Available with a free Klarifi account
See the full treatment train at MSD Coldwater WWTP: 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 MSD Coldwater WWTP in EPA's ICIS system.
- Formal actions
- 1
- 0 since FY2020
- Penalties assessed
- $100,000
- all cases
- EPA inspections
- 0
- none on record
Latest case · Apr 2003
METROPOLITAN ST. LOUIS SEWER DISTRICT (MSD)
Judicial case · CWA, Clean Water Act · Final Order With Penalty · Penalty $100,000 · The case also names 1 other plant, and its amounts cover all of them
Source: EPA ECHO, civil enforcement case 07-1985-0156.
Full case history with a free Klarifi account
Every action against MSD Coldwater WWTP with dates, milestones, violation types and EPA's complete case summaries, plus inspections and informal actions.
Key contacts
3 verified contacts for MSD Coldwater WWTP, with validated emails and direct phone numbers.
Unlock 3 verified contacts
Names, validated emails and direct phone numbers for decision-makers at MSD Coldwater WWTP, plus the full compliance history and discharge data.
Nearby wastewater treatment plants in Missouri
Portage Des Sioux · 9 mi away
—
St. Louis · 10 mi away
123.06 MGD
St. Charles · 11 mi away
4.2 MGD
St. Charles · 14 mi away
—
Saint Charles · 16 mi away
4.45 MGD
Saint Peters · 18 mi away
5.65 MGD
St. Louis · 19 mi away
105.45 MGD
Valley Park · 21 mi away
12.6 MGD
MSD Coldwater 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 12, 2026; facility record last updated May 20, 2025.
Wastewater terms: POTW · MGD · NPDES permit · Inflow and infiltration · Equalization tank · Centrate · all terms