Clean Water Act discharge permit · NPDES MO0136425

DCSD, TREATMENT PLANT 4, Wentzville, MO: NPDES MO0136425 discharge permit, effluent exceedances, inspections, penalties

EffectivePermit status
MinorDischarger class
15Pollutants under a numeric limit
1Pollutants with an effluent exceedance
0Inspections on file
0Formal enforcement actions

DCSD, TREATMENT PLANT 4, held by Duckett Creek Sanitary District, holds NPDES permit MO0136425, which discharges to Tributary To Dardenne Cr.. EPA’s file records it issued July 1, 2025 and expiring June 30, 2030.

DCSD, TREATMENT PLANT 4, Wentzville, Missouri: Individual permit MO0136425, held by Duckett Creek Sanitary District; Publicly owned treatment works; Effective; issued July 1, 2025, term to June 30, 2030; discharges to Tributary to Dardenne Cr..

Oil and grease [soxhlet extr.] tot.: 2 limits, 2 violations of any kind, 2 effluent exceedances, latest July 31, 2025, largest 633% over the limit.
Nitrogen, ammonia total [as N]: 18 limits, 0 violations of any kind, 0 effluent exceedances.
Nitrogen, Kjeldahl, total [as N]: 4 limits, 0 violations of any kind, 0 effluent exceedances.
Nitrite + Nitrate total [as N]: 4 limits, 0 violations of any kind, 0 effluent exceedances.
Phosphorus, total [as P]: 4 limits, 0 violations of any kind, 0 effluent exceedances.
BOD, 5-day, 20 deg. C: 3 limits, 0 violations of any kind, 0 effluent exceedances.
Solids, total suspended: 3 limits, 0 violations of any kind, 0 effluent exceedances.
pH: 2 limits, 0 violations of any kind, 0 effluent exceedances.
Flow, in conduit or thru treatment plant: 2 limits, 0 violations of any kind, 0 effluent exceedances.
E. coli: 2 limits, 0 violations of any kind, 0 effluent exceedances.
Toxicity [acute], Ceriodaphnia dubia: 1 limit, 0 violations of any kind, 0 effluent exceedances.
Toxicity [chronic], Ceriodaphnia dubia: 1 limit, 0 violations of any kind, 0 effluent exceedances.
Toxicity [acute], Pimephales promelas [Fathead Minnow]: 1 limit, 0 violations of any kind, 0 effluent exceedances.
BOD, 5-day, percent removal: 1 limit, 0 violations of any kind, 0 effluent exceedances.
Solids, suspended percent removal: 1 limit, 0 violations of any kind, 0 effluent exceedances.

Missouri holds 756 Publicly owned treatment works coverages of this permit type in EPA’s file; 752 were issued before MO0136425. Duckett Creek Sanitary District holds 9 permits in Missouri.

Other permits held by Duckett Creek Sanitary District

DCSD WASTEWATER TREATMENT PLANT 2, St. Charles: MO0116572, issued October 25, 2021
DCSD AUGUSTA SHORES WWTP, Augusta: MO0120529, issued December 14, 2016
DCSD STEVEN A. ROGERS WWTP, St. Charles: MO0129763, issued January 13, 2016
DCSD RIVERDALE SUBDIVISION WWTP, St. Paul: MO0132152, issued December 12, 2018
DUCKETT CREEK SANITARY DISTRICT, O'Fallon: MOL116572, issued January 1, 2021
DUCKETT CREEK SANITARY DISTRICT PLANT #4, Ofallon: MORA21886, issued June 23, 2022
DUCKETT CREEK SANITARY DISTRICT PLANT #4, Ofallon: MORA22892, issued October 31, 2022
DUCKETT CREEK SANITARY DISTRICT PLANT #4, Ofallon: MORA22893, issued January 12, 2023

Coverages issued nearest MO0136425

September 13, 2024: BOLIVAR WWTP, Bolivar, MO0022373, held by Liberty Utilities (Missouri Water) LLC
January 1, 2025: CCSD CATAWISSA WWTF, Catawissa, MO0115410, held by Calvey Creek Sewer District
February 27, 2025: FAIR PLAY WWTF, Fair Play, MO0113514, held by City of Fair Play
April 1, 2025: CAMDEN POINT, Camden Point, MO0139505, held by City of Camden Point
June 1, 2025: WARRENTON WWTP, Warrenton, MO0087912, held by City of Warrenton
September 1, 2025: ASHLAND WWTP, Ashland, MO0106844, held by City of Ashland
March 17, 2026: CALIFORNIA SOUTH WWTP, California, MO0023272, held by City of California
April 1, 2026: ROCKWOOD VALLEY MIDDLE SCHOOL WWTF, Wildwood, MO0113735, held by Rockwood School District (RSD)

DCSD, TREATMENT PLANT 4 among its neighbors

EPA’s permit file holds 102 discharge permits in the Upper Dardenne Creek subwatershed (HUC 071100090103), MO0136425 among them. Its county holds 774, 9 of them major permits; MO0136425 is a minor permit.

Other permits in the Upper Dardenne Creek subwatershed (HUC 071100090103)

155 RUCKMAN LANE, Defiance: MORA29120, minor permit, discharging to Tributary to Cunningham Branch, permit term to February 7, 2027
3151 HOPEWELL ROAD, Wentzville: MORA29281, minor permit, discharging to Tributary to Dardenne Cr., permit term to February 7, 2027
360 STEALEY ROAD, Wentzville: MORA28410, minor permit, discharging to Tributary to Dardenne Cr., permit term to February 7, 2027
635-CALEDONIA OTR, O'Fallon: MORA21844, minor permit, discharging to Tributary to Dardenne Cr., permit term to February 7, 2027
AMBERLEIGH - LOMBARDO HOMES, O'Fallon: MORA20936, minor permit, discharging to Tributary to Dardenne Cr., permit term to February 7, 2027
AMBERLEIGH #2 - LOMBARDO, Wentzville: MORA27781, minor permit, discharging to Tributary to Dardenne Cr., permit term to February 7, 2027
AMERICAN CRICKET ACADEMY PARK, Wentzville: MORA29496, minor permit, discharging to Tributary to Dardenne Cr., permit term to February 7, 2027
ASPEN ACADEMY, Ofallon: MORA27442, minor permit, discharging to Tributary to Dardenne Cr., permit term to February 7, 2027
AUDEN MEADOW, New Melle: MORA27617, minor permit, discharging to Tributary to Dardenne Creek, permit term to February 7, 2027
AUDEN MEADOW LOT 8, New Melle: MORA29726, minor permit, discharging to Tributary to Dardenne Creek, permit term to February 7, 2027

Identity

Facility as filed	DCSD, TREATMENT PLANT 4
Permittee as filed	Duckett Creek Sanitary District
NPDES ID	MO0136425
Permit status	Effective
Permit type	Individual permit
Discharger class	Minor discharger
Facility type	Publicly owned treatment works
Program	Publicly owned treatment works
Issued	July 1, 2025
Expiration date	June 30, 2030
Address	Wentzville, MO 63385
Receiving water	Tributary to Dardenne Cr.
Receiving water impaired	303(D) Listed
Subwatershed	Upper Dardenne Creek (HUC 071100090103)

Effluent limits and exceedances

15Pollutants on file
15Under a numeric limit
1With a violation of any kind
1With an effluent exceedance

An effluent exceedance is a discharge monitoring report value over the permit’s numeric limit (EPA’s violation code E90). A violation of any kind also counts a report not filed. Each row is EPA’s own count for that pollutant.

Pollutant or measure	Limits	Violations, any kind	Effluent exceedances	Latest exceedance	Largest exceedance, as filed
Oil and grease [soxhlet extr.] tot.	2	2	2	July 31, 2025	633% over the limit
Nitrogen, ammonia total [as N]	18	0	0
Nitrogen, Kjeldahl, total [as N]	4	0	0
Nitrite + Nitrate total [as N]	4	0	0
Phosphorus, total [as P]	4	0	0
BOD, 5-day, 20 deg. C	3	0	0
Solids, total suspended	3	0	0
pH	2	0	0
Flow, in conduit or thru treatment plant	2	0	0
E. coli	2	0	0
Toxicity [acute], Ceriodaphnia dubia	1	0	0
Toxicity [chronic], Ceriodaphnia dubia	1	0	0
Toxicity [acute], Pimephales promelas [Fathead Minnow]	1	0	0
BOD, 5-day, percent removal	1	0	0
Solids, suspended percent removal	1	0	0

Inspections, violations and enforcement

0Single-event violations

EPA’s single-event violation file, as loaded, holds no violation for NPDES MO0136425.

Inspections

EPA’s inspection file holds no inspection for NPDES MO0136425.

Formal enforcement and penalties

0 formal actions, 0 of them with a penalty assessed. Federal and state penalties are separate figures from separate authorities and are shown as each was filed, never added together.

Informal enforcement

EPA’s informal enforcement file holds no action for NPDES MO0136425.

Watch this permit

One permit holder, $99/month. Watch the register for one permit holder and the places and receiving waters tied to its permits. Choose “One permit holder” and enter this permit’s NPDES ID, MO0136425.

Start the watch

How we handle your data → Privacy

Nearby on the register

Figures from EPA’s ICIS-NPDES download, loaded September 15, 2026.

This public-records page covers NPDES permit MO0136425 for DCSD, TREATMENT PLANT 4 in Wentzville, MO, held by Duckett Creek Sanitary District, which discharges to Tributary To Dardenne Cr. The permit is listed as Effective and was issued July 1, 2025, expiring June 30, 2030, with 15 pollutants on file, 1 under a numeric limit, and 1 with an effluent exceedance.