SW

Stormwater Directory

Missouri

Missouri Department of Natural Resources

Compare with other states →Suggest a correction

Quick Summary

For most Missouri projects disturbing 1 acre or more, you need both a state NPDES permit and a State Land Disturbance (SDS) permit, plus a SWPPP. On-site inspectors must hold the mandatory CESSI certification.

State-DelegatedVerified 2026-03

Construction Permit

Permit Document ↗
Permit Name
NPDES/SDS Land Disturbance General Permit (MOR100000)
Threshold
≥ 1 acre of total land disturbance (or < 1 acre if part of a larger common plan of development or sale that will ultimately disturb ≥ 1 acre); also applies to any earth-disturbing activity that the Director determines has the potential to cause water quality violations
NOI Lead Time
Land Disturbance Permit (LDP) application and NOI must be submitted and authorization received before any land-disturbing activities begin. Missouri requires a minimum 2-business-day processing period for complete applications; applicants should allow 5–10 business days in practice
Application Method
Online via Missouri's Environmental Online Permitting System (myMOEnvironment portal at my.moenv.org); paper applications also accepted at MDNR regional offices
Fee
$75 application fee for disturbances < 5 acres; $150 for 5–10 acres; $225 for > 10 acres; annual renewal fees apply if permit coverage extends beyond one year
Permit Expires
December 31, 2027
Apply for Permit ↗

SWPPP Requirements

Permit Document ↗
SWPPP Required
Yes
PE Cert Required
No
Template Available
Yes
A Stormwater Pollution Prevention Plan (SWPPP) is required and must be developed before the NOI is submitted. The SWPPP must be signed by the permittee and kept on-site at all times. A professional engineer stamp is not required by state rule, but the SWPPP preparer must be a Certified Erosion, Sediment and Stormwater Inspector (CESSI) or similarly qualified person. MDNR provides a SWPPP template and BMP guidance materials through its Land Disturbance program page.

Inspection Requirements

Permit Document ↗
Frequency
At least every 14 days and within 24 hours after any measurable precipitation event (defined as ≥ 0.5 inches of rainfall in a 24-hour period). Inspections must also be conducted after any snowmelt that causes a discharge.
Rain Trigger
Within 24 hours of any measurable precipitation event producing ≥ 0.5 inches of rainfall in a 24-hour period; also required after snowmelt causing a discharge
Inspector Qualification
Missouri requires that at least one Certified Erosion, Sediment and Stormwater Inspector (CESSI) be identified for each project. CESSI certification is obtained through MDNR-approved training programs (e.g., CPESC, CESSWI, or equivalent). This is a state-mandated certification requirement, making Missouri one of the more stringent states for inspector qualifications.
Accepted Certifications
CESSI (Certified Erosion, Sediment and Stormwater Inspector) designation REQUIRED by Missouri DNR; CPESC, CESSWI accepted as equivalents through MDNR-approved training programs

Discharge Standards

Permit Document ↗
Turbidity Limit
No numeric NTU effluent limit in the Land Disturbance General Permit MOR100000
Discharges must not cause or contribute to violations of Missouri's water quality standards (10 CSR 20-7.031), which include narrative criteria prohibiting aesthetically objectionable conditions and abnormal turbidity. Visual monitoring of discharge points is required at every inspection. Effluent characterization sampling may be required by MDNR for larger sites or sites discharging to sensitive or impaired water bodies.

Post-Construction

MDNR ↗
Required
Yes
Post-construction stormwater management is required for projects in Phase I and Phase II MS4-regulated areas. Regulated MS4 communities must adopt post-construction stormwater management programs consistent with MDNR's MS4 general permit. There is no standalone state-level post-construction general permit; compliance is enforced through local MS4 ordinances and the land disturbance permit conditions requiring final stabilization and permanent BMP installation.

Impaired Waterbody / TMDL Requirements

Standard Provisions

Missouri DNR's land disturbance permit (NPDES) has standard provisions. No specific permit conditions are systematically triggered by proximity to 303(d)-listed impaired waters in the general permit; standard stormwater BMPs apply. Projects near impaired segments of the Missouri or Meramec Rivers should consult MoDNR directly for any site-specific requirements.

Program Contact

Contact Page ↗
Phone
(573) 526-2082
Email
epermitting@dnr.mo.gov

State-Specific Notes

Missouri's requirement for a CESSI-certified inspector is a notable state-specific quirk — one of a minority of states mandating formal inspector credentialing. The myMOEnvironment online portal (my.moenv.org) consolidated multiple prior legacy systems. Missouri also regulates land disturbance under its state Surface Water Protection Law (Chapter 644 RSMo) in parallel with the federal NPDES program, meaning the state Land Disturbance Permit (LDP) and the NPDES general permit are issued together as a combined authorization. Projects near Outstanding State Resource Waters (OSRWs) face additional anti-degradation requirements.

Disclaimer: This information is provided for general reference only and may not reflect the most current regulatory requirements. Always consult the MDNR website and applicable regulations before beginning any construction activity.