Michigan SWPPP inspection requirements

The short version
Rain trigger
Any precipitation event that results in a discharge from the site (no inch threshold)
Post-rain deadline
Within 24 hours
Routine inspections
Every 7 days
Permit
NPDES Permit-by-Rule / Part 91 Soil Erosion Program
Agency
Michigan Department of Environment, Great Lakes, and Energy (EGLE)

How Michigan handles construction stormwater

Construction sites in Michigan disturbing one acre or more need coverage under the NPDES Permit-by-Rule / Part 91 Soil Erosion Program, administered by Michigan Department of Environment, Great Lakes, and Energy. Michigan runs construction stormwater through its Part 91 soil erosion program (county/municipal enforcing agencies) plus an NPDES Permit-by-Rule; sites of 5+ acres file a Notice of Coverage via MiWaters. Inspect weekly and within 24 hours of any discharge-producing precipitation. Local requirements vary by enforcing agency.

Inspector qualifications

Inspections must be performed by a Michigan Certified Stormwater Operator (CSWO).

Official sources

Common questions

What triggers a SWPPP inspection in Michigan?

Under the NPDES Permit-by-Rule / Part 91 Soil Erosion Program, any precipitation event that results in a discharge from the site (no inch threshold) triggers an inspection, within 24 hours. Routine inspections: every 7 days.

Who can perform SWPPP inspections in Michigan?

Inspections must be performed by a Michigan Certified Stormwater Operator (CSWO).

Who administers the construction stormwater program in Michigan?

Michigan Department of Environment, Great Lakes, and Energy (EGLE) administers the NPDES construction stormwater program in Michigan under the NPDES Permit-by-Rule / Part 91 Soil Erosion Program.

What are the penalties for SWPPP violations in Michigan?

Federal Clean Water Act civil penalties can reach $68,445 per day per violation, and EGLE can issue administrative orders and state penalties on top. Missing rain-triggered inspections is among the most commonly cited violations in stormwater audits.

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