Colorado SWPPP inspection requirements

The short version
Rain trigger
Any precipitation or snowmelt event that causes surface erosion (no inch threshold)
Post-rain deadline
Within 24 hours
Routine inspections
Every 7 or 14 days
Permit
COR400000 Construction Stormwater General Permit
Agency
Colorado Department of Public Health and Environment (CDPHE)

How Colorado handles construction stormwater

Construction sites in Colorado disturbing one acre or more need coverage under the COR400000 Construction Stormwater General Permit, administered by Colorado Department of Public Health and Environment. The current permit is effective April 1, 2024 – March 31, 2029. Choose every 7 days, or every 14 days plus within 24 hours after any erosion-causing storm ends (up to 72 hours at temporarily idle sites). Sites discharging to Outstanding Waters must use the 7-day schedule; the first inspection is due within 7 days of construction start.

Inspector qualifications

A qualified person designated by the operator. Check the current state permit for certification requirements.

Official sources

Common questions

What triggers a SWPPP inspection in Colorado?

Under the COR400000 Construction Stormwater General Permit, any precipitation or snowmelt event that causes surface erosion (no inch threshold) triggers an inspection, within 24 hours. Routine inspections: every 7 or 14 days.

Who can perform SWPPP inspections in Colorado?

A qualified person designated by the operator. Check the current state permit for certification requirements.

Who administers the construction stormwater program in Colorado?

Colorado Department of Public Health and Environment (CDPHE) administers the NPDES construction stormwater program in Colorado under the COR400000 Construction Stormwater General Permit.

What are the penalties for SWPPP violations in Colorado?

Federal Clean Water Act civil penalties can reach $68,445 per day per violation, and CDPHE 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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