SW

Stormwater Directory

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MT(3 more)

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Field
MT
Montana
NPDES ProgramState-Delegated
Permitting AgencyMontana Department of Environmental Quality (MT DEQ)
Permit NameMontana Pollutant Discharge Elimination System (MPDES) General Permit for Stormwater Discharges Associated with Construction Activity (MTR100000)
Construction Threshold≥ 1 acre of land disturbance (or < 1 acre if part of a larger common plan of development or sale that will ultimately disturb ≥ 1 acre); individual construction sites < 1 acre may also require coverage if they discharge to impaired waters
NOI Lead TimeA Notice of Intent (NOI) must be submitted to MT DEQ at least 10 days before construction begins. Permit coverage is granted upon MT DEQ's issuance of an authorization number.
Application MethodPaper NOI form submission to MT DEQ Water Protection Bureau; online submission option available through MT DEQ's Environmental Management System (EMS) portal — verify current portal availability at deq.mt.gov
Permit Fee$200 application fee for construction sites disturbing < 5 acres; $500 for sites disturbing 5 acres or more; fee is a one-time application fee for the duration of the project
SWPPP RequiredYes
PE Certification RequiredNo
SWPPP Template AvailableYes
Inspection FrequencyAt least every 14 days and within 24 hours after any precipitation or snowmelt event that causes or has the potential to cause a stormwater discharge from the site
Inspector QualificationNo state-mandated inspector certification program; inspections must be conducted by qualified personnel who are knowledgeable in the principles and practice of erosion and sediment control and who possess the skills to assess conditions at the site and implement corrective measures. MT DEQ recommends but does not require certifications such as CPESC or CESSWI.
Post-Construction RequiredYes
Turbidity StandardNo numeric NTU effluent limit in the Construction General Permit MTR100000