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NPDES Stormwater Permit for Ada County Highway District MS4 in Idaho

Below are EPA's National Pollutant Discharge Elimination System (NPDES) municipal separate storm sewer system (MS4) final permit and supporting documents for the Ada County Highway District (ACHD) in Idaho.

  • Permit number: IDS028185
  • Effective date: February 1, 2021
  • Permit expires: January 31, 2026

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