In 2015, the Maryland Department of Transportation State Highway Administration (MDOT SHA) received an NPDES MS4 permit (No. 11-DP-3313) from the Maryland Department of the Environment (MDE) to control storm-drain-system pollutant discharges in MS4-designated areas (see map below). The permit requires that we use restoration practices to treat 20% of existing MDOT SHA impervious surfaces and address stormwater wasteload allocations (WLAs) established under US Environmental Protection Agency (EPA)-approved Total Maximum Daily Loads (TMDL).  

MDOT SHA also performs the following activities to control storm drain system pollutants along MDOT SHA roads.:

• Map MDOT SHA's storm drain system.
• Assess the effectiveness of restoration projects through chemical, physical and biological monitoring.
• Implement comprehensive management programs for -
• Stormwater management.
• Erosion and sediment control.
• Illicit discharge detection and elimination.
• Public education and outreach.
• Property management and maintenance.

Impervious Restoration and Coordinated TMDL Implementation Plan

• Part I – Program Introduction (10/09/2018).
• Part II – Impervious Restoration Plan & Chesapeake Bay TMDL Compliance (10/09/2019).
• ​ Part III – Coordinated TMDL Implementation Plan (10/09/2019).
• Part IV – MDOT SHA Watershed TMDL Implementation Plans (10/09/2018).
• Entire Plan (10/09/2019).  

​Review and Comment on Draft Implementation Plans

• Review Latest Draft MDOT SHA TMDL Implementation Plan.
  

2023 TMDL Implementation Plan

• ​Non-Tidal Baltimore Harbor Watershed Sediment TMDL Implementation Plan​​
  

2020 TMDL Implementation Plans

• Implementation Plan for Various TMDLs In Maryland.
• Marsh Run Watershed Sediment TMDL Implementation Plan.
• Non-Tidal West River Watershed Sediment TMDL Implementation Plan.
• Piscataway Creek Watershed Sediment TMDL Implementation Plan.

2019 TMDL Implementation Plans

• Other West Chesapeake Watershed Sediment TMDL Implementation Plan.
• Non-Tidal Back River Watershed Sediment TMDL Implementation Plan.
• Non-Tidal Patuxent River Lower Watershed Sediment TMDL Implementation Plan.
• Non-Tidal Patuxent River Middle Watershed Sediment TMDL Implementation Plan.

Current MS4 Permit and Annual Reports

• MDOT SHA MS4 Permit Issued October 9, 2015, Modified November 8, 2019.
• 2024 MS4 Annual Report.​
  
• 2023 MS4 Annual Report.
  
• 2022 MS4 Annual Report.
• 2021 MS4 Annual Report.
• 2020 MS4 Annual Report.
• 2019 MS4 Annual Report.   
• 2018 MS4 Annual Report (122 MB).
• 2017 MS4 Annual Report (488 MB).
• 2016 MS4 Annual Report (91.9 MB).    

Related Documents

• MDOT SHA Existing Water Quality Grass Swale Identification Protocol.
• MDOT SHA Alternative Headwater Channel and Outfall Crediting Protocol.