About the NPDES MS4 Permit:
In 1972, the United States Environmental Protection Agency first administered the Clean Water Act to protect and restore the chemical, physical, and biological integrity of the Nation’s water resources. Regulating point and nonpoint source pollution, the Act is the foundation by which Federal and state agencies manage water resources. In November 1990, the U.S. EPA issued final regulations requiring National Pollutant Discharge Elimination System Permits (NPDES) for stormwater discharges from municipal separate storm sewer systems and industrial activities. The Maryland Department of the Environment administers this Federal requirement, and Anne Arundel County was among the first of Maryland’s jurisdictions to receive a Phase I NPDES Municipal Separate Storm Sewer System (MS4) permit (issued in 1993).
Within Anne Arundel County, the Department of Public Works is the lead department tasked with ensuring compliance with permit conditions. Permit compliance requires the cooperation of multiple County agencies. These agencies have primary responsibility for successfully implementing the various permit requirements. The Ecological Assessment Program has overall responsibility for administering this permit, interfacing with Federal and State regulators regarding permit compliance, coordinating activities among the responsible County agencies, and reporting permit compliance to MDE on an annual basis.
- Current Fifth-Generation NPDES MS4 Permit (issued November 5, 2021)
- County MS4 Jurisdiction Map
- County MS4 Impervious Map
Annual Reports:
2022 NPDES MS4 Annual Report with Appendices (PDF)
2022 NPDES MS4 Annual Report - Cover Letter
MDE Review Comment Letter
Appendix A: Geodatabases
- FY22 MS4 Geodatabase (Zip folder)
- README - FY22 MS4 Geodatabase
- FY22 Stormwater Infrastructure Geodatabase (Zip folder)
- FY22 Industrial and Commercial Sources Geodatabase (Zip folder)
- Anne Arundel County Comments on the November 2021 MS4 Geodatabase Schema
Appendix B: Program Documents
- MDE Erosion & Sediment Control Delegation Review Letter
- AASCD Resolution 2021-1
- Blue Notice IP-21-17
- Memo: Stormwater BMP Hand-Off Meeting
- Stormwater BMP Hand-Off Meeting - Bulletin for HOA
Appendix C: Illicit Discharge Detection & Elimination (IDDE) Program
- IDDE 2022 Annual Report
- IDDE Outfall Screening Prioritization Process: FY22-FY26
- IDDE Standard Operating Procedures
Appendix D: Impervious Area Restoration
- BMP Portfolio - Completed Restoration Year 1 & Year 2
Appendix E: Countywide Stormwater TMDL Implementation
- Countywide TMDL Stormwater Implementation Plan - FY22 Annual Report
- TIPP Spreadsheets (Zip file)
Approved TMDL Restoration Plans:
- Countywide Bacteria TMDL Restoration Plan - 01/2017
- Baltimore Harbor Nutrient TMDL Restoration Plan - 11/2016
- Baltimore Harbor (+ Curtis Creek/Bay) PCB TMDL Restoration Plan - 11/2016
- Patapsco (Lower North Branch) Sediment TMDL Restoration Plan - 11/2016
- Upper Patuxent Sediment TMDL Restoration Plan - 11/2016
- Little Patuxent Sediment TMDL Restoration Plan - 11/2016
- West Chesapeake Watershed Sediment TMDL Restoration Plan - 01/2019
- Non-Tidal, Lower, and Middle Patuxent Sediment TMDL Restoration Plan - 01/2020
Draft TMDL Restoration Plans:
- Patuxent PCB TMDL Restoration Plan - 01/2019
- Non-Tidal West River Sediment TMDL Restoration Plan - 12/2021
- Non-Tidal Baltimore Harbor Sediment TMDL Restoration Plan - 12/2022
- Non-Tidal South River Sediment TMDL WLA Attainment Report - 12/2022
PCB Source Tracking:
- PCB Source Tracking in Anne Arundel County - 01/2022
- Work Plan for PCB Source Tracking in Anne Arundel County - 05/2022
- Baltimore Harbor and Curtis Creek/Bay PCB TMDL Action Strategy - 07/2019
Bacteria Monitoring:
- Marley Creek and Furnace Creek Bacteria TMDL Monitoring Annual Report
- Pet Waste Outreach - Bacteria Monitoring Year 2 Summary Report
- Discrete Sewage Pumping Station Upgrade Projects in Bacteria TMDL Watersheds, Active or Completed in FY22
- County CIP Urban Stormwater Retrofits in Bacteria TMDL Watersheds, Completed and Proposed 2012-2025
Appendix F: Assessment of Controls
- Anne Arundel County Comprehensive Plan for Watershed Assessment Monitoring: Biological and Habitat Monitoring
- PCB Source Tracking (Zip file)
- Pooled Monitoring Program (Zip file)
Appendix G: Program Funding
- FY22 Financial Assurance Plan
- AACo FY22 WPRP Annual Report (Excel file)
- Anne Arundel County FAP Resolution No. 37-22
2021 NPDES MS4 Annual Report with Appendices (PDF)
2021 NPDES MS4 Annual Report - Cover Letter
Appendix A: Digital Data (including MS4 Geodatabases)
- README - FY21 MS4 Geodatabase
- FY21 MS4 Geodatabase (Zip folder)
- FY21 Stormwater Infrastructure Geodatabase (Zip folder)
- FY21 Industrial and Commercial Sources Geodatabase (Zip folder)
- FY13-FY20 Chemical Monitoring Data (Zip folder)
Appendix B: Program Documents
- Anne Arundel County Bill 67-20
- Anne Arundel County Delegation Review Letter
- FY21 Pooled Monitoring Program Documentation Letter
Appendix C: Church Creek and Parole Plaza Monitoring Report
- Chemical and Geomorphic Characterization of the Church Creek and Parole Plaza NPDES Monitoring Stations: 2020-2021
Appendix D: Picture Spring Branch Monitoring Report
- Geomorphological Condition in the Picture Spring Branch Sub-Watershed, Severn River Watershed, Anne Arundel County, Maryland: FY2021
Appendix E: Illicit Discharge Detection & Elimination (IDDE) Report
- Illicit Discharge Detection and Elimination - 2021 Annual Report
- IDDE Outfall Screening Prioritization Process: FY22-FY26
Appendix F: Litter and Floatables Comprehensive Plan
- Litter and Floatables Comprehensive Plan
Appendix G: Property Management
Bureau of Utilities:
- Annapolis Water Reclamation Facility
- Anne Arundel Utilities Operations Center
- Broadneck Water Reclamation Facility
- Broadwater Water Reclamation Facility
- Cox Creek Water Reclamation Facility
- Maryland City Water Reclamation Facility
- Patuxent Water Reclamation Facility
Piney Orchard Water Reclamation Facility
Bureau of Waste Management Services:
- Millersville Landfill and Resource Recovery Facility
- Northern Recycling Center
- Southern Recycling Center
Bureau of Highways:
- Central District - Crownsville Yard Road Operations Facility
- Central District - Odenton Yard Road Operations Facility
- Central District - St. Margaret's Yard Road Operations Facility
- Northern District - Dover Yard Road Operations Facility
- Northern District - Mountain Yard Road Operations Facility
- Southern District - Davidsonville Yard Road Operations Facility
- Southern District - Friendship Yard Road Operations Facility
Appendix H: Countywide TMDL Stormwater Restoration Plans
- Anne Arundel Countywide TMDL Stormwater Implementation Plan - FY21 Annual Progress Report
- Countywide Bacteria TMDL - 2021 Annual Assessment
Approved TMDL Restoration Plans:
- Baltimore Harbor Nutrient TMDL Restoration Plan - 11/2016
- Baltimore Harbor (+ Curtis Creek/Bay) PCB TMDL Restoration Plan - 11/2016
- Patapsco (Lower North Branch) Sediment TMDL Restoration Plan - 11/2016
- Upper Patuxent Sediment TMDL Restoration Plan - 11/2016
- Little Patuxent Sediment TMDL Restoration Plan - 11/2016
- Countywide Bacteria TMDL Restoration Plan - 01/2017
- West Chesapeake Watershed Sediment TMDL Restoration Plan - 01/2019
- Non-Tidal, Lower, and Middle Patuxent Sediment TMDL Restoration Plan - 01/2020
NEW Draft TMDL Restoration Plans:
- Patuxent PCB TMDL Restoration Plan - 01/2019
- Non-Tidal West River Sediment TMDL Restoration Plan - 12/2021
PCB Source Tracking:
- PCB Source Tracking in Anne Arundel County - 01/2022
- Baltimore Harbor and Curtis Creek/Bay PCB TMDL Action Strategy - 07/2019
- Work Plan for PCB Source Tracking in Anne Arundel County
Appendix I: FY2021 Financial Assurance Plan and Report
- FY21 MS4 Annual Financial Report (Excel file)