MS-4

What is MS-4?
MS-4 is an abbreviation for Municipal Separate Storm Sewer System. The “Municipal” part pertains to being in municipal or urbanized areas, as defined by the U.S. federal census bureau. Every ten years, the census bureau publishes the location of urbanized areas of the United States. The city of Manassas falls within one of these urbanized areas.

"Separate Storm Sewer System" pertains to those urbanized areas that have their sewer treatment systems separate from their stormwater infrastructure. There are separate regulations overseeing how sewer systems are maintained and operated, while the MS-4 permit regulates how these dedicated stormwater management systems are operated and maintained.

MS-4 in the City of Manassas
There are 5,320 storm drains that connect to 23 public and approximately 34 private stormwater facilities in the city. Surface water in the city flows into either Broad Run or Bull Run. Both of these watersheds drain into the Occoquan River, which in turn, empties into the Chesapeake Bay.

We want to hear from YOU
City stormwater staff are pleased to answer questions and accept comments on the below stormwater program plans and reports at anytime. Please submit your comments for the Chesapeake Bay TMDL Action Plan here or send us an email about other projects at stormwater@manassasva.gov. Thank you for your input!
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Categories always sorted by seq (sub-categories sorted within each category)
Documents sorted by SEQ in Ascending Order within category

2023-2028 General Permit2 documents

  • 2023-2028 General Permit Overview
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  • 2023-2028 General Permit
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Annual Reports19 documents

2023 Annual Report15 documents

  • Appendix 1 - Coverage Statement
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  • Appendix 2 MCM1 Public Education
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  • Appendix 3 MCM2 Public Participation
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  • Appendix 4 MCM2 NVCWP Survey
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  • Appendix 5 MCM3 Storm Sewer Map
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  • Appendix 6 MCM3 Dry Weather Screening
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  • Appendix 7 MCM4-ESC Noncompliance Report
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  • Appendix 8 MCM5 Private SWMF Report
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  • Appendix 9a MCM5 Public SWMF Inspections
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  • Appendix 9b MCM5 Public SWMF Report
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  • Appendix 10 MCM6 P2GH SOPs
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  • Appendix 11 MCM6 NMPs Approvals
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  • Appendix 12 MCM6 Training Documentation
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  • Appendix 13 TMDLs UOSA Documentation
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  • City of Manassas PY23 Annual Report
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2022 Annual Report1 document

  • Final PY22 MS4 Annual Report City of Manassas.pdf
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Older Reports3 documents

  • MS4 2021 Annual Report
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  • MS4 2020 Annual Report
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  • MS4 2019 Annual Report
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Chesapeake Bay TMDL Action Plan1 document

  • Chesapeake Bay TMDL Action Plan
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Program and Action Plans4 documents

  • 2018 VADEQ MS4 General Permit
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  • MS4 2020 Program Plan
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  • Local TMDL Action Plan- 2021 Update
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  • Phase II Chesapeake Bay TMDL Action Plan
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Program Ordinances4 documents

  • Illicit Discharges
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  • Erosion and Sediment Control
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  • Virginia Stormwater Management Program
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  • Stormwater Utility
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