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Maryland State Government Maryland Department of the Environment

This page provides links to online maps and GIS downloads to assist in implementing TMDLs. The resources below include maps of every approved TMDL (categorized by pollutant) as well as shapefiles relating to the implementation process. Two separate TMDL maps are provided for nitrogen, phosphorus and sediment; one map for those TMDLs that were developed by the state, and one map for those TMDLs which are part of the 2010 Chesapeake Bay TMDLs. All downloads are provided as zipped shapefiles.

TMDL Maps by Pollutant

  Nutrients    Bacteria
    Nitrogen: State TMDLs
(view | download)     E. coli (view | download)
    Phosphorus: State TMDLs
(view | download)     Enterococci (view | download)
    Nitrogen & Phosphorus: 2010 Bay TMDLs (view | download)     Fecal Coliform (view | download)
  BOD: Biochemical Oxygen Demand   Trash
    BOD / CBOD / NBOD (view | download)     Trash (view | download)
  Low pH   Sediment
    Calcium Carbonate Equivalents
(view | download)     Sediment: State TMDLs (view | download)
    pH Surrogates (view | download)     Sediment: 2010 Bay TMDLs (view | download)
  Metals   Organochlorides
    Aluminum (view | download)     Chlordane (view | download)
    Iron (view | download)     PCBs: Polychlorinated Biphenyls (view | download)
    Mercury (view | download)    

                                                                                                                                               TMDL Data Center Updates


Additional geographic resources for TMDL implementation

     Watershed Delineations

         County Boundaries

         Stormwater Delineations

         Land Cover


    Other mapping resources