Sign In
Maryland State Government Maryland Department of the Environment

TMDL Stormwater Implementation Resources

This webpage provides a set of technical resources for Maryland jurisdictions developing Stormwater WLA Implementation Plans. The guidance documents on this page were developed by MDE's Science Services Administration and are recommendations only.

Optional Worksheet for MS4 SW-WLA Implementation Planning

Two spreadsheets are available for download below:

  • Optional Worksheet for MS4 SW-WLA Implementation Planning. This spreadsheet is meant to accompany the submittal of Stormwater Wasteload Allocation (SW-WLA) Implementation Plans to MDE. Local jurisdictions are not required to use this spreadsheet (its use is optional). The spreadsheet is provided to simplify the county planning process. It condenses the pertinent information needed to assess county plans to meet SW-WLAs. It should not be submitted to MDE in place of full implementation plans, but rather, it could be included as an appendix to the plans and cited within the report. There are two forms included within the spreadsheet: a short form and a long form. Jurisdictions are free to use either of the forms. The long form includes a more detailed list of BMPs available for restoration, and the short form includes a more general list. An example of how to fill out the short form is included.

    In an effort to improve and streamline the SW-WLA implementation planning process, jurisdictions are encouraged to provide feedback and suggest improvements for this spreadsheet. All communications regarding this worksheet should be directed to Jeff White at jeff.white@maryland.gov.

 

General Guidance

Maryland's Stormwater Management Program website provides guidance on accounting for stormwater waste load allocations (SW-WLAs) and implementing environmental site design practices. A good starting point for developing a stormwater implementation plan is the Stormwater Management Program's guidance document, Accounting for Stormwater Wasteload Allocations and Impervious Acres Treated.

Additional guidance has also been developed by Maryland Department of the Environment's Science Services Administration, which expands upon and provides recommendations for many of the technical aspects included in the accounting for SW-WLAs document.

The Maryland Department of the Environment presented a webinar on the features of the new TMDL Data Center website on June 11, 2014. This presentation gives an overview of the function and use of the resources available on the TMDL Data Center website for developing SW-WLA Implementation Plans.

 

Nutrients and Sediment TMDL Guidance

This guidance applies to any approved Nutrient or Sediment TMDL for which a SW-WLA Implementation Plan needs to be developed under an MS4 Permit. It provides recommendations for identifying sources of nutrients and sediments, selecting management strategies for reducing nutrient/sediment loads, and modeling load reductions from selected management strategies. This document also provides guidance on using MAST and BayFAST to develop implementation scenarios for local TMDLs and developing comprehensive implementation scenarios addressing both bay and local stormwater targets.

Maryland's Stormwater Management Program provides specific guidance on developing stormwater implementation plans for nutrient and sediment TMDLs.

This online watershed model allows users to develop watershed implementation plans to address nitrogen, phosphorus and sediment TMDLs.

 

PCBs TMDL Guidance

This guidance applies to any approved PCB TMDL for which a SW-WLA Implementation Plan needs to be developed under an municipal separate storm sewer system (MS4) Permit. It provides recommendations for PCB source identification, source monitoring, accounting for WLA credit and consideration of alternative or adaptive approaches. A slideshow presentation on MDE's PCB guidance, as it relates to Montgomery County, is provided here.

 

Bacteria TMDL Guidance

This guidance applies to any approved Bacteria TMDL for which a SW-WLA Implementation Plan needs to be developed under an MS4 Permit. It provides recommendations for identifying sources of bacteria, selecting management strategies for reducing bacteria loads, and modeling load reductions from selected management strategies.

 

Mercury TMDL Guidance

This guidance applies to any approved Mercury TMDL for which a SW-WLA Implementation Plan needs to be developed under an MS4 Permit. It provides recommendations for identifying sources of mercury (both local and atmospherically deposited) and creating systems to account for reductions in mercury air deposition from state and federal programs and potential reductions in local sources.

 

Trash TMDL Guidance

This guidance applies to any approved Trash/Debris TMDL for which a SW-WLA Implementation Plan needs to be developed under an MS4 Permit. It provides recommendations for identifying sources of trash and debris, selecting management strategies for reducing trash and debris loads, and modeling load reductions from selected management strategies.

This guidance provides additional recommendations for monitoring programs associated with Trash/Debris TMDLs. Because trash is a new and emerging pollutant in the TMDL program, limited data is available. Additional trash loading rate data will provide MDE with updated information on how trash loads may be changing over time. It can also be used by MS4 permit holders to evaluate effectiveness of selected management strategies in reducing trash.

 

Federal Facility Loading Targets

Per EPA requirements, Maryland has set interim nutrient loading targets for federal facilities. These targets represent loading reductions associated with a 20% retrofit of impervious surfaces with stormwater management that does not provide adequate water quality treatment. This is consistent with implementation strategies outlined in Maryland's Phase II WIP for Phase II MS4s. These planning targets represent an interim goal towards overall 2025 load reductions. Revised planning targets to meet 2025 goals will likely be provided to the federal facilities in 2018 as part of Maryland's Phase III WIP process. The planning targets are available for download below for all facilities that submitted land-use or BMP data to MDE.

 

Glossary

Definitions of terms and abbreviations used in the TMDL Data Center.

Contact Information

Please direct questions or comments concerning this project to Maryland's TMDL Program at (410) 537-3572.


Click to link back to top of page