Maryland Department of the Environment

Maryland’s NPDES Municipal Separate Storm Sewer System (MS4) Permits

​Department of the Environment Issues Stormwater Permits for Large Maryland Jurisdictions, Advances Climate Resiliency and Equity​

​The Maryland Department of the Environment (MDE) has issued a series of municipal stormwater permits to advance Chesapeake Bay restoration while reducing flooding and making communities more resilient to the effects of climate change.

​​“Aggressive and achievable stormwater requirements for large Maryland jurisdictions are a critical part of our comprehensive, science-based plan for restoring the Chesapeake Bay,” said Maryland Environment Secretary Ben Grumbles. “MDE’s new municipal stormwater permits, along with our new climate action plan and innovative financing strategies for stormwater management, will help prevent stormwater pollution, reduce flooding and increase climate resiliency and equity to help ensure healthy watersheds and a green and growing Maryland economy.”

Maryland’s Municipal Stormwater Permits

When it rains, stormwater washes excess nutrients, chemicals, and dirt from impervious surfaces, such as buildings, roads, and parking lots into local waters and the Chesapeake Bay. Excess stormwater runoff can also flood local communities, scour sediment from waterways, and degrade the health of stream systems.

MDE’s MS4 permits continue the state’s robust work to reduce nutrient and sediment pollution from stormwater as part of a larger effort that requires all sectors, such as sewage treatment plants and septic systems, in Maryland and the surrounding region to protect and restore the Chesapeake Bay.

The MS4 permits are a result of extensive stakeholder engagement. The permits require local jurisdictions to maintain previous stormwater pollution reduction efforts. They also require additional  stormwater pollution reduction, including restoring impervious surface areas that have little or no stormwater treatment with green infrastructure and other techniques. These new permits meet our Chesapeake Bay commitments and also increase accountability, enhance public education and include innovative and cost-effective monitoring options.
   
In the next five years the new permits add another 11,000 acres to the 35,000 impervious acres restored under prior permits. This restoration encourages climate resiliency and green infrastructure even as it continues to advance innovations such as pay-for-performance contracting, public-private partnerships, and new technologies. The permits also include new incentives for climate resiliency and green infrastructure projects.

Maryland’s 11 phase I urban jurisdictions have established themselves as national leaders in reducing stormwater pollution by collectively investing $745 million in clean water infrastructure. Since July 2019, MDE’s Water Quality Finance Administration has guaranteed $117.8 million in low interest loans to counties and local governments for stormwater restoration projects, and another $218.6 million in low interest loans are pending for planned projects. During the prior MS4 permit term, which started in 2014, the Chesapeake Bay Trust awarded an additional $36.5 million in grants to stormwater programs for restoration projects, which leveraged another $27.7 million in matching funds. Maryland continues to push for additional federal funding for local stormwater projects – especially for those that increase climate resiliency in underserved communities and for those that help sustain our Chesapeake Bay restoration efforts for decades to come.

Advancing Stormwater Resiliency in Maryland

Urban flooding is a growing issue in Maryland. The increasing number of extreme rainfall events that produce intense precipitation will continue to lead to more urban flooding events unless steps are taken to mitigate their impacts. The Maryland General Assembly recognized the need to address urban flooding with the passing of Senate Bill 227. The Bill tasks the Maryland Department of the Environment (Department) with developing plans to evaluate current flooding risks and update regulations to improve urban stormwater flood management. The "Advancing Stormwater Resiliency in Maryland" report provides a roadmap towards modernizing stormwater management in Maryland.​

Where Do We Start?

The Department is taking action through collection of data sets, development of tools and web applications, targeting funding opportunities, developing outreach and education and updating stormwater regulations. Step one is performing a statewide comprehensive urban flood management assessment. With the help of local floodplain and stormwater managers, the Department will identify and characterize Maryland’s urban flooding events and report the current state of local stormwater and flood management programs.​ For more information on this effort, please visit the Advancing Stormwater Resiliency in Maryland ​page here​.




Notice of Tentative Determination to Issue Stormwater Permit to Carroll County (March 11, 2022)

 

The Maryland Department of the Environment, Water and Science Administration (The Department) has reached a tentative determination to issue a National Pollutant Discharge Elimination System permit to Carroll County for Discharges from Medium Municipal Separate Storm Sewer Systems (Discharge Permit No. 22-DP-3319, NPDES No. MD0068331).  The Department has drafted a permit designed to comply with the United States Environmental Protection Agency's (EPA) regulations and to control stormwater pollutant discharges from the County's storm drain system.  The permit is issued for five years.

Under the conditions of the permit, Carroll County is required to possess the legal authority to control storm drain system pollutants, maintain its storm sewer system, monitor stormwater discharges, and develop and implement comprehensive management programs.  The permit also sets new requirements for impervious area treatment, property management and maintenance, and options for comprehensive water quality monitoring.  The County is also required to develop and implement plans to address waste load allocations established under EPA approved total maximum daily loads.  Penalties for failure to comply with the terms of the permit are provided.

The draft permit and fact sheet can be viewed here:

MS4 Guidance Includes:

The Department used the following documents to help assess the physical and financial capacity of Carroll County to meet restoration goals proposed in the permit.

These analyses were based on instructions and spreadsheets sent to the County.  These instructions may be found here: 

Hard copies of the draft permit may also be procured at a cost of $0.36 per page. Written requests for copies should be directed to Raymond P. Bahr, Maryland Department of the
Environment, Water and Science Administration, Stormwater, Dam Safety and Flood Management Program, 1800 Washington Boulevard, Ste. 440, Baltimore, Maryland 21230-1708. Additional information on stormwater management in Maryland can also be found on the Department's website or by calling the Stormwater, Dam Safety and Flood Management Program at 410-537-3543 or 1-800-633-6101.

In accordance with COMAR 26.08.04, the Department will hold an informational meeting and public hearing regarding the tentative determination permit on April 12, 2022 from 3pm to 5pm, at the Carroll County Office building, 225 N. Center St., Room 311, Westminster, MD.

Comments on this tentative determination permit will be accepted by Raymond Bahr, Maryland Department of the Environment, Water and Science Administration, Stormwater, Dam Safety and Flood Management Program, 1800 Washington Boulevard, Baltimore, Maryland, 21230, or Raymond.Bahr@Maryland.gov, if received within 90 days of publication of this notice. The 60-day extension of the comment period allowed for by section 1-606 (d) (1) (ii) of the Maryland Environment Article is being invoked to extend the usual 30-day comment period to 90 days. The Department will respond to all pertinent comments during the Final Determination process. Once the Final Determination is issued, the public will have 30 days to request a judicial review of the permit.​

Notice of Tentative Determination to Issue Stormwater Permit to Charles County (March 11, 2022)

 

The Maryland Department of the Environment, Water and Science Administration (The Department) has reached a tentative determination to issue a National Pollutant Discharge Elimination System permit to Charles County for Discharges from Medium Municipal Separate Storm Sewer Systems (Discharge Permit No. 22-DP-3322, NPDES No. MD0068365).  The Department has drafted a permit designed to comply with the United States Environmental Protection Agency's (EPA) regulations and to control stormwater pollutant discharges from the County's storm drain system.  The permit is issued for five years.

Under the conditions of the permit, Charles County is required to possess the legal authority to control storm drain system pollutants, maintain its storm sewer system, monitor stormwater discharges, and develop and implement comprehensive management programs.  The permit also sets new requirements for impervious area treatment, property management and maintenance, and options for comprehensive water quality monitoring.  The County is also required to develop and implement plans to address waste load allocations established under EPA approved total maximum daily loads.  Penalties for failure to comply with the terms of the permit are provided.

The draft permit and fact sheet can be viewed here:

MS4 Guidance Includes:

The Department used the following documents to help assess the physical and financial capacity of Charles County to meet restoration goals proposed in the permit.

These analyses were based on instructions and spreadsheets sent to the County.  These instructions may be found here: 

Hard copies of the draft permit may also be procured at a cost of $0.36 per page. Written requests for copies should be directed to Raymond P. Bahr, Maryland Department of the Environment, Water and Science Administration, Stormwater, Dam Safety and Flood Management Program, 1800 Washington Boulevard, Ste. 440, Baltimore, Maryland 21230-1708. Additional information on stormwater management in Maryland can also be found on the Department's website or by calling the Stormwater, Dam Safety and Flood Management Program at 410-537-3543 or 1-800-633-6101.

In accordance with COMAR 26.08.04, the Department will hold an informational meeting and public hearing regarding the tentative determination permit on April 27, 2022 from 5pm to 7pm, at the Charles County Government Building, 200 Baltimore Street, La Plata, MD 20646.

Comments on this tentative determination permit will be accepted by Raymond Bahr, Maryland Department of the Environment, Water and Science Administration, Stormwater, Dam Safety and Flood Management Program, 1800 Washington Boulevard, Baltimore, Maryland 21230, or Raymond.Bahr@Maryland.gov, if received within 90 days of publication of this notice. The 60-day extension of the comment period allowed for by section 1-606 (d) (1) (ii) of the Maryland Environment Article is being invoked to extend the usual 30-day comment period to 90 days. The Department will respond to all pertinent comments during the Final Determination process. Once the Final Determination is issued, the public will have 30 days to request a judicial review of the permit.​

Notice of Tentative Determination to Issue Stormwater Permit to Frederick County (March 11, 2022)

 

The Maryland Department of the Environment, Water and Science Administration (The Department) has reached a tentative determination to issue a National Pollutant Discharge Elimination System permit to Frederick County for Discharges from Medium Municipal Separate Storm Sewer Systems (Discharge Permit No. 20-DP-3321, NPDES No. MD0068357).  The Department has drafted a permit designed to comply with the United States Environmental Protection Agency's (EPA) regulations and to control stormwater pollutant discharges from the County's storm drain system.  The permit is issued for five years.

Under the conditions of the permit, Frederick County is required to possess the legal authority to control storm drain system pollutants, maintain its storm sewer system, monitor stormwater discharges, and develop and implement comprehensive management programs.  The permit also sets new requirements for impervious area treatment, property management and maintenance, and options for comprehensive water quality monitoring.  The County is also required to develop and implement plans to address waste load allocations established under EPA approved total maximum daily loads.  Penalties for failure to comply with the terms of the permit are provided.

The draft permit and fact sheet can be viewed here:

MS4 Guidance Includes:

The Department used the following documents to help assess the physical and financial capacity of Frederick County to meet restoration goals proposed in the permit.

These analyses were based on instructions and spreadsheets sent to the County.  These instructions may be found here: 

Hard copies of the draft permit may also be procured at a cost of $0.36 per page. Writtenrequests for copies should be directed to Raymond P. Bahr, Maryland Department of the Environment, Water and Science Administration, Stormwater, Dam Safety and Flood Management Program, 1800 Washington Boulevard, Ste. 440, Baltimore, Maryland 21230-1708. Additional information on stormwater management in Maryland can also be found on the Department's website or by calling the Stormwater, Dam Safety and Flood Management Program at 410-537-3543 or 1-800-633-6101.

In accordance with COMAR 26.08.04, the Department will hold an informational meeting and public hearing regarding the tentative determination permit on April 21, 2022 from 2pm to 4pm, at the Winchester Hall, 12 E. Church Street, Frederick, Maryland in the Winchester Room on the 2nd floor.

Comments on this tentative determination permit will be accepted by Raymond Bahr, Maryland Department of the Environment, Water and Science Administration, Stormwater, Dam Safety and Flood Management Program, 1800 Washington Boulevard, Baltimore, Maryland, 21230, or Raymond.Bahr@Maryland.gov, if received within 90 days of publication of this notice. The 60-day extension of the comment period allowed for by section 1-606 (d) (1) (ii) of the Maryland Environment Article is being invoked to extend the usual 30-day comment period to 90 days. The Department will respond to all pertinent comments during the Final Determination process. Once the Final Determination is issued, the public will have 30 days to request a judicial review of the permit.

Notice of Tentative Determination to Issue Stormwater Permit to Harford County (March 11, 2022)

 

The Maryland Department of the Environment, Water and Science Administration (The Department) has reached a tentative determination to issue a National Pollutant Discharge Elimination System permit to Harford County for Discharges from Medium Municipal Separate Storm Sewer Systems (Discharge Permit No. 20-DP-3310, NPDES No. MD0068268).  The Department has drafted a permit designed to comply with the United States Environmental Protection Agency's (EPA) regulations and to control stormwater pollutant discharges from the County's storm drain system.  The permit is issued for five years.

Under the conditions of the permit, Harford County is required to possess the legal authority to control storm drain system pollutants, maintain its storm sewer system, monitor stormwater discharges, and develop and implement comprehensive management programs.  The permit also sets new requirements for impervious area treatment, property management and maintenance, and options for comprehensive water quality monitoring.  The County is also required to develop and implement plans to address waste load allocations established under EPA approved total maximum daily loads.  Penalties for failure to comply with the terms of the permit are provided.

The draft permit and fact sheet can be viewed here:

MS4 Guidance Includes:

The Department used the following documents to help assess the physical and financial capacity of Harford County to meet restoration goals proposed in the permit.

These analyses were based on instructions and spreadsheets sent to the County.  These instructions may be found here: 

Hard copies of the draft permit may also be procured at a cost of $0.36 per page. Written requests for copies should be directed to Raymond P. Bahr, Maryland Department of the Environment, Water and Science Administration, Stormwater, Dam Safety and Flood Management Program, 1800 Washington Boulevard, Ste. 440, Baltimore, Maryland 21230-1708. Additional information on stormwater management in Maryland can also be found on the Department's website or by calling the Stormwater, Dam Safety and Flood Management Program at 410-537-3543 or 1-800-633-6101.

In accordance with COMAR 26.08.04, the Department will hold an informational meeting and public hearing regarding the tentative determination permit on April 27, 2022 from 6pm to 8pm, at the Harford County Government Offices, 1st floor conference room, 220 South Main Street, Bel Air, Maryland 21014.

Comments on this tentative determination permit will be accepted by Raymond Bahr, Maryland Department of the Environment, Water and Science Administration, Stormwater, Dam Safety and Flood Management Program, 1800 Washington Boulevard, Baltimore, Maryland, 21230, or Raymond.Bahr@Maryland.gov, if received within 90 days of publication of this notice. The 60-day extension of the comment period allowed for by section 1-606 (d) (1) (ii) of the Maryland Environment Article is being invoked to extend the usual 30-day comment period to 90 days. The Department will respond to all pertinent comments during the Final Determination process. Once the Final Determination is issued, the public will have 30 days to request a judicial review of the permit.

Notice of Tentative Determination to Issue Stormwater Permit to Howard County (March 11, 2022)

 

The Maryland Department of the Environment, Water and Science Administration (The Department) has reached a tentative determination to issue a National Pollutant Discharge Elimination System permit to Howard County for Discharges from Medium Municipal Separate Storm Sewer Systems (Discharge Permit No. 20-DP-3318, NPDES No. MD0068322).  The Department has drafted a permit designed to comply with the United States Environmental Protection Agency's (EPA) regulations and to control stormwater pollutant discharges from the County's storm drain system.  The permit is issued for five years.

Under the conditions of the permit, Howard County is required to possess the legal authority to control storm drain system pollutants, maintain its storm sewer system, monitor stormwater discharges, and develop and implement comprehensive management programs.  The permit also sets new requirements for impervious area treatment, property management and maintenance, and options for comprehensive water quality monitoring.  The County is also required to develop and implement plans to address waste load allocations established under EPA approved total maximum daily loads.  Penalties for failure to comply with the terms of the permit are provided.

The draft permit and fact sheet can be viewed here:

MS4 Guidance Includes:

The Department used the following documents to help assess the physical and financial capacity of Howard County to meet restoration goals proposed in the permit.

These analyses were based on instructions and spreadsheets sent to the County.  These instructions may be found here: 

Hard copies of the draft permit may also be procured at a cost of $0.36 per page. Written requests for copies should be directed to Raymond P. Bahr, Maryland Department of the Environment, Water and Science Administration, Stormwater, Dam Safety and Flood Management Program, 1800 Washington Boulevard, Ste. 440, Baltimore, Maryland 21230-1708. Additional information on stormwater management in Maryland can also be found on the Department's website or by calling the Stormwater, Dam Safety and Flood Management
Program at 410-537-3543 or 1-800-633-6101.

In accordance with COMAR 26.08.04, the Department will hold an informational meeting and public hearing regarding the tentative determination permit on April 26, 2022 from 7pm to 8pm, at the Howard County Government, George Howard Building, Columbia/Ellicott City Room, 3430 Court House Drive, Ellicott City, Maryland 21043.

Comments on this tentative determination permit will be accepted by Raymond Bahr, Maryland Department of the Environment, Water and Science Administration, Stormwater, Dam Safety and Flood Management Program, 1800 Washington Boulevard, Baltimore, Maryland, 21230, or Raymond.Bahr@Maryland.gov, if received within 90 days of publication of this notice. The 60-day extension of the comment period allowed for by section 1-606 (d) (1) (ii) of the Maryland Environment Article is being invoked to extend the usual 30-day comment period to 90 days. The Department will respond to all pertinent comments during the Final Determination process. Once the Final Determination is issued, the public will have 30 days to request a judicial review of the permit.

Notice of Final Determination to Issue Stormwater Permits to Anne Arundel County, Baltimore City, Baltimore County, and Montgomery County (November 5, 2021)

 

The Maryland Department of the Environment (Department) reached a final determination to issue a National Pollutant Discharge Elimination System (NPDES) permit to Anne Arundel County (Discharge Permit No. 20-DP-3316, NPDES Permit No. MD0068306), Baltimore City (Discharge Permit No. 20-DP-3315, NPDES Permit No. MD0068292), Baltimore County (Discharge Permit No. 20-DP-3317, NPDES Permit No. MD0068314), and Montgomery County (Discharge Permit No. 20-DP-3320, NPDES Permit No. MD0068349) for Discharges from Large Municipal Separate Storm Sewer Systems (MS4) on November 5, 2021. These permits cover stormwater discharges into, through, or from the storm drain system owned or operated by these Counties.  Permit requirements include implementing comprehensive stormwater management programs for addressing runoff from new and redevelopment projects, restoring urban areas where there is currently little or no stormwater management, and working toward meeting stormwater wasteload allocations for local water resources and Chesapeake Bay.  Also included in the permits are conditions that require the County to possess the necessary legal authority to control stormwater discharges, map its storm drain system, monitor urban runoff, and eliminate illicit discharges to the storm drain system.  The Department has met with various stakeholders over the past several years regarding these permits, held public hearings to accept testimony and accepted public comments.  It is the Department's final determination that these permits comply with the United States Environmental Protection Agency's NPDES regulations to control stormwater pollutant discharges from Counties' storm drain systems to the maximum extent practicable.  

The final permits, fact sheets, and Response to Comments can be viewed here:

MS4 Guidance Includes:

Notice of Tentative Determination to Issue Stormwater Permit to Prince George's County (November 5, 2021)

 

​The Maryland Department of the Environment, Water and Science Administration (The Department) has reached a tentative determination to issue a National Pollutant Discharge Elimination System permit to Prince George’s County for Discharges from Large Municipal Separate Storm Sewer Systems (Discharge Permit No. 20-DP-3314, NPDES No. MD0068284).  The Department has drafted a permit designed to comply with the United States Environmental Protection Agency’s (EPA) regulations and to control stormwater pollutant discharges from the County’s storm drain system.  The permit is issued for five years.

Under the conditions of the permit, Prince George’s County is required to possess the legal authority to control storm drain system pollutants, maintain its storm sewer system, monitor stormwater discharges, and develop and implement comprehensive management programs.  The permit also sets new requirements for impervious area treatment, property management and maintenance, and options for comprehensive water quality monitoring.  The County is also required to develop and implement plans to address waste load allocations established under EPA approved total maximum daily loads.  Penalties for failure to comply with the terms of the permit are provided.

The draft permit and fact sheet can be viewed here:

MS4 Guidance Includes:

​The Department used the following documents to help assess the physical and financial capacity of Prince George's County to meet restoration goals proposed in the permit. These analyses were submitted in July 2019 and April 2020 and some of the information contained within do not incorporate continued program activity and updates. 

These analyses were based on instructions and spreadsheets sent to the County.  These instructions may be found here: 

Hard copies of the documents may also be obtained directly from the Department at a cost of 36¢ per page. ​

The Department held a public hearing concerning this tentative determination from 1:00 PM to 2:30 PM on December 15, 2021 at the Prince George’s County Department of the Environment’s 1st Floor Conference Room located at 1801 McCormick Drive, Largo, MD 20774. A copy of the transcript of this hearing may be found here:


​

Notice of Proposed Settlement - Prince George's County (January 29, 2021)

 

​​The Maryland Department of the Environment and the Prince George’s County Department of Environmental Protection have reached tentative agreement on a consent decree to be filed in Prince George’s County Circuit Court resolving issues with the county’s performance pursuant to the National Pollutant Discharge Elimination System (NPDES) Municipal Separate Storm Sewer System (MS4) permit issued January 2, 2014.  The five-year permit expired on January 1, 2019.  

While a public comment period is not required by Maryland law as part of the review and approval of such a settlement, the parties are aware of public interest in this and other county MS4 stormwater permits.  Accordingly, the Department of the Environment is distributing copies of the tentative settlement to interested parties and making it available on the Department’s web page.  The tentative settlement can be viewed here:

Comments will be accepted through March 2, 2021.  Those comments may be submitted electronically to Raymond.bahr@maryland.gov or mailed to the attention of Raymond Bahr, Suite 400, Maryland Department of the Environment, 1800 Washington Boulevard, Baltimore, MD  21230.  

The consent decree imposes a $475,000 penalty for failure to complete all of the restoration work required by the 2014 permit.  The penalty can be satisfied through the construction of one or more Department-approved Supplemental Environmental Projects by December 31, 2024.  In addition, the decree requires that the restoration work remaining under the terms of the 2014 MS4 permit be completed in the same timeframe.  The settlement calls for additional penalties for failure to meet interim goals.  

Prince George’s County initiated efforts to address urban stormwater runoff well before the Chesapeake Bay Total Maximum Daily Load (TMDL) was established in 2010 and has been diligent in its efforts.  This consent decree requires the county to complete the impervious surface restoration work that remains to be performed notwithstanding the expiration of the 2014 permit.

"We appreciate Prince George’s County's commitment to improved environmental performance under its state permit and collaboration on the consent decree, including provisions on penalties, schedules, and supplemental environmental projects”, said Secretary Ben Grumbles.  “Preventing stormwater pollution can be challenging but it's important for local water quality and the Chesapeake Bay and the state will continue to enforce its laws and provide assistance to counties and communities."


Additional Resources

 

​Guidance for Maryland's NPDES Stormwater Permits

NPDES municipal separate storm sewer system permits in Maryland require the restoration of a certain percent of a jurisdiction's impervious surface area (e.g., 20%) that has little or no stormwater management. How to calculate impervious surface requirements and treatment credits has generated numerous questions. This document standardizes procedures for reporting of traditional, new, and alternative best management practices (BMPs) and the impervious area each controls. The guidance can be found below.

The Department has revised Appendix B of the Accounting for Stormwater Wasteload Allocations and Impervious Acres Treated (MDE, November 2021). The revision corrects a technical error and provides additional clarification related to the calculation of total nitrogen load reductions for measuring progress toward meeting total maximum daily load (TMDL) goals. The revision ensures consistency with the guidance and the reporting criteria found in the Department’s Urban Stormwater Management Credit Calculator for TN, TP, TSS (MDE, April 28, 2022) and the TMDL Implementation Progress and Planning (TIPP) Tool (MDE, April 6, 2022).

The following documents were developed to help the Department assess the physical and financial capacity of Phase I Large permittees to meet proposed restoration goals. The first documents are the instructions and spreadsheets sent to each Phase I large permittee:
Other Guidance Documents:

Since 2014, MDE has distributed several memoranda that provide additional guidance concerning BMPs and impervious area crediting.  Please note that these memoranda are intended to clarify, supplement, or replace the information found in the Accounting for Stormwater Wasteload Allocations and Impervious Acres Treated (MDE, 2014).  When there are conflicts between these memoranda and the original 2014 guidance, the newest shall supersede. These documents may be found here:
Additionally, in March 2018, MDE sent a letter to OptiRTC, Incorporated that established requirements and interim credits for the use of continuous monitoring and adaptive control (CMAC) systems for restoration.  While this letter is addressed to OptiRTC, the conditions and restrictions apply to CMAC systems in general, includiong those marketed by others.  A copy of this letter is available here:
Phase I Large MS4 Permit Tentative Determination Comments

The Maryland Department of the Environment, Water and Science Administration (the Department) reached a final determination to issue a National Pollutant Discharge Elimination System (NPDES) permit to Anne Arundel County (Discharge Permit No. 20-DP-3316, NPDES Permit No. MD0068306), Baltimore City (Discharge Permit No. 20-DP-3315, NPDES Permit No. MD0068292), Baltimore County (Discharge Permit No. 20-DP-3317, NPDES Permit No. MD0068314), and Montgomery County (Discharge Permit No. 20-DP-3320, NPDES Permit No. MD0068349) for Discharges from Large Municipal Separate Storm Sewer Systems (MS4) on November 5, 2021. The Department met with various stakeholders over the past several years regarding these permits, held public hearings to accept testimony on each permit through online webinars in November 2020, and accepted public comments through January 21, 2021. The written comments recieved by the Department and the transcripts of the public hearings are posted below. 
​​

NPDES Phase I Permits

 

​You can view background information on each jurisdiction by clicking on the municipality's name in the chart below. Initial permits, current permits, and links to the agency responsible for administering each local permit are also accessible by clicking on the respective links below.

 

 Initial Permit Issued Current Permit Issued Local Agency Responsible for Annual Reporting

Large Jurisdictions

Anne Arundel County

12/02/1993

11/05/2021

Dept. of Public Works / Watershed Protection and Restoration

Baltimore County

11/17/1994

11/05/2021

Dept. of Environmental Protection & Sustainability (EPS) / NPDES

Baltimore City

11/17/1993

11/05/2021

Dept. of Public Works

Montgomery County

03/15/1996

11/05/2021

Dept. of Environmental Protection

Prince George’s County

11/17/1993

01/02/2014

Dept. of Environment

Medium Jurisdictions

Carroll County

05/30/1995

12/30/2014

Land Use, Planning & Development

Charles County

05 /01/1997

12/26/2014

Planning & Growth Management

Frederick County

11/15/1994

12/30/2014

Sustainable Development - Watershed Management

Harford County

05/17/1994

12/30/2014

Dept. of Public Works - Water Resources

Howard County

04/17/1995

12/18/2014

Dept. of Public Works / Stormwater Management Division

State Storm Drain Systems

State Highway Administration

01/08/1999

10/09/2015

Office of Environmental Design

Summary of Local Requirements
 
NPDES municipal stormwater permits require the jurisdictions to develop comprehensive programs to reduce storm drain system pollution to the MEP. Typical NPDES stormwater permit conditions require jurisdictions to: 
  • Legal Authority: provide certification from appropriate legal counsel that adequate authority exists to control discharges from the municipal storm drain system
  • Source Identification: map storm drain pipes and best management practices (BMPs), land use, impervious cover, and watershed restoration projects in geographical information system (GIS) format
  • Management Programs: implement erosion and sediment control, stormwater management, illicit connection detection and elimination, and public education and outreach programs
  • Watershed Assessment: evaluate all urban watersheds thoroughly regarding water quality and develop goals and action plans for restoration,
  • Restoration Projects: restore 20% of uncontrolled impervious surfaces based on watershed assessments during each five-year permit cycle
  • Assessment of Control: document work toward meeting watershed restoration goals, including total maximum daily loads (TMDLs)*, using chemical, biological, and physical monitoring
  • Program Funding: provide an annual fiscal analysis of the capital, operation, and maintenance expenditures necessary to comply with permit conditions
More information on TMDLs may be found on MDE's webpage here: Introduction to TMDLs
 

 Contact Info

Questions about NPDES municipal permits may be directed to the Sediment, Stormwater, and Dam Safety Program at 410-537-3543 or emailed to Mr. Raymond Bahr at Raymond.Bahr@maryland.gov. ​​​

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