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Stormwater Regulation & the County's Efforts

For most urban areas like Montgomery County, what goes into our storm drains (stormwater) makes its way into our local streams. Those streams are part of larger watersheds that lead to major rivers, like the Potomac River, and eventually the Chesapeake Bay. Because our waters are interconnected and not defined by county or state lines, the federal government regulates everything that goes through storm drain systems. 

The federal government regulates storm drains through a permit process called the Municipal Separate Storm Sewer System Permit Program (AKA the MS4 Permit Program).  

Montgomery County has an MS4 Permit that mandates the County to meet certain water quality standards. The Permit is given every 5 years and our latest permit ended February 2015.  For a more detailed explanation of the MS4 Permit and to read the permit, click here. 


The County's Progress at Cleaning Our Waters

In the most recent Annual Report on our MS4 Permit, the County noted the following progress towards meeting its MS4 Permit Requirements:


Watershed Restoration Planning and Implementation 

The Department of Environmental protection (DEP) is the lead agency for projects to reduce stormwater runoff impacts. During Fiscal Year 2014, DEP:

  • Had stormwater restoration projects in design or construction that will treat the runoff from over 3,976 acres of impervious areas.
  • Completed watershed studies, including identifying restoration projects within the Seneca Creek, Patuxent River, Lower Monocacy, and Upper and Lower Potomac Direct watersheds.
  • Provided stormwater management to over 12 acres of impervious area through the RainScapes Program, which supports and constructs small scale residential stormwater management practices for both single lots and neighborhoods.
  • Watershed restoration projects are monitored to assess achievement of stream habitat and biological improvement.


Image of a stormwater management pond
The new pond installed at the National Institutes of Health captures and slows stormwater and removes pollutants.


Reducing Pollution

DEP is the lead agency for enforcement of water quality laws that reduce pollution to our waterways. During Fiscal Year 2014, DEP:

  • Assessed 154 storm drain outfalls in the Little Falls watershed for illegal discharges.
  • Discovered 3 illegal discharges through the storm drain system, and identified and remediated the sources.
  • Responded to 264 water quality related complaints resulting in 68 enforcement actions.

DEP also partnered with other County agencies to reduce pollution.

  • DEP, the Department of General Services (DGS) and the Department of Transportation (DOT) work together to reduce pollution from County Highway Depots. During FY14, the DGS upgraded the used oil handling area at the Brookville Depot. In addition, all County Depots are now routinely swept.
  • All County industrial facilities submitted Notice of intents (NOIs) for coverage under the MDE’s new General Discharge permit for Stormwater Associated with Industrial Activities, and updated their Stormwater Pollution prevention Plans.
  • The DEP and the DOT jointly funded street sweeping that covered 8,413 curb miles, removing 1,387 tons of street pollutants
  • The DOT removed 217 tons of roadway pollutants from storm drain inlets and pipes through its infrastructure maintenance program.
  • The Department of Permitting Services (DPS) conducted 18,151 erosion and sediment control inspections, resulting in 250 Notices of Violation and 160 civil citations during construction of development projects.


Image of a street sweeper
County contractors removed 916 tons of roadway
pollutants from County Streets.


Meeting County Total Maximum Daily Loads (TMDLs)

The MS4 Permit requires implementation plans showing how the County will achieve pollutant load reductions to meet waste load allocations for any Environmental Protection Agency approved Total Maximum Daily Load (TMDL). Watershed Implementation Plans for all County TMDLs approved as of 2010 can be found in the Countywide Implementation Strategy. 

DEP made progress towards meeting the Chesapeake Bay TMDL by reducing nitrogen and phosphorous through watershed restoration and other stormwater best management practices. In Fiscal Year 14, County pollutant reductions achieved 4.4% of the nitrogen pollution reduction goal required to meet County’s share of Chesapeake Bay TMDL, and 20% of the phosphorous pollution goal. 

Learn more about Total Maximum Daily Loads


Maintaining Existing Stormwater Management (Facilities)

DEP oversaw triennial inspection of 1,143 stormwater management facilities, and oversaw maintenance and repairs on 1,871 facilities. DEP also began contracting for routine maintenance of publically owned ESD practices.


Educating and Engaging Coomunities

The DEP is the lead for implementing the Public Outreach and Education Workplan. The workplan was developed in the County Coordinated Implementation Strategy to highlight targeted restoration and outreach activities for the County to develop and refine. During Fiscal Year 2014, DEP :

  • Continued to expand outreach and education to increase stormwater awareness by reaching out to 12,639 residents at 140 events.
  • Continued the Stream Stewards program to train County volunteers to further watershed outreach in communities.
  • Supported local watershed groups through capacity building and training workshops.
  • Focused efforts to provide outreach to culturally diverse communities.
  • Conducted a pet waste program, working with homeowner’s associations to install pet waste stations in high use areas.
  • Conducted a storm drain art program to raise stormwater pollution awareness. 
  • Developed a “Caching the Rain” geocaching trail with a stormwater pollution focus.
  • Established a local chapter of the national Frogwatch program.


Image of the Geneva Day School conservation landscaping
Volunteers at the Geneva Day School 
Train the Trainer Workshop


Montgomery County Public Schools

Montgomery County Public Schools (MCPS) is an MS4 Co-Permittee and thus required to implement and report on programs to address runoff pollution. MCPS is responsible for maintaining many of the Stormwater Best Management Practices on their sites and for implementing stormwater pollution prevention programs at the MCPS Bus Depots.

MCPS participates with DEP to identify and implement stormwater retrofit opportunities, including Environmental Site Design (ESD) practices on school property. MCPS is aggressively incorporating ESD practices into school building renovations.


Reducing Litter

In May 2011, the County adopted a carry-out bag fee to increase awareness about the problem of litter in our local streams and to offset costs of clean up for those who chose to use disposable bags. The law went into effect in January 2012. DEP is the lead agency for regional efforts to reduce trash and litter to the Potomac River and its tributaries through the Regional Anti-Litter Campaign with the Alice Ferguson Foundation. During FY14, DEP:

  • Continued tracking the results of the carryout bag law program on reducing plastic bags in the environment. DEP currently does not have enough data to definitively report a change in bag usage in the County.
  • Used the regional anti-litter campaign materials in mass media outreach, including on metro buses and at bus stops.
  • Worked with volunteers for litter clean ups in streams and at stormwater management ponds.
  • Participated in the annual Potomac Trash Summit sponsored by the Alice Ferguson Foundation.
  • Targeted the White Oak neighborhood in Silver Spring for an anti-littering campaign.
Image of a Stream Steward educating a Montgomery County resident
The Stream Steward program trains volunteers to serve as ambassadors for the DEP. 



DEP is the lead agency for the monitoring required in the MS4 Permit. The MS4 permit requires the County to conduct monitoring to determine how well stormwater management practices reduce stormwater quantity and pollution. DEP is constructing several small scale stormwater management practices in the Breewood tributary, a small subwatershed of the Anacostia.

The County currently monitors biological, water chemistry, and physical conditions in the Breewood tributary to document pre-restoration conditions. DEP also monitors the physical condition of streams in the Clarksburg Special Protection Area (SPA) to determine the effectiveness of stormwater management meeting the criteria of the Maryland Stormwater Design Manual. DEP monitors County streams to assess stream biological and habitat conditions.



The County reported that $51,728,358 was budgeted to meet the MS4 Permit required programs. The majority of these funds are provided through the Montgomery County Water Quality Protection Charge (WQPC). In FY14, the WQPC provided $24,101,094.


What is the MS4 Permit?

In Maryland, the Maryland Department of the Environment is responsible for issuing all NPDES permits in the state, including the MS4 Permits. Read more about the Maryland MS4 Permitting program. (The state of Maryland has the authority to issue permits on behalf of EPA.)

The MS4 Permit Programwas established to reduce and eliminate stormwater pollution throughout the United States. The primary goal of the program is to restore and maintain the chemical, physical, and biological integrity of the nation's waters.

The County's Permit requires the County to restore poor quality streams and meet water quality protection goals. To protect our local streams and meet regulatory requirements, runoff must be captured, slowed and treated by stormwater best management practices.

The Department of Environmental Protection is the lead department coordinating a multi-department/agency response to meet the requirements of the MS4 Permit. The permit is a key driver of the County's strategic watershed management program. 

View the County's MS4 Permit. (PDF, 1.3MB)


MS4 Permit Requirements

The MS4 Permits are issued for a five year cycle.  The County’s current MS4 Permit was issued on February 16, 2010 and expires February 15, 2015.  If the County does not comply with the MS4 Permit requirements, it may be subject to civil or criminal fines.

Image of a restored section of Booze Creek
The restoration of Booze Creek was one of many projects completed to meet the MS4 Permit requirements.

During this five-year cycle, the County is required to: 


Current Permit: Annual Report


Annual Reports


Interjurisdictional Agreements

Montgomery County is situated in the central corridor of Maryland between Baltimore and Washington, D.C. The County, given its drainage area size and population density, has a considerable impact on both regional and local environmental resources. It is a signatory to regional watershed protection agreements and coordinates watershed management with neighboring jurisdictions to protect and improve shared resources.



Anacostia Watershed Restoration Agreement

The Anacostia River flows through Montgomery and Prince George's counties into Washington, D.C., and then to the Potomac River. It has been identified as one of the three most polluted rivers in the entire Chesapeake Bay watershed. In 1987, the Anacostia Watershed Restoration Agreement was signed by the local, state, and federal agencies with land and management responsibilities in the Anacostia watershed. Since the agreement was signed, significant strides have been made to:

  • Develop a committee structure to determine how the goals of the agreement are to be reached

  • Establish a process for developing a work plan and milestones for the various restoration activities

  • Provide a framework for evaluating pollution control efforts with regard to observed water quality and aquatic life benefits

  • Institute mechanisms and measures for tracking progress and reporting on it as it occurs

The Metropolitan Washington Council of Governments supports the website on behalf of the members of the Anacostia Watershed Restoration Partnership. Visit for background on natural and cultural resources, along with news, meeting minutes, recent progress reports, and other watershed-based information.


Patuxent River Commission

Montgomery County is a member of the Patuxent River Commission, an interjurisdictional group that addresses environmental protection issues throughout the Patuxent River watershed. The 930-square-mile watershed is entirely within Maryland. It has been the focus of innovative policy, planning, and implementation efforts since 1980, beginning with a "charrette" that resulted in establishing the state's first nutrient reduction goals for wastewater treatment plants.

Commission members are committed to identifying relative roles and responsibilities to protect the watershed, tributaries, river, and reservoirs in the Upper Patuxent. They established six priority resources for protection:

  • Reservoirs

  • Tributary streams

  • Aquatic life

  • Terrestrial habitat

  • The watershed's rural character and landscape

  • People in the watershed

Every year the Commission reports on funding and policy commitments and progress in achieving long-term protection of these water resources.


Image of a litter bus ad produced by the Potomac Watershed Trash Initiative.

Potomac River Watershed Trash Treaty 

Since 1989, the Alice Ferguson Foundation has organized annual cleanups along the Potomac and its tributaries. In 2003, the Foundation began to galvanize federal, state, and local elected officials to participate in a strategy to prevent trash from entering local waterways. Montgomery County signed the Potomac River Watershed Trash Treaty and has committed, along with other local jurisdictions, to achieving a trash-free Potomac by 2013 by:

  • Supporting and implementing regional strategies aimed at reducing trash and increasing recycling

  • Increasing education and awareness of the trash issue throughout the Potomac River watershed

  • Reconvening annually to discuss and evaluate measures and actions addressing trash reduction


Maryland Local Government Agreement for Chesapeake Bay Restoration

In 1992, the Chesapeake Bay Program completed a reevaluation of the status and trends in water quality of the bay and its tidal tributaries. This led to both the allocation of nutrient reduction targets among the signatory states and the Maryland Local Government Agreement. Originally signed by the Governor, counties, and the City of Baltimore in 1993, the Agreement was updated in 2000 to outline commitments by the state and local governments to address the goals of the Chesapeake Bay Agreement at the local level.


Maryland Water Monitoring Council

The Maryland Water Monitoring Council was created in 1996 by the Maryland Department of Natural Resources. The Council serves as a statewide collaborative body to help achieve effective collection, interpretation, and dissemination of environmental data related to issues, policies, and resource management objectives involving water monitoring.

The Council addresses the full range of aquatic resources—groundwater and surface waters; freshwater, estuarine, and marine environments—and associated watershed resources in Maryland. Montgomery County has participated in all Council activities since 1996, which helps to protect and manage the County's aquatic resources with increased scrutiny from a broad scientific and water resource management network.


Financial Assurance Plan


The 2015 revisions to Section 4-202.1 of the Maryland Environment Article, Watershed Protection and Restoration Programs, require all Maryland Phase I National Pollutant Discharge Elimination System Municipal Separate Storm Sewer System (MS4) Permit jurisdictions to submit a Financial Assurance Plan (FAP) demonstrating that each jurisdiction will have adequate funding to meet their permit requirement for impervious surfaces restoration. The jurisdictions must submit a FAP to the Maryland Department of the Environment (MDE) by July 1, 2016, and every two- years thereafter on the anniversary date of its MS4 permit, that details the following:


  • All actions required to meet MS4 Permit requirements
  • Annual and projected five-year costs necessary to meet the “impervious surface restoration plan” (ISRP) requirement, more commonly known as the 20% restoration requirement in current permits
  • Annual and projected five-year revenues that will be used toward meeting the 20% restoration requirement
  • Any and all sources of funds used toward meeting MS4 Permit requirements
  • All specific actions and expenditures undertaken in the previous fiscal years to meet the 20% restoration requirement


The FAP format is an excel workbook developed by MDE to capture most of the information needed to meet the requirements of the law. “All actions required to meet MS4 Permit requirement” are detailed in the executive summary of Montgomery County’s FY15 NPDES MS4 Annual Report, submitted to MDE in March 2016.


Maryland law (Md. Code Ann., Envir. § 4-202.1 (j) (4) (ii)) states that funding in the FAP is sufficient as long as it demonstrates that the County has dedicated revenues, funds, or sources of funds to meet 75% of the projected costs of the County’s MS4 Permit required impervious surface restoration plan for the two-year period immediately following the filing date of the FAP (FY17 and FY18). The FAP demonstrates that the County has sufficient funding in the current fiscal year and subsequent fiscal year budgets to meet 100% of the estimated costs of its impervious surfaces restoration plan for the two-year period following the filing of this plan. The Montgomery County Department of Environmental Protection completed the FAP using the recommended FY2017 Operating budget and the recommended FY2017-FY2022 CIP budget.


Section 4-202.1 requires a jurisdiction’s local governing body to hold a public hearing and approve the FAP before it can be submitted to MDE.


The Department of Environmental protection (DEP) is the lead agency for projects to reduce stormwater runoff impacts. During Fiscal Year 2014, DEP: