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Development Process Resources

Development Plan Review

Before new construction in Montgomery County can take place, a property owner, developer, or builder must demonstrate that each building requiring sanitary service will have both an adequate fresh water supply and a wastewater disposal system. This service may be provided by public water and sewerage systems, by private wells and septic systems, or by a combination of public and private service.


DEP Input to the Development Review Committee

A developer typically proposes a subdivision plan to divide a tract of land into building lots, streets, and open space. The developer submits the plan to the Montgomery County Department of Planning in one or more of several forms (e.g., preliminary plan, site plan, project plan) depending on the site's zoning and development concept. These proposed plans are reviewed by the Development Review Committee (DRC), an interagency committee that reviews and comments on new and revised development plans. The DRC's recommendations are brought before the five-member Montgomery County Planning Board for consideration and final action.

The DRC is made up of staff from

The DRC meets in regularly scheduled sessions that are open to the public but are not public hearings. DEP verifies whether the water and sewer service systems proposed for each plan are consistent with the policies and service area designations in the Water and Sewer Plan. DEP staff members report their findings for each proposed plan scheduled for the DRC meeting to the Maryland-National Capital Park and Planning Commission (M-NCPPC), the Washington Suburban Sanitation Commission (WSSC) and the Department of Permitting Services (DPS). They send a copy of the comments to the project engineer or planner designated on the M-NCPPC plan review application form.

M-NCPPC staff members forward recommendations on subdivision plans to the Montgomery County Planning Board for consideration and action. Plans that do not satisfy the Water and Sewer Plan's requirements cannot proceed to consideration and approval by the Montgomery County Planning Board until all inconsistencies are resolved. In some cases, the development site completes a service area category change request. In others, the plan is altered to conform to the type of sanitary service designated for that area of the County.

Developers or project engineers may find it helpful to contact DEP staff to discuss the water and sewer proposals for new projects—especially those that may require a category change approval—before submitting a development plan to M-NCPPC. For further assistance, contact the Department of Environmental Protection at or call 311.


Water/Sewer Service Coordination with the Master Planning Process

Local area master plans and sector plans are crucial to coordinating the development planning and water/sewer planning processes. These plans direct the character, pattern and density of development in the County's communities. The level of coordination between master plans and water/sewer service planning varies. A sector plan for downtown Bethesda, an area served exclusively by public systems, will not deal much with water and sewer service. However, the recently approved master plan for Damascus, where the boundaries between areas served by public utilities and private water and sewer systems have changed, will deal with the subject at more length. For master plan areas such as Damascus, DEP staff members are usually involved in the master plan development, review, and approval process from the early stages.


Record Plat Approvals and RPIF

DEP's coordination with the development review and approval process continues through the recordation of subdivision plats. In most cases, this is DEP's final verification that proposed development will conform to the requirements of the County's Water and Sewer Plan. For each plat submitted, DEP staff cross check the sanitary systems proposed with the existing service area categories in the Water and Sewer Plan. This includes verifying consistency with any service conditions or restrictions applied to those water and sewer categories (e.g., single hookups, use of cluster, multiuse systems).

For plats that propose sewer service from Washington Suburban Sanitary Commission, DEP also calculates a daily anticipated sewage treatment capacity for the development resulting from each plat. This calculation is based on standard treatment flow factors for various types of development as provided by WSSC. For example:

  • A single-family house has a treatment flow of 300 gallons per day (GPD).
  • A townhouse has a treatment flow of 230 GPD.

  • A public elementary school has a treatment flow of 5.38 GPD for each student and teacher.

  • A bank has a treatment flow of 0.044 GPD for each gross square foot of the building.

These treatment flows are reported to WSSC and placed in reserve at the specific wastewater treatment plant receiving the flow from that development project; for example, Blue Plains Wastewater Treatment Plant or Seneca. This effort results from a mandate from the State of Maryland to ensure that the County and WSSC have reserved sufficient wastewater treatment capacity for approved development. The County's plat-processing and flow calculations do not cover Rockville, Gaithersburg, or Washington Grove at this time.


Record Plat Information Form

The DEP Record Plat Information Form (RPIF) is intended to provide the information needed for DEP to complete its review and approval of the plat. This avoids delays in processing while DEP stops to contact the project engineer to verify the intended sanitary service or the type and amount of development proposed.

DEP requires that the project engineer submit a single copy of the draft plat and a completed DEP Record Plat Information Form (RPIF) to DEP for each plat. The RPIF should be returned to: Water & Wastewater Division, DEP, 255 Rockville Pike Suite #120, Rockville, MD 20850.

Download a copy of the Record Plat Information Form (RPIF) (.doc, 77.5KB)

Be Aware! DEP should receive these materials only after the draft plat has been assigned an M-MCPPC file number (e.g., 2-09478 or 220094780).


Real Estate Transaction Disclosures

When considering any property purchase, it's important to understand how that property gets its water supply and handles wastewater disposal. In real estate transactions in Montgomery County, the seller must disclose information concerning the availability of water and sewer service. The Greater Capital Area Association of Realtors (GCAAR) has developed a disclosure form for this and other purposes (e.g., property taxes, special protection areas, forest conservation). On the disclosure form, the seller can provide the buyer with information on the following water and wastewater issues:

  • Existing water and sewer service, public (WSSC, Rockville, or Poolesville) or private (on-site well and septic system)

  • Status of proposed water and sewer service, typically for unimproved properties or those changing from private systems to public service

  • Water and sewer service area categories

  • Master plan recommendations for water and sewer service

  • Status of County Water and Sewer Plan amendments that affect the availability of water and sewer service to the property

  • Location of private, on-site wells and septic systems, by means of a copy of the recorded subdivision plat and any on-site system limitations or restrictions

  • Private company utility assessments, which may include those charged for public water and sewer main installation. Note that utility installation assessments from WSSC, in the form of front foot benefit charges, appear on the property tax bill.

The seller's agent provides the disclosure form as part of the materials needed for settlement of the property transaction. 

If you need water and sewer category information to complete a disclosure form, please feel free to contact DEP staff by email at or by telephone at 311.  (Outside of the county call 240-777-0311.) You may also contact DEP if a disclosure form provided to you by a seller does not include service area category information you want to see.  Note that, in the majority of cases researched by DEP, a property currently served by public water and sewerage systems is already designated as categories W-1 and S-1.