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Public Water & Sewer Service

Image of a community utilizing a public water service.

The water from the faucets in your home or business is piped in from a water filtration plant—probably some distance away—by the local water/wastewater utility. When you flush the toilet or pull a drain plug, the wastewater is piped out of your home or business to a wastewater treatment plant—again, probably some distance away—by the local utility.

The utility owns and operates the water supply and wastewater disposal system facilities (or infrastructure), and you pay the utility to provide the service.

This arrangement is referred to as "public" water and sewer service. Some people might refer to it as "city water and sewer"; Maryland classifies it under state law as "community water and sewer service."


Is Public Service Available Everywhere in the County?

Residents and businesses in Montgomery County use a combination of public water and sewer service and private, on-site service (wells and septic systems), depending on their location. Public water and sewer service in Montgomery County is generally available where higher density development patterns exist or are planned—in the down-county region straddling the I-495 Beltway and along the major transportation corridors in the up-county. These areas include:

  • The I-270 and Maryland Rte. 27 (Ridge Road.) corridor running out through Germantown, Clarksburg, and Damascus.

  • The Maryland Rte. 97 (Georgia Avenue) corridor running out through Aspen Hill, Olney, and Brookeville.

  • The U.S. Highway 29 (Columbia Pike) corridor running out through Fairland and Burtonsville.

In the lower-density suburban and rural areas of the County, where public service is usually not available, private, on-site systems (almost always wells and septic systems) provide sanitary service.


Public Service Map

Properties designated as categories 1 and 3 are eligible to receive public water and/or sewer service. Read the full description of property water and sewer categories to determine your property's eligibility for service. 

Visit the Montgomery County Map Viewer to display a map of the County and learn what type of service your property gets.

Learn how to display the map and find your property's service category.  


Where Does Your Water Come From?

Montgomery County's public water supply comes from the Potomac River or the Patuxent River. The Potomac River supplies most of the public system in the County, while the Patuxent River serves a smaller area in the eastern part of the County.

A typical public water system starts off with a raw (untreated) water source from which the state has authorized the water/wastewater utility to draw its supply. The source may be a surface water source (e.g., river, reservoir) or an underground source. Montgomery County's source water is the water flowing in the Potomac and Patuxent rivers. The raw water goes through a filtration and treatment process to ensure that it meets federal drinking water standards.

Once the water is treated, the utility pumps it through a series of pressurized water mains and storage tanks and finally through relatively small connections into customers' homes and businesses. The treatment plants in Montgomery County are the Potomac Water Filtration Plant and the Patuxent Water Filtration Plant.

Where Does Your Wastewater Go?

A typical public sewerage system starts with wastewater (or sewage) generated in a home or business, which flows through a service connection into sewer mains along the street. The sewage in the local mains are collected by progressively larger mains and pumping stations until they reach a wastewater treatment plant. The wastewater system is usually constructed to allow sewage flows to travel downhill by gravity through the system. Wastewater pumping stations are needed to pump into pipelines that occasionally go uphill.

Most of the wastewater generated in Montgomery County flows to a large pipeline that runs parallel to the Potomac River until it reaches the pumping station and the Blue Plains Wastewater Treatment Plant in Washington, D.C. After the wastewater is treated at the Blue Plains Wastewater Treatment Plant to a very high level of purity, it is discharged to the Potomac River near the southern tip of Washington, D.C.


Public Service Providers

Three public utilities own and operate the public water and sewer systems that serve the residents and businesses in Montgomery County:

1. The Washington Suburban Sanitary Commission

The Washington Suburban Sanitary Commission (WSSC) is a bi-county agency created in 1917 by an act of the Maryland legislature to build, own, and operate the public water and wastewater systems in Montgomery and Prince George's counties. WSSC also has service agreements with the City of Rockville and Washington, D.C. Of the three public utilities, WSSC is by far the largest, serving thousands of households, businesses, and institutions. WSSC serves customers in the unincorporated parts of the County and in municipalities like Gaithersburg, Kensington, and Brookeville. Its potential service area, designated as the Washington Suburban Sanitary District (WSSD), includes almost all of Montgomery County. The exceptions are most of the City of Rockville and all of the Town of Poolesville.

2. The City of Rockville

Public water and sewer systems owned and operated by the City of Rockville serve most properties within the city, although the WSSC also provides service to some Rockville neighborhoods. The City of Rockville's own water filtration plant takes advantage of its proximity to the Potomac River for its water supply. WSSC pipelines transport wastewater from Rockville to the Potomac Interceptor, from which it is sent to the Blue Plains Wastewater Treatment Plant in Washington, D.C.

3. The Town of Poolesville

Public water and sewer systems owned and operated by the Town of Poolesville now serve or will serve all properties within the town. Poolesville's wastewater treatment plant, near Dry Seneca Creek, also serves customers in the adjacent Jonesville and Jerusalem communities through a contract with WSSC.