The Washington Suburban Sanitary Commission determines what sewer line extensions may be necessary to service a particular development approved by the County Sewerage Plan. The WSSC also determines the conditions under which any needed extensions will be built, or sewer connections, or hook-ups authorized.

The WSSC permit system involves three basic types of sewer service permits which must be obtained. The type of permit needed depends upon the location and situation of the site in relation to the existing sewerage system.

Authorization Permit
The first requirement for a developer whose property is not served by an existing water or sewer line is an authorization. The authorization is a commitment by WSSC to build a new line from the closest existing line to the location of the new development site, and to size that line so that it will accommodate at least the volume of water needed and sewage flow estimated to be generated by the proposed development. An approved authorization implies that the subsequent required approvals for a connection and a hook-up will be granted so long as the developer meets established engineering standards, and capacity is available within the system.

Connection Permit
The next requirement is connection. That permit is a commitment by WSSC to build a connecting line from the main line in the street adjacent to the property to the edge of the property line of the proposed structure. Approval of a connection implies that subsequent approval of a hook-up will be granted so long as the developer meets established engineering standards.

Hook-Up Permit
The final step needed to allow the building to use the WSSC system is the hook-up. It permits the developer to install a pipe across his property to hook-up the plumbing in the building with the connecting lines that WSSC has built in the street.