DCWASA will extend sanitary sewers to serve a house or building upon request by the owner or the authorized agent. When a sanitary sewer is not available to serve a new house or building, DCWASA will extend the sanitary sewer to the proposed point of connection with the sewer lateral upon request by the owner or the authorized agent. When an application for sanitary sewer extension is received by the Documents and Permit Section (DPS), it is reviewed to assure that it contains all the necessary information, which consists of the Application for Extension Form, sewer map, site plan and assessors plat if available. A sewer extension is required for a single-family lot when the existing sewer is more than 100 feet measured along the centerline of the street or public way abutting the lot. For all other types of buildings, a sewer extension is required when the existing sewer is more than 250 feet measured along the centerline of the street or public way abutting the lot.

If the application is complete, the DPS forwards the application with a copy of the counter map and proposed extension annotated to the Chief, Water, and Sewer Design Branch (WSDB). A Capital Improvement Project is established and forwarded for approval. It can take two years for the approval, design, and construction of a sewer extension.