D.C. Code § 34-2405.05
Property in the County of Washington, not subdivided into blocks or lots, or both, shall not be assessed for water mains or service sewers until subdivided; provided, that where houses are built on any unsubdivided land and connection is made with a water main or service sewer, assessment shall be made as herein provided for in the case of subdivided property by assessing a frontage of 50 feet on each side of said connection with a depth of 100 feet, except that no double assessment shall be levied; said assessment to be levied within 60 days after said connection is made; and if such unsubdivided land is thereafter subdivided into blocks or lots, such lots shall be assessed as herein provided as to subdivided lands, but the 50 feet on each side of said connection, with a depth of 100 feet, shall not be again assessed; provided further, that assessments at the rate and in the manner herein provided for shall be levied against each lot or parcel of land abutting any water main or service sewer in all subdivisions of land, within 60 days after the recording of such subdivision in the office of the Surveyor of the District of Columbia, except in cases where said lots or parcels of land have been previously assessed for the same main or service sewer.
D.C. Code § 34-2405.05