Before anyone digs for a sewer line: the 811 rule in New York
Updated October 30, 2026 · 2-minute read · Old House Sewer Lines
In New York, whoever machine-digs for a sewer line must dial 811 first, giving the one-call center a window of 2 to 10 working days before the dig starts. The day of the call does not count, and member utilities then mark their buried lines.
The rule is in the state's Part 753 regulation, 16 NYCRR 753-3.1 (Cornell LII copy). In Westchester the call reaches UDig NY, the state-recognized one-call center, also known as Dig Safely New York; New York 811, Inc. serves New York City and Long Island. The NYS Department of Public Service, in an April 2026 release, said dialing 811 reaches the right center (DPS). The request is free.
Who has to call
Part 753 puts the notice duty on an "excavator", defined as anyone in a trade or business that includes excavation or demolition. It defines excavation as work with mechanized equipment or blasting; digging with hand tools and vacuum excavation are not "excavation" under the rule (16 NYCRR 753-1.2). UDig NY tells homeowners that a hired contractor is required by state law to place the request (UDig NY, Homeowners). Con Edison's guidance is broader: whoever is digging, homeowner or contractor, should call 811 before excavating, and it names repairing drainage pipes as one example (Con Edison).
Sewer replacement, pipe bursting pits and spot repairs by open cut are licensed contractor work with permits. So on a hired sewer job, the contractor makes the 811 request. Ask for the ticket number before the machine arrives.
What gets marked, and what does not
UDig NY's member utilities must respond within two business days, not counting the day the request is submitted. Their marks show the utilities' own lines. UDig NY states plainly that members "do not locate and mark private facilities on your property." The sewer lateral from the house to the main belongs to the property owner, according to Westchester County, so it is not on the markout.
That gap has consequences in both directions. A crew digging for a sewer can hit an unmarked private line. A crew boring for a new gas service can hit an unmarked sewer lateral, which is how cross bores happen. A sewer camera inspection records the lateral from the inside, and the video survey the state code requires before bursting must note connection depths.
The tolerance zone
Part 753 sets a tolerance zone around each marked line: half the line's known diameter plus 2 feet on each side of the marked center line, or 2 feet each side when the diameter is unknown. Inside that zone, gas lines must be exposed and verified by hand-dug test holes before machines work nearby (753-3.6(b)). Con Edison's contractor guide reproduces that text.
Background: the NYS Department of Public Service oversees the one-call system under Part 753, and its 2026 release placed Westchester in UDig NY's area in 2026. An earlier 2025 release worded the boundary differently, which is one reason "dial 811" is the simplest instruction.
Video from CommonGroundAlliance, an outside channel: A dramatized call to 811 shows how the one-call center notifies utilities, who then mark buried lines before digging. Nothing loads from YouTube until you press play.
Key facts
- Notice must be given at least two but not more than 10 working days ahead, excluding the call date (16 NYCRR 753-3.1).
- Hand tools and vacuum excavation are not "excavation" under Part 753 (753-1.2).
- Member utilities must respond within two business days (UDig NY).
- One-call members do not mark private facilities such as the sewer lateral (UDig NY).
- The tolerance zone is half the known diameter plus 2 feet on each side of the center line (753-1.2).