811 Dig Safely New York July 11, 2017
According to the web site Dig Safely New York (https://www.digsafelynewyork.com/homeowners):

“Whether you are landscaping, building a fence or a deck, or installing a pool, no project that involves digging is too small or insignificant. If you are planning to dig on your property for any reason, state law requires you to place a location request with Dig Safely New York at least two (2) full working days, but no more than 10 working days, before beginning your project, to ensure all underground utility lines are properly marked by their owners.”

“If you do not plan to perform the excavation yourself, you do not need to contact Dig Safely New York; however, for your safety, you should verify your contractor has contacted Dig Safely New York.”
You can make the request by calling 811, or you can place the request online.