We were involved in a recent project to upgrade electric transmission cables on a large company’s building complex. We were hired to locate and test hole conflict points for the trenching operations in the interior of the complex. At the same time a directional drilling company began working on installing the run along the edge of the property. The project management team had decided because the directional drilling would take place along public right of way they would rely on one-call 811 services to mark the existing utilities in that area and only use us for the portions of the project inside the site. During drilling operations they cut into a major telephone line and disabled communications over more than half of the site. One-call 811 had not marked it because that section of cable was the responsibility of the site even though it ran along public right of way. Although no one was injured during this incident, the damage to this important cable cost a loss of time for the drill crew and the facility itself. Private locating in combination with one-call 811 is the best way to ensure all utilities in the project area are marked and proper precautions taken to protect them.