DTD has specialised in the environmental applications of horizontal directional drilling since its founding in 1996. Following acquisition by Ellingson Companies in 2019, DTD expanded its personnel and equipment capabilities, enabling broader reach and more robust project support. With offices in Bellefonte, Pennsylvania, Mineral Wells, Texas, and Ellingson facilities in West Concord, Minnesota and Fargo, North Dakota, DTD has completed wells throughout the United States and across multiple European locations. DTD leads the industry in installed footage of completed operational wells, and in partnership with Mears/HDD, designed and installed both the longest horizontal remediation wells and the longest horizontal monitoring wells in the world.