DitchWitch ground penetrating radar[]
http://www.ditchwitch.com/dwcom/Product/ProductView/11038
The new 2150GR ground penetrating radar is your eyes underground. Use it to detect and locate both metallic and non-metallic pipes and cables to depths up to 19’ (6 m), depending on soil conditions and antenna selection. With the ability to survey in both forward and reverse, and with survey speeds up to four times faster than the competition, the Subsite® 2150GR has eyes you can trust, from the most trusted name in underground electronics.
The HDD operators under HorizontalDirectionaldrilling all have GPRadar machines that can be hired.