Leak detection system for underground access chambers using conductivity

An electrically conductive probe, such as a probe similar to those utilized in other electric leak detection systems, is positioned electrically adjacent to different regions of a wall of an underground access chamber, for detection of leaks therein. In one embodiment, the probe is positioned at an elevation and circumferential position which is sequentially adjusted so that the probe can scan regions of the wall for leaks. In another embodiment, a modified probe remains centrally located within the underground access chamber and only moved vertically. The modified probe is fitted with whiskers extending radially. The modified probe includes sectors circumferentially spaced from each other and with each whisker associated with one of the sectors. A selector switch electrically connects one sector to the electrically conductive cable. Data collected by either probe can be graphed or otherwise analyzed with regions of high conductivity correlating with leaks in the underground access chamber.