The present invention relates to using a rectifier, a groundbed consisting of four copper rods, power supply, three coppercopper sulfate reference electrodes, a data logger for detecting and identifying buried lead and copper service pipes by their electrochemical potentials. The controller receives GUI HTML5 and Javascript from each connected hardware module, such as a camera, microphone, lighting controller and the like. The fumigant compositions also have low toxicity and low Global Warming Potential. Other methods are described and data processing systems and machine readable media are also described. This methodology is based on minimizing an objective function, wherein the objective function includes a loss term representing the performance of the objective function on a training dataset comprising at least two separate, adjustable weighting constants associated with classification errors for data points in-class and not-in-class, respectively. The method further comprises the following steps: identifying wavelengths that are usable along each of the route segments; and constructing a graph in which the vertices are the wavelengths usable in the route segments and the arcs joining each of two consecutive vertices are the transitions between the wavelengths represented respectively by said consecutive vertices.