Mr. Paul Mulvaney:

The remedial work is the easier piece. Finding the leak can take time. We have invested in new technology such as sniffer vans. We put gas into the fluid and if it leaves the cable, a passing van can take a sample of the gas. We also have a gas concentrator and a chromatograph that studies the gas and can pick up a concentration. Assuming the gas is penetrating the ground, one can home into the leak within a radius of 3 m.