AES Kilroot Power Station (KPS), near Carrickfergus, some 12 miles northeast of Belfast, is an oil and coal burning power station that produces around one third of Northern Ireland’s electricity. Being such an important power generator for the area, however, the current facility must be kept at its best efficiency and operational performance at all times. As part of the ongoing maintenance work to ensure this performance is achieved, a CCTV survey of the existing 420 mm diameter, steel, sea water pipelines which have been in use for over 30 years was undertaken. The survey showed signs of severe encrustation and corrosion, with, in places, up to 30% of the pipe cross section being obstructed. Corrosion had also removed a length of approximately 7.0 m in the invert of one pipe and there were also numerous small holes throughout the length of the pipes which allowed the ingress of water in the form of jets and seepage.