Office of Rail and Road (ORR)  25 Cabot Square, London, E14 4QZ Railway services  Water Services Regulation Authority (Ofwat) Centre City Tower 7 Hill Street Birmingham B5 4UA Water and sewerage services in England and Wales  Northern Ireland Authority for Utility Regulation (NIAUR) Queens House 14 Queen Street Belfast BT1 6ED Electricity, gas, water and sewerage services in Northern Ireland  Civil Aviation Authority Aviation House Beehive Ringroad Crawley West Sussex RH6 0YR Airport operation and air traffic services