BRISBANE CITY COUNCIL WATER DISTRIBUTION IMPLEMENTATION OF AN ASSET MANAGEMENT PLAN FOR CATHODIC PROTECTION OF BURIED AND SUBMERGED METALLIC INFRASTRUCTURE

摘要

The structure of the Asset Management Plan (AMP) for Cathodic Protection adopted by Brisbane City Council Water Distribution (BCCWD) is based on the model outlined in the 2006 edition of the International Infrastructure Management Manual, Version 3.0. This paper covers some of the opportunities discovered in the development of the AMP [1]. The need for automatic data retrieval using a telemetry system became obvious as pictures started to emerge from data stored in filing cabinets. The data was then coordinated on a geographical interface system (GIS) to assist in spatial analysis. The visual representation combined with the user friendly database query methods was useful. Low protection levels on some water trunk mains were also identified. Overall the results indicated excellent protection levels. Economic analysis indicated a need to ramp up retrofitting to existing mains to maximise the economic benefit. Benchmarking the protection current densities compared favourably with international standards. Areas for improvement were listed in a comprehensive GAP analysis to be addressed over a five year period. Research was immediately started on a telemetry system for CP both to improve data management and to free up resources to focus on CP installation rather than monitoring. A three year research grant was established with the Queensland University of Technology to examine corrosion protection for inner surfaces of water pipes. Income and expense cash flow projections for cathodic protection of trunk water mains have been made for different rates of expenditure. Reference Figures X. & XI Economic assessment indicated that the optimum expenditure for installing cathodic protection on the existing mains should be increased in two steps from $440K to $900K per annum in order to have all mild steel trunk water mains cathodically protected within 15 years. The annual savings will then increase.