Planned approach needed to ensure clean water supply
The Selangor Water Works Department (JBAS) has recently announced that all existing asbestos cement (AC) pipes, about 5,000 km of various diameters and ages, would be replaced with pipes of other materials at an estimated cost of RM1.2 billion. This project is aimed at reducing the high level of leakage in pipelines and solving the perennial problem of dirty tap water. The Federal Government is also providing a soft loan of RM500 million for this project.

The response from the public is predictably very supportive, as most consumers in the State, particularly in Klang Valley, believe that soon they would be able to enjoy an uninterrupted supply of clear potable water and dispense with the use of water filters.

However, the wholesale AC pipe replacement alone, if carried out without any strategic planning, will not be cost-effective and not be able to solve all the inherent weaknesses of the present distribution system.

In Selangor, the total length of AC pipes laid amounts to over 5,000 km, which accounts for about 50% of the total reticulation mains in the State. The rest are mild steel, uPVC, ductile iron, cast iron and high/medium density polyethylene. Due to rapid development, particularly in the Klang Valley, the distribution networks have expanded and become very complex. It is not uncommon to find a mixture of two or more types of pipes in the network giving rise to their own problems.

Apart from AC pipes, others are leaking as well. This could be due to corrosion of metallic pipe walls and fittings, aging of pipes and poor workmanship in pipeline installation and jointing. Changes in the environment of the pipe can also lead to breakage of pipelines and dirty water problems. These include increased vehicular traffic loading, redevelopment in an area, changes in water pressures in the system and reversal of flow. Therefore, mere replacement of all AC pipes cannot be a cure-all for all the woes currently faced by JBAS and consumers in Selangor.

In a very complex distribution network like the Klang Valley's, which has deteriorated over the years due a lack of investment and maintenance, the solution of its various problems cannot be so simple that it can be economically rectified without a significant degree of investigation and planning.

What is needed is a planned holistic approach in pipeline rehabilitation and/or replacement. JBAS should first prepare a plan showing the physical works, both immediate and long term, required to bring the water supply networks back to a steady state. This way, predetermined service standards like pressure, flow, interruptions, reliability and water quality complying with Ministry of Health's Drinking Water Quality Standards can be met.

This plan is commonly known in the water industry as the Underground Asset Management Plan (AMP). This AMP is a strategic programme of capital works to be carried out over a given period of time, say in 5-year segments over a 20-year period, to meet the identified shortfalls in the network's performance and condition. An important component of this AMP is the provision for monitoring the effectiveness of such a programme to ensure the objectives are being met.

Without an AMP, JBAS traditionally adopts an ad hoc replacement of pipelines when recurring difficulties have become intolerable. Although this form of alleviation may be effective in the short term, it does not allow a proper controlled programming of expenditure and does not identify the root causes of the problems.

The soft loan of RM500 million from the Federal Government is a golden opportunity for JBAS to initiate a first ever 5-year AMP to rehabilitate the long neglected water supply distribution systems in the State. 2007