Annual Water Pipe Leaks in Last Decade

8 Mr Leon Perera asked the Minister for the Environment and Water Resources what is the number of water pipe leaks each year for the past 10 years.

The Senior Minister of State for the Environment and Water Resources (Dr Amy Khor Lean Suan) (for the Minister for the Environment and Water Resources): Mr Deputy Speaker, the Public Utilities Board (PUB) operates a 5,500-kilometre network of pipes to deliver water to 1.5 million customer accounts. Over the last seven years, Singapore has experienced about six leaks per 100 kilometres (km) of pipes per year. This is down from about 10 leaks per 100 km of pipes per year in 2003 and 2004, and as I have noted earlier, among the lowest incidence in the world.

PUB has a stringent pipe laying regime to ensure that pipelines are well designed and implemented. PUB also constantly looks out for improved methods and materials, for example, the use of more corrosion-resistant polyurethane coating.

However, despite the best design and implementation, leaks do occur mainly because of corrosion, uneven soil settlement or damage from construction work. Corrosion and soil settlement can impact all pipes, especially as they age.

PUB has a comprehensive leak detection process to pick up leaks as early as possible. PUB conducts physical checks of its entire pipe network at least once a year, or more frequently where necessary. Portable acoustic leak noise data loggers are used to aid leak detection. Beyond detecting leaks, PUB has a Pipe Renewal Programme to pro-actively replace older pipes or pipes which are more prone to leaks due to local conditions. The renewal rate has increased from 20 km per year in 2016 to 30 km per year in 2017 and will reach 50 km per year in 2018.

For leaks due to construction damage, PUB takes tough action against errant parties, which could include the issue of a stop work notice to cease construction activities immediately and the imposition of financial penalties if pipes are damaged. Regulations were strengthened in 2017 to require companies to notify or seek approval from PUB before undertaking construction activities that may affect the pipe network and to ensure appropriate protection measures.

When leaks occur, PUB seeks to fix them quickly. Most instances are resolved within a few hours. Occasionally, due to the need to ensure that water supply to residents is not disrupted when leaking pipelines are isolated from the rest of the network, more time is required to switch residents over to an alternative supply pipeline before the affected pipeline can be shut off.

Water is precious and everybody needs to do his or her part to conserve it. I would like to assure Members and Singaporeans that PUB engineers will continue to do their best to maintain Singapore's water supply network and ensure good water supply to customers round the clock.

Mr Deputy Speaker: Does the Member still have supplementary questions after such a long reply?

Mr Leon Perera (Non-Constituency Member): Just a few, Mr Deputy Speaker.

Mr Deputy Speaker: Okay, Mr Perera.

Mr Leon Perera: Thank you. I would like to thank the Senior Minister of State for her comprehensive reply. Just a few supplementary questions.

Firstly, will the Senior Minister of State be able to share the figure for the number of leaks each year for the last seven years? I believe the Senior Minister of State said, on average, it is six leaks per 100 km over the last seven years. But what I am trying to get at is has the number been increasing, decreasing or remaining more or less the same? So, can that information be shared? That is the first one.

The second one is: will the PUB consider publishing this data on an annual basis if that is not being done right now? I say that also in the context of the statement that we have one of the best rates of water leakage in the world, which is commendable. I presume that that is using data that is published from other countries. So, presumably, other countries do publish this data. So, if that is not being done, will that data on the number of leaks per year be published on a regular basis?

My third and last supplementary question: is the PUB working or moving beyond just leak detection and response towards proactive leak anticipation or prediction? I believe that there are research projects and there are initiatives in other parts of the world – I am not sure if that is being done in Singapore – where models are constructed using data to predict and anticipate where a fault or a leak is likely to occur, so that preventive action can be taken before the leak actually occurs. I know in Sydney, this has been going on for some time. The Water Research Foundation believes that through failure prediction —

Mr Deputy Speaker: Mr Leon, can you round up your question?

Mr Leon Perera: Yes. So, through the creation of software models that take into account different factors we can anticipate that. So, is that being done or can that be considered to be done?

Dr Amy Khor Lean Suan: With regard to the first set of questions about the trend in the incidence rate of the leaks, I would say that, generally, it has been hovering around there for the last seven years. In fact, for 2017, we anticipated that the incidence rate will be about six leaks per 100 km. So, that has been the general trend in the numbers. There has been no discernible uptrend in the leak incidence rates.

With regard to publication, we will take the Member's suggestions on board. But from time to time, we do actually report and publish such rates in any case.

For the other countries, we also get information from published literature but I am not sure if everyone publishes it on an annual basis or on a regular basis. We will have to check.

As I have said, we have one of the lowest incidence in the world. Just to give the Member an example from data that we have got: Berlin as well as Munich in Germany, it is about seven leaks over 100 km. In United Kingdom's eastern region, it is about 13 leaks per 100 km. In Sydney, Australia, it is 28 leaks per 100 km. These are some of the data that we have.

With regard to proactively identifying leaks, as I have said, we have a comprehensive leak management programme. This also includes proactively trying to prevent leaks from happening. So, our annual inspection of 5,500 km of water pipeline network that we have is a proactive or pre-emptive measure because we also utilise our portable acoustic leak noise data loggers to try and identify these leaks before they surface, through visual inspection as well as using these tools. In fact, in more hotspot areas where leaks may occur because of soil condition and all that, we inspect it even more than once – maybe up to two to three times a year.

In addition, proactively, we also have a pipe renewal system. The average age of our pipe network is about 25 years, which is actually well within the useful lifespan of these pipelines. We have been able to do this because since the 1980s, we have an ongoing pipe renewal programme and we have been increasing the length of pipe that we replace each year. We also do that with better materials, more corrosion-resistant materials. We are constantly looking at improved methods and technologies to prevent or reduce leak incidence rates.