How do we ensure that our water networks are efficient – and at the same time build in resilience and sustainability? Some thoughts leading to the 2018 Global Water Summit.
Volumes of non-revenue water (NRW) – that is the combined volume of water lost from leakage (physical losses) and from inaccurate customer meter readings and theft of water (commercial losses) – can be very high, with utilities frequently losing half the annual volume of water they produce.
With better access to updated water company data, a recent study estimates that global NRW is in excess of 100 billion cubic metres per year. It is therefore no surprise that managing and reducing leakage and NRW is still one of the major operational tasks facing water utility operators.
Resilience of supply
In the light of climate change mitigation and adaptation, regulators and operators are putting a greater emphasis on water efficiency – not previously part of economic regulation. With a predicted 20 per cent increase in the UK’s population over the next 20 years, much of it in drier areas, and a predicted 20 per cent reduction in summer rainfall by 2050, as well as the risk of too much water being taken from rivers, the key lies with demand management, a policy that is now firmly ‘at the heart of resilience’.
Leakage and customer demand
Question: Can operators work more closely with customers to help drive down leakage?
Customers are already encouraged to report visible leaks or changes to pressure, but can they accept behaviour change to become more active in managing their demand and reducing per capita consumption? This will require accepting new developments retrofitting water-efficient household devices, introducing compulsory household metering and ‘smart meters’ to identify excessive use and leakage in the customer’s house, and a greater emphasis on rainwater harvesting and effluent re-use.
Essex and Suffolk Water is engaged in a home retrofit project, Every Drop Counts, which has carried out audits of water use in 25,000 homes, then is working with customers and plumbers who want to take up the retrofit scheme. Water saving is 22 litres per house per day for the 20 per cent of customers who have taken part in the scheme, and the company is looking at how best to structure and frame incentives to encourage others.
Another question: Is the customer responsible for more internal plumbing losses and leakage than we currently believe?
Waterwise, a UK not-for-profit organisation promoting water efficiency, has found that around four per cent of water-efficient (dual flush) toilet cisterns fitted to new homes leak, losing on average 215 litres per day per cistern – 400 million litres per day. So do we need a new strategy to train and certify plumbers and builders to remove poor practice and ensure high quality installations?
Some water companies are trialling an innovative strap-on flow measurement device to measure household consumption more simply and at lower cost than a fitted water meter.
Then there is the challenge of changing customer behaviour. One UK water company (Essex and Suffolk) is looking at how best to structure and frame incentives to persuade customers to take part in a programme of home retrofit. Early results show that metered households are more likely to take part and high users, less likely.
Smart metering is not just about giving customers a more accurate bill – it can be an aid to finding leaks on customer supply pipes and in the house. It can also be a big driver to reducing leakage and customer use. Low-cost clip-on sensors are already being piloted by several water companies to replace the more expensive permanent meters. Thames Water’s smart metering roll-out programme is well underway, demonstrating the evolution from ‘dumb’ meters, through automated meter reading (AMR) to full-blown advanced metering infrastructure (AMI).
As well as saving water, water loss reduction programmes can reduce or recover ‘embodied’ energy by means of energy auditing and rating, and by benchmarking energy efficiency measures. An example of this is harnessing micro-hydropower in the distribution network and in the home.
The role of innovation
Is there sufficient emphasis on innovation in the global water industry? What innovation is still needed to drive leakage down to a level for the supply demand balance to be sustainable?
- How do water companies obtain funding for innovative projects?
- Where does the funding come from and how are projects selected?
- How are the cost benefits measured?
Several European companies are integral to EU-funded programmes such as Smart Water for Europe and WISDOM.
There have been great developments in acoustic sensor technology, and one UK water company, Affinity Water, has just undertaken the largest-ever deployment of telemetry-linked noise logging with 20,000 units installed in an area of their network. But how are these vast amounts of data managed – and used to best effect?
But such sensor units are still cost-prohibitive for full network spread. What are the options – and the likelihood – for developing low-cost sensors? Can simple sensors do the job (the simpler the better)? How do they communicate with all the data coming from disparate and remote locations in the water network? How can we harness the IOT concept to ensure that ‘big data’ are compatible with legacy systems?
When will the ultimate in low-cost sensors – ‘sensor dust’ scattered across the network – become a reality? Can we do more with robotics and drone technology? Drones are not yet seen as fully fledged connected IOT technology, but could play a significant part in the IOT acting either as a sensor or by providing a connection between sensors and data collection points. But can they work together with other drones to collect and act on the data?
And what are the developments with satellite imaging technology? Early results of the latest water company trials show that the cost of finding a leak is around £500 – how does this compare with drone technology, or the more conventional leak detection exercise?
Managing upstream losses
Large diameter trunk (transmission) mains have always been the ‘bête noire’ of water networks – they are invariably large diameter, at low pressure, made of non- metallic materials, and often laid in rural areas – the worst combination for meter selection, meter accuracy, leakage monitoring and leak localisation. What technologies do we have for improving this scenario? It is acknowledged as one of the most difficult areas of the network to monitor, but one which is essential for a correct water balance. Anglian Water is the first UK water company to trial thermal imaging drones to localise leaks in the rural areas of Norfolk. The drones identify changes in soil temperature, with area of interest followed up by a leakage technician to confirm the leak position.
Age is not necessarily a factor leading to pipe deterioration and increasing burst frequency. But pressure transients and sudden hydraulic changes to the network are a major cause of pipe breaks. Can we predict pipe breaks based on modelling historic pipe burst events and the estimated cause of failure – and by analysing the causes of transients – to help solve the ‘repair or replace’ conundrum (planned maintenance)?
Condition assessment is also crucial for replacing only those areas of the network that will benefit. The Public Utilities Board (PUB) in Singapore, despite having one of the lowest leakage rates in the world, wants to be ‘the best in the industry’ and have just let a 150 million SD (110 million USD) contract to examine the condition of their cast iron pipes.
Speed and quality of repairs is one of the four major influences on the volume of losses in a water network (along with pressure, active leakage control and pipeline management). Four million holes are excavated in the UK water network each year, at a cost of one billion GBP. We hear much about better technologies for monitoring and finding leaks, but where are the innovative technologies for repairing leaks? Minimum excavation technologies can be difficult for water, especially when not all the pipes in a network are accurately recorded. Trialling of in-pipe repair technologies seem to have stalled, and water utilities globally are still practising traditional excavation techniques. Are there new technologies out there? Could repairs be an essential part of innovation funding? Could GPS and satellite technology help to pinpoint the pipe breaks for lower-cost repairs?
Is ‘contracting out’ some leakage strategy operations more cost-effective than training and using in-house staff? What operations tasks are most suited to performance-based contracts (PBCs) and which are not? There is now a wealth of experience in the cost-benefits and successes of PBCs from NRW case studies in Jamaica, the Philippines and Bahrain.
Global Water Summit 2018
The issues raised above are all topics for discussion at the 9th Global Leakage Summit taking place in London on 13th-14th March 2018. With the title and keynote addresses focussed on ‘Ensuring Efficiency, Resilience and Sustainability’, the summit will look at developments in leakage detection and resilience planning, smart metering developments and the results of studies on customer water use behaviour trends as well as topics raised above. To find out more, visit the website: