Supply pipes – time to adopt?
It’s autumn – time of chestnuts and that hoary old chestnut of supply pipe adoption is resurfacing. WRc technical experts are now convinced that adoption is the way forward and should be a key consideration for PR24 with the transition happening over AMPs 8 and 9. Why? Let’s consider some of their reasons.
Leakage – there is considerable uncertainty about customer side leakage, both in terms of the overall amount and the relative proportions of supply pipe and plumbing losses. What is clear is that reducing these losses is necessary if the industry is to meet current and future leakage targets. Joints are some of the most likely sources of leaks. WRc’s experience across projects with many water companies suggests that the quality of boundary box installation is variable, to say the least – whilst many are good, many have multiple joints and convoluted pipe work – even on new installations. A one-piece pipe from the main to the property would eliminate joints and hence, potential sources of leaks. Also, we know that the materials used for many older supply pipes make them more likely to leak. Since these are on older properties, they are less likely to be metered contributing to the uncertainty on customer side losses.
Lead – the report WRc compiled for Department for Environment, Food and Rural Affairs (Defra), published in January 2021, concluded that “compliance with
regulation which mandated the minimisation of lead in drinking water would be extremely difficult, if not impossible, without remediation up to the compliance point (normally the kitchen tap)”. This highlights one of the anomalies with the current model where the water supplier is responsible for water quality at the tap, yet has limited powers as regards the supply pipe which can be a major source of lead at the tap.
Metering – putting the meter at the property has other advantages aside from leakage management. It provides a clear demarcation between pipe and plumbing losses – allowing for targeted interventions where continuous flows are identified. Also, our tests have shown that AMR/AMI reading reliability and range is significantly improved when meters are located above ground, such as in a wall box or under the kitchen sink, compared with meters underground in boundary boxes.
As many customers are unaware of their responsibility for their supply pipe, persuading them to upgrade their supply pipes to meet targets being imposed on water companies would be extremely difficult. Of course, even if supply pipes are adopted, sorting the lead and leakage issues will not be an overnight fix, but it would give water companies more control of those assets and hence the powers to begin to address those issues. After all, other utilities – gas, telephone, electricity, broadband – are to the house, why should water be any different?