At some point, the world will run out of phosphorous rock for mining. The question is, when?
Before this happens, we’ll likely see policies introduced to slow down and control the use of phosphate, and industries will be encouraged to find sustainable alternatives wherever they can.
Phosphate is most known for its use in fertiliser and is credited for increasing the amount of food produced globally. However, phosphate is also used in the water industry for managing lead – we add it in treatment to reduce the amount of lead that is leached from historic lead pipes and fittings, and ensure that water meets regulatory standards to be considered safe.
The water industry needs to reduce the amount of mined phosphate it uses before the drop-off in global supply to ensure we don’t see high demand when prices are high or availability is low.
The water industry’s next step is to explore how far it will need to reduce phosphate dosing and by when, and what this means for retrofitting to remove and manage lead.
Innovation and policy will both play vital, determining roles in setting these ambitions. Here are two key areas for innovation in tackling lead, and one ‘blocker’.
Opportunity: removing lead
Most lead in the drinking water network is found in aging customer-owned pipes connecting houses to communications pipes.
Trials have been carried out in the UK for the free replacement of lead supply pipes but found that disruption was a barrier to uptake, despite the cost element being removed. Innovation will help us understand how we can reduce the time it takes to replace a pipe; how we can make that process more cost-effective; and how can we make this less disruptive.
Removing lead will cost billions of pounds over the coming three or four decades. The Drinking Water Inspectorate’s research has put some numbers to this, estimating it will cost up to £7 billion to remove lead from the mains pipe to the kitchen tap over 34 years – this is a conservative scenario, based only on England.
Removing lead is clearly the enduring solution. However, this will be extremely disruptive.
Water companies are already exploring innovative approaches to removing lead – and engaging with customers whilst they do. Severn Trent received funding through Ofwat’s Green Recovery programme to remove customer-owned lead pipes in up to 26,000 homes, and Scottish Water’s project works with independent nurseries and schools to test for lead.
Opportunity: managing lead
To safely move away from phosphate dosing, we will need to use all the tools in our toolbox. What we don’t know yet is whether we will ever be able to reduce phosphate dosing to zero.
It may never be feasible to remove all of the lead in our water network either because it is not possible or, in some cases, it may be too expensive, for example in historic buildings or under busy streets.
This is where lead management might play a continued role.
Lining is one such option, which involves coating the inside of lead pipes and fittings, to create a physical barrier between lead and the water. Lining has a co-benefit in that it helps prevent leakage, which could support the industry to meet its commitment to triple the rate of sector-wide leakage reduction by 2030.
At the moment, this is not an enduring solution, as pipes need to be relined eventually. In general, having a ‘single intervention solution’ tends to be better from a customer perspective, but we must balance this against cost. How could we make lead lining more enduring? How can we increase customer acceptance to multiple interventions, over a single intervention?
Phosphate recycling could also enable phosphate dosing to continue, albeit at a reduced capacity. It may be necessary if we cannot remove all the lead from the network, including within customers’ homes. Phosphate recycling would involve extracting phosphate from wastewater – this phosphate comes from the food we eat and from agricultural run-off – but currently phosphate recycling can be expensive and energy intensive.
Blocker: policy and communications
A key blocker for ambitious action to tackle lead pipes is that there is no clear government position on lead.
If we look at countries abroad that are further along in their lead policy, many have a similar feature: an environmental health commitment to reduce or prevent exposure from lead. This is because lead exposure comes from a range of environmental sources, with exposure from drinking water a fraction of this. In most instances, it is this environmental health commitment that drives action through drinking water policy.
We must not reach a point where public concern about lead outpaces government and industry action. Instead, we need a concerted plan to reduce phosphate dosing and tackle lead which embeds maintaining and bolstering public trust at its heart. Through the water industry’s Lead Strategy Board and Steering Group, we are aiming to deliver just that.
So, what will make a difference?
- Water companies investigating the long-term chemical resilience of phosphate and subsequently determining what this means for the timeline for mitigating lead.
- Water companies continuing to work with supply chain partners to explore innovation for lead removal, management and communications, and to further bring government and regulators into these discussions.
- Defra and the Environment Agency making an environmental health commitment to end preventable exposure to lead – including through soil and dust – creating a policy incentive for Ofwat and Defra to fund lead pipe removal.
Water companies are already tackling the issue of lead in the network and, through the Lead Strategy Board, we’re driving innovation but we also need clear direction from government sooner rather than later.
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