Ian Walker, innovation director at research body WRc, is quite clear. “It is not acceptable for children to drink water that contains lead,” he says. But the regulatory framework is not so absolutist, and change would take political leadership.
Lead is a toxic substance, which has a cumulative effect, so chronic exposure at low levels builds up. It is known to raise blood pressure, cause kidney problems and has even been associated with raised levels of violent crime.
Children under six are particularly vulnerable, because their brains are growing fast and they have higher absorption rates. Lead exposure can affect how children develop, impairing IQ and cognitive function, which can lead to special educational needs and behavioural problems. In the longer term, it can hit productivity and earning power. “To put it crudely,” says Walker, “children are growing up thicker than they could have been.”
Since 1970 it has been prohibited to use lead in paint, petrol and mains water pipes. However, up to 40 per cent of UK homes still have lead water supply pipes – the bits of the network that connect properties to water company mains.
There is no safe level of lead, with damaging effects found at even low exposures. However, Europe takes a pragmatic view and only requires lead levels in drinking water to be kept below 25 micrograms per litre (µg/l). On 25 December 2013, in a Christmas present to children, that will drop to 10µg/l. WRc expects the level of failures in the UK to double, despite the industry having targeted 10 µg/l for the past five years. Principal toxicologist Paul Rumsby says: “Many companies are doing this compliance thing. One or two are in denial.”
Water companies have to make sure the water coming out of the tap meets the standards, but are not in control of all the infrastructure leading up to it. Crucially, the last bit of pipe between the stop tap and the property is the homeowner’s responsibility.
The industry has a temporary fix: dosing water with phosphates, which lines the rogue pipes and helps to prevent lead leaching into the household supply. In the jargon, it reduces “plumbosolvency”. The softer the water, the more phosphate is needed. Around nine-tenths of the population is understood to get water treated with phosphates.
Phosphate rock is a scarce and volatile commodity, with global deposits concentrated in the disputed territory of Western Sahara. The raw material cost shot up sevenfold in 2008, when there was an earthquake in China, another significant supplier. It is in high demand as a fertiliser. Production is estimated to peak in 2030 and reserves could run out in 50-100 years, at current consumption rates.
As well as paying to put it in, water companies pay to take phosphate out at the other end. They use iron to remove phosphate at sewage works and prevent it entering the environment.
The obvious alternative to this chemical solution is to replace the offending pipes. The equally obvious objection is the cost of doing so. According to a recent report by UK Water Industry Research (UKWIR), the cost to one large water and sewerage company of replacing all lead communication pipes (between the main and the stop tap) would be an extra £390 million, taking into account chemical savings. Taking on the customer side too (from the stop tap to the property) would cost £890 million. UKWIR reckons chemical costs would have to increase by at least a factor of 20 before lead replacement would be economically viable.
A number of water companies have programmes to replace lead communication pipes. While they can encourage customers to do the same on their side, they cannot force the issue. And as long as one household has a lead pipe, they can’t stop dosing.
When it last set prices in 2009, Ofwat did not allow companies to invest in replacing customer-owned supply pipes. A spokesman says: “We believe that customers as a whole should not meet the cost of such work, particularly as some have already paid to have their lead supply pipes replaced and most continue to have no problems with lead.” It is too early to say what the approach will be in the 2014 price review, he adds.
The Drinking Water Inspectorate (DWI), which monitors compliance, says phosphate dosing has been a successful approach and companies have been able to reduce levels as it has taken effect. It expects water companies to take a “holistic, risk-based approach” to meeting the new standard. That includes working with local authorities and public health officials to target advice at vulnerable groups, and replacing communication pipes where the 10µg/l standard is not met. “Opportunistic” lead pipe replacement should be considered as one of a number of benefits from planned work on the distribution system, the DWI advises.
UKWIR is planning to research why customers are reluctant to pay to replace their lead pipes. Replacing a supply pipe costs just under £300 a household: about the price of a high-end baby buggy, says Walker, speaking from personal experience as a grandfather. However, homeowners may not see the point, because many people assume that if the water meets the regulatory standard it must be “safe”.
Walker does not accept the regulatory position. “Ofwat says you can’t cross-subsidise, and yet everybody is paying for the phosphate, so why can’t everybody pay for the lead to be removed?”
It would be cheaper to replace pipes in a co-ordinated programme than piecemeal, he says. Costs are coming down, with techniques to draw the pipe out without digging a trench, or to reline it with resin. And lead is a valuable resource – just ask the thieves who target church roofs. It sells for around £1,000 a tonne, which could go some way to mitigate the recovery costs.
After the transfer of private sewers to water company ownership, Walker asks why not do the same for supply pipes? “Some companies would welcome the opportunity – it increases their asset base.”
Water supply pipes are not the only source of lead exposure in the UK, but they are perhaps the most readily isolated and tackled. It is for government to decide whether it will continue to tolerate their toxic legacy.
Lead exposure costs to society
The most comprehensive attempt to quantify the costs of lead exposure in a developed country comes in a French study published in Environmental Health in 2011. It uses results from a 2008 survey on the concentrations of lead in the blood of French children aged between one and six. Exactly half the children had some level of exposure.
Keeping blood-lead in children below 15 µg/l for a given generation would benefit the French economy by €22.72 billion (£19.5 billlion) a year at 2008 values, the study concluded. This took into account lost earnings, special educational needs and violent crime attributable to lead poisoning, as well as direct health costs.
For the general European population, food is the major source of exposure, it said, but tap water can be an “important contributor” in some cases.
This article first appeared in Utility Week’s print edition of 8th February 2013.
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