What once seemed like a good idea can often turn out to be a terrible idea many years down the line. The pipe world is no stranger to this concept, with more than one type of pipe going from innovative and safe to the worst material possible over varying periods of time.
We sometimes get asked by concerned homeowners what are the very worst pipe material still running through our buildings and under our streets.
If this is a question keeping you up at night – or just nagging away whenever you have a glass of water from a tap – then the good news is that dangerous pipe materials are few and far between in modern Britain.
That is not to say that they do not exist, however. Here is some information about three of the worst pipe material found worldwide in the 21st century.
Lead pipes
The number one offender on the worst pipe material list has to be lead because of the threat it poses to human health. Lead was one of the most commonly used materials not just in piping, but in practically everything up until its dangers became known in the 1970s.
Petrol, paint, electrics, plumbing… lead stretched into all areas of life. Once it became clear just how hazardous it is, the British government prohibited its use with the ban encompassing water supply pipes in the 1970s.
Any house or property built in the last 50 years is therefore safe from lead, as are those from before the 1970s which have been renovated or had plumbing systems replaced.
If you still have lead pipes running through your home, then you should contact your water company. They will carry out a free test on the water being dispensed from your kitchen tap to detail how much lead – if any – is contaminating your supply.
A safe standard is 10 micrograms per litre. If your water contains lead above this level, then the only way to truly reduce the risk of exposure is to have all lead pipes replaced.
Any pipes which run underneath the property after the stop tap are the homeowner’s responsibility. Pipes before the stop tap are the responsibility of the local water company.
Before undertaking any work, you should always inform your water company of your intention to replace lead pipes on your property.
If the supply line falling under the remit of your supplier is also lead, then they legally have to replace their own pipework providing that you request they do so in writing, are willing to replace the pipes which are your responsibility and tests have shown that lead is present above the safe standard.
Replacing pipes is obviously not a cheap exercise and grants are available for lower income homes. If you need to save up to afford the work, then there are a couple of measures that you can take to try and keep yourself safe in the meantime.
Running the cold water tap to fill up your kitchen sink every morning will flush out stagnant water that has been sat in lead piping overnight. If you are still concerned, then switching from tap water to bottled water will help prevent ingestion.
Prestressed concrete cylinder pipe (PCCP)
Prestressed concrete cylinder pipe (PCCP) was all the rage when it burst onto the scene in North America in 1942, combining the compressive strength of concrete with the tensile strength of steel.
The original design of PCCP included a high factor of safety as engineers played it conservatively because of their lack of knowledge about the strength of the new composite.
By the time the 1970s arrived, PCCP manufacturers felt confident enough to change their structural designs in an attempt to reduce costs, reducing the thickness and the number of steel wires in place to produce a uniform compressive pressure in the core, offsetting the tensile stresses in the pipe.
This proved to be a terrible decision. Although these fewer, thinner wires were made from stronger steel, their lack of thickness made them brittle and susceptible to corrosion.
When the wires rusted away, the concrete pipe was suddenly in danger of suffering massive blowouts under immense pressures – making it one of the worst materials that has ever been used for major pipelines.
The chickens are coming home to roost now for 1970s PCCP as below-specification pipes reach the end of their 50-year-lifespan, resulting in an increasing number of failures across North America.
Amongst the more spectacular incidents caused by PCCP blowouts are a 2008 explosion north of Washington DC which led to motorists being rescued by boat and helicopter from a torrent of water.
Three years later and a water main blew out doors and walls in an office park in the town of Capitol Heights, sending a highly pressurised jet of water 40 feet into the air.
Because of the scale of damage caused when PCCP fail, it is one of the most difficult-to-repair compounds in the world.
The quantity of materials required is enormous and the disruption huge, as 700,000 residents of Irvine, Southern California can attest to when they went without any running water for a week after a PCCP blowout spilt 22 million litres in 1999.
There is no quick, easy or cheap fix for these PCCP problem facing the US in particular. According to the American Concrete Pressure Pipe Association (ACPPA), 90 of the 100 largest water utility companies in the country have prestressed concrete cylinder pipe on their networks.
Any of these pipes manufactured between the below-specification period of 1970 and 1979 – when standards were tightened – is at serious risk of failure over the next few years.
Nationwide repairs and reinforcements could cost more than $40 billion according to a technical assessment carried out by the US Environmental Protection Agency and the American Water Works Association
Polybutylene pipe
Our friends in the US do not have much luck with their pipes. PCCP runs under their streets. Homes built between 1975 and 1996 meanwhile were fitted with polybutylene pipes, a material that came with a significant flaw and resulted in hundreds of millions of pounds of water damage.
The problem with polybutylene is that it significantly weakens when it comes into contact with chlorine. When public water is treated and purified in plants before being distributed around the supply network, chlorine is the chemical used.
You can probably see where this is going. Water containing chlorine interacts with polybutylene piping in the 10 million buildings it is estimated to be installed in across the US, pipes become brittle and leak-prone and leaks beginning happening all over the country.
So severe were the problems caused by polybutylene pipe that several class-action lawsuits were filed, including Cox v Shell Oil Company.
During the 1970s and 1980s, Shell and Hoechst Celanese Corporation (HCC) had participated in the manufacturing and marketing of a polybutylene piping system with Cox arguing that they were therefore responsible for the damage caused by the poor quality of the product.
The Cox Case eventually settled and, under the Cox Settlement Agreement, HCC and Shell agreed – without admitting liability – to provide the qualifying Cox Class members relief.
Homes and buildings which still contain polybutylene pipes will often find themselves having to pay higher insurance premiums or being offered restricted coverage. Other brokers refuse to even insure a building with polybutylene, confirming its reputation as one of the worst pipe material around.
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