DIY Plumbing and Pollution

One of the greatest eureka moments in human history was the discovery that many diseases were contracted by people drinking contaminated water supplies.

These horrible diseases plagued our early towns and cities and were compounded by the lack of sanitation and the fact that human activity created waste compounds that were not being correctly disposed of. Blood and waste products from animal slaughter, toxins and heavy metals produced by manufacturing processes and the faecal and food waste products from human habitation trickled through open street troughs and into the nearest river or watercourse. These same watercourses provided much of the drinking water the inhabitants who could not afford cheap ale were forced to drink.

Life expectancy was short and early childhood mortality was the norm.

Today, things are much different. Sewage and other foul water wastes are carefully directed along dedicated pipe networks to vast treatment plants. Here they are carefully treated to clean out most of the harmful components before they are allowed to enter streams, rivers and oceans.

Surface water from roofs and other surfaces are kept separate and, because of their relative cleanliness, directed straight into streams and other watercourses where they become diluted and rendered harmless.

All very notable and efficient. Or is it?

Unfortunately, too much material that should be sent into the sewage system for treatment is currently being wrongly directed into the surface water system. Although not entirely the cause of the problem, much of the blame is being placed at the door of over enthusiastic DIY operatives who incompetently plumb appliance’s wastewater discharge pipes into the wrong drain. Dishwashers, washing machines, baths and sinks, even toilets can inadvertently have their waste flushed into the wrong pipe.

This rise in DIY activity is believed to be one of the contributing factors. The proliferation of daytime TV DIY and house renovation programmes seems to have spurred an increase in inexperienced householders keen to save money by carrying out their own installations and home improvement work. This, coupled with the recession, which has deterred people from moving house and motivated them to alternatively embark on home improvement projects instead, has compounded the problem.

Today, the ease at which DIY appliances, fittings and other components and tools can be sourced, and the relatively cheap price of these items, has made DIY a leisure activity for many.

The recession has also meant that affording the services of qualified trades people has become increasingly beyond the financial means of many householders.

As a result, more and more effluent and other toxic substances are finding their way into the wrong drains and subsequently directly into the natural water systems.

DEFRA predicts that by 2017, over half a million properties in the UK will have misconnected and technically illegal drainage connections installed. Currently, in some areas, one in five households is known to have incorrectly plumbed drainage systems.

The damage caused to the environment is substantial. The decomposing material in rivers and seas removes oxygen from the water. This suffocates fish and encourages eutrophication, or the proliferation of algae, which forms dense blankets on water surfaces cutting out sunlight. Salmon, perch, pike and trout all succumb to this unnatural imbalance created by the disruption of normal environmental processes.

Toxic chemicals can cause undesirable mutations in wildlife. The endocrine disrupters released from contraceptive pills and flushed directly into clean watercourses can cause gender alterations in fish and other aquatic life.

However, not all problems are caused by hapless DIY operatives.

Too often toxic materials are deliberately discarded into drains, particularly street drains. Oil, antifreeze, and other motoring products are often flushed directly into them by inconsiderate vehicle owners.

The increase in the construction of external hardcover surfaces prevents natural drainage and following a rain downpour, water, and the debris collected on these surface gushes into storm drains, causing considerable pollution.

Not only is a polluted water course unattractive, the smell of decomposing organic material coupled with the myriad of unexpected chemical reactions that may occur can be quite unpleasant for neighbouring households.

So concerned are various environmental groups about this growing problem, that many are now monitoring watercourses to detect sewage contamination. Dyes can be added to pipe networks to discover the origins of contamination points.

Fly populations that inhabit waterside environments are being monitored to detect alterations in normal populations caused by trace contaminants. When detected, the Environment Agency is informed. The Agency is then obliged to carry out further investigations to try to determine the source of the problem before it becomes a serious issue.

The government has also set up the Connect Right campaign. This body provides information and advice to homeowners and developers about connecting appliances to the correct drainage system. It also provides links to accredited Water Safe plumbing engineers. These plumbers and fitters have the relevant experience and the technical understanding of environmental issues to ensure that any work is correctly undertaken.

Homeowners with older properties are also recommended to have their drainage systems regularly checked to ensure correct operation. Deterioration of older pipe-work can cause seepage of contaminants into the wider environment causing harm to wildlife and human populations alike.

For homeowners and DIY enthusiasts, taking care to ensure that drainage systems are correctly identified prior to embarking on installations will help to reduce the problems associated with incorrect connection issues.

Where any plumbing work lies beyond the scope or experience of the householder, employing a professional and competent plumber will ensure that our natural habitats remain as unaffected by human activity as is possible.

Backflow in Plumbing

Clean, wholesome drinking water. We can take it for granted. Turn on the cold-water tap and it is there.

Wastewater. The grey soup from washing machines, washbasins, baths, and showers. It disappears down sinks and drains never to be seen again.

It would seem quite important that the two should never be allowed to mix and be inadvertently consumed by members of the household, or indeed other unsuspecting households connected to the supply.

Yet without precautions, clean water can become contaminated with materials that can have serious implications for human health. Toxic chemicals and dangerous micro-organisms can infiltrate domestic water supplies if suitable barriers are not in place to prevent them doing so.

The importance of maintaining an effective barrier between clean (potable) drinking water and the water using devices and appliances connected to the mains supply within the home should not be under-estimated. There are thousands of domestic water contamination incidents recorded each year, with some resulting in fatalities.

The biggest cause of problems involving domestic potable water contamination results from cross-connection issues. A contaminated source of water has the potential to be drawn into the clean water supply when it is connected to it. For example, a garden hose connected to the water supply could create a cross connection. If the flow of water through the connected hose is induced in the opposite direction this is referred to as backflow.

There are numerous cross connection unions in the typical home, from dishwashers and washing machines to combi boilers and mixer taps.

Backflow can be initiated by a number of adverse conditions such as a burst water main causing a sudden drop in pressure, a high demand for water on a supply line or frozen pipes interfering with the flow.

There are two main types of backflow. Siphonage and backpressure.

Siphonage may occur when the pressure of the mains water is not great enough to overcome the tendency for water to flow to its lowest level. For example, when siphoning a liquid from one container to another, a vacuum is created within the siphon tube by removing the air. So long as the siphon tube exit is positioned at a lower level than the level of the siphon tube entrance, the liquid will flow to its lowest level. This facilitates the flow of the liquid from one container to another.

Likewise, a garden hose with one end attached to the mains water supply and the other left submerged in a garden pond has the potential to contaminate the mains supply by the process of siphonage.

Backpressure is caused where the pressure in a system connected to the mains supply is able to overcome the mains pressure supplying it. For example, when water is heated by a combi boiler the water expands. As a result, the increased pressure has the potential to overcome the mains water pressure and cause a reversal of flow back into the mains water system. The same thing has the potential to occur with central heating fluids if the filling loop is left in place in the absence of a backflow prevention device.

The Water Supply (Water Fittings) Regulations 1999 makes the fitting of backflow prevention devices and techniques mandatory. The regulations also make it incumbent on the homeowner or a competent engineer, to install and maintain systems to comply with the regulations. They must prevent contamination and also give notice to the local council of any installation work that falls under The Buildings Regulations notification requirements.

The type of prevention device or method that must be employed can be established by referring to the list of water categories set out in the regulations. This list categorises the seriousness of contamination fluid risk on a score of one to five, with five being the most serious.

The simplest method of backflow prevention is to create an air gap. This is very effective and can be seen in operation with kitchen taps, sink taps, and toilet cisterns. The distance provided by the air gap is determined by the risk as set out in the regulations.

A tundish can also act as a backflow prevention device by virtue of the air gap it produces.

For direct connection, and in compliance with the necessary precautions determined by the Act, check valves, either single or double provide an effective barrier against potential contamination risks. These are easily fitted into the pipe-work where connections are made. A garden tap is required to be fitted with a check valve between a hose connection point and the tap bib.

Other forms of backflow prevention include ball valves in water storage tanks, where the water outlet must be above any overflow outlet, and integral protectors, such as are often found in mixer taps and non-return valves.

Reduced pressure zone valves (RPZ) may also be installed where required, but must be installed by a competent person.

Although it is not always necessary to fit check valves on mixer taps that do not have integral protectors, it is advisable.

It is also important to remember that tap outlets are a prime source of contamination and should be regularly cleaned. It is not uncommon to see contaminated material being placed in contact with the outlet or splashing back into it. Microbiological contaminants can thrive on tap outlets and contaminate further supplies.

When purchasing fittings it is important to ensure that they comply with the Water Regulations. It is not illegal to sell fittings that do not comply, but it is illegal to fit them.

The Act also stipulates that any fittings are installed in such a manner that they are easily accessible for maintenance and are adequately protected against frost.

The Water Regulations Advisory Scheme (WRAS) can provide copies of the Water Regulations (Water Fittings) Act 1999 and provide advice regarding compliance and the suitability of fittings.

Problems with Dead Legs

I recently bought a new washing machine. Not that there is anything particularly out of the ordinary in doing so. The working life of a modern washing machine seems to be considerably shorter than that of the robust models of the past. Whether that is due to the increasing complexity of the electronics or the designed-in time-dependent failure of its components is a matter of opinion.

The main thing that did attract my attention was the fact that the new machine had just one water inlet hose. My previous washing machine had two independent water inlet hoses, one for hot and the other for cold water supply.

It seems that now one cold supply hose is the only water inlet connection required.

This naturally left a length of redundant hot water supply pipe. Although it was fitted with an inline valve to close of the hot water flow, I decided to fit a blanking cap to the hose connection end as a secondary precaution against leaks.

Unknown to me I had just created a dead leg.

That might have been the end of the story had I not read an article about the increasing awareness of the potential problems of microbial proliferation in domestic water supplies, particularly in dead legs.

A dead leg is a section of water pipe that branches from a T-junction and is blanked-off due to it no longer being required. It can also refer to a section of water pipe that services an appliance that is infrequently used.

Apparently, such lengths of pipework can become traps for silt and organic material. This provides the perfect environment for the development of microbial agents that can pose a danger to householders.

This is particularly the case in respect of dead legs on hot water systems.

Although hot water may be flowing through the domestic system at a temperature and flow rate that prevents microbial development, a dead leg remains as a sump for collecting debris.

The water temperature in the main domestic circulation is usually at a high enough temperature to inhibit microbial growth, but in a dead leg, the water stagnates at a lower temperature.

The dead leg on a hot water system may pool water at the optimum temperature to allow scale formation. The surface provided by developing scale, the presence of nutrients from collected sludge and the warmth from the water provide the ideal environment for the development of dangerous organisms.

Organisms such as Amoebae, Ciliates, Coliforms and Algae may proliferate and disperse into the main circulation. However, Legionella and Pseudomonas bacterium can also flourish.

So how do these organisms get into the hot water supply to begin with?

Mains cold water from the provider is chlorinated to destroy most potentially harmful organisms, but contamination can still occur due to leaking supply pipes or unprofessional plumbing work.

Perhaps the greatest source of contamination is a water storage tank, particularly one that is uncovered or that has an unscreened overflow pipe.

Although regular flushing of the hot water system, either intentionally as a maintenance task or by continual domestic usage, will help to prevent microbial contamination, dead legs will remain un-flushed and prone to scale formation. The scale provides a perfect material for organisms to adhere to.

Fragments of contaminated scale can break away from formations in dead legs and become suspended in the domestic water flow.

In the case of Legionella, the bacterium can survive the flowing hot water temperature and then incubate in lengths of T-pipes supplying hot water outlets when the temperature drops in-between outlet demand.

The bacterium can also thrive in showerheads in-between usage, particularly where scale buildup in the showerhead provides niches for development.

Although microbes in contaminated hot water can be harmful if ingested, bacterium like Legionella pneumophilia can be dangerous when inhaled.

The inspiration of aerosol particles can penetrate deep into the lungs.

Aerosols are minute water droplets suspended in the air. They are created by water falling onto a hard surface; such as occurs when running a tap, a bath, or having a shower. Flushing a toilet or spraying water will also produce aerosols.

Whirlpool and Jacuzzi type bath installations are now being identified as potential sources of microbial incubation and harmful aerosol formation, particularly where regular sanitation and cleaning maintenance is neglected.

Aerosol particles in the air can remain suspended and circulate on air currents for over twenty minutes.

Although Legionella infections are not passed from person to person, they do occur in clusters. The symptoms can vary from mild flu-like conditions to life-threatening pneumonia. People with compromised immune systems or pre-existent lung conditions are the most vulnerable to acquiring Legionella infection. The mortality rate can be high among confirmed cases in susceptible people.

However, it is thought that many mild cases go undiagnosed and that the incidence of Legionella infections amongst the population is much higher than the identified and confirmed cases suggest.

On the Continent, plumbing procedures encourage the installation of loop systems rather than T installations to help to prevent microbial development problems in domestic hot water supplies.

Best practice and Water Regulations now issue guidance on dead legs and associated blind ends. It is recommended that redundant T water pipes are removed and the T replaced with a standard in-line pipe connection.

It is also worth noting that landlords of rented properties must undertake a risk analysis of the potential for water-borne infectious agents to develop in services installed in properties they let. They must also take action to make safe any potential sources of microbial contamination. Failure to do so can expose the landlord to criminal action and substantial litigation issues should subsequent related harm occur to a tenant.

I have now removed my blind end and in conjunction with a regular flushing of my entire domestic hot water system, can rest assured I am doing as much as practical to reduce the chances of my household contracting a water-borne infection.




Attaching a Copper Pipe to a Lead Pipe Supply

Although the use of lead for new plumbing purposes has long been prohibited, it is not uncommon to find it still installed in older properties. Most homes built before the 1950’s depended on either iron or lead pipe-work for their water supply.

As new plumbing materials were developed for transporting water and gas supplies, most accessible lead plumbing was removed from buildings as part of a normal upgrading of supply networks. In domestic properties, the need to facilitate water supplies to new appliances took advantage of the versatility of copper. Copper pipes were easy to work with and could be cut and joined to accommodate any requirement.

Lately, plastics have started to replace copper as a lightweight and durable alternative. Water supply companies have utilised plastic pipes on a grand scale to upgrade their deteriorating and previously poorly maintained supply networks.

However, it is not uncommon to still find some older domestic properties still supplied with potable water from a lead rising main. Lead pipes are usually conspicuous by their dull, grey colour. When the soft, grey surface is scraped away, the shining, silvery material that is exposed will provide confirmation.

Wherever possible, these old lead rising mains should be removed and replaced with a suitable alternative material. A lead rising main may still be present in an older building for a variety of reasons. It might simply have been overlooked.

Not surprisingly, the most common reason for leaving a lead rising main, and the rest of the lead pipework supplying it, in place is the cost of replacing it. The cost of removing and replacing old lead pipes back to the boundary of the property must be met by the property owner. In many cases, this considerable cost provides a disincentive.

How much of a health risk is perpetuated by leaving a lead main in place is a matter of conjecture. Undisturbed lead pipes can develop an interior coating of mineral deposits that inhibit the transfer of lead into the potable water supply.

Where a homeowner has concerns about a possible health hazard from existing lead pipework, water testing will indicate whether lead is a problem.

Perhaps one of the most common problems to occur with an existing lead rising main is leakage around an old copper to lead union. In the past, internal lead pipe-work was removed and copper was joined to the remaining lead main using a soldering technique called ‘wiping’.

A wiped joint was created by stretching the cut end of the remaining lead mains and inserting a length of clean and fluxed copper pipe into the widened and cleaned neck. Widening the neck also produced a cupped shape, which had a practical purpose. Firstly, a suitable length of metal rod was inserted into the top of the copper pipe and extending into the lead pipe to prevent movement between the two pipes. Then, bar solder was melted with a blowtorch and allowed to fill the cup on the lead pipe neck. This formed a union between the two pipes. The solder was gradually built up by periodically wiping the molten material with moleskin, or other suitable cloth to form something resembling a thick bandage. Part of the skill was to complete this task without melting the lead.

Although this procedure was prohibited by the Water Regulations some years ago, it is still regarded as a true plumber’s skill and is sometimes used as a temporary measure to repair leaking unions.

Over time, these previously wiped joints are susceptible to corrosion. This is often caused by the electro-potentially dissimilar properties of copper and lead. The corrosion eventually causes leaks in the wiped union that need to be repaired.

To repair on old copper to lead union, or to install a copper ‘T’ component into a lead pipe, a brass coupling called a lead-lock or other similar brass or plastic compression fittings are now the only couplings permitted for joining onto lead.

With the mains water turned off, the old wiped joint can be removed with a hacksaw, or the lead pipe cut at a suitable position to accommodate the lead- locks.

A lead-lock compression fitting works by creating a tight seal onto the lead pipe by utilising an internal gripper and friction ring to compress a large rubber ‘O’ ring against the surface of the lead pipe. This forms a watertight seal. The lead-lock fitting is made of brass, and so eliminates the problems associated with connecting dissimilar metals. The opposite end of the lead-lock has normal compression fittings to accommodate conventional copper or plastic pipework. Other permitted joining components use a similar technique.

Where possible, a small cut-off section of the lead pipe should be taken to the plumber’s merchants to ensure that the correctly sized lead-lock is obtained. Old lead pipes were manufactured in different gauges and were usually categorised by weight. Each different weight corresponded with a particular diameter.

Where it is not possible to remove a section of lead pipe for comparison, possibly because the remaining lead pipe is too small, a length of cotton can be wrapped around the lead pipe, and where one end joins another, the cotton can be cut. This piece of cotton, when measured, will provide the circumference, which when divided by 3.142 will establish the lead pipe diameter.

Nevertheless, when trying to fit a suitable lead-lock, it may be necessary to file away any external grooves or raised surfaces on the lead pipe to ensure a snug-fitting ‘O’ ring and water-tight connection.

It is also very important to prevent the soft lead pipe from kinking, bending twisting or deforming when applying tension to lead-lock couplings during tightening. A suitable set of grips applying an opposite force will prevent this problem occurring.

When completing the join, the mains water should be turned on gradually and the new connection closely monitored for signs of leakage. Where a leak is detected, the lead pipe can be filed to modify it and the fitting replaced or sometimes adjusted and re-fitted.

Unfortunately, a lead rising main is often located in the most inaccessible of places and working on it requires considerable patience and manual dexterity. If this is the case, it is often more appropriate to employ the services of a qualified plumber to undertake any connections to a lead main. Where a subsequent joint failure occurs due to an incompetently installed fitting, insurance cover for water damage may be affected.

After disturbing any existing lead plumbing, it is a wise precaution to run the cold-water tap for ten minutes or so to flush through any minute lead fragments that may have become dislodged. It is also good practice to run cold water through a lead supplied drinking water outlet for a few minutes prior to using, particularly if the water tap has not been operated for a day or more.

Although no longer used for installations, old lead pipe-work can continue to provide safe water for domestic consumption. However, where possible, old lead pipes should be removed.

Water Filtration and Treatment Devices

When it comes to public health issues, improvements in the quality and safety of drinking water have played a significant role in extending life expectancy and reducing infant mortality across the UK population.

However, in recent years concerns about chemical residues from agricultural and medicinal applications, and pollutants in general entering the water supply have gained momentum. Bottled water sales have increased and a vast array of domestic water filtration and treatment appliances have come onto the market. Some filtration devices have become quite sophisticated using processes such as reverse osmosis to try to improve the taste and quality of the domestic water supply.

Not that water filtration is a new process. It has been used extensively in industrial situations for many years where clinical water purity has been necessary for various chemical processes to occur. However, attaining such water purity does not improve drinking quality. It can remove most of the essential dissolved minerals that are necessary for human health.

So, how necessary are many of these filtration and softening appliances, and how justified are the manufacturer’s claims about contaminants, their effect on consumers and water using domestic appliances?

There can be no doubt whatsoever that untreated water supplies are likely to be contaminated with a variety of undesirable and possibly dangerous substances. However, highly efficient water treatment plants and strict monitoring of water quality usually maintains a water supply that should be of no concern to domestic consumers. Chemical residues and other undesirable substances are at levels so insignificant that further filtration is unlikely to reduce traces further.

Evaporation and distillation may reduce possible unwanted substances further, but the cost of doing so would be prohibitive and the resulting distilled water would lack the palatability of fresh, aerated tap water.

Perhaps the two main practical reasons for filtering and softening water supplies are to remove the taste of chlorine and to reduce the levels of hard water minerals, which can accumulate and restrict pipe-work, and which form lime-scale when heated. Lime-scale formation in boilers and other water using appliances can seriously reduce their operating life.

Filtration to remove the taste of chlorine is usually performed using activated charcoal filters. These can easily be installed as a device directly into the mains water supply. This will ensure that water entering the home is filtered prior to use. These filtration devices vary in cost and complexity, however regular filter changes are required to maintain effective operation and prevent bacterial colonies forming on old clogged up filters.

Portable filtration devices are also available where the householder fills a filter jug as required. These devices certainly neutralise the chlorine taste. However, the same effect can be achieved by cooling unfiltered tap water in the refrigerator.

Water softening devices are designed to remove minerals from water supplies and are particularly suitable for installation in areas of the UK that have a hard water supply.

Hard water is of no concern in regards toxicity or human health. On the contrary, the extra mineral content is beneficial. However hard water can cause problems for people with certain skin complaints. Soaps and detergents are also affected by hard water. When used with hard water, they are reluctant to form lathers and are prone to leaving scum marks on clothing and around sink and bath surfaces.

High mineral content can cause problems when it collects as deposits in pipe-work causing restriction to flow. Lime-scale formation in hot water systems can cause serious problems for boilers and other hot water using appliances. Encrustations of lime-scale on boiler heat exchangers and on electric kettle and water cistern heating elements can reduce operating efficiency, increase operating costs and seriously reduce the working life of appliances.

Fitting a water softener to the mains supply at a point where it services boilers and the domestic hot water supply can be very effective at reducing mineral content.

The majority of water softeners on the market work by a process known as ion exchange. Calcium and magnesium ions in hard water are exchanged for sodium ions attached to a resin bead medium. This produces a soft water caused by the reduction in magnesium and calcium ions. However, due to the process, the soft water becomes high in sodium.  It is necessary to regenerate the resin beads regularly to facilitate efficient ion exchange. This is done by washing the resin beads with a salt solution. Waste from this washing process is disposed of into the drain. Some appliances do this automatically as a programmed cycle. The householder simply supplies a regular addition of salt. The type of salt to be used will be specified in the appliance operator’s manual.  Common table salt is not suitable.

Because there are no moving parts, very little additional maintenance procedures are required with these appliances.

High levels of sodium can cause problems for adults with heart and circulatory problems and those on a low salt diet. It can also cause serious harm to babies who are bottle fed with breast milk replacement feeds. These feeds contain the daily-recommended dose of sodium for babies. Additional salt can be harmful.

It is essential that water softeners are installed in such a manner that will ensure a supply of un-softened mains cold water is available through cold-water taps for drinking and cooking.

Alternatively, the effects of hard water and lime-scale formation in boilers and water heating appliances can be controlled by the introduction of scale inhibitors in central heating systems and the use of specialised detergents and lime-scale cleaning chemicals in other hot water using devices. Steel coils placed in kettles protect heating elements from lime-scale formation.

If it is the householder’s preference to fit water filtration and water softening devices, the installation is usually quite straightforward and can be easily accomplished by a DIY enthusiast. However, the manufacturer’s installation instructions should be followed to the letter. It is important to ensure that check-valves are fitted and that installations comply with the relevant legislation under the Water Supply (Water Fittings) Regulations 1999.

It is always advisable to seek the advice of your water provider prior to installing water filtration and softening devices. They can often advise whether such devices are necessary and provide water sampling and analysis to confirm residue levels.

When buying water treatment devices and appliances never purchase from door to door salespeople. Always purchase from a reputable source.

At the end of the day, the installation of water filtration and softening appliances is a matter of personal choice. There are many good appliances on the market and the householder should choose carefully to ensure that the appliance will meet with expectations.