Water Quality FAQ
The water supplied to you by the Company undergoes a thorough treatment process to ensure that, when you turn on the tap, the water is of a high quality and meets the quality parameters laid down by law. We continually test our water to ensure that the high standard is maintained consistently throughout the year.
There may be occasions, however, when you are concerned about the taste, odour or appearance of your water. In order to assist you in identifying the probable cause of common problems we have looked at some of the most frequently asked questions concerning water quality. The information below provide details of how the problems occur, what impact they have on the water and what can be done to remedy the problem.
If you have a particular query that is not covered below, we will visit if necessary your property free of charge and take samples of your mains water away for testing.
Taste and Odour
The water smells or tastes unusual
There are several possible causes of unusual tastes or odours in water:
Chlorine is used in the treatment process to disinfect the water and kill bacteria. The levels of chlorine are harmless in the quantities which are used.
A small quantity of residual chlorine remains in the water after treatment to ensure that the treated water system remains disinfected from the treatment works to your tap. You may occasionally experience a slight smell or taste of chlorine coming from the water in your taps. This does not mean that there is anything wrong with the water.
An easy and safe way to overcome the taste and smell of chlorine in water is to cool the water. Fill a plastic water bottle and cool it in the fridge before drinking.
Chlorine is also commonly noticed in swimming pools, where it is used in much higher concentration as a disinfectant. The levels are entirely different from the amounts used in the water treatment process.
I have moved house – the water tastes and smells different
The makeup of water (including the levels of chlorine) varies from area to area and this will mean that the water may taste or smell slightly different from the water that you were used to (especially so when you compare it to water from outside of the island).
Another reason may be due to our having to alter the treatment process slightly depending on the weather, demand and time of year. These factors all affect the levels of chlorine that we must add to the water which in turn will slightly affect the taste and smell.
My water tastes salty
Incorrectly installed water softeners, fitted to washing machines for example, can cause salty tastes and contaminate the drinking water supply. Do not drink water from water softeners because it contains high levels of salt – you should always use a tap with unsoftened water for cooking and drinking.
Is it my plumbing that is causing the problem?
One of the main factors affecting the taste and/ or odour of water is the customer’s own internal plumbing. Water is highly susceptible to materials and chemicals – all of which can affect its taste.
The most common problems are detailed below:
- New copper pipe work – can cause a metallic or bitter taste.
- Plastic pipe work and plastic kettles – can cause a plastic/ chemical smell or taste.
- Tap washers – can cause a rubbery or metallic taste.
- Tap washers, plastic pipework, and particularly the hoses used to connect washing machines or dishwashers – can cause a disinfectant or ‘TCP’ type taste.
- Note that plastic pipe work is vulnerable to contamination from chemicals and solvents. If your water tastes of petrol, a chemical or solvent the cause may be due to a plastic water pipe on your property being contaminated and allowing the chemical or solvent to bleed through into the water. You should investigate sources of potential contamination (e.g. your oil tank) and obtain further advice from the Company.
Do not drink or cook with water from bathroom taps or the hot water system. This water usually comes from a storage tank in the loft and is not as fresh or safe as water that comes directly from the mains. You should use cold water from the kitchen tap for all drinking and cooking requirements.
If the taps have not been used for a while, if you have been on holiday for example, you may find a metallic taste from the pipe work and possible discolouration in the water. Run the tap clear to get rid of water that has been standing in the pipes, before drinking.
How will I know if my plumbing is causing the problem?
You can get advice from a professional plumber to find out if any taste, odour or discolouration problem is due to your own household plumbing.
The water coming out of the taps is discoloured
Depending on the colour of the water this may well be a problem with your internal plumbing.
If the problem is coming from all cold taps except the kitchen cold tap it is likely that the water is being affected after it has entered your property. If you have a cold water storage tank you should check to ensure that nothing has fallen into it (there should be a fitted lid with air vents to prevent this from happening).
If the problem is also affecting the cold water kitchen tap (which should be fed directly from the mains) then it is likely that water is being affected before it reaches your internal plumbing.
The water is cloudy
White and / or cloudy water can mean one of two things.
If the water clears from the bottom to the top, that simply means there is some dissolved air in the water – this is not a quality issue.
If the water clears from the top to the bottom, this could mean some type of dissolved solid or sediment is in the water. This needs further investigation. Contact us via email or contact our main switchboard.
The water is a reddish/brown colour
Reddish or brown coloured water is most commonly associated with iron contamination, generally from corroded steel and iron pipe work.
If the corrosion is on your pipe work then this will need to be addressed by your plumber. The corrosion may however be coming from Jersey Water pipes. Before engaging a plumber to investigate your pipe work contact us via email or contact our main switchboard and we will establish the source of the problem.
The water is green in colour
This is most commonly associated with the corrosion of copper pipe work. In this case the cause of the problem is almost certainly due to the corrosion of internal pipe work which is a job for your plumber.
Chemicals and minerals in the water
Aluminium occurs naturally, both in the environment and at low levels in most waters and also forms an ordinary part of the water treatment process. Treated water actually contains less aluminium than untreated water. The use of aluminium in the treatment process is quite safe.
You will absorb more aluminium from food and cooking utensils than from water, which provides only a fraction of your daily intake.
Water supplied by the Company must comply with the quality parameters set down for lead. Occasionally, the concentrations of lead in water may exceed these levels and this is normally due to Customers’ internal pipe work being made of lead.
If you have lead pipework and are seeking to replace it, the Company will also replace (free of charge) any lead communication pipes that may supply your property. The service is free of charge on the basis that the lead service pipe is replaced with one of an equivalent diameter and that the Customer replaces all lead pipe work connected to their treated water plumbing.
Nitrates occur naturally at low levels in most water. Additional levels of nitrate can also arise in areas where nitrogenous fertilisers are used (i.e. agricultural areas). In Jersey the extensive use of nitrogenous fertilisers in the Potato industry can result in higher than normal levels of nitrates in untreated water collected in the reservoirs for treatment. This pollution of the Island’s waterways can result in higher than normal levels of nitrates in the treated water supplied by the Company.
The levels of nitrates rise and fall depending on the time of year and the rainfall – the highest levels of nitrates are usually experienced in Spring when rainfall washes down the nitrates that have just been put on the land by farmers.
The sustainable way to remove nitrates from the water is to tackle the problem at source and control the volume of nitrogenous fertilizers being put onto the land. This has been achieved with limited success over the past 10 years by the introduction of new land management techniques that seek to control the use of chemicals in agriculture. The Company advocates the implementation of ‘Water Catchment Management Areas’ (WCMAs) in Jersey that would strictly control the use of the land in water catchment areas. Until WCMAs are in place and operating effectively the Island will continue to have levels of nitrates that exceed legal limits from time to time.
The level of pesticides found in our treated water comply with regulatory and legal standards and the water supply is regularly analysed for herbicides and pesticides.
Fluoride in water
Jersey Water does not add any fluoride to the water as part of the treatment process, a small amount of naturally occurring fluoride is present in the water in Jersey, typically at a rate of 0.1 mg/l.
Fluoride is added in some countries to improve the development of adult teeth in adolescence, but this is not the case in Jersey.
Hard water / soft water
‘Hard’ or ‘soft’ water relates to the percentage of dissolved minerals in the water. Rain water is naturally soft and contains very little dissolved matter, but as it seeps through the ground it picks up various minerals from the soil and rocks that it passes through.
The hardness of the mains tap water in Jersey is classified as slightly to moderately hard.
Hard waters are most often found associated with chalk and limestone areas, which contain calcium and magnesium compounds. Soft waters are associated with impermeable rocks such as granite. In general surface waters such as streams are softer than ground water such as boreholes, as there has been less contact with the minerals present in the earth.
The problems associated with hard water include pipes furring up and scale which collects in kettles, causing them to work less efficiently. This is normal and does not mean there is something wrong with the water. Although kettles in Jersey do not tend to get scale forming inside them it is quite common for a brown deposit to form on the sides. This is manganese which occurs naturally in local waters, which although not pleasant to the eye, is totally harmless.
Waters are classified using the following description.
Hardness as mg CaCO3/l Water hardness 0-50 Soft 50-100 Moderately soft 100-150 Slightly hard 150-250 Moderately hard 250-350 Hard >350 Very hard
Appliance settings (dishwashers)
More soap is needed to create lather in hard water areas. To overcome this, dishwasher manufacturers often recommend the addition of salt to soften the water, and so enable less soap to be used, which is better for the environment.
The hardness of the mains tap water in Jersey is classified as slightly to moderately hard and tends to fall in the following range (hardness is often quoted in different units by dishwasher manufacturers so the most commonly used are also listed).
108 - 179 mg/l as CaCO3 7.7 - 12.8 as Clarks degrees 6.4 - 9.5 as German degrees 10.8 - 17.9 as French degrees
Should I use a water filter?
Where customers decide to install or use any kind of filtration system, including water filters and jugs, care and attention to the instructions are very important. All such appliances should be used in strict accordance with the manufacturer’s recommendations to avoid bacteriological growth and therefore contamination of the water which passes through these filters.
If the filter is not used and replaced in strict accordance with the manufacturer’s instructions bacteria can form on the filter and contaminate all water passing through it. This can result in food poisoning.
Jersey Water is perfectly safe to drink without using a filter.