The quality of the water in Jersey meets all the required parameters

From Howard Snowden, managing director and engineer, Jersey Water.

I WRITE further to Advocate Sinel’s letter (JEP, 16 July) regarding the taste and quality of the mains water supply.

Unfortunately, I am unable to comment on the assessment of the quality of mains water carried out by the imported ‘expert witness’ to whom Advocate Sinel refers, as Jersey Water were not party to this and the company has no knowledge of the results of the study.

I should like to take this opportunity to provide the facts about the quality of the mains water supply in Jersey. The quality of water is governed by the Water (Jersey) Law 1972, which defines the ‘wholesomeness’ of water in terms of the maximum allowable concentrations of physical, bacteriological and chemical parameters. The quality parameters listed under Jersey law and the frequencies of sampling water to test its quality follow the current regulations in England and Wales, the Water Supply (Water Quality) Regulations 2000.

The primary purpose of quality parameters is to ensure that water supplied is clean and safe to drink. Jersey Water undertakes more than 18,000 analyses a year of the water at various stages from source to tap to ensure that quality compliance levels are met. The overall compliance levels of the mains water supplied in Jersey are above 99.8 per cent, which is in line with compliance levels reported by water companies in England and Wales.

It is important to note that the virtual elimination of water-borne diseases such as cholera and typhoid in the western world has come about through the advent of clean and sterile mains water supplies for drinking and bathing. Mains water in Jersey, as in all other developed countries, is sterilised using chlorine.

The sterilisation process is essential in ensuring that water remains free from harmful bacteria. As well as being a necessary part of the treatment process, chlorine is equally important in guarding against post-contamination in private plumbing systems. Sterilisation of the water is the final part of the treatment process.

A very small residual amount remains in the treated water as it passes through the distribution network and private plumbing systems. This residual chlorine, which is present in the water that comes out of taps, is necessary to keep the water clean and safe, which is Jersey Water’s primary objective.

The taste of water is a very subjective matter and is generally dependant on the temperature and mineral content. It is a completely different issue from its quality. One of the main parameters relating to ‘taste’ of any fluid is temperature. In Jersey all the mains water supply is derived from surface water reservoirs, which are relatively small and shallow. The geology of the Island does not provide sufficient volumes of groundwater to meet the total public demand. Consequently, in the summer months the temperature of the mains water can reach 25ºC.

Customers who are concerned about the ‘taste’ or chlorination can be assured of the quality of the water and assured that the chlorine ‘smell’ is not harmful.

Taste can also be affected by private plumbing systems and storage tanks within a customer’s property. In terms of taste, customers may choose to keep tap water in bottles in the refrigerator during the summer, as this can make a difference to the taste and can be more refreshing.

By way or note, some years ago a major study in the north of England was carried out following customer complaints about the taste of mains water. The conclusions of the investigation were that the majority of taste issues originated from the leaching effect of flexible plastic hoses and fittings that are used in the home to connect washing machines and dishwashers to cold water feeds. These hose connections are generally connected under the kitchen sink and close to the tap, which is also most used for drinking purposes. Regular changing of flexible hoses may reduce the effect of any taste this may have.

The investigation also concluded that while the water may have had a ‘taste’, the results showed that it complied with all the necessary quality requirements and was safe to drink.

I would also take the opportunity to say that most bottled waters are from groundwater sources (Ash Bourne, Buxton, Harrogate, etc). Water from these sources is high in minerals, as the water abstracted from these chalk and limestone aquifers has taken at least 30 years to pass through the ground and become mineralised.

The comparison of taste, therefore, with mains water in Jersey, which is derived from surface water, can only be subjective and down to individual likes, dislikes and a person’s own taste buds.

Jersey Water publicises a water quality report each year and this is available as a download on our website (www.jerseywater.je). A printed copy of the report is also available to anyone interested by contacting us on 707301.