07 July 2006
An investigation is to be carried out into whether or not supplies of fresh water that exist deep underground in Jersey come from the European mainland.
Well drillers and water diviners have identified two sites on the Island where they believe underground streams from Europe enter Jersey. The sites are on the east coast at La Rocque and St Catherine.
Test drillings will take place and groundwater will be sampled from the base of each borehole. The water samples will then be examined to determine the ratio of heavy and light isotopes (the isotopic signature). By using this ‘signature’ it will be possible for scientists to conclude whether the water sampled from the identified underground stream fell as rain on Jersey or whether it derived from a source in mainland Europe. Test pumping will be undertaken on each borehole to determine the amount of groundwater available from them.
Drilling, supervision, analysis and interpretation costs are expected to be in the order of £61,000. Jersey Water has agreed to make a contribution of £20,000 toward these costs. Equipment is being assembled and work will start by the end of the month.
Following a statement to the Sates today on this matter, Planning and the Environment Minister Senator Freddie Cohen said: ‘This is an important step forward that will conclusively prove, once and for all, whether a groundwater connection between Jersey and mainland Europe exists. Before bringing a Water Resources Law back to the States, it is essential that we have hard evidence about the existence of a possible new supply of fresh water. I am pleased that Jersey Water is making a financial contribution to this project. The proposed tests will confirm both the source of the water and the abstraction capabilities of these deep boreholes’.
Water Diviner George Langlois, a member of the Deep Groundwater Advisory Group and long time supporter of the view that a water resource originating from outside the Island exists deep underground, said “I am pleased that there is going to be a proper investigation”. He and other members of the Group have agreed to accept the results of this evidence-based, scientific investigation.
The Chairman of the Environment Scrutiny Panel, Deputy Rob Duhamel endorsed this view and noted that a common sense approach to the negotiations had been achieved in line with one of the recommendations of last year’s Water Resources Scrutiny review. He looked forward to the results of the drilling tests which would confirm or reject the hypothesis within a conventional scientific framework.
Additional Information
As measured by the conventional approach - which divides the effective rainfall of an area by the size of the population it has to support - Jersey falls into the category of “water scarce”. The need to properly manage this scarce shared resource for the benefit of all users and the environment forms the basis for the draft Water Resources (Jersey) Law.
An alternative view is that Jersey does not need to be totally reliant on rainfall as there are great reserves of water deep underground that have their origin in mainland Europe from where they flow as streams under the sea-bed.
The Deep Groundwater Advisory Group was set up by the previous Environment and Public Services Committee following the publication of the Scrutiny Panel report on the draft Water Resources (Jersey) Law 2000- to examine the significance of deep groundwater and specifically the claim that its origin is from outside Jersey.
Members of the group include:
Dr Ralph Nichols (chair) - geologist
Dr John Renouf - geologist
Mr Lewis de la Haye - well driller
Mr Neville George - well driller
Mr George Langlois - water diviner
Mr Howard Snowden - Managing Director of Jersey Water
Mr Chris Newton - Director of Environment
Deputy Sarah Ferguson - States Member
Deputy Rob Duhamel - States Member
Isotope testing
The water molecule consists of H20. The stable isotopes of hydrogen (1H and 2H) and oxygen (16O and 18O) have identical chemical properties but have slightly different physical properties. During rainfall events the heavier 2H and 18O isotopes tend to fall out as rain at a higher rate than the lighter isotopes (16O and 1H). Thus is it possible to make maps of the isotope composition of water and use it to determine the area that groundwater originally fell as rain.
Further information:
Senator Freddie Cohen 07797 714550
or Chris Newton 01534 441610
gov.je