Hydrochemistry
Nick’s bachelors’ degree was in Geology with Geochemistry and 20% of his degree comprised a project on the hydrochemistry of mine waters in old Copper Mines at Alderley Edge, south of Manchester. His PhD was on geochemical changes in mudrocks and involved a range of stable isotope (18/16O, 13/12C, 34/32S, 87/86Sr), inorganic chemistry and organic chemistry analytical and interpretative techniques.
Natural water chemistry provides clues to the origin of a water and the route that water takes up to the point of sampling or discharge. Despite routine water quality sampling by a number of parties, hydrochemical interpretation is an underused approach, often due to a discomfort with the subject by hydrogeologists. Examples of Nick’s consultancy experience in this area includes:
- Identifying the controls on water quality (including Tritium content, and 18O and 2H stable isotope ratios) in the vicinity of the Sellafield and Dounreay potential deep nuclear repository sites. Reports prepared for Nirex in 1993 and 1997. The work included checking evidence of deep saline water discharge, water rock interaction and identifying waters contaminated from farming practices (fertiliser application).
- Interpretation of water chemistry to provide evidence of recharge and flow routes in the Chalk of East Anglia, the Carboniferous Limestone of the Mendips, and a range of sedimentary and igneous strata in Qatar and Oman.
- Understanding the hydrochemical controls (CO2 degassing, nutrients, biofilms) on tufa (calcium carbonate) deposition at springs, which could be impacted by the deepening of a large limestone quarry. This work continued with an advisor role for a PhD student.
- Helping resolve the source of deep water in the States of Jersey, including working with BGS on the interpretation of trace gas (CFCs and SF6) gases for age dating (see Cheney, C.S et al 2006 in Publications).
- Differentiating between water types either as part of hydrogeological conceptualisation or in support of bottled water source designation.
In addition to Nick’s project experience, he has prepared and delivered training courses on natural hydrochemistry. Nick has undertaken hydrochemical modelling in the past, but not recently. His experience does however provide him with a good understanding of the key controls on natural water chemistry.