My main interests are in: Groundwater dating; System Dynamics; Water Resources Management; and Aquifer Sustainability issues.
I am the academic lead for the Environmental Tracers Laboratory (ETL) which I established at QUB in 1999 to: advance the use of natural and applied tracers for geohydrology (ie with emphasis on the 'hydrologic or fluid flow aspects of groundwater') and the investigation and characterisation of environmental and engineering systems; so as to promote sustainable use and practice and to increase fundamental understanding of gas and dissolved phase bio/geochemical processes in the surface and subsurface (unsaturated and saturated) zones; and to use this understanding to predict and mathematically model fate and transport processes for compounds of environmental concern.
Environmental tracer methods here are broadly taken to be techniques for obtaining information (eg transit times of material in media, permeability, dispersivity, subsurface activities, etc.) about an environmental and/or engineering system or some part of a system by observing the behaviour of a specific substance either injected into or inherently added within a system. This may involve, the direct application (injection) or artificial infiltration of tracers into the subsurface (eg Cl, organo-dye, and Kr, Xe, SF6 tracing in groundwaters – the noble gases in particular providing environmentally-friendly tracer technology), or the addition of (either natural or anthropogenic) tracers via natural infiltration and recharge processes to the subsurface (eg 14C, 3H, δ18O, δ2H, CFCs, SF6, noble gases), or through tracing the natural addition or loss within the subsurface (eg water-rock interactions), and also dissolved, bulk-partitioning, noble gases in open systems such as surface waters particularly can also be used to trace gas transfers across eg the air-water interface.
An ideal tracer is a substance that behaves in a system exactly as the traced material as far as the sought parameters and properties are concerned, but has one property that makes it distinguishable analytically from the traced material. In practice even substances which have other sources/sinks or relevant properties can be regarded as tracers if these sources/sinks/properties can be accounted for, or if their influence is negligible within the measurement accuracy. Tracers may and should be used “intelligently”. Thus, multi-tracer techniques to characterise a range of system parameters (eg multi-isotope techniques tracing water and solute sources) and/or a combined use of tracers differing by a single relevant property relevant to a parameter determination can be used. Examples of the latter are the use of conservative tracers of flow with non-conservative tracers of reaction (eg Cl- and Na+, the latter sensitive to cation exchange parameters in an aquifer), the use of several injected inert substances of differing molecular weight sensitive to diffusive parameters (eg noble gas tracing in dual-porosity media), and the use of bulk or interfacial partitioning tracers (to delimit eg subsurface phase characteristics). The benefit of tracing methods generically is that they can be used to validate eg conceptual and structural models of the system (potentially helping to reduce uncertainty) and/or can be conducted at the scale of interest (ie tracers responded to the integrated, swept-out volume in a system over the length/time scales investigated) to assess effective transport and fate parameters.
Thus, I use ambient, natural, Environmental Tracers (major, minor, trace elements, stable isotopes, noble gases, CFCs, radiogenic & radioactive isotopes) in both Environmental and Engineered Systems to characterise water quality controls, transit and residence times (especially groundwater dating, but including groundwaters as archives of past climatic change and future climate change effects), and mixing dynamics of systems. I have worked particularly in regional-scale aquifer systems and both porous & fissured media (eg London & Berkshire Chalk, East Yorshire Chalk, Lagan Valley Sandstone, Algerian Continental Intercalaire & Complexe Terminal Sandstone, etc.), and am currently working on the Guarani super-aquifer in Brazil. Recent work has also addressed for example mixing dynamics in the pumping of flooded, abandoned coal mines as a remediation strategy for Acid Mine Drainage impacts. The ETL also specialises in and deploys Environmentally-friendly, Applied, and Intelligent Tracers in subsurface systems (aquifers; karst systems; engineered Permeable Reactive Barriers, PRBs), and also for reaeration and gas evasion studies (eg noble gas injection and monitoring downstream for dilution/dispersion and loss across air-water interface) in streams.
I have been a past Associate Editor of Hydrogeology Journal(Springer; 2002-2006 inclusive) and on the Editorial Board and Hydrology & Earth Systems Science (HESSD & HESS: European Geoscience Union; 2005-2012 inclusive), and am currently on the Editorial Board of the open-access journal Water (MDPI; since 2014).
Environmental Legislation for Engineers & Scientists (civ8035); Chemistry of Natural Waters (civ8004/7018/4018); Engineering Surveying I /Surveying & Measurement I (civ1010); Statistical Tools and Research Methods (civ7010).
(Google Scholar Citations profile: if link does not work directly then copy and paste URL)
(Editor - Environmental Tracers, Water, Special Issue, 2014)
I am a Member of the UK Institute of Physics and a Chartered Physicist (CPhys, MInstP; since 1992), a Fellow of the Geological Society of London (FGS; since 1993), and a HEA Licensed Practitioner (FHEA; since 2003).
I was on the Board of Directors for NI2000 (Waste Management/Environmental charity; 2002-2003 inclusive), was Elected Chair for the Technical Committee for the Unsaturated Zone (TC-UZ) of the European Geosciences Union, EGU [2003-2006 inclusive], an External Examiner for MSc Hydrogeology in the School of Earth & Environment, University of Leeds, UK [2008/09-2011/12 inclusive], and am currently an External Examiner for both MSc Hydrogeology & MSc Environmental Engineering for the Department of Civil and Environmental Engineering, University of Strathclyde, UK [since 2014/15].
2007 Winner, Outstanding Paper Award, Water & Environment Journal (CIWEM) for ‘Direct measurements of reaeration rates using noble gas tracers in the River Lagan Northern Ireland’ by Sally E. Reid, Pauline A. Mackinnon & Trevor Elliot
Performance of a field-scale biological permeable reactive barrier for in-situ remediation of nitrate-contaminated groundwater.
Research output: Contribution to journal › Article
Development of Guidelines for the Integrated Use of Hydrological, Geochemical and Isotope Tools in Mining Operations; The Primer
Research output: Book/Report › Book
Hydrogeochemical and isotopic indicators of vulnerability and sustainability in the GAS aquifer, São Paulo State, Brazil
Research output: Contribution to journal › Article
Geological Society of London
Scopus rating (2018): SJR 0.443 SNIP 0.695
Scopus rating (2018): CiteScore 3.22 SJR 0.988 SNIP 1.438
Scopus rating (2018): CiteScore 3.77 SJR 1.624 SNIP 1.362
Additional searchable ISSN (Electronic): 1520-5851
American Chemical Society
Scopus rating (2018): CiteScore 7.38 SJR 2.514 SNIP 1.959
Additional searchable ISSN (Electronic): 1573-2983
Scopus rating (2018): CiteScore 3.06 SJR 0.759 SNIP 1.184
Activity: Visiting an external institution types › Research and Teaching at External Organisation
Activity: Publication peer-review and editorial work types › Editorial activity
Integrated hydraulic data and environmental tracers for monitoring dynamics of pumped minewaters from abandoned, flooded mines - Deerplay and Frances Collieries, UK
Activity: Talk or presentation types › Invited or keynote talk at national or international conference
Contribution to conference papers, events and activities