Water Resource Management – Monitoring,Conceptualisation, and Groundwater Flowand Transport Modelling, Field Investigation
ESI is the UK’s leading independent scientific and environmentalconsultancy specialising in water resource management, land quality andground source energy. As a technical specialist advisor to corporate andgovernmental clients ESI is respected for its pragmatism, sound scienceand strong commercial focus.Water Resource Management – Monitoring,Conceptualisation, and Groundwater Flow andTransport Modelling, Field Investigation.Consultancy Services for Water ResourcesESI is a specialist consultancy dealing with flow and transport modelling ESI is recognisedall aspects of groundwater science and as the leading independent provider of watergroundwater resource management and has resource services. Groundwater support isone of the largest and most technically capable provided to a diverse group of clients who needgroundwater teams in the UK. With a detailed to understand, assess, map and plan, including:technical understanding and experience of Utility companies, Developers, Extractive, Miningthe key issues involved in field investigation, and Tunneling companies, Local Authorities andmonitoring, conceptualisation, and groundwater the Environment Agency.Low Flow Studies and Hydro-ecology Traditionally, water resource assessments for groundwater abstraction have focused on the impacts at a relatively large or catchment scale. Ecological concerns are often very local and site specific. Low flow studies and hydro-ecology assessments therefore need to combine the broad catchment scale approach with a more detailed local understanding. ESI’s combination of strong technical skills with a detailed experience of local scale processes is essential to resolving these issues.ESI has over 15 years of experience working with a range of clients, particularly in the waterindustry, to develop more targeted and efficient ways of defining the impact of groundwaterabstraction on surface water ecology (hydro-ecology). With multiple and complex projectscompleted ESI has a record of working alongside other specialists (e.g. in aquatic ecology andhydrology) as part of a team to deliver clear answers to these problems.
Groundwater ModellingGroundwater models can improve our In order to produce a groundwater modelunderstanding of how aquifer systems that can be used as a reliable managementbehave and can be used to make tool, it is essential to base it on a carefullypredictions about the system’s future worked out conceptual model. This requiresbehaviour. Specific questions that can be a thorough review of all the relevantaddressed using a groundwater model data. The consultancy team at ESI hasinclude: extensive experience and are able to use their knowledge in this area to select the• How might a change in abstraction be right groundwater modelling approach for used to improve river flows or reduce the problem being faced. Groundwater impacts on a wetland? models should never be more complex• Is a potential river support scheme than the problem requires or available effective? data allows.• How might climate change influence ESI has one of the largest and most by their clients. Groundwater models have available resources? technically capable groundwater modelling been developed to solve problems involving teams in the UK. Over the last decade the water resource management, borehole• Will this abstraction cause saline team has consistently delivered technically yield, tunnel dewatering, quarry dewatering, intrusion? robust groundwater models that are climate change, saline intrusion and• How might changes in abstraction affect used to provide practical answers to the groundwater contamination (including petrol groundwater quality? important water resource questions faced spills and landfill issues). Borehole Drilling and Testing and Deployable Outputs ESI has built an experienced team of quality assured data to ensure total groundwater scientists with a good accuracy in its reporting. balance between pragmatic field Water companies are required to plan experience and in-depth quantitative extensively for the future with detailed skills for the analysis of field results. Water Resource Management Plans All contractors used to support projects for the next 25 years of operation. are carefully chosen, all must meet a A key building block of these plans is work standard dictated by ESI and all the source reliable output assessments are required to provide copies of their for all groundwater sources. ESI’s own Quality and Health and Safety strengths in applied groundwater standards and accreditations. All science and experience of borehole contractors are supervised, whether yield assessment have been critical to on small site investigations or on major developing an accurate assessment of production borehole drilling and testing the water available from these sources contracts. ESI is committed to providing for clients across the UK.Groundwater Control and DewateringThe development of sophisticated ESI’s senior team has extensivetunnelling techniques on major experience of handling complexengineering projects has led to the dewatering projects and has providedincreased demand for accurate innovative solutions to the issues faced.predictions of rates of dewatering The consultancy team has successfullyrequired. In the extractive industry, developed and are operatingplanning constraints on the lateral groundwater models of some of theextensions to quarries has put largest dewatering schemes in theincreased pressure to deepen existing UK. ESI’s approach in all of its projectssites below the water table. In both of is to work closely with clients tothese industries, the energy costs of determine the most appropriate level ofdewatering have become significant assessment required for each site. Thisoperational factors, whilst environmental ensures that the most cost effectiveconstraints are often critical to the solutions can be achieved in all cases.feasibility of these schemes.
Dealing with Climate ChangeThe impact of climate change on recharge, as has been experienced ingroundwater resources is a complex recent years. The increase in variabilityissue and does not lend itself to an will make it more likely that an extendedeasy solution. Most global climate sequence of dry winters could occurmodels suggest that on average with potentially significant implicationsthere will be wetter winters and drier for water resource management. Thesummers in the UK. This should imply reliability of these model predictions isthat on average there will be more still a topic for debate, in the meantimewinter recharge to the aquifer providing it is clear that increased uncertaintyincreased groundwater availability requires increased resilience of waterthan at present. However, increased supply systems.variability is also a significant feature ofcurrent climate change predictions and ESI’s strengths in quantitativenot all winters will have higher rainfall hydrogeology (including a proven trackthan average. Furthermore, an increase record in calculating recharge ratesin the number of intense summer from meteorological data) are wellstorms may provide significant summer suited to assessment of the risks to water resources from climate change.Groundwater Flood Risk Assessment and Mapping Groundwater floods occur after long susceptible to groundwater flooding. periods of high rainfall, when the water In addition, civil engineering work can table rises above the ground surface. often have very localised effects on Insurance companies estimate that shallow groundwater levels resulting in groundwater flooding claims amount to damage to adjacent properties. In all between £50 million and £100 million cases, understanding the causes of per year. Each event costs about three groundwater flooding and development times as much as fluvial or tidal flooding of robust mitigation measures requires because a groundwater flood can last a thorough quantitative understanding for weeks or months. 1.6 million homes of the local groundwater conditions, in the UK that are outside existing something that ESI’s experienced staff fluvial and tidal flood risk areas may be are well placed to provide.Case StudiesInvestigation of the London AquiferThe aquifer beneath London is subject influence Chalk stratigraphy on aquiferto a considerable number of stresses properties. The robust and quantifiedincluding rising groundwater levels, conceptual model has formed the basisabstraction sustainability, artificial for the construction of a numericalrecharge, saline intrusion, groundwater MODFLOW model. The conceptualflooding, and the growth of ground and numerical models will aid thesource energy. ESI has recently Environment Agency manage waterundertaken two key projects for resources.the Environment Agency to aid themanagement of these pressures in a ESI has developed a coupledsustainable and cost effective manner. groundwater flow-heat transport FEFLOW model of central London,Following consolidation and analysis of building on recent work undertakenthe available data and a comprehensive on the ‘Cooling the Tube’ project forliterature review, ESI has formulated the London Underground. The aim ofa detailed conceptual understanding the model was to provide a tool to aidof the key hydrogeological processes the Environment Agency effectivelywhich occur within the London manage and make regulatory decisionsBasin aquifer. Using the most-up- regarding open-loop ground sourceto-date interpretation of the geology energy schemes. A series of modelsbeneath London, ESI furthered current were developed to simulate heatunderstanding of geological controls on transport under a range of operationalgroundwater flow, most notably faulting scenarios, including ‘worst case’ and aand structure within the basin and the range of realistic operating conditions.
Low Flow Investigation SitesOver the last ten years ESI has worked dropped from the programme.closely with Severn Trent Water onkey low flow sites in the Midlands, ESI drew up a scope of furtherspanning the AMP3, AMP4 and investigations for each site andAMP5 programmes in 40 catchments was then appointed with partnersand reviewing over 60 PWS to carry out the works. In AMP4abstraction boreholes. this involved detailed site surveys, 15 new observation boreholesThe sites were initially flagged up by and an extensive programme ofthe Environment Agency and included groundwater level and spot flowseveral SSSIs and a Habitats Directive gauging (80 sites) over a 3-5 yearsite. ESI worked closely with STWL, period at each site. The datathe regulators and other specialists collected was regularly reviewed andto determine whether these concerns annual reports presented. At thewere justified. At several of the sites it end of the monitoring period, ESIwas quickly apparent that either there prepared impact assessment reportswas a significant low flow problem to summarise the improvementand the site could progress to options of understanding of the problemappraisal or there was no significant and to make an assessment of thePWS impact and the sites could be significance of any impacts.Cornelly Group of Quarries The planning permissions for the boreholes and borehole and surface Cornelly Group of Quarries were geophysics), monitoring (level, flow subject to review under the provisions and quality), tracer tests, data review of the Environment Act 1995 and analysis, development of a (ROMP). The National Assembly for conceptual model and preparation of Wales (NAW) had concerns about the Environmental Statement. the potential impacts of further working of the quarries; the regulators Negotiation and technical discussion had particular concerns about the with the regulators was a central potential for dewatering Special part of the assessment due to the Areas of Conservation under the complexity of the local hydrogeology Habitats Directive. and the potential degree of uncertainty in any predictions that could be made. The NAW requested Environmental The work was carried out in a phased Statements to assist in the manner to allow results from the early determination of the ROMP stages to be circulated and the scope submissions. Tarmac appointed for later phases to be adjusted in ESI to carry out a hydrogeological the light of these findings. Work has investigation and impact assessment, progressed through the EIA stage and the work involved field investigations is now focussed around future water (construction of 20 new monitoring management at the site.Croydon Cable TunnelNational Grid’s plan to construct a mitigating the potential risks to water10 km tunnel to house its new 400kV supplies and supporting discussionsline through South Croydon was a with the Environment Agency andgreat way of avoiding years of traffic Thames Water.disruption. The tunnel needed to be The risks to the sources werebuilt carefully through the chalk aquifer, minimised by changes to the design ofan important source of public water the tunnel and an ongoing groundwatersupply, passing within a few hundred level and quality monitoring programmemetres of several of Thames Water’s throughout the course of the project.critical supply boreholes, without Detailed contingency measures wereaffecting water supplies. The contract designed that would be actioned iffor the detailed design and construction certain triggers were breached. Theof the tunnel was awarded to Morgan tunnel was completed on time andEst. ESI were a technical partner to budget with no significant adverseinvolved in finding pragmatic ways of impacts on the environment.
Expert Witness SupportESI has a team of senior consultants with experience of delivering Expert Witnesssupport in groundwater, groundwater flooding, land contamination, ground sourceenergy and in relevant sub-specialisms. The Expert Witness team is supported byindustry leading technical consultants.EurGeol Mark Fermor Expert WitnessBSc MSc DUC MBA CGeol FGSManaging Director ESI LtdMark Fermor is a hydrogeologist with particular expertise in quantitative methods for resource management, contaminationassessment and groundwater modelling. He has practical experience of investigating and remediating a wide range ofcontamination hazards in soil and groundwater and in undertaking hydrogeological risk assessments using both qualitativeand quantitative methods. Mike Streetly Expert WitnessBSc MSc CGeol FGSWater Resources Director ESI LtdMike Streetly is a very experienced hydrogeologist and project director/manager who is well known throughout the industry for hisskills and experience in water resource assessment. He has strong numerical skills which have been applied to solving a wide varietyof hydrogeological problems. He also has extensive practical experience, particularly in the design, installation and operation ofhydrometric networks and pumping tests. Dr Steve Buss Expert WitnessMA MSc PhD FGS CGeolPrincipal Hydrogeologist, ESI LtdDr Steve Buss is a Chartered Geologist with extensive experience of understanding and modelling groundwater flow andcontaminant transport. He has led projects that have examined groundwater flow and contaminant transport in all the principal UKaquifers; from the site scale to the scale of regional aquifers. These have included: assessments of groundwater resource availability,the impact of groundwater abstraction on stream flows, the impacts of changes in groundwater flow on groundwater chemistry, andrisk assessments for groundwater flooding. ESI LtdNew Zealand House160 Abbey ForegateShrewsburySY2 6FDT: +44 (0) 1743 276100E: email@example.comW: www.esinternational.com