Bath, Adrian

Evans, Rick

Ferguson, Grant

Foster, Stephen

Lakshmanan, Elango

Scanlon, Bridget

Tyson, Gillian

Younger, Paul

English

Enlighten

How does the energy sector interact with the  groundwater domain ?The generation, consumption and management of energy interacts with the groundwater domain in surprisingly varied ways.  In consequence specific inputs from hydro-geological science are needed to understand these linkages, and for risk assessment and effective management of the interactions.   To facilitate discussion it is helpful to classify the interactions under the following headings :• sustainable exploitation of renewable energy resources• groundwater impacts of non-renewable energy sources• energy consumption for groundwater pumping and use.  How is renewable energy development linked with groundwater ?   • High Enthalpy Hydrogeothermal ResourcesThese resources usually occur deep underground and are characterised by high temperature (>150° C) and in-situ pres-sure, but are of limited geographical distribution being mainly associated with volcanic activity. Where present  they can be exploited by extracting water directly for power generation. GEOTHERMAL POWER PLANTTHE ENERGY SECTOR & GROUNDWATERInternational Association of Hydrogeologists Strategic Overview SeriesKEY MESSAGES• the energy sector interacts with    groundwater in many ways and applied   hydrogeological science is required to   understand and manage the linkages• this is highly relevant to the  sustainable development of hydro-  geothermal energy (particularly ‘very   low enthalpy’ resources used for space   cooling/heating) and to the nuclear   power sub-sector for power station   siting and radioactive waste disposal• in non-renewable hydrocarbon   development the principal concern is   to prevent shallow aquifer pollution   with formation brines, hydrocarbon  	 compounds	and	fracking	fluids• injection into gas and oil wells is   important for hydrocarbon waste   management, but knowledge of  the   ‘intermediate zone’ between aquifers   exploited for groundwater supply and   deeper hydrocarbon-producing strata   is generally inadequate• globally groundwater pumping, notably   for irrigated agriculture, is a major   energy consumer and much more effort  needs to be put into reducing  	 inefficient	use	due	to	aquifer	depletion	  and inappropriate waterwell design • effective land management for   municipal groundwater source   protection is an urgent need to avoid   the large energy cost associated with   water-supply treatment to remove   pollutants (such as nitrates, pesticides   and industrial chemicals)   This Series is designed both to inform professionals in other sectors of key interactions with groundwater resources  and hydrogeological science, and to guide IAH members in their outreach to related sectors.Hydrogeological investigations are required to assess the design of geothermal wells and their sustainable yield/temperature relation. • Low Enthalpy Hydrogeothermal ResourcesThere is a current boom in exploiting shallow, very low enthalpy resources (< 50° C at atmos-pheric pressure) using either : • ground-coupled heat-pumps for winter space heating and summer air conditioning (with warm water injected for later recovery)• groundwater directly for space cooling.  Indeed some cities are having to regulate well construction to avoid thermal (as well as hydraulic) interference between neighbouring  installations.  Given the high standards of thermal insulation in modern office buildings (and the ubiquitous presence of transformer heat sources), it is commonplace for such buildings to have very limited heating needs but to have almost year-round cooling requirements.   Hydrogeological analysis and modelling are  crucial for the assessment of just how sustainable such systems are in relation to borehole spacing, aquifer properties and thermal breakthrough.     • Nuclear Power Stations & Waste Disposal Groundwater conditions are a key siting  consideration for nuclear power-generation plants – and the possibility of groundwater flood-ing is one of the numerous hazards that must be evaluated. Risk assessment and management of radionuclide release from nuclear installations relies on understanding groundwater flow, hydro-geochemical conditions affecting radionuclide mobility, and how potential contamination might impact biological receptors.  Radioactive waste management is a chronic technological challenge posed by all nuclear activities (including medical radionuclide use, uranium mining and processing) not only power generation. Safe long-term disposal of radwaste is the ultimate aim, and geological disposal is widely recognised to impose least burden on future generations and lowest risk in the context of climatic and environmental change. Ground-water can affect both the integrity of engineered barriers and the transport of released radio-nuclides. When assessing potential host rocks and adjacent formations the relatively great depth involved poses a hydrogeological  challenge. Characterisation and modelling of these deep low-permeability systems is necessary to assess ground capacity to retain radionuclides and prevent their transport to the surface.  The role of the subsurface as a barrier and  attenuating mechanism must be moderated by credible assessment of risks to groundwater resources. Hydrogeological expertise needs to be engaged by both implementing organisations and regulatory agencies to ensure :•  acquisition of site-specific data, interpretation  of groundwater processes, and statistical evaluation of hydrogeological uncertainty• development and testing of conceptual  hypotheses for long-term processes in these unusual groundwater environments• calibration of numerical groundwater models at appropriate scales and degree of complex-ity relative to potential radionuclide release, and their application for prediction under ‘realistic’ and ‘worst-case’ scenarios.   IRRIGATED OIL-SEED CULTIVATION 2• Biofuel Crop CultivationThe extensive cultivation of crops destined for biofuel production widely implies large  applications of fertilisers and pesticides, and sometimes requires significant crop irrigation and process water. For example, in the USA bioethanol production from soya beans under groundwater irrigation has expanded rapidly since the introduction and amplification of subsi-dies in 1998 and 2005 respectively. Evaluation of the impact of such cultivation on groundwater  systems should follow a similar approach to that used for other agricultural land-use practices.    • Solar Energy CaptureIn countries like India major impetus is now  being put on the capture of solar energy.  Farmers are strongly encouraged to use solar panels for powering pumps in irrigation water-wells. Other solar energy panels in arid terrains require water for regular cleaning, and a dedi-cated waterwell is often the preferred source. Which groundwater impacts can arise from  non-renewable energy sources ?    • Conventional On-Shore Hydrocarbon  ExploitationThe development of hydrocarbon resources (oil and gas) can require the use of substantial groundwater resources and can pose a significant risk to the quality of shallow groundwater through infiltration or seepage of formation brines and/or hydrocarbon compounds from surface lagoons.  The activity requires full hydrogeological risk  assessment, appropriate environmental regulation and diligent operational control. But there is now extensive global experience as regards the  processes and procedures to follow.  • Unconventional On-Shore Hydrocarbon Exploitation  The current boom in unconventional hydrocar-bon development, especially for shale gas (and sometimes shale oil) deploys directional drilling techniques and then fluid injection at high- pressure (>2000 kg/cm2) in horizontal gas-well sections at 1,500-2,000m depth to generate  fissures (usually <300 m length).  The technique, known as ‘fracking’, requires 8,000-30,000 m3/well of injection fluid (90% water plus sand and various additives). ‘Flow-back fluids’ (fracking liquids, formation water, and possibly leached salts and radionuclides) are extracted from shale-gas wells after fracking and stored at the surface before re-use or deep-well disposal. Fracking has been conducted in vertical gas-wells to enhance production for many years, but its deployment in horizontal gas-well sections (often >1 km long) requires much larger fluid volumes and more complex additives. Although the utilisation of natural gas in power plants can greatly reduce their water-supply demand some concern has been voiced about :  • surface infiltration of formation waters and/or fracking fluids leading to contamination of shallow groundwater • gas migration through natural and induced  faults and fractures, and fugitive gas leakage from active or abandoned gas-wells. To reduce these risks good design and sound construction are essential, and more hydrogeo-COMPARITIVE SUB-SURFACE COMPLETION OF CONVENTIONAL AND UNCONVENTIONAL GAS-WELLIRRIGATED OIL-SEED CULTIVATION 3logical monitoring and evaluation of operations are required to identify those settings in which shallow groundwater is more susceptible to  degradation. Addressing this will require im-proved cooperation and joint research between hydrogeologists and hydrocarbon reservoir engineers.The same can be said of other unconventional hydrocarbon exploitation techniques such as: • coal-bed methane extraction, which is  generally from shallower depths (< 1,000m), and can require fracking with nitrogen gas • coal-bed gasification, which involves  injecting oxygenated steam to transform coal into a gas-stream.• Subsurface Wastewater InjectionMore generally injection into gas and oil wells is an effective waste management facility for the hydrocarbon sub-sector – but the risks remain poorly understood and are becoming more  apparent with the need to handle much larger  volumes of wastewater. Very large numbers of wells can be involved – for example 7% the 700,000 wells in Western Canada have already been used for injection. Cumulative injection  volumes are large compared to natural ground-water flow, and responsible for the bulk of recharge to deep aquifers – thus changes in groundwater flow pattern are inevitable. Not enough effort is made to track injected brines. The distribution and properties of aquitards  confining deep formations into which water is injected is often inadequately characterised, leading to a risk that the brine can migrate  upwards to shallower formations.  Too many  areas lack adequate injection infrastructure, and the understanding and experience needed to predict the subsurface response and risk of  potable aquifer contamination. • Impacts of Coal-Mine Drainage & Water-Table ReboundIn some regions major open-cast or subsurface coal mining continues to supply thermal power plants. In many cases this involves large-scale groundwater dewatering to facilitate safe mining, and this modifies the regional flow system and reduces resource availability for other users. Such activity is best planned using detailed hydrogeological knowledge, which will also be required to manage water-table rebound following mine closure. If this is not managed and treated appropriately, it is likely that  unpredictable highly acidic spring discharges will appear, which can contain elevated  concentrations of heavy metals. There is a huge  historical legacy in this regard, which is  presenting a major environmental challenge.   ACIDIC SPRING DISCHARGE FROM COAL-MINE WATER-TABLE REBOUNDA SHALE-GAS FRACKING OPERATION4• Carbon Capture & Storage at Conventional Power StationsContinued reliance on some fossil fuel use is unavoidable for a few more decades. Thus ways need to be found to reduce its carbon footprint. One option is to deploy carbon capture-and- storage at conventional power stations using hydrocarbon energy. There is a pressing need for better understanding of the hydrogeologi-cal principles underlying the injection of com-pressed carbon dioxide (which has the density of a liquid) into target deep aquifers (at depths of >650m) to displace existing groundwater and accumulate below confining aquitards, such that very little will escape via geological faults or inadequately-completed boreholes over a very long time horizon (> 10,000 years).How does groundwater exploitation affect  energy consumption ? • Energy Consumption for Waterwell PumpingThe vast majority of groundwater supply sources (except for springheads and overflowing artesianwaterwells) require considerable energy for pumping (but far less energy for treatment than surface-water sources).  The bulk of energy consumption is by irrigation waterwells (and this is said to represent as much as 15% of global  energy use), but it also represents a significant  issue for public water-supply utilities.  Advances in pumping technology can only deliver marginalefficiency gains – since most energy is used for  raising a given mass of water against a certain lift.  However, improved waterwell design can signifi-cantly reduce head losses and a rational distribu-tion of waterwells in a wellfield can optimise the total drawdown required for a given yield. Groundwater pumping can be an important  component of national and local energy demand, and needs to be appraised in related energy sec-tor policies. India has over 10 Mha of agricultural land under groundwater irrigation of which 70% uses electric-motor pumps, consuming a colossal 87,000 GWhr. The remaining 30% is irrigated with waterwell pumps powered by diesel fuel.  In states with a high coverage of rural electrifi-cation (Gujurat, Maharastra, Andhra Pradesh & Tamil Nadu) farmers rely exclusively on electric-engined pumpsets and receive a large subsidy via ‘flat-rate tariffs’ (only paying for 20% or less of the electricity they consume).  In areas with rapidly-depleted aquifers (such as the weathered hard-rock systems of Peninsular India), there is a  very high consumption of energy per unit of groundwater pumped, with much being consumed 															ESCALATING WATERWELL ENTRY LOSSES & UNIT ENERGY CONSUMPTION WITH DEWATERING OF A SHALLOW AQUIFER5because of very high well-entry and pump-friction losses.  Rural energy subsidies exert a major influence over farmer attitudes towards waterwell use – and policy harmonization is required to provide a clear incentive for energy conservation.  Moreover, much more effort needs to be put into critically assessing and  improving waterwell efficiency, and into reducing aquifer  depletion to mitigate this effect. • Groundwater Supply Treatment &  Desalination  The operation of treatment plants for the removal of nitrates, pesticides and/or industrial chemicals at water-utility ground-water sources implies a substantial electrical energy cost, which can be largely avoided by implementing effective  co-management of the neighbouring land as part of systematic groundwater source protection programmes.  Brackish groundwater will be much preferred to sea-water as the source-water for desalination, because it will  generally be of lower salinity and sediment free – and thus  reduce energy consumed and operational cost.   Hydrogeological evaluation and monitoring are required to design sustainable waterwells for brackish groundwater  abstraction.                         SELECTED BIBLIOGRAPHY•  Banks D  2009  An introduction to ‘thermogeology’ and the exploitation of ground source      heat. Quarterly Journal of Engineering Geology & Hydrogeology 42 •  Chapman N  2009 A geological disposal facility for the UKs radioactive wastes.        Proceedings of Institution of Civil Engineers 162 • Delgado A et al 2015 Thirsty energy - understanding the linkages between energy       and water.  World Bank Live Wire Series 94655 (Washington DC)•  Ferguson G  2015  Deep injection of waste-water in the Western Canada Sedimentary      Basin. Ground Water 53 •  Hazeldine R S  2009  Carbon capture and storage – how green can black be ?         Science 325 •  Jackson R E et al  2013 Groundwater protection and unconventional gas extraction : the      critical need for field-based hydrogeological research. Ground Water 51  •  Scanlon B R 2014 Will water scarcity in semi-arid regions limit hydraulic fracturing of shale      plays . Environmental Research Letters 9•  Younger P L 2014  Hydrogeological challenges in a low-carbon economy.      Quarterly Journal of Engineering Geology & Hydrogeology 47PRIORITY ACTIONS  • long-term monitoring and modelling of   groundwater system response to very   low enthalpy hydrogeothermal   development is needed to assess   sustainabiity and to improve design  •	 political	and	public	confidence	needs	  to be built-up on the ability of        hydrogeological science to guide the     selection of safe geological repositories  for radioactive waste  • on-shore hydrocarbon exploitation of   all types requires full hydrogeological   risk assessment, appropriate   environmental regulation and diligent   operational control• improved cooperation and joint   research between hydrogeologists and   hydrocarbon reservoir engineers is   required to monitor and evaluate the   groundwater impacts of shale-gas  	 fracking	and	fluid	injection	wells	 • energy consumption due to ground-  water resource over-exploitation needs   to be more critically assessed, and   coordinated trans-sector policies put in  place that constrain energy use for   groundwater pumping and conserve   aquifer storage reserves  • improved protection of potable   groundwater sources through effective   land management is required to avoid   the large energy cost associated with   water-supply treatment to remove   nitrates, pesticides and industrial   chemicals THE ENERGY SECTOR & GROUNDWATERInternational Association of Hydrogeologists Strategic Overviews SeriesCOORDINATION :   Stephen Foster & Gillian TysonCONTRIBUTIONS :  Grant Ferguson, Paul Younger, Adrian Bath, Rick Evans, Bridget Scanlon & Elango LakshmananMANAGEMENT :      Bruce Misstear & John Chilton  

The Energy Sector and Groundwater

Enlighten: Publications

How does the energy sector interact with the  
groundwater domain ?
The generation, consumption and management of energy 
interacts with the groundwater domain in surprisingly 
varied ways.  In consequence specific inputs from hydro-
geological science are needed to understand these linkages, 
and for risk assessment and effective management of the 
interactions.   To facilitate discussion it is helpful to classify 
the interactions under the following headings :
• sustainable exploitation of renewable energy resources
• groundwater impacts of non-renewable energy sources
• energy consumption for groundwater pumping and use.  
How is renewable energy development linked with 
groundwater ?  
 
• High Enthalpy Hydrogeothermal Resources
These resources usually occur deep underground and are 
characterised by high temperature (>150° C) and in-situ pres-
sure, but are of limited geographical distribution being mainly 
associated with volcanic activity. Where present  they can be 
exploited by extracting water directly for power generation. 
GEOTHERMAL POWER PLANT
THE ENERGY SECTOR & GROUNDWATER
International Association of Hydrogeologists 
Strategic Overview Series
KEY MESSAGES
• the energy sector interacts with   
 groundwater in many ways and applied  
 hydrogeological science is required to  
 understand and manage the linkages
• this is highly relevant to the 
 sustainable development of hydro- 
 geothermal energy (particularly ‘very  
 low enthalpy’ resources used for space  
 cooling/heating) and to the nuclear  
 power sub-sector for power station  
 siting and radioactive waste disposal
• in non-renewable hydrocarbon  
 development the principal concern is  
 to prevent shallow aquifer pollution  
 with formation brines, hydrocarbon  
	 compounds	and	fracking	fluids
• injection into gas and oil wells is  
 important for hydrocarbon waste  
 management, but knowledge of  the  
 ‘intermediate zone’ between aquifers  
 exploited for groundwater supply and  
 deeper hydrocarbon-producing strata  
 is generally inadequate
• globally groundwater pumping, notably  
 for irrigated agriculture, is a major  
 energy consumer and much more effort 
 needs to be put into reducing  
	 inefficient	use	due	to	aquifer	depletion	 
 and inappropriate waterwell design 
• effective land management for  
 municipal groundwater source  
 protection is an urgent need to avoid  
 the large energy cost associated with  
 water-supply treatment to remove  
 pollutants (such as nitrates, pesticides  
 and industrial chemicals)
  
 
This Series is designed both to inform professionals in other sectors of key interactions with groundwater resources  
and hydrogeological science, and to guide IAH members in their outreach to related sectors.
Hydrogeological investigations are required to 
assess the design of geothermal wells and their 
sustainable yield/temperature relation. 
• Low Enthalpy Hydrogeothermal Resources
There is a current boom in exploiting shallow, 
very low enthalpy resources (< 50° C at atmos-
pheric pressure) using either : 
• ground-coupled heat-pumps for winter space 
heating and summer air conditioning (with 
warm water injected for later recovery)
• groundwater directly for space cooling.  
Indeed some cities are having to regulate well 
construction to avoid thermal (as well as 
hydraulic) interference between neighbouring  
installations.  Given the high standards of 
thermal insulation in modern office buildings 
(and the ubiquitous presence of transformer heat 
sources), it is commonplace for such buildings 
to have very limited heating needs but to have 
almost year-round cooling requirements.   
Hydrogeological analysis and modelling are  
crucial for the assessment of just how sustainable 
such systems are in relation to borehole spacing, 
aquifer properties and thermal breakthrough.     
• Nuclear Power Stations & Waste Disposal 
Groundwater conditions are a key siting  
consideration for nuclear power-generation 
plants – and the possibility of groundwater flood-
ing is one of the numerous hazards that must be 
evaluated. Risk assessment and management of 
radionuclide release from nuclear installations 
relies on understanding groundwater flow, hydro-
geochemical conditions affecting radionuclide 
mobility, and how potential contamination might 
impact biological receptors.  
Radioactive waste management is a chronic 
technological challenge posed by all nuclear 
activities (including medical radionuclide use, 
uranium mining and processing) not only power 
generation. Safe long-term disposal of radwaste 
is the ultimate aim, and geological disposal is 
widely recognised to impose least burden on 
future generations and lowest risk in the context 
of climatic and environmental change. Ground-
water can affect both the integrity of engineered 
barriers and the transport of released radio-
nuclides. When assessing potential host rocks 
and adjacent formations the relatively great 
depth involved poses a hydrogeological  
challenge. Characterisation and modelling of 
these deep low-permeability systems is necessary 
to assess ground capacity to retain radionuclides 
and prevent their transport to the surface.  
The role of the subsurface as a barrier and  
attenuating mechanism must be moderated by 
credible assessment of risks to groundwater 
resources. Hydrogeological expertise needs to 
be engaged by both implementing organisations 
and regulatory agencies to ensure :
•  acquisition of site-specific data, interpretation  
of groundwater processes, and statistical 
evaluation of hydrogeological uncertainty
• development and testing of conceptual  
hypotheses for long-term processes in these 
unusual groundwater environments
• calibration of numerical groundwater models 
at appropriate scales and degree of complex-
ity relative to potential radionuclide release, 
and their application for prediction under 
‘realistic’ and ‘worst-case’ scenarios.   
IRRIGATED OIL-SEED CULTIVATION 
2
• Biofuel Crop Cultivation
The extensive cultivation of crops destined for 
biofuel production widely implies large  
applications of fertilisers and pesticides, and 
sometimes requires significant crop irrigation 
and process water. For example, in the USA 
bioethanol production from soya beans under 
groundwater irrigation has expanded rapidly 
since the introduction and amplification of subsi-
dies in 1998 and 2005 respectively. Evaluation of 
the impact of such cultivation on groundwater  
systems should follow a similar approach to that 
used for other agricultural land-use practices.    
• Solar Energy Capture
In countries like India major impetus is now  
being put on the capture of solar energy.  
Farmers are strongly encouraged to use solar 
panels for powering pumps in irrigation water-
wells. Other solar energy panels in arid terrains 
require water for regular cleaning, and a dedi-
cated waterwell is often the preferred source. 
Which groundwater impacts can arise from  
non-renewable energy sources ? 
   
• Conventional On-Shore Hydrocarbon  
Exploitation
The development of hydrocarbon resources 
(oil and gas) can require the use of substantial 
groundwater resources and can pose a significant 
risk to the quality of shallow groundwater through 
infiltration or seepage of formation brines and/or 
hydrocarbon compounds from surface lagoons.  
The activity requires full hydrogeological risk  
assessment, appropriate environmental regulation 
and diligent operational control. But there is now 
extensive global experience as regards the  
processes and procedures to follow. 
 
• Unconventional On-Shore Hydrocarbon 
Exploitation  
The current boom in unconventional hydrocar-
bon development, especially for shale gas (and 
sometimes shale oil) deploys directional drilling 
techniques and then fluid injection at high- 
pressure (>2000 kg/cm2) in horizontal gas-well 
sections at 1,500-2,000m depth to generate  
fissures (usually <300 m length).  The technique, 
known as ‘fracking’, requires 8,000-30,000 m3/
well of injection fluid (90% water plus sand and 
various additives). ‘Flow-back fluids’ (fracking 
liquids, formation water, and possibly leached 
salts and radionuclides) are extracted from shale-
gas wells after fracking and stored at the surface 
before re-use or deep-well disposal. 
Fracking has been conducted in vertical gas-
wells to enhance production for many years, but 
its deployment in horizontal gas-well sections 
(often >1 km long) requires much larger fluid 
volumes and more complex additives. Although 
the utilisation of natural gas in power plants can 
greatly reduce their water-supply demand some 
concern has been voiced about :  
• surface infiltration of formation waters and/
or fracking fluids leading to contamination of 
shallow groundwater 
• gas migration through natural and induced  
faults and fractures, and fugitive gas leakage 
from active or abandoned gas-wells. 
To reduce these risks good design and sound 
construction are essential, and more hydrogeo-
COMPARITIVE SUB-SURFACE COMPLETION OF 
CONVENTIONAL AND UNCONVENTIONAL GAS-WELL
IRRIGATED OIL-SEED CULTIVATION 
3
logical monitoring and evaluation of operations 
are required to identify those settings in which 
shallow groundwater is more susceptible to  
degradation. Addressing this will require im-
proved cooperation and joint research between 
hydrogeologists and hydrocarbon reservoir 
engineers.
The same can be said of other unconventional 
hydrocarbon exploitation techniques such as: 
• coal-bed methane extraction, which is  
generally from shallower depths (< 1,000m), 
and can require fracking with nitrogen gas 
• coal-bed gasification, which involves  
injecting oxygenated steam to transform coal 
into a gas-stream.
• Subsurface Wastewater Injection
More generally injection into gas and oil wells 
is an effective waste management facility for the 
hydrocarbon sub-sector – but the risks remain 
poorly understood and are becoming more  
apparent with the need to handle much larger  
volumes of wastewater. Very large numbers of 
wells can be involved – for example 7% the 
700,000 wells in Western Canada have already 
been used for injection. Cumulative injection  
volumes are large compared to natural ground-
water flow, and responsible for the bulk of 
recharge to deep aquifers – thus changes in 
groundwater flow pattern are inevitable. Not 
enough effort is made to track injected brines. 
The distribution and properties of aquitards  
confining deep formations into which water is 
injected is often inadequately characterised, 
leading to a risk that the brine can migrate  
upwards to shallower formations.  Too many  
areas lack adequate injection infrastructure, and 
the understanding and experience needed to 
predict the subsurface response and risk of  
potable aquifer contamination. 
• Impacts of Coal-Mine Drainage & Water-
Table Rebound
In some regions major open-cast or subsurface 
coal mining continues to supply thermal power 
plants. In many cases this involves large-scale 
groundwater dewatering to facilitate safe 
mining, and this modifies the regional flow 
system and reduces resource availability for 
other users. Such activity is best planned using 
detailed hydrogeological knowledge, which will 
also be required to manage water-table rebound 
following mine closure. If this is not managed 
and treated appropriately, it is likely that  
unpredictable highly acidic spring discharges 
will appear, which can contain elevated  
concentrations of heavy metals. There is a huge  
historical legacy in this regard, which is  
presenting a major environmental challenge.   
ACIDIC SPRING DISCHARGE FROM COAL-MINE 
WATER-TABLE REBOUND
A SHALE-GAS FRACKING OPERATION
4
• Carbon Capture & Storage at Conventional 
Power Stations
Continued reliance on some fossil fuel use is 
unavoidable for a few more decades. Thus ways 
need to be found to reduce its carbon footprint. 
One option is to deploy carbon capture-and- 
storage at conventional power stations using 
hydrocarbon energy. There is a pressing need 
for better understanding of the hydrogeologi-
cal principles underlying the injection of com-
pressed carbon dioxide (which has the density 
of a liquid) into target deep aquifers (at depths 
of >650m) to displace existing groundwater and 
accumulate below confining aquitards, such that 
very little will escape via geological faults or 
inadequately-completed boreholes over a very 
long time horizon (> 10,000 years).
How does groundwater exploitation affect  
energy consumption ? 
• Energy Consumption for Waterwell Pumping
The vast majority of groundwater supply sources 
(except for springheads and overflowing artesian
waterwells) require considerable energy for 
pumping (but far less energy for treatment than 
surface-water sources).  The bulk of energy 
consumption is by irrigation waterwells (and this 
is said to represent as much as 15% of global  
energy use), but it also represents a significant  
issue for public water-supply utilities.  Advances 
in pumping technology can only deliver marginal
efficiency gains – since most energy is used for  
raising a given mass of water against a certain lift.  
However, improved waterwell design can signifi-
cantly reduce head losses and a rational distribu-
tion of waterwells in a wellfield can optimise the 
total drawdown required for a given yield. 
Groundwater pumping can be an important  
component of national and local energy demand, 
and needs to be appraised in related energy sec-
tor policies. India has over 10 Mha of agricultural 
land under groundwater irrigation of which 70% 
uses electric-motor pumps, consuming a colossal 
87,000 GWhr. The remaining 30% is irrigated 
with waterwell pumps powered by diesel fuel.  
In states with a high coverage of rural electrifi-
cation (Gujurat, Maharastra, Andhra Pradesh & 
Tamil Nadu) farmers rely exclusively on electric-
engined pumpsets and receive a large subsidy 
via ‘flat-rate tariffs’ (only paying for 20% or less 
of the electricity they consume).  In areas with 
rapidly-depleted aquifers (such as the weathered 
hard-rock systems of Peninsular India), there is a  
very high consumption of energy per unit of 
groundwater pumped, with much being consumed 


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ESCALATING WATERWELL ENTRY LOSSES & UNIT ENERGY CONSUMPTION WITH DEWATERING OF A SHALLOW AQUIFER
5
because of very high well-entry and pump-friction losses.  Rural 
energy subsidies exert a major influence over farmer attitudes 
towards waterwell use – and policy harmonization is required 
to provide a clear incentive for energy conservation.  Moreover, 
much more effort needs to be put into critically assessing and  
improving waterwell efficiency, and into reducing aquifer  
depletion to mitigate this effect. 
• Groundwater Supply Treatment &  
Desalination  
The operation of treatment plants for the removal of nitrates, 
pesticides and/or industrial chemicals at water-utility ground-
water sources implies a substantial electrical energy cost, 
which can be largely avoided by implementing effective  
co-management of the neighbouring land as part of systematic 
groundwater source protection programmes.  
Brackish groundwater will be much preferred to sea-water as 
the source-water for desalination, because it will  
generally be of lower salinity and sediment free – and thus  
reduce energy consumed and operational cost.   
Hydrogeological evaluation and monitoring are required to 
design sustainable waterwells for brackish groundwater  
abstraction. 
         
               
SELECTED BIBLIOGRAPHY
•  Banks D  2009  An introduction to ‘thermogeology’ and the exploitation of ground source  
    heat. Quarterly Journal of Engineering Geology & Hydrogeology 42 
•  Chapman N  2009 A geological disposal facility for the UKs radioactive wastes.   
     Proceedings of Institution of Civil Engineers 162 
• Delgado A et al 2015 Thirsty energy - understanding the linkages between energy  
     and water.  World Bank Live Wire Series 94655 (Washington DC)
•  Ferguson G  2015  Deep injection of waste-water in the Western Canada Sedimentary  
    Basin. Ground Water 53 
•  Hazeldine R S  2009  Carbon capture and storage – how green can black be ?     
    Science 325 
•  Jackson R E et al  2013 Groundwater protection and unconventional gas extraction : the  
    critical need for field-based hydrogeological research. Ground Water 51  
•  Scanlon B R 2014 Will water scarcity in semi-arid regions limit hydraulic fracturing of shale  
    plays . Environmental Research Letters 9
•  Younger P L 2014  Hydrogeological challenges in a low-carbon economy.  
    Quarterly Journal of Engineering Geology & Hydrogeology 47
PRIORITY ACTIONS  
• long-term monitoring and modelling of  
 groundwater system response to very  
 low enthalpy hydrogeothermal  
 development is needed to assess  
 sustainabiity and to improve design  
•	 political	and	public	confidence	needs	 
 to be built-up on the ability of  
      hydrogeological science to guide the    
 selection of safe geological repositories 
 for radioactive waste  
• on-shore hydrocarbon exploitation of  
 all types requires full hydrogeological  
 risk assessment, appropriate  
 environmental regulation and diligent  
 operational control
• improved cooperation and joint  
 research between hydrogeologists and  
 hydrocarbon reservoir engineers is  
 required to monitor and evaluate the  
 groundwater impacts of shale-gas  
	 fracking	and	fluid	injection	wells	
 
• energy consumption due to ground- 
 water resource over-exploitation needs  
 to be more critically assessed, and  
 coordinated trans-sector policies put in 
 place that constrain energy use for  
 groundwater pumping and conserve  
 aquifer storage reserves  
• improved protection of potable  
 groundwater sources through effective  
 land management is required to avoid  
 the large energy cost associated with  
 water-supply treatment to remove  
 nitrates, pesticides and industrial  
 chemicals
 
THE ENERGY SECTOR & GROUNDWATER
International Association of Hydrogeologists 
Strategic Overviews Series
COORDINATION :   Stephen Foster & Gillian Tyson
CONTRIBUTIONS :  Grant Ferguson, Paul Younger, Adrian Bath, Rick Evans, Bridget Scanlon & Elango Lakshmanan
MANAGEMENT :      Bruce Misstear & John Chilton 
 


http://eprints.gla.ac.uk/109953/1/109953.pdf

The Energy Sector and Groundwater

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