1. Focus on
the Southeast

2. ESI has been providing services to clients in South East England for over 15
years. In December 2011 ESI increased the support provided to clients in the
region with the opening of a new office in Reading. The addition of an office and
closer proximity to key clients enables ESI to further increase the level and scope
of services we provide in the region.
ESI is the UK’s leading independent scientific and environmental consultancy
specialising in water management, land quality, landfill and waste management,
and ground source energy. As a technical specialist advisor to business clients of
all sizes (corporate and SME) and governmental clients ESI is respected for its
pragmatism, sound science and clear commercial understanding.
This brochure provides an opportunity to summarise some of the main services we
provide from the new Reading office, and also present a few examples of our work
in the region by way of case study summaries to further illustrate our capabilities.
Water Resources
ESI is a specialist consultancy dealing with all aspects
of groundwater science and water resource
management and has one of the largest and most
technically capable groundwater teams in the UK. With
a detailed in-depth understanding and experience of
the key issues involved in field investigation, monitoring,
conceptualisation, groundwater surface water
interactions, and groundwater flow and transport
modelling ESI is recognised as the leading independent
provider of water resource services.
Groundwater support is provided to a diverse group of
clients who need to understand, assess, map and plan,
including: Utility companies, developers, extractive,
mining and tunnelling companies, local authorities and the Environment Agency.
Land Quality Investigation, Risk Assessment
and Management
ESI provides solutions as a technical specialist advisor to the land issues facing both
corporate and governmental clients; from simple Phase 1 assessments to complex,
Phase 2 quantitative investigations or on-the-ground support. ESI has a reputation for
pragmatism, sound science and a strong, clear commercial focus. Their Clients benefit
from their experience and knowledge of the fast changing landscape of regulatory
guidance and best practice.
Specialist services include site investigation to support Brownfield development,
environmental monitoring, data management, contaminant transport modelling, risk
assessment and remedial design: all delivered by experienced Project Managers and
qualified technical teams.

3. Landfill and Waste Management
ESI delivers a leading capability in
landfill management in the UK and
Europe and has extensive
experience across all types of
waste disposal sites, including
hazardous, non-hazardous and
inert landfills. Support is provided
throughout the landfill life cycle from
concept with the environmental risk
assessment for the environmental
permit application, to work in
support of a landfill surrender
application. In addition, expert
waste classification advice is
provided which links contaminated
land assessment with pragmatic waste management solutions. With a detailed technical
understanding, coupled with the experience of the key issues involved in regulation,
data management, and ongoing monitoring and risk assessment ESI is the consultancy
of choice for these services.
Renewable Energy - Ground Source Energy
ESI is a leading consultancy for the design of Ground Source Energy solutions and has
delivered successful projects in the UK and other European regions. With a technical
understanding of the issues faced in both open and closed loop designs, ESI is the
ideal consultancy to select when considering Ground Source Energy as a low carbon
energy option.
Each project is handled by a project manager from start to finish drawing on the
expertise of fellow consultants to meet the requirements of individual clients. Services
are provided to Owner Occupiers, Architects and Building Designers, Ground Source
Energy System Installers and Mechanical and Engineering Contractors.
Expert Witness
ESI has a highly experienced team of senior consultants, experienced in delivering
Expert Witness support in groundwater, groundwater flooding, land contamination,
ground source energy and in relevant sub-specialisms.
ESI's Expert Witness structure provides services to suit a wide range of projects from
small, site specific court cases to some of the largest and most complex planning
applications, waste management and contaminated land issues in the country. By
listening carefully to clients and understanding the critical aspects of each case from a
legal perspective, ESI is able to offer effective solutions to difficult problems. Well
written evidence that clearly distinguishes fact from opinion is recognised as a key
requirement, all senior staff having appropriate training in the role of the Expert Witness.

4. Case Studies
Investigation of the London chalk aquifer
The chalk aquifer beneath London is subject to a considerable number of stresses
including rising groundwater levels, abstraction sustainability, artificial recharge, saline
intrusion, groundwater flooding, and the growth of ground source energy. ESI has
recently undertaken two key projects for the Environment Agency to aid the
management of these pressures in a sustainable and cost effective manner. Following
consolidation and analysis of the available data and a comprehensive literature review,
ESI has formulated a detailed conceptual understanding of the key hydrogeological
processes which occur within the London Basin aquifer.
Using the most up-to-date interpretation of the geology beneath London, ESI furthered
current understanding of geological controls on groundwater flow, most notably faulting
and structure within the basin and the influence of the Chalk stratigraphy on aquifer
properties. The robust and quantified conceptual model has formed the basis for the
construction of a numerical MODFLOW model. The conceptual and numerical models
will aid the Environment Agency manage water resources.
Groundwater monitoring during tunnel construction, Croydon
National Grid commissioned Morgan Est to construct a 10 km tunnel to house a new
400kV line through South Croydon. The tunnel needed to be built carefully through the
chalk aquifer, passing within a
few hundred metres of several
of Thames Water’s critical
supply boreholes. ESI was
involved in finding pragmatic
ways of mitigating the potential
risks to water supplies and
supporting discussions with
the Environment Agency and
Thames Water.
The risks to the sources were
minimised by changes to the
design of the tunnel and an
ongoing groundwater level and
quality monitoring programme,
detailed contingency measures were designed. The tunnel was completed on time and
to budget with no significant adverse impacts on the environment.
Groundwater dewatering - Channel Tunnel Rail Link
ESI provided expertise in groundwater modelling to optimise the installation of boreholes
used for dewatering whilst the tunnel was being driven. Due to access constraints ESI’s

5. expertise was invaluable in the location and effectiveness of the boreholes. The model
was comprehensive and included actual time series data for groundwater levels prior to
and during dewatering; it also simulated actual and predicted future drawdown and
recovery over a six year period.
Saline Intrusion Modelling, Southern England
ESI has carried out a thorough review of the hydrogeology of a block of Chalk aquifer
that suffers from saline intrusion. Careful review of hydrograph and water quality data
allowed convincing correlations to be developed. A scoping model was constructed in
FEFLOW to simulate the development of the saline wedge with time. This provided
strong numerical support for the conclusion that levels of salinity observed in boreholes
was more strongly controlled by antecedent rainfall than by actual abstraction rates.
Environmental impact assessment – Beckton sewage
treatment works,
East London
Thames Water Utilities were
undertaking the wholesale
redevelopment of the
Beckton sewage treatment
works situated on the banks
of the River Thames. The
work was designed to both
modernise the facility and
accommodate the end point
of the Lee Tunnel sewage
pipeline. ESI was tasked to
provide risk assessment
services to support
requirements for a planning application to protect human health or controlled waters
under continued site use. Additional advice was provided as to the suitability of site-won
materials for subsequent re-use in other parts of the site.
Hydrogeological Risk Assessment for an active landfill,
Cambridge
In order to comply with the PPC permit issued for a large, active landfill located in
Cambridgeshire the client was required to submit to the Environment Agency a four-
year review of the Hydrogeological Risk Assessment for the site. ESI was asked to
complete this assessment to determine whether the conceptual model that
underpinned the original study was still applicable, and to assess the potential impacts
of the landfill on the Lower Greensand major aquifer. ESI reviewed the data and
appropriate changes to the leachate levels and concentrations in the risk assessment
model were made. The results of the additional modelling continued to support the
original HRA conclusions and showed that there was no additional impact to controlled

6. waters as a result of the changes.
Low river flow
assessments, Kent
ESI was appointed by
Southern Water Services to
investigate the hydrogeology of
the catchment of the Little
Stour river in Kent. The study
was focussed on the flow
regime in the lower reach of
the river where, in the past, the
original channel had been
modified and rerouted to
supply water to a group of
mills. The artificial channel
suffered from significant
leakage to the underlying
gravel and chalk aquifers, with adverse results on the river ecology and amenity value.
The Environment Agency (EA) was concerned that groundwater abstraction was
reducing the flow into the affected reach. ESI compiled extensive data, and a literature
review exercise was undertaken in cooperation with the Environment Agency and the
water companies in the area from which ESI was able to make recommendations to
resolve the issues.
Quarry extension - hydrogeological impact assessment,
Reading, Berkshire
CEMEX intended to apply for planning permission to extend an existing quarry, located
in gravel deposits that form a locally important minor aquifer. ESI was instructed to
provide specialist hydrogeological services, to assess the potential hydrogeological
impacts associated with the scheme, on part of an adjacent hydrologically sensitive
Sight of Special Scientific Interest and related watercourses. The Planning permission
was subsequently approved.
Ground Source Energy (GSE) - Groundwater modelling to
support “Cooling the Tube”,
London
ESI has developed a coupled groundwater
flow-heat transport FEFLOW model of
central London, building on recent work
undertaken on the ‘Cooling the Tube’ project
for the London Underground. The aim of the
model was to provide a tool to aid the

7. Environment Agency effectively manage and make regulatory decisions regarding open-
loop ground source energy schemes.
Groundwater Risk Assessments, Abbey Mills, London
The Lee Tunnel will be London’s deepest-ever tunnel, the first of two which will
collectively capture an average of 39 million tonnes of sewage a year, the four-mile
tunnel will run beneath the London Borough of Newham. ESI undertook a quantitative
risk assessment (DQRA) for dewatering activities to investigate concerns that
groundwater contamination present within the lower groundwater system might be
drawn into the relatively clean aquifer at the shaft site. ESI also conducted the human
health risk assessment in relation to piling and a proposed culvert construction at the
Abbey Mills site.
Ground Source Energy
(GSE) - Modelling of
an open loop design –
Tate Modern, London
The geology at the Tate Modern
site comprises made ground, drift
and river terrace gravels overlying
a substantial thickness of London
clay. FEFLOW (hydrogeological
finite element modelling software)
was used to develop a single
layer model of the open loop
scheme. A steady state model
was used to assess the
maximum abstraction rates
achievable and the likely impact
on local groundwater levels. It
also assessed the sensitivity of
the GSE scheme performance to
the borehole locations and
uncertain hydrogeological parameters. The scheme is now being installed, and will
make a renewable and efficient contribution to the building’s energy use.
Source Protection Zone (SPZ) review, Thames Region
The Environment Agency Thames Region required a review of some SPZs, and
delineation of a new set of SPZs for recently licensed abstractions. ESI developed some
new groundwater models, for others, original two-dimensional Flowpath models were
converted into MODFLOW models. Abstraction rates were updated appropriately and
particle tracks were developed for the required travel times. GIS was used to trace SPZs
around the particle tracks, and at this step expert hydrogeological judgment was used to
make small adjustments with regard to topography and river networks. A total of 100

8. Phil Aldous Director, ESI Ltd.
Phil is respected in the water industry as
an experienced environmental manager,
and project director who understands the
issues facing water companies and the
broader environment. His expertise
covers water resource management,
pollution issues and regulatory and
compliance management. Originally a
hydrogeologist at the UK Water Research
Centre, Phil’s extensive water industry
experience was gained at Thames Water,
where he held a variety of environmental
roles supporting their water and
wastewater business and the
development of commercial and
international operations.
He has represented the water industry
both nationally and internationally through
Water UK, negotiating the structure of
regulatory compliance legislation and
defending legal challenges. Phil also contributed to industry research programmes
through UKWIR. His experience is supported by degrees in environmental science,
hydrogeology, environmental law and a diploma in management studies. He has also
served as a member of the Geological Society’s hydrogeological group editorial board.
Phil joined ESI in December 2011 as a Board Director to support the continued growth
of the business and to lead the development of a regional, south east office in Reading.
ESI
Davidson House
Forbury Square
Reading Offices in
RG1 3EU Shrewsbury
T: +44 (0) 118 9000829 Reading
E: info@esinternational.com London