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Environmental Impacts of Hydraulic Fracturing
Related to Exploration and Exploitation of Unconventional Natural Gas
Deposits – Short Version
„Mindful also of its responsibility toward future generations,
the state shall protect the natural foundations of life and
animals by legislation and, in accordance with law and
justice, by executive and judicial action, all within the
framework of the constitutional order.“
Basic Law for the Federal Republic of Germany, Article 20 a
This publication is part of the public relations work of the Federal Ministry for
the Environment, Nature Conservation and Nuclear Safety. It is distributed free
of charge and is not intended for sale.
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Published by: Federal Ministry for the Environment, Nature Conservation and Nuclear Safety (BMU)
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Edited and designed by: ahu AG, Aachen
Printed by: Druck Center Meckenheim
Photo credits:
Title: Georg Meiners
Fig. 1, 3, 4 and 5: ahu AG 2012
Fig. 2: BGR 2012
Fig. 6: IWW 2012
Fig. 7: IWW and ahu AG 2012
Date: November 2012
First Print: 50 copies
The contents of this publication do not necessarily reect the ofcial opinions.
Environmental Research Plan (Umweltforschungsplan)
of the Federal Ministry for the Environment,
Nature Conservation and Nuclear Safety (BMU)
FKZ 3711 23 299
Environmental Impacts of Hydraulic Fracturing Related to Exploration
and Exploitation of Unconventional Natural Gas Deposits –
Risk Assessment, Recommendations for Action and Evaluation of
Relevant Existing Legal Provisions and Administrative Structures
SHORT VERSION
by
Dr. H. Georg Meiners / Dr. Michael Denneborg / Frank Müller
ahu AG Wasser · Boden · Geomatik,
Kirberichshofer Weg 6, 52066 Aachen
Dr. Axel Bergmann / Dr. Frank-Andreas Weber / Prof. Dr. Elke Dopp / Dr. Carsten Hansen /
Prof. Dr. Christoph Schüth
IWW Rheinisch-Westfälisches Institut für Wasser – Beratungs- und Entwicklungsgesellschaft mbH,
Moritzstr. 26, 45476 Mülheim a.d. Ruhr
in cooperation with:
Hartmut Gaßner / Dr. Georg Buchholz
[Gaßner, Groth, Siederer & Coll.] Rechtsanwälte Partnerschaftsgesellschaft,
Energieforum Berlin, Stralauer Platz 34, 10243 Berlin
Prof. Dr. Ingo Sass / Dipl.-Ing. & MSc. Sebastian Homuth / Dipl.-Ing. Robert Priebs
Technische Universität Darmstadt, Institut für Angewandte Geowissenschaften,
Fachgebiet Angewandte Geothermie, Schnittspahnstraße 9, 64287 Darmstadt
UNDER COMMISSION TO THE FEDERAL ENVIRONMENT AGENCY (UBA)
November 2012
Contents
1 Introduction 1
2 Unconventional gas deposits in Germany 3
3 Scientic and technical parameters and risk assessment 5
3.1 System analysis, impact pathways and risk analysis 5
3.1.1 System analysis 5
3.1.2 Impact pathways 5
3.1.3 Risk analysis 7
3.2 Equipment and techniques 9
3.2.1 Site layout and design 9
3.2.2 Modelling, control and monitoring of fracture propagation 10
3.2.3 Long-term integrity of wells 10
3.3 Fracking uids 10
3.3.1 Overview 10
3.3.2 Fracking uids used in Germany 11
3.3.3 Hazard potentials 12
3.3.4 Possible fracking procedures that use no chemical additives 15
3.4 Flowback 15
3.4.1 Quantities and composition 15
3.4.2 Disposal pathways 16
4 Legal regulations and administrative structures 18
4.1 Mining law 18
4.2 Water law 18
4.3 Handling of fracking uids and owback 19
4.4 Coordination and integration of authorization procedures under mining law and water law 19
4.5 Development of general standards 20
4.6 Water protection areas 20
4.7 Environmental impact assessment (EIA) and public participation 20
4.8 Responsibilities 21
5 Recommendations for action and procedures 23
5.1 Overarching recommendations 24
5.2 Special recommendations 26
5.2.1 Special recommendations with regard to the area of environment / geological systems 27
5.2.2 Special recommendations with regard to the area of equipment / techniques 28
5.2.3 Special recommendations with regard to the area of substances 29
5.2.4 Special recommendations with regard to the area of legislation / administration 30
References 34
Tables
Tab. 1. Potential unconventional gas deposits in Germany 3
Tab. 2. Special issues to be considered in risk analysis relative to selected geo systems 5
Tab. 3. Functions of additives in fracking uids (based on UBA 2011, Tyndall Centre 2011) 11
Tab. 4: Fracking uids that have been used in, or would be suitable for, unconventional deposits, and that were
selected for assessment of their hazard potential 14
Figures
Fig. 1: Structure of the study (long version) 1
Fig. 2: Mining authorizations in Germany (= yellow, last revision: 31. December 2011) for exploration for
unconventional hydrocarbon deposits (ochre = regions with the basic geological conditions for formation
of shale gas) 4
Fig. 3: Schematic depiction of potential impact pathways 6
Fig. 4: Assessment of environmental impacts via effective factors 7
Fig. 5: Structure of risk analysis for assessment of unconventional gas production 8
Fig. 6: Substance concentration to be assessed at the surface or base (red circles) of a near-surface, exploitable
aquifer (blue) when substances enter via input pathways from the surface (pathway group 0) and via
migration from the fracking horizon (pathway groups 1-3) 13
Fig. 7: Schematic depiction of owback formation via mixing of fracking uids and formation water in connection
with hydrogeochemical processes 16
Environmental Impacts of Hydraulic Fracturing – Short Version
1
1.2 Procedure, and structure of the study
A well-founded risk analysis will be based on a pre-
cise description of the existing relevant system (its
sensitivity), of the impacts related to the project (in-
tervention) and of the relevant cause-and-effect rela-
tionships. The existing system and its sensitivity must
be assessed site-specifically.
The nature, extent and duration of the project’s envi-
ronmental impacts can vary in keeping with the pos-
sible combinations of types of deposits and the tech-
nologies used to exploit them. As a result, the two
subsystems “environment” and “technology” have to
be considered first; then, the two can be combined in
useful ways for systematic, comprehensive analysis of
the possible cause-and-effect relationships.
1.3 Structure of the study
The structure of the present study is shown schema-
tically in Figure 1. Following a general introduction,
the long version of the study is divided into four
parts: Description of the physio-geographic, techni-
cal and substance-related factors involved in fracking
(Part A), applicable legal frameworks and administ-
1 Introduction
1.1 Current situation, and objectives
The exploration and exploitation of unconventional
gas deposits especially as it involves hydraulic fractu-
ring (”fracking”) has been generating intensive public
discussion. Such discussion has focused especially on
the potential impacts on the environment and on
human health – in particular, on how the techniques
and substances used in fracking can affect the envi-
ronment and human health. The Federal Environ-
ment Agency (UBA) has published a statement report
on shale gas exploitation in Germany.1 A number
of the aspects that the Federal Environment Agency
statement report has introduced have since been de-
tailed and scientifically analyzed in the framework of
an extensive study. The study has focused especially
on substances used in fracking, which are toxic for
humans and for aquatic organisms, on the potential
impact pathways and on the relevant legal frame-
work. The present short version of that study summa-
rizes its results and recommendations.
The study describes the potential environmental im-
pacts of fracking, and the potential risks for people,
along with the additional findings and knowledge
that are needed in order to properly assess such im-
pacts and risks. In addition, it describes the existing
applicable provisions under (the German) mining
law, environmental law and – especially – water law,
and analyzes those provisions with regard to areas
in which they agree, areas in which they differ and
areas they fail to address. The objectives of the overall
project include:
1. Assessing the risks of exploitation of unconventi-
onal gas deposits (especially of such exploitation
via fracking) from scientific, technical and legal
standpoints.
2. Describing the available technical alternatives.
3. Developing recommendations for action and pro-
cedures that legislative authorities and enforce-
ment authorities can implement as a basis for
managing the risks entailed in exploitation of
unconventional gas deposits. This also includes
development of suitable criteria for public par-
ticipation in the framework of environmental
impact assessment (EIA).
1 http://www.umweltbundesamt.de/chemikalien/publikatio-
nen/stellungnahme_fracking.pdf
Fig. 1: Structure of the study (long version)
2
rative structures (Part B), risk and deficit analysis (Part
C) and derivation of recommendations for action and
procedures (Part D).
This study was prepared mostly on the basis of open-
ly accessible information and data. To assess the risks
related to fracking, we had to rely on the extensive
range of relevant literature available internationally
(such as US EPA 2004, US EPA 2011, Tyndall Centre
2011) and on information provided by this country’s
national authorities and operating companies. In
Germany, extensive experience with fracking has
been obtained in connection with tight gas deposits
(primarily in Lower Saxony). To our knowledge, no
systematic study of the types, quantities, behavior
and fate of the substances employed in those deposits
has been carried out, nor have the relevant envi-
ronmental impacts been monitored specifically and
systematically.
Environmental Impacts of Hydraulic Fracturing – Short Version
3
The following types of unconventional gas deposits
are differentiated:
• Tight gas: Tight gas is gas that has moved from
a parent rock formation into sand or limestone
formations with very low permeability. In Ger-
many, such formations normally occur at depths
greater than 3,500 m. The productivity of a given
tight gas deposit depends on its permeability and
porosity and on the way the gas is distributed
throughout the rock.
• Shale gas: Shale gas is thermo genic gas created
via cracking of organic matter at high tempera-
tures and pressures. Under such processes, the
gas is absorbed into the parent rock in various
ways. The exploration and exploitation tech-
niques used with such gas involve breaking the
relevant bonds and creating suitable pathways
for gas migration. While some shale gas deposits
in Germany are presumed to lie at relatively shal-
low depths, beginning at about 500m (overlying
alum shale in the Rhenish Massif), many of the
deposits are known to be at considerably greater
depths.
• Coal bed methane (CBM): Coal bed methane is
formed via coalification of organic matter in coal
deposits. Such deposits are found at a number of
different depths in Germany. The pressure of the
formation water in such deposits binds the gas to
the surface of the coal. Consequently, before gas
can be extracted from them, such deposits first
have to be drained of water. It remains to be seen
whether gas exploitation from such deposits al-
ways requires hydraulic stimulation (fracking).
In Germany, unconventional gas deposits are thought
to be present in a number of different types of geo-
logical formations. Table 1 presents an overview of
2 Unconventional gas deposits in Germany
Tab. 1. Potential unconventional gas deposits in Germany
Type of deposit Most promising deposits Regions
Coal bed methane
(source rocks)
Seam-bearing Upper Carboniferous Northern Ruhr region / Münsterland Basin (NRW)
Ibbenbüren (NRW)
Saar Basin (Saarland)
Shale gas
(source rocks)
Tertiary clay formations (e.g. Fischschiefer) Molasse Basin (BW)
Posidonia Shale (Black Jurassic) * Northwest German Basin (e.g. Lünne) (NI)
Molasse Basin (BW)
Upper Rhine Graben
Wealden clay formations (Lower Cretaceous) * Weser Depression (NRW / NI)
Permian clay formations
(e.g. black shale („Stinkschiefer“), copper shale)
Northeast German Basin (NI / SA)
Carboniferous and Devonian clay formations
e.g. alum shale (Lower Carboniferous) *
Northern edge of the Rhenish massif (NRW)
Northwest German Basin
Harz Mountains (NI / SA)
Silurian slates Northeast German Basin
Cambro-Ordovician clay formations („alum shale“) (not yet studied in detail)
Tight gas
(deposit rocks)
Red sandstone Northwest German Basin (NI / SA)
Permian sandstones (Rotliegend) and
carbonates (Zechstein)
Northeast German Basin (e.g. Leer) (NI)
Permian sandstones (Rotliegend) and
dolomite (Stassfurt series) sandstones (Triassic)
Thuringian Basin (TH)
Upper Carboniferous sandstones Northwest German Basin (e.g. Vechta) (NI)
* = relevant potential shale gas deposits pursuant to the Federal Institute for Geosciences and Raw Materials (BGR; 2012)
4
potential target geological formations for exploration
of unconventional gas deposits in Germany, broken
down by the different types of unconventional gas
deposits involved. It also lists the deposits that are
currently thought to offer the greatest promise for
exploitation.
According to current estimates (BGR 2012), the tech-
nologically recoverable gas reserves (assumption:
10 % of the gas in place (GIP) are technologically
recoverable) present in shale gas deposits in Germa-
ny amount to about 700 to 2,300Bill. m3. The GIP
in coal bed methane deposits is estimated to exceed
3,000 Bill. m3 (GD NRW 2011). The technological re-
coverability of coal bed methane reserves in Germany
has not yet been analyzed.
Most of the hydrocarbon provinces known in Germa-
ny already contain approved or applied-for explora-
tion fields for exploration of, and exploitation from,
conventional and unconventional oil and gas depo-
sits. Figure 2 shows the areas that contain (planned)
activities for exploration for unconventional gas de-
posits in Germany (BGR 2012). To our information, no
permits have yet been issued for exploitation of natu-
ral gas from unconventional shale gas and coal bed
methane deposits. Furthermore, we have not yet seen
any specific planning detailing such exploitation.
Fig. 2:
Mining authorizations in Germany
(= yellow, last revision: 31. December 2011)
for exploration for unconventional hydro-
carbon deposits (ochre = regions with the
basic geological conditions for formation of
shale gas)
(source: BGR 2012)
Environmental Impacts of Hydraulic Fracturing – Short Version
5
3.1 System analysis, impact pathways and
risk analysis
3.1.1 System analysis
Unconventional gas deposits are parts of larger geo
systems, which differ in terms of their geology and
hydrogeology. As a result, exploration methods and
exploitation strategies have to be locally specific.
Also the methods and strategies have to be assessed
specifically, using suitably differentiated perspectives,
in terms of their environmental impacts and risks.
A “geo system” within the meaning of the present
study is a large-scale unit that forms a geological
and hydrogeological system (e.g. Molasse Basin, etc.).
To understand local flow systems within such a geo
system, in the context of a site-specific consideration,
and to assess the pertinent risks, one must under-
stand/analyse the large-scale system involved.
In the long version of the study, selected sample
geo systems and their possible unconventional gas
deposits are described and analyzed with regard to
the specific issues they present for risk assessment (cf.
Tab. 2).
3.1.2 Impact pathways
Potential water-related impact pathways resulting
from exploration and exploitation of unconventional
gas deposits via fracking are shown schematically in
Figure 3. Both technical impact pathways (such as fai-
lures of well casings) and geological impact pathways
(such as faults) have to be considered. For a geolo-
gical impact pathway to be relevant, it must entail
both, permeability and a potential difference (pressu-
re difference), the two factors needed for a directed
3 Scienticandtechnicalparameters,andriskassessment
Tab. 2. Special issues to be considered in risk analysis relative to selected geo systems
Type of deposit Region Subsystem Special issues to be considered in risk analysis
Tight gas Northern German
Basin
Deposits overlying
Zechstein
Other geological barriers
Existence of continuous faults
Permeability of covering strata
Distribution of regional groundwater ow systems
Deposits underlying
Zechstein
Barrier function / effect of Zechstein deposits
Other geological barriers
Coal bed methane
gas
Münsterland Basin Central Münsterland Permeability of Emscher marl (including naturally formed gas rises)
Permeability and potential deposits of Cenoman/Turon limestones
Existence and relevance of continuous faults
Impacts of exploratory wells from hard-coal mining
Mining zone Scenarios for further use of water resources (development of mine water ma-
nagement, etc.) and its impacts on the hydraulic system
Hydraulic connections to mine-water-management areas
Perimeter areas of
Münsterland
Impairment of source lines
Permeability and potential deposits of Cenoman/Turon limestones
Shale gas Molasse Basin Western area Structure of regional groundwater ow systems
Groundwater ows ascending from deeper aquifers
Existence of continuous faults
Competing uses – for example, geothermal uses
Harz Mountains Position of target horizons
Existence and permeability of continuous faults
Rise of brine
6
flow. Whether or not the two factors are present will
depend on a) the relevant natural conditions and b)
the nature and scope of the intervention involved.
Pathway group 0
Pathway group 0 refers to (pollutant) discharges that
occur directly at the ground surface, and especially
in handling of fracking fluids (transport, storage,
etc.) and in management of flowback (not including
disposal; see below). Often, such discharges will be
preceded by a failure of the equipment being used.
Pathway group 0 is relevant especially during the
fracking phase, when handling of fracking fluids and
of flowback – including transport, storage and dis-
posal – is most intensive. Pollutant discharges at the
ground surface can occur via accidents, disruptions
or improper handling.
Pathway group 1
Pathway group 1 refers to potential (pollutant) di-
scharges and spreading along wells, i.e. to artificial
underground pathways. With regard to the impact
pathways involved, a distinction has to be made bet-
ween production wells and old wells, such as wells
from other exploration and uses. Options for control-
ling and monitoring fracture formation in fracking
play an important role with regard to old wells (cf.
section 3.2.2), since fractures can open up sudden
hydraulic connections to old wells.
In production wells leakages can occur during the
fracking process that can lead to undesired entry of
fracking fluids into the annulus or into the neighbou-
ring rock; in addition, failures of cementations and/
or casings can become impact pathways in the long
term.
Pathway group 2
Pathway group 2 comprises all impact pathways
along geological faults. Significantly, the permeability
along any given fault can vary, section-wise. Whereas
deep-reaching, continuous faults can often be moni-
tored, since the near-surface locations of their out-
crops are usually known, faults that affect only parts
Fig. 3:
Schematic depiction of
potential impact pathways
Environmental Impacts of Hydraulic Fracturing – Short Version
7
of the overburden are difficult to monitor. Options
for controlling and monitoring fracture formation in
fracking play an important role also with regard to
pathway group 2 (cf. section 3.2.2), since fractures
can open up sudden hydraulic connections to faults.
Pathway group 3
Pathway group 3 comprises extensive rise, as well as
lateral spreading, of gases and fluids through geo-
logical strata (for example, via an aquifer), without
preferred pathways similar to those described for pa-
thway groups 1 and 2. Impact pathways in pathway
group 3 depend primarily on the prevailing geologi-
cal and hydrogeological conditions.
With regard to fracking, the phases actually invol-
ving fracking itself – at the depths > 1,000 m that
are currently being discussed – are considered to be
too short to be able to directly impair near-surface
groundwater resources via this pathway. During ex-
ploitation, uncontrolled rise of gases via these impact
pathways would be the primary relevant factor. These
impact pathways are also considered significant for
post-operational phases, subject to the condition that
there are sufficient permeabilities and groundwater
potentials.
Summation and combination of different impact pathways and
long-term impacts
Summation and combination of the aforementioned
impact pathways play a role in all operational phases
considered, and they must be appropriately taken
into account. Since many flow processes in the deep
underground take place very slowly, the relevant
long-term impacts have to be estimated – also in con-
nection with effects that must be summed. Such esti-
mation is possible only on the basis of an extensive
understanding of the geological and hydrogeological
conditions prevailing in deep underground layers. In
our view, for no geo systems are data currently availa-
ble, along with corresponding numerical forecast mo-
dels, that would suffice to support such estimation.
Flowback disposal via disposal wells
Operators currently refer to injection options as an
important parameter for (cost-effective) exploitation
of unconventional gas deposits. From the perspective
of the study authors, flowback disposal via deep-un-
derground injection can entail risks. For this reason,
so our view, any deep-underground injection calls for
site-specific risk analysis and monitoring.
3.1.3 Risk analysis
Along with direct environmental impacts (noise,
land use, substance emissions, etc.) exploration and
exploitation of unconventional gas deposits present
Fig. 4:
Assessment of environmental
impacts via effective factors
8
(like any technical-plant operations) a range of other,
delayed and spatially separated risks for humans and
the environment (indirect environmental impacts)
(cf. Figure 4). Such risks include, for example, gas rise
and groundwater contamination via rising fluids.
In the present case, involving exploitation of uncon-
ventional gas deposits, it is difficult to determine the
relevant risks – primarily as a result of the paucity
of available data. On the one hand, key basic data,
especially data relative to geology and hydrogeology,
are lacking; on the other, while some experience has
been gained in Germany with tight gas exploitation,
no concrete experience has been gained in Germany
with exploitation of shale gas and coal bed methane.
For this reason, we propose that the (site-specific) risk
analyses required at the present time be carried out
using a combination of various risk-analysis methods
(cf. Fig. 5).
Impact pathways (intervention intensity)
In consideration of the risks that exploitation of un-
conventional gas deposits can pose for exploitable
groundwater resources, impact pathways are consi-
Fig. 5: Structure of risk analysis for assessment of unconventional gas exploitation
Environmental Impacts of Hydraulic Fracturing – Short Version
9
dered instead of intervention intensity (see above) (cf.
section 3.1.2). The reason for this is that a risk can
lead to actual damage only if the pertinent impact
pathway is relevant.
For technical impact pathways, substantiated proba-
bilities of occurrence or failure can be determined
if adequate data are available. Geological impact
pathways depend on the geo systems involved. They
are defined primarily via the two parameters perme-
ability and hydraulic potential (referred to below as
“potential”). Without suitable numerical quantifica-
tion, the relevance of any impact pathways can only
be approximated, with great uncertainties.
Hazard potential
Suitable methods for assessing the hazard potential
of fracking fluids, of formation water, of flowback
and, if relevant, of applicable mixtures, are described
in section 3.3. In the component-based methods used,
assessment is based on the toxicological and eco
toxicological effective concentrations of the individu-
al substances involved. Since specific fracking-fluid
recipes, and formation-water and flowback constitu-
ents, can be suitably assessed only site-specifically, the
hazard potential of such fluids, water and flowback
is assessed in the following via a generic, i.e. overar-
ching, site-independent approach. To differentiate
between low, medium and high levels of hazard po-
tential, in any scientifically sound way, one must use
exposure scenarios for specific resources/assets, such
as scenarios developed with the help of numerical
models.
Flowback, and the fluids that can be released via
pathway groups 1, 2 and 3, consist of variable mixtu-
res of fracking fluids and formation water. Since the
fractions in such mixtures vary by site and over time,
it is assumed that the hazard potential of such fluids
is determined by the higher hazard potential of the
initial components of such mixtures, namely fracking
fluids and formation water.
Risk assessment
Consideration of the hazard potential of fluid-water
mixtures focuses on near-surface groundwater re-
sources. Mixing with formation water (for example,
following migration of such water from deeper lay-
ers) is not considered to be dilution that would lower
the hazard potential, since formation water normally
has negative impacts on near-surface groundwater re-
sources. The risk is then obtained by considering the
relevant pathway(s) (intervention intensity) together
with the hazard potential of the pertinent fluids (fra-
cking fluids and formation water). As Figure 5 shows,
the risk can then be divided into different categories
of degree – for example, in a five-part scale.
3.2 Equipment and techniques
The entire process of exploration of, and exploitation
from, unconventional deposits includes the following
phases, inter alia:
• Exploration,
• Selection and preparation of the drilling site,
• Drilling and completion of the well,
• Stimulation,
• Exploitation,
• Retreat from the drilling site / renaturation.
With regard to techniques used, the key fracking-spe-
cific aspects to consider include specifications for site
layout and design (single well or clusters of wells); the
manner in which frac propagation is modeled, cont-
rolled and monitored; and the long-term integrity of
wells (cementation and casing).
3.2.1 Site layout and design
Selection of drilling sites forms part of the authori-
zation procedure, under mining law, for approving
operational plans for exploration for, and production
of hydrocarbons. In comparison to gas production
from conventional deposits, however, exploitation of
unconventional deposits requires a significantly grea-
ter number of wells (and, thus, of drilling sites). Gene-
rally several wells are drilled from a single well-pad.
This is done by moving the drilling rig to different
starting points within a well-pad (cluster drilling).
To protect surface water and groundwater from any
pollutant spills above ground, the drilling site – and
especially those areas where substances hazardous to
water are stored and handled– has to be sealed. Rain-
water has to be collected and treated in conformance
with applicable laws (WEG 2006).
Drilling techniques and drilling-site layouts/design
are subject to a range of standards and legal provi-
sions. These include the federal state ordinances on
deep-drilling (Tiefbohrverordnungen der Bundeslän-
der – BVOT) and various technical guidelines and
industry standards (WEG 2006). In our view, the issue
of the extent to which such standards and regulati-
ons can be applied to the new requirements involved
10
(such as cluster drilling, multilateral drilling, etc.), or
may need to be supplemented, has to be reviewed.
3.2.2 Modeling, control and monitoring of fracture
propagation
Fracking processes are used to create pathways (nor-
mally, fractures) in deposits with low permeability, in
order to increase permeability for fluids (liquids and
gases). Prior to actual fracking, fracture formation
can be modeled with the help of coupled hydraulic-
mechanical models (cf. also BGR 2012). For such
modeling, one requires a detailed knowledge of the
geomechanical properties of the target formation
and of the stresses prevailing underground.
The primary risk connected with “uncontrolled”
fracture formation is that it can form an (undesired)
connection to a hydraulically active element (old
well, fault, permeable rock layer), thereby creating
the possibility of gas and fluid rise.
While simulations of fracture formation can be
carried out prior to fracking, such simulations are
subject to some uncertainties, in keeping with the pa-
rameters selected; it is not possible to predict fracture
propagation precisely (cf. also US EPA 2011).
The fracking process is controlled primarily through
the pressure applied via the fracking fluid, while mo-
nitoring of fracture formation is carried out geophy-
sically, with the help of geophones. However, there
are no binding requirements specifying the degree of
accuracy with which the position and orientation of
fracs is to be predicted and determined.
Overall, the authors of the study see a need for im-
provement in modeling, control and monitoring of
fracture propagation, since the position and size of
created fracs can be key factors in determining the
relevance of the impact pathways of pathway groups
1 through 3, and in derivation of pertinent “safety
distances” (cf. also US EPA 2011).
3.2.3 Long-term integrity of wells
Cementing of the casing in a well provides the key
barrier against contamination of aquifers via migrati-
on/penetration of hydrocarbons, formation water or
fracking fluids. In addition, the cement used for this
purpose shields the casing from corrosive formation
fluids, and it considerably enhances the stability of
the well.
No specific binding technical requirements exist
regarding well completion for exploitation of uncon-
ventional gas deposits via hydraulic stimulation – for
example, requirements specifying the strength of
well casings and their connections. The dimensions
of casings and well cementation are determined on
the basis of existing regulations, taking account of
the stresses caused by the applied fracking pressures
(WEG 2006). In some cases, operators apply their own
safety standards in this area. No consistent, binding
(national) requirements and standards are yet in
place.
There continues to be a lack of reliable data on the
long-term stability of cementations, especially data
relative to the thermal and hydrochemical conditions
prevailing at the depths at which unconventional gas
deposits in Germany are encountered.
3.3 Frackinguids
3.3.1 Overview
The hydraulic medium used to apply pressure to the
rock strata inducing fracture formation is referred to
as “fracking fluid”. With the fracking fluid, prop-
pants (such as quartz sand) are generally injected into
the created fractures in order to keep fractures from
closing under the pressure of the surrounding rock
and thus to ensure that the pathways created remain
accessible for gas migration during the production
phase. Fracking fluids also contain other additives,
with functions such as facilitating transport of prop-
pants into fractures; preventing formation of precipi-
tates, microbiological growth, formation of hydrogen
sulphide and swelling of clay minerals within the frac
horizon; preventing corrosion; and reducing fluid
friction at high pump rates. Table 3 provides an over-
view of the functions of certain additives.
Environmental Impacts of Hydraulic Fracturing – Short Version
11
Based on the extensive studies on fracking additives
used in the U.S. (US EPA 2004; US EPA 2011; Waxman
et al. 2011; Tyndall Centre 2011; NYSDEC 2011) infor-
mation on the fracking fluids and additives used to
date in Germany were compiled. A method is presen-
ted for assessing the hazard potentials of the fracking
fluids employed with regard to groundwater, espe-
cially with regard to human use of groundwater as
drinking water and to aquatic organisms. Selected
fracking fluids used in Germany and possible new
improvements of such fluids are assessed.
3.3.2FrackinguidsusedinGermany
To obtain information on the fracking fluids used
in unconventional deposits in Germany, we relied
primarily on publicly accessible data; only in some
cases we were able to obtain information from non-
publicly accessible sources (ExxonMobil 2011; BR
Arnsberg 2011). The information presented below on
the composition of the fracking fluids used is based
mainly on analyses of safety data sheets of the com-
mercial products used to prepare fracking fluids. We
found that these safety data sheets are often the only
available source of information on the identity and
the concentrations of the additives used. For appro-
val authorities, this situation creates considerable
uncertainties and lack of knowledge regarding the
additives that are actually injected in the well and
the loads involved.
In the following, we discuss the prepared fracking
products (products produced by services companies
that are sold under brand names and that usually are
mixtures of various chemicals) and fracking fluids
(the fluids that are injected into the well; they are
usually prepared by combining several products with
water). “Fracking additives” refers to all substances
that are mixed with a carrier medium and injected,
as part of the fracking fluid, into the well.
Quantities used
Information on fluid quantities was available for a
total of 30 fracking fluids used in various unconven-
tional deposits (and in one conventional deposit) in
Germany between 1982 and 2011. Most of the depo-
sits involved were tight gas deposits in Lower Saxony.
Tab. 3. Functions of additives in fracking uids (based on UBA 2011, Tyndall Centre 2011)
Additive Function
Proppants Keeping the fractures created open under the pressure of the surrounding rock and allows
gas/uid to ow to the well bore
Scale inhibitors Preventing deposits of poorly soluble precipitates, such as carbonates and sulphates
Biocides Preventing bacterial growth, biolm formation and formation of hydrogen sulphide by sulpha-
te-reducing bacteria
Iron control Preventing iron-oxide precipitation
Gelling agents Improving proppant transport
High-temperature stabilizer (temperature stabilizer) Preventing gel decomposition at high temperatures within the target horizon
Breakers Reducing the viscosity of gel-containing fracking uids for depositing proppants
Corrosion inhibitors Protecting against equipment corrosion
Solvents Improving the solubility of additives
pH regulators and buffers (pH control) Controlling the pH of fracking uids
Crosslinkers Increasing viscosity at higher temperatures, to improve proppant transport
Friction reducers Reducing friction within fracking uids
Acids Pretreating perforated sections of the well, and cleaning them of cement and drilling mud;
dissolving acid-soluble minerals
Foams Supporting proppant transport
H2S scavengers Removing toxic hydrogen sulphide to protect equipment against corrosion
Surfactants Reducing surface tension of uids
Clay stabilizers Reducing swelling and migration of clay minerals
12
The quantities used varied considerably, depending
on the type of fracking fluids and the characteristics
of the deposits. The quantities of fracking fluids used
per frack ranged from less than 100 m3 to more than
4,000 m3. With the modern gel fluids used since
2000, an average of about 100 t of proppants and
about 7.3 t of additives (of which usually less than 30
kg were biocidal products) were injected per frack.
The quantities used can be quite large especially with
multi-frack stimulations and/or use of slickwater flu-
ids: for example, a total of about 12,000 m3 of water,
588 t of proppants and 20 t of additives (of which 460
kg were biocides) were injected into the Damme 3
well in three frack operations in 2008.
Commercial fracking products
According to the available information, at least 88
different products have been used to prepare fra-
cking fluids in Germany. However, since data are
available on only 21 fracking fluids (corresponding to
about 21 % of the some 300 fracks carried out in Ger-
many), it must be assumed that other products have
also been employed.
For 80 of the 88 products, the study authors were
able to obtain manufacturers’ or importers’ safety
data sheets that were either current or valid at the
time the fracks were carried out. Evaluation of the
available 80 safety data sheets revealed that
• 6 products are classified as toxic,
• 6 are classified as dangerous to the environment,
• 25 are classified as harmful,
• 14 are classified as irritant,
• 12 are classified as corrosive and
• 27 are classified as non-hazardous
according to Directives 67/548/EEC or 1999/45/EC,
respectively. Several products are classified in more
than one hazard class. According to the information
in the safety data sheets,
• 3 preparations are classified as severely hazar-
dous to waters (“Wassergefährdungsklasse 3”),
• 12 preparations are classified as hazardous to wa-
ters (“Wassergefährdungsklasse 2”),
• 22 preparations are classified as low hazardous to
waters (“Wassergefährdungsklasse 1”),
• 10 preparations are classified as not hazardous
for water.
A total of 33 of the safety data sheets available to
the study authors provided no information on the
“Wassergefährdungsklasse” (water hazard class) of
the product.
Fracking additives
Information on the fracking additives used was
available to the study authors for 28fracking fluids.
Those fluids were used in about 25% of the some
300 fracks carried out in Germany.
Evaluation of those 28 fracking fluids showed that,
overall, at least 112 substances / substance mixtures
have so far been used in Germany. For 76 of the 112
substances / substance mixtures, either unique CAS
numbers1 were provided or it proved possible to cor-
rect or determine the CAS number on the basis of a
unique given substance name. A total of 36 substan-
ces / substance mixtures could not be uniquely iden-
tified, either because their composition was unknown
or because the available safety data sheets referred
only to unspecific chemical group names (such as
aromatic ketones, inorganic salts, etc.).
3.3.3 Hazard potentials
Assessment method
Under water law, the key requirement to be applied
in assessing releases of substances into the groundwa-
ter is that releases must not adversely affect the water
quality (Art. 48 (1) Federal Water Resources Manage-
ment Act (WHG)). An adverse effect on the quality
of near-surface groundwater – i.e. of the exploitable
groundwater that is integrated within natural cycles
– has occurred, if water quality has worsened more
than slightly.
An adverse effect on the water quality of groundwa-
ter must be assumed if relevant legal and sub-legal
limit values, guide values and maximum values, and
especially the “Geringfügigkeitsschwellenwerte” (de
minimis thresholds) of the Federal/Länder Working
Group on Water (LAWA 2004), are exceeded in ex-
ploitable groundwater. Those de minimis thresholds2
are based primarily on the maximum permitted
concentration specified by the Ordinance on Drin-
king Water (TrinkwV), and on toxicologically and eco
1 The CAS number (Chemical Abstracts Service) is an inter-
national standard for identification of chemical substances.
Every chemical substance known in the open scientific lite-
rature has a unique CAS number.
2 The de minimis threshold (Geringfügigkeitsschwelle –
GFS) for a substance is the maximum concentration of the
substance at which, in spite of an increase in groundwater
with respect to regional background values, no relevant
eco toxicological effects can occur, and conformance with
the requirements of the TrinkwV, or with pertinent derived
values, is still assured (LAWA 2004).
Environmental Impacts of Hydraulic Fracturing – Short Version
13
toxicologically established effect thresholds, in order
to ensure that groundwater remains available as
drinking water for human consumption, and remains
intact as a habitat and as part of natural cycles.
For the majority of the substances used as fracking
additives, no de minimis thresholds, or other water-
law-based assessment values, are available. For such
substances, therefore, hygienic guidance values3 or
health orientation values4 and eco toxicologically
established PNEC values5 were researched, or derived
using published methods, following the concept of
LAWA (2004).
In the case of substance discharges at the surface
(pathway group 0 in Fig. 6), the relevant substance
concentration for assessment must be considered at
the groundwater surface (seepage water). By analo-
gy, in the case of a possible release from the fracking
horizon (and related migration via pathway groups
1 through 3), the concentration at the base of the
exploitable aquifer should be used for assessment (cf.
Fig. 6).
The relevant substance concentrations can properly
be assessed only site-specifically, for possible migra-
tion and exposure scenarios, using suitable models
that take account of all relevant hydraulic and geo-
3 The health-related guidance value for drinking water
(GVDW) is the maximum concentration of a substance in
drinking water that can be tolerated for a lifetime without
suffering adverse effects on health.
4 The health orientation value (HOV) is a precautionary value
for substances that cannot (or can only partially) be toxico-
logically assessed (UBA 2003).
5 The PNEC value (Predicted No Effect Concentration) is the
maximum concentration of a substance at which no effects
on organisms of an aquatic ecosystem are expected (EC TGD
2003).
chemical transport, mixing, decomposition and reac-
tion processes along the underground flow pathways.
No such models are available at present that have the
necessary resolution. As long as suitable models are
lacking, we propose to assess hazard potentials on
the basis of substance concentrations in (undiluted)
fracking fluids and formation water. Based on the
current state of knowledge, we consider it not suita-
ble to presume a considerable reduction of their ha-
zard potential due to dilution along the underground
flow pathways, because along the flow path dilution
occurs mainly by mixing with saline groundwater,
which can have considerable hazard potential of its
own; thus, mixing with such water would not neces-
sarily reduce the hazard potential of fracking fluids.
The pertinent hazard potentials of the fluids are as-
sessed on the basis of the individual constituents.
This is achieved by calculating substance-specific risk
quotients of substance concentrations and assessment
values (de minimis threshold (GFS), GVDW, HOV or
PNEC)):
When a substance has a risk quotient < 1, no ha-
zard potential is expected, while a risk quotient ≥ 1
represents a toxicological or eco toxicological hazard
potential. In the present study, a risk quotient >1,000
is assumed to represent a high hazard potential. This
value is given as an example and has not been sci-
entifically established; it needs to be site-specifically
reviewed on the basis of exposure scenarios – for ex-
ample, using numerical models.
Since recipes for fracking fluids are normally tailored
to specific deposits, the hazard potentials of each
fluid need to be assessed individually. In the present
Fig. 6:
Substance concentration to be assessed at the
surface or base (red circles) of a near-surface,
exploitable aquifer (blue) when substances
enter via input pathways from the surface
(pathway group 0) and via migration from the
fracking horizon (pathway groups 1-3)
14
study, detailed assessment was carried out of a fluid
used recently in a tight gas deposit in Lower Saxony,
and of the only two fluids used to date in shale gas
and coal bed methane deposits in Germany (Tab. 4).
Planned improvements were taken into account by
assessing two fracking fluids mentioned by an opera-
tor as potentially being suitable for shale gas deposits
and, possibly, coal bed methane deposits (improve-
ments of slickwater and gel fluids, Tab. 4).
Results
The assessments of the fluids listed in Table 4 find
that the selected fracking fluids have high, or me-
dium-to-high, toxicological and eco toxicological
hazard potentials. The two improved fracking fluids
are also expected to have a high hazard potential,
primarily because of their high concentrations of a
biocide and the lack of available data for assessing
that biocide.
Current developments aiming at reducing the
numbers of additives used, at finding substitutes for
substances that are highly toxic, carcinogenic, mu-
tagenic or toxic for reproduction and at reducing or
replacing biocidal agents, point to potential progress
in the development of environmentally compatible
fracking fluids. However, the study authors can cur-
rently not evaluate the feasibility or progress of such
efforts.
The replacement of three hazardous additives that
were still being used in 2008 by substances with con-
siderably lower hazard potentials must be critically
evaluated, since it highlights the fact that additives
used in the recent past were found to be replacea-
ble or improvable within just a few years. Since the
underlying database for assessing those additives has
been available for years, it is necessary to review whe-
ther, in the past, service companies, operators and/or
authorities have adequately considered the possibili-
ties for finding substitutes for hazardous additives.
Tab. 4: Fracking uids that have been used in, or would be suitable for, unconventional deposits, and that were selected for assessment
of their hazard potential
Tight gas
Söhlingen Z16
Rotenburg district (Wümme),
Lower Saxony
9 Fracs in 2008
Final depth: 6,872 m
Dethlinger sandstone (late rotliegend)
Gel:
Water:
Proppants:
Additives:
824 m3
170,100 kg
38,079 kg
Shale gas
Damme 3
Vechta district,
Lower Saxony
3 fracs in 2008
Wealden clay formation
1,045 to 1,530 m
Slickwater
Water:
Proppants:
Additives:
12,119 m3
588,000 kg
19,873 kg
Coal bed methane
Natarp
Warendorf district,
North Rhine – Westphalia
2 fracs in 1995
Seam-bearing Carboniferous
1,800 to 1,947 m
Gel:
Water:
Nitrogen:
Proppants:
Additives:
121 m3
81,750 kg
41,700 kg
1,230 kg
Future improvements
Slickwater
Figures of Exxon Mobil
(Last revised 04 Feb. 2012)
Planning Slickwater
Water:
Proppants:
Additives:
1,600 m3
unknown
5,600 kg
Gel:
Figures of ExxonMobil
(Last revised 04 Feb. 2012)
Planning Gel:
Water:
Proppants:
Additives:
1,600 m3
unknown
6,530 to 7,080 kg
Environmental Impacts of Hydraulic Fracturing – Short Version
15
3.3.4 Possible fracking procedures that use no chemical
additives
Along with efforts to find substitutes for individual
additives, efforts are being made to develop fracking
fluids that are completely free of certain additive
groups. For example, UV light is being tested as a
technique for inhibiting growth of microorganisms
and thereby reducing application of biocides.6 Ano-
ther research project is testing a process that relies
solely on water, bauxite and corn starch.7 As such
examples indicate, while various techniques are
currently being developed and tested, much more
research will be required before fracking processes
become available that do completely without che-
mical additives. The present study can only cite the
current relevant development, since we were cur-
rently unable to assess such projects in terms of their
practicability.
Fracking without chemical additives would elimina-
te the hazard potential of the substances employed.
However, it would not reduce the hazard potential
of the formation water and the flowback. The risks
presented by formation water, along possible impact
pathways, are always site-specific and depend prima-
rily on the water’s chemical composition and minera-
lization.
3.4 Flowback
3.4.1 Quantities and composition
After pressure has been applied to the gas-bearing
formation, some of the injected fracking fluids are
recovered along with the gas and formation water
that is extracted from the well; the majority of the
proppants used remains in the fractures. The flu-
id that usually has to be extracted and disposed of
throughout the entire gas-production phase is known
as “flowback”.
Flowback consists of varying proportions of injected
fracking fluids and co-extracted formation water. In-
itially, fracking fluids account for the larger share of
flowback; later, formation water begins to predomi-
6 http://www.halliburton.com/ps/Default.aspx?navid=93&pag
eid=4184&prodid=PRN%3 a%3aKWTBF215&TOPIC=Hydrauli
cFracturing]
7 http://www.wirtschaftsblatt.at/home/boerse/bwien/omv-will-
mega-gasvorrat-im-weinviertel-ab-2020-foerdern--504947/
index.do?_vl_pos=r.1.NT
nate. As a result of various hydro geochemical proces-
ses that can occur within the deposit horizon (Fig. 7),
flowback can contain a number of other substances
in addition to fracking additives and formation water
constituents.
At the high pressures and temperatures prevailing in
the target horizon, injected fracking additives may
undergo chemical transformation and decomposition
reactions in the presence of saline formation water.
Microbiological decomposition reactions may occur
as soon as the effects of the injected biocides dimi-
nish. In the process, stable metabolites can form that
can pose toxicological and eco toxicological risks that
can even exceed the risks posed by the parent subs-
tances that were injected.
Because the characteristics of formation water are al-
ways deposit-specific, and because the proportions of
extracted fracking additives vary, the characteristics
of flowback have to be individually assessed for each
site and pertinent time. Little information is availa-
ble about the constituents of formation water in
tight-gas, shale-gas and coal-bed-methane deposits in
Germany, such as information about primary, secon-
dary and trace components, dissolved gases, organic
substances and NORM8; regional and depth-oriented
data is often missing.
Assessments of flowback from the Damme 3 well
carried out by Rosenwinkel et al. (2012), concluded
that only 8 % of injected fracking fluids were being
recovered as part of the flowback. Even though that
percentage can be expected to increase as production
continues, it seems certain that a substantial propor-
tion of the fracking additives injected remain under-
ground.
As noted, flowback is a mixture of fracking fluids, for-
mation water and possible reaction products. At pre-
sent, there is a lack of the reliable analyses and mass
balances that would allow for quantification of the
variable mixing fractions, the fraction of the extrac-
ted fracking fluid and possible reaction products. To
date, no systematic measurements have been carried
out for the purpose of identifying transformation and
decomposition products in the flowback.
Fracking additives that remain underground pose a
risk for near-surface (exploitable) groundwater, if the-
re is a possibility (probability of occurrence) that they
could migrate into near-surface (exploitable) ground-
8 Naturally Occurring Radioactive Material.
16
water via one or more of the aforementioned impact
pathways, and if they result in a significant deterio-
ration of the groundwater quality. The question of
whether, and to what extent, substance transport
in the direction of exploited groundwater resources
occurs thus depends on the relevant, site-specific,
geological and hydrogeological conditions, as well as
on the sorption properties of fracking additives and
the surrounding rock.
3.4.2 Disposal pathways
As noted, flowback composition is always deposit-spe-
cific, because (i) fracking additives are selected site-
specifically and (ii) the quality of the formation water
is also site-specific. Possible technical processes for
treating flowback are described in Rosenwinkel et al.
(2012). Rosenwinkel et al. (2012) conclude that none
of those flowback-treatment processes, at present,
qualifies as “best available technology” within the
meaning of the Federal Water Resources Act (Was-
serhaushaltsgesetz). In general, the following options
are available for disposing of / recycling of flowback:
• Injection via disposal wells,
• Treatment, for discharge into surface water,
• Treatment, for discharge into the sewer system,
• Reuse in future fracks,
• (Atomization / evaporation / agricultural irrigati-
on).
At present, formation water and flowback are com-
monly disposed of via injection wells / disposal wells
in those regions in which conventional and uncon-
ventional gas production are already taking place,
usually in depleted oil or gas deposits, or other rock
horizons with the necessary permeability and capa-
city.
Flowback can present significant hazard potentials. In
the view of the study authors, flowback disposal via
injection into underground horizons can pose risks
that can be analyzed and assessed solely in the frame-
work of site-specific risk analyses. To our knowledge,
the binding requirements that would be needed to
assure such analysis are lacking.
Fig. 7: Schematic depiction of owback formation via mixing of fracking uids and formation water in connection with hydrogeochemical processes
Environmental Impacts of Hydraulic Fracturing – Short Version
17
Treating flowback in industrial wastewater-treatment
facilities is seen by operators as an option that is tech-
nically feasible but not economically feasible. There-
fore, the disposal via injection and disposal wells is
currently preferred.
The question of whether, and to what extent, it would
be technically feasible to reuse/recycle flowback can
be answered only after analysis of the characteristics
and concentrations of the recovered fluids.
18
The legal section of the study considers issues of wa-
ter protection and water-pollution control related to
procurement, handling, use and disposal of injected
and extracted fluids. The key regulations applying
to such activities include provisions of mining and
water law, along with regulations relative to environ-
mental impact assessment. The study focuses espe-
cially on use of substances during actual fracking and
on handling and disposal of flowback. In addition, it
considers legal requirements pertaining to procure-
ment, storage and transport of fracking fluids.
The present short version of the study includes a sum-
mary of the deficits seen, from a legal standpoint,
with regard to applicable regulations and administra-
tive structures, also in light of the prevailing scientific
and technical parameters and of relevant risk assess-
ment.
4.1 Mining law
Mining law establishes central requirements for fra-
cking projects, including prerequisites for approvals
of operational plans, and the Länder ordinances on
deep-drilling (Tiefbohrverordnungen der Bundes-
länder – BVOT). Such requirements mandate that
precautions must be taken to guard against risks, in
conformance with generally accepted rules for safety
technology and with special requirements, in ordi-
nances on deep-drilling, designed to prevent damage.
At the same time, mining law does not have a “con-
centration effect” (blanket effect with regard to ap-
provals). Neither does it take precedence over water
law. In fact, requirements under water law have to be
reviewed either as part of review of whether harmful
impacts (for the public sphere) must be expected (Art.
55 (1) No. 9 Federal Mining Act (BBergG)) or as part
of review of whether approval of the relevant opera-
tional plan would conflict with predominating public
interests (Art. 48 (2) Sentence 2 BBergG).
Where an approval procedure under water law is re-
quired, water-law aspects must be given priority in re-
view within the procedure. This results from general
jurisdiction on delineation of parallel authorization
procedures. On the other hand, for deep-drilling, mi-
ning authorities have not, to date, routinely carried
out approval procedures under water law.
4.2 Water law
Applicable water law requires the execution of an ap-
proval procedure under water law for drilling of wells
for which fracking is planned (for some future date),
for fracking itself and for injection of flowback.
Discharging of substances directly into groundwa-
ter, in connection with fracking or with flowback
injection, is deemed to constitute a “real use” (“echte
Benutzung”) that is subject to permit requirements.
Discharging of substances into geological formations
in which groundwater is not directly encountered is
deemed to constitute an “artificial use” (“unechte Be-
nutzung”) that is also subject to permit requirements.
On the one hand, applicability of permit require-
ments can result in that an indirect adverse effect on
groundwater in the immediate or wider surround-
ings of the deepest point of the well cannot be ruled
out with a sufficient degree of certainty. On the other
hand, the Water Framework Directive requires such
applicability, since that directive allows the introduc-
tion of substances into geological formations only
when the relevant conditions have been found to
be suitable for such introduction (Art. 11 (3) Letter j
WFD). Under German water law, the suitability of the
prevailing conditions must be determined as part of
the relevant approval procedure under water law.
In the case of wells drilled for later fracking, the
applicability of permit requirements results in that
all drilling introduces substances into groundwater
(drill bits, drilling fluid, casing, cement), as well as in
that the planned fracking poses a risk of substance
discharges into groundwater via failure of the sealing
function of the casing and cementation. To ensure
that groundwater is properly protected, the appli-
cable requirements for casing and cementation have
to be reviewed, and defined, in a water-law procedu-
re carried out prior to the insertion of the casing.
A permit under water law may be issued only if no
adverse impacts on groundwater must be expected
(principle of prophylactic water protection, Art. 48 Fe-
deral Water Resources Management Act (WHG)). The
principle of prophylactic water protection applies to
both “real” and “artificial” uses.
No adverse impact on groundwater is deemed to be
present if the de minimis thresholds derived from ap-
plicable maximum permitted levels, and via toxicolo-
4 Legal regulations and administrative structures
Environmental Impacts of Hydraulic Fracturing – Short Version
19
gical and eco toxicological standards, are not excee-
ded in exploitable groundwater integrated within
natural cycles.
Groundwater is subterranean water in the saturation
zone that is in direct contact with the ground or with
underground regions. It includes deep groundwater
containing salt or pollutants. With regard to deep
groundwater containing pollutants, the “suitability
for protection”, i.e. any presence of an adverse effect,
must be determined on an individual-case basis.
For such groundwater, exceeding of the de minimis
thresholds developed for exploitable groundwater
integrated within natural cycles does not directly con-
stitute an adverse impact on groundwater.
The principle of prophylactic water protection ac-
cepts not even the smallest possibility of water conta-
mination; i.e. it requires that such contamination be
completely improbable in light of human experience.
The law is extremely stringent in this area. In any in-
dividual case, all circumstances must be considered.
This extends to the possibility of disruptions / inci-
dents, improbable developments and extensive and
long-term impacts.
And even when all permit requirements are fulfilled,
the decision on whether a permit under water law is
actually granted is subject to management discretion.
Under such management discretion, residual risks
for the safety of the drinking water supply, and for
the quality of groundwater, may be considered apart
from specific precautions with regard to adverse im-
pacts on groundwater and weighed against the eco-
nomic benefits of gas exploration and exploitation.
To be sure, these stringent requirements under water
law have been upheld by jurisdiction. And yet, water
law, like mining law, contains many hazy legal con-
cepts that leave room for interpretation, latitude that
can be exploited – and is exploited – by the compe-
tent authorities, in various ways. It can be argued
that, in practice, such interpretive latitude can lead
to a considerable neglect of various aspects of water
law. For this reason, the aforementioned situation
should be clarified, in the interest of consistent inter-
pretation of water law and of assuring the necessary
groundwater protection. This should be accomplis-
hed in connection with mining-sector projects, at a
suitable level – i.e. either via amendment of federal
or Länder law or simply via internal administrative
regulations or directives of authorities.
4.3 Handlingoffrackinguidsandowback
With regard to above-ground handling of substances,
a distinction has to be made between a) procurement
and handling of water and additives, and of the fra-
cking fluids formed by mixing them, and b) handling
of flowback.
Procurement of water is subject to the normal requi-
rements, under water law, applying to removal of
groundwater and surface water, except in cases in
which the water is obtained by other means. Pro-
curement and handling of additives are subject to
requirements under laws on chemicals and substan-
ces (REACH Regulation, laws on biocides), mining law
(ordinances on deep-drilling), water law (facilities for
handling substances hazardous to water) and occu-
pational health and safety legislation (mining ordi-
nances, Ordinance on Hazardous Substances (Gefahr-
stoffverordnung)). Pursuant to requirements under
laws on chemicals and substances, for each substance
and each mixture involved, it must be determined
whether a general or special prohibition on use, a
constrainment on approval, a registration obligation
or an obligation to prepare a safety data sheet or a
use-based safety study applies. For many substances,
provisions on transitional periods and on exemptions
apply (for example, below certain concentration le-
vels).
Handling of flowback is subject to requirements
under legislation on mining waste and on wastewa-
ter. Where they are radioactive residues, sludge and
deposits fall under legislation on radiation protec-
tion, except where compliance with legally defined
monitoring limits is assured. Flowback is both liquid
mining waste and wastewater, since flowback – reco-
vered water – contains both (unaffected) formation
water and injected water that has been affected via
human use – addition of additives, injection, mixing
with formation water and extraction.
4.4 Coordination and integration of authorization
procedures under mining law and water law
To date, mining law and water law contain no provi-
sions on coordination of parallel procedures. All au-
thorization procedures for mining projects should be
completely coordinated – as has been accomplished
for legislation on authorization of industrial plants
– in order to ensure that before any project commen-
ces all relevant conditions for authorization have
been met and all required authorizations have been
20
issued. In addition, minimum requirements pertai-
ning to submitted application documents should be
established.
The procedure for approval of operational plans
should be redesigned, via a federal-level legislati-
ve amendment, as an integrated project-approval
procedure under environmental law. This would
ensure that comprehensive review, under water law,
is always carried out, without creating the need for
an additional approval procedure to achieve that
aim. Compliance with requirements under water law
should be ensured either a) by making the mining
authority, which serves as the environmental and
water-quality authority, subject to the specialized
supervision of the highest-level water authority, or b)
ensuring that approvals may be issued only with the
consent of the water authority.
4.5 Development of general standards
The key deficits applying to execution of authorizati-
on procedures under mining law and water law, for
fracking projects, include a lack of specific material
standards – especially with regard to requirements
under water law – and discrepancies in the stringen-
cy of co-existing requirements under mining law and
water law.
The applicable requirements level under mining law
is the level of generally accepted rules and princip-
les of sound engineering practice. By contrast, under
water law, discharges of substances into groundwater
are subject to the principle of prophylactic water pro-
tection, without any weakening via clauses pertai-
ning to equipment/technology/engineering. Under
wastewater law, the higher requirements level of the
“best available technology” applies.
The differences between the requirements levels of
mining law and of water law have practical impli-
cations in that requirements under mining law are
detailed via pertinent technical regulations, while
either no specifications, or only very general speci-
fications, exist with regard to the principle of pro-
phylactic water protection, relative to groundwater
protection, and to “best available technology” requi-
rements for wastewater-treatment equipment used
in connection with mining projects. This complicates
the task, for mining and water authorities, of relia-
bly assessing requirements under water law. Requi-
rements under mining law (which tend to be less
stringent) are easier to apply.
To eliminate this deficit, use of “best available techno-
logy” should be made a standard condition for appro-
val under mining law, as it already is under legislati-
on on authorization of industrial plants.
4.6 Water protection areas
At present, ordinances on protected areas usually
contain constraints on approvals for drilling and for
certain uses of substances hazardous to water. They
also contain prohibitions on discharges of substances
hazardous to water, and of wastewater, into under-
ground regions. Normally, such regulations should
already mean that drilling and operation of wells for
fracking and for injection are prohibited, in general,
in water protection areas and may be approved only
via special exemptions.
Legislative deficits apply to fracking projects within
water protection areas in that actual drilling is sub-
ject only to certain constraints on approval, while
fracking is only prohibited insofar as it is carried out
using substances hazardous to water. Currently, it
cannot be concluded, with sufficient certainty, that
the risks posed by fracking using no substances ha-
zardous to water would be significantly lower than
those posed by fracking with substances hazardous
to water. For this reason, all fracking – even fracking
that uses no substances hazardous to water – should
generally be prohibited in water protection areas.
4.7 Environmental impact assessment (EIA) and
publicparticipation
Under German national law, EIA obligations current-
ly apply solely to projects, subject to obligations to
prepare operational plans, oriented to gas exploita-
tion at daily production levels greater than 500,000
m3. That scope violates the provisions of the EIA
Directive, however. That directive mandates that EIAs
be carried out for deep-drilling, and for above-ground
facilities for gas production, even for projects below
that threshold, taking account of certain selection
criteria. Pursuant to the jurisdiction of the European
Court of Justice (ECJ), such projects may not be com-
pletely exempted from EIA obligations. What is more,
so the ECJ, the applicable selection criteria must be
applied either directly via the thresholds or via (sup-
plementary) individual-case review. Since the German
EIA ordinance for the mining sector (UVP-V Bergbau)
does not fulfil those requirements, the EIA Directive
already applies directly, because it takes precedence.
Environmental Impacts of Hydraulic Fracturing – Short Version
21
For each individual case, it requires that preliminary
review be carried out to determine if the specific pro-
ject involved, at the site in question, is subject to EIA
requirements.
Apart from that requirement, the EIA Directive has
to be transposed via directive-conformal redefinition
of EIA obligations for fracking projects. According
to current findings, it cannot be denied that such
projects could have extensive, lasting and irreversible
adverse impacts on the drinking water supply and on
the natural environment. In light of the precautiona-
ry and preventive-action principle, this indicates that
the threshold for EIA obligations should be set very
low for the time being, i.e. that general EIA obliga-
tions should be introduced for fracking projects. To
ensure they are able to take pertinent new findings
into account, the Länder could be given the option,
for certain projects carried out under certain geo-
logical conditions, of imposing EIA obligations only
following preliminary review in individual cases.
In general, EIA obligations should be oriented to dril-
ling and operation of wells in which fracking takes
place or flowback is injected. And EIA obligations
should apply even to set-up and operation of drilling
sites with a single well (for example, an exploration
well). Furthermore, the obligations should apply to
all drilling and auxiliary facilities taking place / used
at a drilling site.
Another central deficit in current legislation is that
thus far it has been possible for fracking projects
to be carried out without any public participation.
Introduction of EIA obligations would immediately
eliminate this deficit, because public participation
forms part of any procedure involving environmental
impact assessment.
Mining projects differ from many other types of en-
vironmentally relevant projects in that their environ-
mental impacts are very difficult to predict before the
projects actually commence. The potential environ-
mental impacts of such projects will become easier to
assess in advance as knowledge and findings in this
area advance. On the other hand, such orientation
to advancing knowledge is somewhat at odds with
the objective of any EIA, namely to ensure that the
relevant impacts on the environment are taken into
account, in keeping with the EIA results, and as early
as possible, in the relevant authorization procedure.
We recommend that advancement of knowledge
relative to fracking projects be taken into account by
providing new possibilities for public participation in
such projects. In addition, it should be ensured that
renewed authorization and EIA obligations, following
preliminary review in individual cases, arise not
solely through project changes that can have signifi-
cant environmental impacts, but also through adver-
se changes in key parameters (such as new findings)
significant to assessment of a project’s environmental
impacts.
Site-related environmental impact assessment is
inadequate to the task of reviewing plans for explo-
ration and exploitation of unconventional gas over
large areas, via numerous wells, i.e. plans for systema-
tic, complete-coverage drilling. Due to their above-
ground implications, and the need they create for
coordination with other area-related planning, such
plans should ideally be subject, and may even need
to be subject, to regulations at the regional-planning
level. The state-wide zoning plans and regional plans
of the Länder are suitable instruments for achieving
such regulation.
4.8 Responsibilities
In various ways, as defined by the relevant Länder
laws in each case, mining authorities are responsible
not only for permits under mining law, but also for
central monitoring tasks under water law and other
environmental legislation. In general, this is to be
welcomed; it is in keeping with modern practice in
environmental protection legislation, which seeks to
have a single authority function as a “fence authori-
ty” (“Zaunbehörde”), i.e. be responsible for all tasks
of relevance for environmental protection. This ap-
proach prevents fragmentation of responsibilities.
On the other hand, mining authorities tend to be
organized as part of ministries for industry and eco-
nomics, and this is problematic. The core tasks of
such authorities include promoting business inte-
rests. Only in some areas – in keeping with applicable
Länder law, within the framework of tasks entrusted
to them under environmental law and, especially,
water law – are mining authorities subject to the
detailed supervision of the supreme environmental
authorities (ministries of the environment). In light
of the significant environmental relevance of mining
projects, and of environment ministries’ responsibili-
ty for enforcing environmental legislation, it should
at least be ensured that all environmentally relevant
decisions, i.e. all decisions relative to approvals under
22
water law, and to environmental impact assessments,
and execution of supervisory measures under envi-
ronmental law, be completely subject to the detailed
oversight of environment ministries. Only environ-
ment ministries have the necessary competence rela-
tive to environmental protection, and environmental
protection law, for such oversight.
In addition, we recommend that overall approval
and monitoring of mining projects, with regard to
environmental and safety legislation, be assigned
to the portfolios of environment ministries. Such
assignment would be in keeping with the way such
tasks are assigned with regard to industrial facilities.
Decades ago, responsibilities for monitoring such
facilities, with regard to environmental legislation,
were transferred from economics ministries to envi-
ronment ministries, in connection with removal of
emission-protection law from the sphere of commer-
cial/industrial law. This was done in order to assure
proper enforcement of environmental law.
Careful, impartial review and monitoring of environ-
mental impacts, by the competent authorities, plays
an especially important role in connection with pub-
licly controversial projects – such as fracking projects.
Without public confidence and trust in such review
and monitoring, even detailed study of pilot projects’
environmental impacts will hardly be likely to meet
with sufficient public acceptance.
Environmental Impacts of Hydraulic Fracturing – Short Version
23
5 Recommendations for action and procedures
Only in combination with technical and geological
impact pathways, the substance-related hazard poten-
tials of fracking projects related to exploration and
exploitation of unconventional gas can become risks
for the environment. We have found that in various
geological systems several of such impact pathways
can occur. No reliable data are currently available
that would provide a basis for the reliable exclusion
of risks to near-surface water resources. Because of
the lack of reliable data, the relevant tools and me-
thods available at present (such as numerical ground-
water models) can yield only approximate results.
In our view there is great lack of basic information
that would be needed for any well-founded assess-
ment of the pertinent risks and the degree to which
they can be controlled by technical means. Examples
of such information include information regarding
the structures and properties of deep geological sys-
tems (permeabilities, potential differences), the iden-
tities of the fracking additives used and the chemical
and toxicological properties of such additives. There
are several reasons for this lack of information and
data: (a)the information and data are not (openly)
accessible, (b) the information and data have not
yet been evaluated, and/or (c) there are gaps in our
knowledge that can be closed only through additio-
nal studies and research.
Mining law and water law establish legal require-
ments that apply to fracking projects, with regard to
groundwater protection. Under water law, fracking
projects and flowback injection have to be reviewed
in order to determine whether any risks of adverse
impacts on groundwater can be ruled out. Such re-
view must be carried out in the form of an approval
procedure under water law. Because the EIA Directi-
ve takes precedence over the German EIA ordinance
for the mining sector (UVP-V Bergbau), all fracking
projects are already subject to the requirement that
preliminary review must be carried out, in each
individual case, to determine if an EIA is required.
Enforcement to date in this area exhibits shortco-
mings. Regulatory deficits are found in implemen-
tation of requirements under the EIA Directive, and
in the uncertainties seen in application of water law
(definition of “groundwater”, applicability of permit
requirements, fulfillment of permit requirements).
The following recommendations for action and pro-
cedures are based on the results of our studies, which
are described in the previous sections.
We expressly note that stimulation in connection
with development of deep geothermal deposits was
not considered in the present context, and that thus
our recommendations cannot be directly applied to
techniques for geothermal stimulation.
24
5.1 Overarching recommendations
In light of the current situation as described, and on
the basis of our assessments, we have developed the
following overarching recommendations:
(1.1) The risks of exploration and exploitation of
unconventional gas projects can be reliably
analyzed only insofar as reliable informati-
on on the relevant geological systems (and
potential impact pathways) is available, along
with information about the characteristics
of the deposits in which the pertinent gas
reserves are found. We thus recommend
that exploration of gas deposits be combined
with exploration of the relevant geological
systems, in order to place the resulting site-
specific information in a larger, regional con-
text. In our view, mining authorities and gas
companies should routinely consult with each
other regarding the issue of what informati-
on is required. The information should be lar-
gely publicly accessible, in order to enhance
public acceptance. In our view, in each case
the authorities and gas companies should
communicate clear information regarding
the geological systems involved, the gas de-
posits involved and the planned exploration
strategies (including their potential impacts).
(1.2) We recommend that the many relevant data
that are available and that have not yet been
evaluated (cadaster of old wells, cadaster of
disposal wells, etc.) be evaluated and that the
results be published. Pertinent experience
should also be so evaluated and published.
At the same time, we maintain that without
new data it will not be possible to answer the
questions of whether, and where, economic-
ally exploitable unconventional gas reserves
are present in Germany and of what tech-
nology (with or without fracking) could be
used to develop them. We thus could support
the idea of carrying out further exploration,
including exploration involving deep drilling
(but without fracking), and carrying out tar-
geted research in the above-described frame-
work, for the purpose of answering those
questions.
(1.3) We recommend that further actions be taken
step-by-step: clear criteria should be estab-
lished for deciding whether or not fracking
should be allowed, at a later time, in wells.
Such criteria should cover both the hazard
potential of fracking additives and the availa-
bility of reliable information about the geolo-
gical and technical impact pathways involved.
We maintain that it should go without saying
that both exploration and any later produc-
tion should be subject to clear criteria for
approval. A catalogue of criteria for appro-
val should be developed step-by-step. In this
area as well, we recommend that transparent
approaches be applied, possibly approaches
involving the interested public.
(1.4) In light of the sketchiness of the currently
available data, and of the fact that environ-
mental risks cannot be ruled out, the study
authors recommend, from the standpoint
of water-resources management, that above-
ground and below-ground activities for un-
conventional gas exploitation should not be
approved, for exploration and exploitation
companies that use fracking, in water pro-
tection areas (classes I through III), in water-
extraction areas for the public drinking water
supply (even if not set aside as water-protec-
tion areas), in mineral spa protection zones
and near mineral water reserves, and that
the aforementioned areas be made off-limits
for such activities. As better data become
available, this recommendation on denial of
approval should be reviewed. In areas known
to have unfavourable – with regard to poten-
tial environmental impacts – geological and
hydrogeological conditions (groundwater
potentials and pathways), no exploration and
exploitation of unconventional gas (via deep-
drilling and fracking) should be carried out.
(1.5) We recommend that research and develop-
ment be intensified in areas such as enhan-
cement of the long-term integrity of wells;
improvement of techniques for forecasting
the widths and lengths of fractures caused by
fracking; and development of fracking fluids
with lower hazard potential. Practical applica-
tion of the relevant research findings should
be monitored scientifically.
Environmental Impacts of Hydraulic Fracturing – Short Version
25
(1.6) Site-specific risk analyses should be carried
out with regard to any future drilling with
fracking, and to drilling and use of disposal
wells for injection of flowback. Such analy-
ses should take account of all relevant fluids,
whether introduced or encountered (fracking
additives, formation water and its reaction
products, and flowback), and of the relevant
geological (and technical) impact pathways.
In addition, risk analysis involving both ove-
rarching and site-specific approaches should
be carried out. We recommend that use of
toxicologically and eco toxicologically hazar-
dous fluids, and flowback disposal in dispo-
sal wells – also in the tight gas deposits in
Germany that have already been exploited for
many years – be reassessed.
(1.7) With regard to EIA obligations, we recom-
mend that fracking projects be subject to
general federal EIA obligations, and that such
obligations include an „opening clause“ to
allow Länder participation. The public partici-
pation required under EIA legislation should
be expanded to include a project-monitoring
component, since many findings regarding
projects‘ potential environmental impacts
cannot be obtained until the projects are
actually underway. Careful review of require-
ments under water law should be assured, via
clarification of pertinent requirements, and
via a) introduction of an integrated project-
approval procedure to be directed by an
environmental authority subordinate to the
Ministry for the Environment, or b) integrati-
on of mining authorities within the environ-
mental administration.
(1.8) In our view, the following two aspects are of
central importance with regard to any con-
tinuation of exploration and exploitation of
unconventional gas in Germany, regardless
of the procedures applied: all work processes
and results should be fully transparent, and
all stakeholders should exercise trust in their
dealings with each other. Efforts to further
these aims should include the establishment
of a publicly accessible cadastre listing all
fracking measures carried out, along with the
quantities of fluids used and the compositions
of the fluids used. To our knowledge, such
a database is currently being prepared, in
Lower Saxony, with the participation of Lower
Saxony‘s state office for mining, energy and
geology (Niedersächsisches Landesamt für
Bergbau, Energie und Geologie – LBEG) and
of the Wirtschaftsverband Erdöl- und Erdgas-
gewinnung (WEG) German oil and gas indust-
ry association. The study authors were unable
to view that database by the time the present
study was completed, however.
(1.9) In our view, it would be useful to carry out
a comparative analysis of the studies car-
ried out to date in Germany with regard to
the risks of exploration and exploitation of
unconventional gas, in order to identify the
areas in which the studies agree, and the are-
as in which they differ, with a view to finding
strategies for resolving the latter. In addition
to the present study, such comparative analy-
sis should especially cover the studies under-
taken as part of the information and dialog
process initiated by ExxonMobil and the study
prepared under commission to the state (Bun-
desland) of North Rhine – Westphalia (ahu
AG et al. 2012). Furthermore, the comparati-
ve analysis should also cover, if possible, any
available (interim) results of the study an-
nounced by the U.S. EPA (US EPA 2011).
26
5.2 Special recommendations
In the following sections, we have developed special
recommendations with regard to further steps relati-
ve to the issue of exploitation of unconventional gas
in Germany. The focus of the recommendations is on
the next phase of pilot exploration, especially explo-
ration in geological systems for which no informati-
on, or very little information, is yet available about
unconventional gas deposits they may contain. The
objectives of our recommendations include:
• Closing gaps in pertinent findings and know-
ledge (sections 5.2.1 through 5.2.4),
• Identifying hydro geologically problematic areas,
and possible impact pathways, at an early stage,
and proposing measures for ongoing monitoring
(section 5.2.1),
• Making pertinent drilling and handling tech-
niques safer (section 5.2.2),
• Reducing the hazard potential of the substances
used, or making it possible to assess such hazard
potential (section 5.2.3), and
• Suitably shaping and structuring legal and orga-
nisational procedures in this area (section 5.2.4).
Environmental Impacts of Hydraulic Fracturing – Short Version
27
The cause-and-effect relationships between deep-
reaching and near-surface groundwater flow sys-
tems are of particular importance with regard to the
water-related environmental impacts of unconventio-
nal gas exploitation projects (impacts on people, flora
and fauna). To properly assess such water-related
risks, and even quantify them, one must have a de-
tailed understanding of the hydrogeological systems
involved.
Analyses of selected geological systems have shown
how widely sites can differ in terms of their specific
geological and hydrogeological characteristics and
parameters. In many cases, the information required
for such analyses can be obtained only through con-
sultation of many different sources. The information
has to be compiled and studied, and then assessed
from an overarching perspective. Such efforts should
include the following main steps:
(2.1.1) Conceptual hydrogeological models should
be prepared that support reliable risk analysis
for all potential impact pathways. The scope
of such conceptual models should be large
enough to support assessment of the impacts
of exploration and exploitation of unconven-
tional gas – via fracking – both for the speci-
fic sites involved and with regard to the large
geological systems involved.
(2.1.2) For areas in which water-related environmen-
tal impacts cannot be ruled out (as shown by
risk analysis), numerical groundwater-flow
models should be prepared/refined with
which the pertinent risks can be quantified.
As a rule, this will entail preparing a regio-
nal-level model that can then serve as a basis
for local models within and around the actual
gas-production area.
(2.1.3) Normally, the work mentioned under (2.1.1)
and (2.1.2) will necessitate additional evalu-
ations and terrain studies (system-oriented
exploration).
(2.1.4) The aforementioned models have to be con-
tinually verified and calibrated on the basis
of data and information obtained through
monitoring (both preliminary and during
the project). For monitoring to be effective, it
must be based on an adequate understanding
of the system involved (see above). At the
same time, the understanding of the system
involved (conceptual or numerical model) can
be improved with the help of data obtained
via monitoring.
Monitoring-based project control requires
meaningful indicators (derived directly from
measurements and/or calculations) for which
an evaluation system is available. Ultimate-
ly, options must be available for stopping,
limiting or reversing any undesired develop-
ments, to ensure that no damage occurs and
that risks do not increase.
The models resulting from the aforementi-
oned work steps provide an important basis
for competent authorities‘ decisions regar-
ding the general authorizability of submitted
projects and design and structuring of ancil-
lary provisions (under water law) for specific
projects.
(2.1.5) The necessary regional and local models must
be prepared by the relevant mining compa-
nies, in the framework of authorization pro-
cedures under mining law and water law, and
in keeping with the requirements imposed by
the competent mining and water authorities.
In the current early phase of use of fracking
technology, however, the competent mining
and water authorities should first develop the
requirements applying to such models. And
such development should be carried out step-
by-step. In our view, a fracking project may
be approved only when enough pertinent
knowledge has been gained, and adequate
precautions have been taken, to rule out the
possibility of an adverse impact on groundwa-
ter.
5.2.1 Special recommendations with regard to the area of environment / geological systems
28
The current key regulations applying, in Germany,
to drilling equipment and techniques for developing
conventional gas resources, and for developing un-
conventional gas deposits, result from the provisions
of the Federal Mining Act (BBergG) and its seconda-
ry legislation – such as ordinances on deep-drilling
(Mining ordinance on deep-drilling, underground
storage areas and on resources extraction via wells
(Bergverordnung für Tiefbohrungen, Untergrund-
speicher und für die Gewinnung von Bodenschätzen
durch Bohrungen – BVOT); such ordinances differ
slightly between states – and from other relevant
environmental provisions specified in the permits for
such operations.
In addition, within this legal framework there are nu-
merous different implementation provisions that may
be applied by gas-production companies.
Companies choose exploration and production stra-
tegies on an individual-case assessment. Criteria they
take into account are the equipment and techniques
to be used, the specific geological and hydrogeologi-
cal characteristics of the site’s deposits and, not least,
their own experience in developing the deposits in
question (companies’ internal standards).
(2.2.1) Approval authorities should apply implemen-
tation provisions consistently and logically
(and, in each individual case, in keeping with
the prevailing geological and technical para-
meters).
(2.2.2) The international drilling standards establis-
hed in the gas-production sector (API stan-
dards, guidelines of the Wirtschaftsverband
Erdöl- und Erdgasgewinnung (WEG) German
oil and gas industry association, etc.) are tech-
nically adequate in terms of the current state
of the art in drilling technology. Nonetheless,
efforts should be made to reconcile operators‘
own internal safety standards, which in some
cases are quite stringent, and to mandate a
binding safety level. Inter-Länder coordinati-
on of such efforts should be sought.
(2.2.3) In order to enhance safety, particular atten-
tion should be given to ensuring compliance
with applicable guidelines for wells and ca-
sings, and to ensuring that casings are fully
cemented. In addition, – and this is also in
keeping with standard practice – we recom-
mend that completed wells be inspected and
checked for pressure-tightness in light of the
fracking pressures expected in them.
(2.2.4) The existing requirements applying to the
leak-tightness of cementations should be
reviewed, and further detailed if necessary,
in light of the specific requirements applying
to fracking. Such review should also include
suitable studies and monitoring procedures
for ensuring the long-term integrity of wells
(casing and cementations).
(2.2.5) For cases involving hydraulic stimulation, we
recommend that frac propagation be monito-
red via suitable procedures. Further research
is required in this area as well, i.e. with a
view to improving modelling and monitoring
of frac propagation, and inter-Länder coordi-
nation should be carried out with a view to
achieving relevant consistent, suitable stan-
dards and minimum requirements.
5.2.2 Special recommendations with regard to the area of equipment / techniques
Environmental Impacts of Hydraulic Fracturing – Short Version
29
Assessment of selected fracking fluids used in un-
conventional gas deposits in Germany, along with
the available information on the characteristics of
flowback, have revealed that injected fluids, and flu-
ids requiring disposal, can pose considerable hazard
potentials. In light of the gaps in knowledge, uncer-
tainties and data deficits identified via the research
and assessment for the present study, the following
recommendations for action are seen as important:
(2.3.1) Complete disclosure of all substances used,
with regard to substance identities and quan-
tities.
(2.3.2) Assessment of the toxicological and eco to-
xicological hazard potentials of substances
used, and provision of all physical-chemical
and toxicological substance data required by
the applicants. If relevant substance data are
lacking, the gaps in the data must be elimina-
ted – if necessary, via suitable laboratory tests
or model calculations. In the process, the ef-
fects of relevant substance mixtures must be
taken into account.
(2.3.3) Substitution of unsafe substances (especially
substances that are highly toxic, carcinogenic,
mutagenic or toxic for reproduction), reduc-
tion or substitution of biocides, reduction of
the numbers of additives used, lowering of
concentrations used.
(2.3.4) Determination and assessment of the charac-
teristics of site-specific formation water, with
regard to constituents of relevance to drin-
king-water quality (salts, heavy metals, Natu-
rally Occurring Radioactive Material – NORM,
hydrocarbons).
(2.3.5) Determination and assessment of the charac-
teristics of site-specific flowback, with regard
to constituents of relevance to drinking-water
quality (salts, heavy metals, NORM, hydro-
carbons), and with regard to additives used
(primary substances) and their transformati-
on products (secondary substances); determi-
nation and assessment of the proportion of
fracking fluids recovered with the flowback.
(2.3.6) Determination of the behavior and fate of
substances in the ground, via mass-balancing
of the additives used.
(2.3.7) Modeling of substance transport, for assess-
ment of possible risks to any exploitable
groundwater, from any ascending formation
water and fracking fluids.
(2.3.8) Technical treatment and “environmentally
sound” disposal of flowback, including de-
scription of all technically feasible treatment
processes and of the possibilities for reusing
substances. In cases involving injection into
disposal wells, site-specific risk analysis, and
description of the impacts on water resources
that accumulate spatially and over time.
(2.3.9) Monitoring and system-oriented examination
(cf. also section 5.2.1), including installati-
on of near-surface groundwater measuring
stations to determine the reference condition
with regard to additives and methane; if ap-
propriate, installation of deep groundwater
measuring stations to determine the charac-
teristics of formation water and the relevant
hydraulic potentials.
5.2.3 Special recommendations with regard to the area of substances
30
The deficits analysis carried out with regard to the
applicable legal framework was based on the wor-
king hypothesis that existing basic concerns about
adverse impacts on groundwater could be eliminated
in the framework of required authorization proce-
dures – at least for a significant number of sites and
projects, and, if necessary, after issue of specifications
relative to technical implementation and to monito-
ring of environmental impacts. In sum, the following
specific recommendations for action have resulted:
(2.4.1) Already under currently applicable laws, pre-
liminary, individual-case review of fracking
projects must be carried out to determine
whether an environmental impact assessment
is required. This results from the direct appli-
cability of the EU EIA Directive. The German
EIA ordinance for the mining sector (UVP-V
Bergbau), and mining authorities‘ existing
practice, based on that ordinance, of not
requiring a preliminary review of EIA require-
ments, do not conform to requirements per-
taining to implementation of that directive as
specified by the European Court of Justice.
(2.4.2) The EIA Directive must be properly transpo-
sed. To that end, EIA obligations should be in-
troduced from which only minor cases would
be exempted. At the same time, the Länder
should be empowered to determine, for all or
parts of their territories, that EIAs for certain
types of projects (to be determined), are re-
quired only if so indicated by the results of a
general or site-specific preliminary review of
EIA requirements, or may be waived if such
results lie below certain thresholds (to be
determined). In the short term, EIA obliga-
tions should be established via amendment
of the German EIA ordinance for the mining
sector (UVP-V Bergbau). In the medium term,
they should be established via amendment
of the Environmental Impact Assessment Act
(UVPG), with integration of provisions on EIA
obligations for mining projects in the list in
Annex 1 of the Environmental Impact Assess-
ment Act.
(2.4.3) The decision on whether an EIA is required,
in a given case, should be made by the mi-
ning authority, in keeping with the pertinent
assessment by environmental authorities, if
the mining authority is not also the envi-
ronmental authority and is subject to the
detailed supervision of the highest environ-
mental authority. This assignment of res-
ponsibilities should be defined at the federal
level.
(2.4.4) Both a) establishment and operation of
drilling sites intended to be used later for
fracking, and b) establishment and operation
of self-contained drilling sites with injection
wells for flowback, should automatically be
deemed projects subject to EIA obligations.
EIA obligations should also apply even to
set-up and operation of drilling sites with a
single well. And they should apply to all wells
drilled and operated from a single drilling
site. Furthermore, as necessary in keeping
with a relevant company‘s project concept,
they should also apply to set-up and operati-
on of drilling sites linked as part of a single
project. Injection wells intended solely as an-
cillary facilities for a unified fracking project
should also be subject, as parts of the project,
to EIA obligations.
(2.4.5) Where EIA obligations apply, EIA require-
ments dictate that public participation is re-
quired. For fracking projects, public participa-
tion should be expanded to include ongoing
participation during the project, to ensure
that the public is informed about whether,
and to what extent, the assumptions are con-
firmed, in the course of further site explora-
tion, that were made in the EIA carried out
prior to the setting-up of the drilling site (for
example, assumptions regarding the lack of
any faults), and to enable the public to ensure
that the competent authority addresses new
risks properly as they emerge. To that end,
the possibility should be provided of establi-
shing monitoring groups modeled after the
„Asse-II Monitoring Group“ (Asse-II-Begleit-
gruppe; focusing on radioactive waste stored
in the Asse II former salt mine); such groups
would include representatives of municipali-
ties and municipal organizations, of environ-
5.2.4 Special recommendations with regard to the area of legislation / administration
Environmental Impacts of Hydraulic Fracturing – Short Version
31
mental groups and of citizens‘ initiatives, and
would engage in ongoing dialog with the re-
levant mining company and mining authority
in each case. In addition, it should be ensured
that renewed authorization and EIA obliga-
tions, following preliminary review in indivi-
dual cases, arise both through project chan-
ges that can have significant environmental
impacts and through adverse changes in key
parameters (such as new findings) significant
to assessment of a project‘s environmental
impacts.
(2.4.6) With regard to the definition of „groundwa-
ter“, which determines the scope of appli-
cation of water law, it should be clarified
that water in deep geological formations is
groundwater within the meaning of the Fede-
ral Water Resources Management Act (WHG),
regardless of the depth at which it occurs,
regardless of any hydraulic connections to
near-surface groundwater and regardless of
its quality. Such clarification is required espe-
cially with regard to the issue of salt content,
because mining authorities sometimes deem
water law to be inapplicable when water salt-
content levels justify classification as brine.
(2.4.7) At the same time, it should be clarified that
an adverse effect on deep groundwater may
be deemed present only for water that qua-
lifies for human uses or that is part of the
biosphere‘s natural systems. „Water that qua-
lifies for human uses“ should refer not only to
uses that are cost-effective at present, but also
to possible uses under changed framework
conditions. The de minimis thresholds used
to evaluate whether an adverse impact on
near-surface groundwater has occurred thus
cannot be used, in the same way, for assess-
ment of changes in deep groundwater.
(2.4.8) In any case, for fracking wells and wells for
flowback injection, review, under water law,
should be carried out with regard to casing
and cementation, as well as with regard to
discharges of substances in connection with
fracking and with injection.
(2.4.9) Preferably, such review under water law
should be carried out in the framework of an
integrated project-approval procedure, and
should have a concentration effect relative to
water law. In addition, it should be carried
out under the direction of an environmental
authority subordinate to the Ministry of the
Environment. For introduction of such proce-
dures, the Federal Mining Act would have to
be amended.
As long as applicable laws have not yet been
suitably amended, it should be clarified that
review with regard to water law must be car-
ried out within an approval procedure under
water law, in agreement with the water au-
thority.
(2.4.10) The conditions for a permit under water law
should be defined via general standards for
required preliminary exploration, for the
design of technical components, for know-
ledge of the systems involved and for monito-
ring of impacts on groundwater. Where such
standards cannot be derived at an abstract
regulatory level, due to a lack of relevant
knowledge, they should be developed, via
a coordinated process, in the framework of
pending individual authorization procedures.
(2.4.11) An integrated project-approval procedure
should also be required by law for facilities
for treatment of flowback, and for pipelines
for transport of flowback, where the project-
approval procedure for the relevant drilling
site does not automatically extend to such
facilities. As long as such a project-approval
procedure is not required by law, it should be
ensured that conformance with requirements
under wastewater law is reviewed within the
relevant procedure under mining law, if no
separate approval procedure under wastewa-
ter law is carried out.
(2.4.12) In general, drilling and operation of fracking
and injection wells should be prohibited
within water-protection zones and mineral
spa protection zones. At the same time, it
should be possible, in individual cases, and in
connection with overriding reasons of the pu-
blic interest, to issue an exemption if a proce-
32
dure with environmental impact assessment
and public participation has been carried out.
If it becomes clear that fracking technology is
to be used on a large scale, as a precautiona-
ry measure, all fracking projects and projects
for flowback injection within a certain radius
(to be defined) of a protected area should be
made subject to a constraint on approval, in
keeping with all available findings at that
time, via amendment of the relevant pro-
tected-area ordinances or via individual-case
decisions.
(2.4.13) In accordance with a step-by-step procedu-
re, water-law permits for pending fracking
projects should be issued first for relatively
low-impact projects, in areas of relatively low
sensitivity, and such permits should be tied to
comparatively stringent requirements rela-
tive to preliminary study, technical design
and ongoing monitoring, as long as concerns
regarding adverse impacts on groundwater
cannot be eliminated for other projects or in
other areas. While requirements applied to
approved projects should primarily have the
purpose of eliminating concerns regarding
projects‘ adverse impacts on groundwater,
they should also be evaluated as a basis for as-
sessing comparable future projects.
(2.4.14) In accordance with a step-by-step procedure,
water-law permits for specific fracking pro-
jects should be structured, via suitable provi-
sions and ancillary provisions, so as to ensure
that measures about which concerns regar-
ding adverse impacts on groundwater cannot
immediately be eliminated are approved only
if assessment of the execution and monito-
ring of authorisable, safe measures (such as
measures with lower pressures, of shorter
durations, or with lower pollutant concentra-
tions or quantities) has shown that measures
with potentially greater impacts also give no
cause for concern.
(2.4.15) In the framework of management discretion
under water law, the (provisional) denial of
a permit under water law may be justified if
relevant concerns falling into the „boundary
area“ between concerns that would auto-
matically lead to denial of a permit and the
remaining residual risks cannot be elimina-
ted, in light of the most recent relevant fin-
dings. In this „boundary area“, management
discretion allows weighing of the economic
interest in development of unconventional
gas deposits against the economic interest in
assuring the drinking water supply. In this
framework, it may also be taken into account
whether, and to what extent, the gas supply
is assured via imports. That criterion may
only be considered, however, if in a relevant
concrete case a residual risk for the drinking
water supply indeed cannot be ruled out. In
this framework, it may also be taken into ac-
count whether findings from ongoing (pilot)
projects will, in the foreseeable future, provi-
de a better basis for assessment, and reconsi-
deration of the decision on whether to issue
a permit should be postponed until then.
Where approval for exploration and exploita-
tion projects is to be denied for reasons other
than considerations related to water-resources
management, or if such approval is initially
to be limited to just a few test or demonstra-
tion projects, the possibility of amending the
Federal Mining Act should be considered (for
example, for introduction of management
discretion under mining law).
(2.4.16) As long as no integrated project-approval pro-
cedure has been defined by law, the autho-
rization procedure under water law, and the
operational-plan procedure under mining law,
could be completely coordinated, in the man-
ner used for parallel authorization procedures
for industrial facilities. Operational-plan appro-
vals for relevant measures subject to permit re-
quirements under water law – specifically, dril-
ling wells and furnishing them with casings;
fracking; and flowback injection – should not
be issued until it is clear, from the status of
the relevant procedures under water law, that
there is no cause for concern regarding adver-
se impacts on groundwater and thus a permit
under water law may be issued.
Environmental Impacts of Hydraulic Fracturing – Short Version
33
(2.4.17) For purposes of review under water law, a
project‘s required application documents
must include a detailed description of the
project (specific technical design, full disclo-
sure of the substances to be used, description
of the relevant operational procedures and
of the boundaries of the operations to be
authorized). The permit issued for a project
must specifically define the content of the
approved measure. For that purpose, it does
not suffice simply to refer to general legal
requirements or to general provisions of tech-
nical regulations, without including a precise
description of the specifically approved mea-
sures.
(2.4.18) While legal provisions, or secondary legisla-
tion, are not absolutely necessary for imple-
mentation of most of these recommendations
for action, such provisions and legislation are
useful. They can be implemented, without
regulatory overhead, in the framework of ap-
plicable laws, via suitable implementation by
the competent mining and water authorities.
We recommend at least that these matters be
regulated via directives of the highest wa-
ter authorities (Länder environment minis-
tries), ideally in cooperation with the highest
mining authorities (usually the ministries of
economics of the Länder; in Baden-Württem-
berg and Hesse, they are also the environ-
ment ministries, however). In the medium
term, requirements pertaining to fracking
projects should be defined via an integrated
procedure under mining law and water law.
This should be achieved via supplementation
of the mining ordinances on deep-drilling,
underground storage areas and on resources
extraction via wells (Bergverordnungen für
Tiefbohrungen, Untergrundspeicher und für
die Gewinnung von Bodenschätzen durch
Bohrungen – BVOT), to provide for relevant
water-law regulations at the Länder level, or
via introduction of an integrated BVOT at the
federal level.
(2.4.19) For the legislation level, we recommend that
safety requirements under mining law be
integrated within environmental law, in an
approach similar to that used in the 1970s in
integrating legislation on authorization of in-
dustrial plants within environmental protec-
tion legislation, in order to assure effective,
efficient environmental protection.
(2.4.20) With regard to responsibilities, we recom-
mend that, overall, approval and monitoring
of mining projects, under environmental and
safety legislation, be sited in keeping with the
approach used in integration of trade over-
sight within environmental administration
– i.e. be assigned to the portfolio of environ-
ment ministries, in order to assure effective,
efficient environmental protection and to
functionally and organizationally separate
business-promoting tasks of economic minis-
tries from efforts to foster trust in authorities‘
oversight, which trust is an indispensable ba-
sis for public acceptance of fracking projects.
As long as responsibilities have not been so
assigned, mining authorities should take all
important environmentally relevant decisions
in keeping with decisions of the primarily
responsible environmental authorities, except
in cases – as in North Rhine – Westphalia –
in which they are themselves environmental
authorities and, as such are subject to the
instructional authority of the environment
ministry.
34
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Edited and designed by: ahu AG, Aachen
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Date: November 2012
First Print: 50 copies
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Environmental Impacts of Hydraulic Fracturing
Related to Exploration and Exploitation of Unconventional Natural Gas
Deposits – Short Version
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