EN ISO 15175:2011

SLOVENSKI STANDARD
01-november-2011
Kakovost tal - Karakterizacija tal v zvezi z varstvom podzemne vode (ISO
15175:2004)
Soil quality - Characterization of soil related to groundwater protection (ISO 15175:2004)
Bodenbeschaffenheit - Ermittlung von Kennwerten des Bodens hinsichtlich des
Wirkungspfads Boden - Grundwasser (ISO 15175:2004)
Qualité du sol - Caractérisation des sols en relation avec la nappe phréatique (ISO
15175:2004)
Ta slovenski standard je istoveten z: EN ISO 15175:2011
ICS:
13.080.40 Hidrološke lastnosti tal Hydrological properties of
soils
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN ISO 15175
NORME EUROPÉENNE
EUROPÄISCHE NORM
June 2011
ICS 13.080.40
English Version
Soil quality - Characterization of soil related to groundwater
protection (ISO 15175:2004)
Qualité du sol - Caractérisation des sols en relation avec la Bodenbeschaffenheit - Ermittlung von Kennwerten des
nappe phréatique (ISO 15175:2004) Bodens hinsichtlich des Wirkungspfads Boden -
Grundwasser (ISO 15175:2004)
This European Standard was approved by CEN on 3 June 2011.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European
Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national
standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member.

This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same
status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland,
Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.

EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2011 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 15175:2011: E
worldwide for CEN national Members.

Contents Page
Foreword .3

Foreword
The text of ISO 15175:2004 has been prepared by Technical Committee ISO/TC 190 “Soil quality” of the
International Organization for Standardization (ISO) and has been taken over as EN ISO 15175:2011 by
Technical Committee CEN/TC 345 “Characterization of soils” the secretariat of which is held by NEN.
This European Standard shall be given the status of a national standard, either by publication of an identical
text or by endorsement, at the latest by December 2011, and conflicting national standards shall be withdrawn
at the latest by December 2011.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech
Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.
Endorsement notice
The text of ISO 15175:2004 has been approved by CEN as a EN ISO 15175:2011 without any modification.

INTERNATIONAL ISO
STANDARD 15175
First edition
2004-05-15
Soil quality — Characterization of soil
related to groundwater protection
Qualité du sol — Caractérisation des sols en relation avec la nappe
phréatique
Reference number
ISO 15175:2004(E)
©
ISO 2004
ISO 15175:2004(E)
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ii © ISO 2004 – All rights reserved

ISO 15175:2004(E)
Contents Page
Foreword. iv
1 Scope. 1
2 Normative references . 1
3 Terms and definitions. 5
4 General. 7
5 Site assessment . 9
5.1 General. 9
5.2 Relevant soil processes . 10
5.3 Impact assessment procedures . 11
5.4 Site and soil description. 13
5.5 Sampling . 14
5.6 Characterization of soil and water . 15
6 Data handling, evaluation and quality . 22
Annex A (informative) Qualitative methods for assessing the potential leaching risk. 25
Annex B (informative) Quantitative methods for assessing the actual leaching risk . 44
Annex C (informative) Types of contaminated site and associated contaminants . 48
Annex D (informative) List of priority pollutants with respect to groundwater pollution . 49
Annex E (informative) Overview of soil leaching and extraction test . 53
Bibliography . 57

ISO 15175:2004(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 15175 was prepared by Technical Committee ISO/TC 190, Soil quality, Subcommittee SC 7, Soil and site
assessment.
iv © ISO 2004 – All rights reserved

INTERNATIONAL STANDARD ISO 15175:2004(E)

Soil quality — Characterization of soil related to groundwater
protection
1 Scope
This International Standard provides guidance on the principles behind, and main methods for, the evaluation of
sites, soils, and soil materials in relation to their role as a source of contamination of groundwater and their
function in transporting, degrading and transforming contaminants. It identifies and lists relevant monitoring
strategies, methods for sampling, soil processing and analytical methods.
This International Standard is applicable to the evaluation of the impact of contaminants on groundwater in
relation to
 drinking water quality,
 irrigation water quality,
 industrial use,
 natural base flow.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ISO 6341, Water quality — Determination of the inhibition of the mobility of Daphnia magna Straus (Cladocera,
Crustacea) — Acute toxicity test
ISO 6468, Water quality — Determination of certain organochlorine insecticides, polychlorinated biphenyls
and chlorobenzenes — Gas chromatographic method after liquid-liquid extraction
ISO 6878, Water quality — Spectrometric of phosphorus using ammonium molybdate
ISO 7150-1, Water quality — Determination of ammonium — Part 1: Manual spectrometric method
ISO 7150-2, Water quality — Determination of ammonium — Part 2: Automated spectrometric method
ISO 7888, Water quality — Determination of electrical conductivity
ISO 7890-1, Water quality — Determination of nitrate — Part 1: 2,6-Dimethylphenol spectrometric method
ISO 7890-2, Water quality — Determination of nitrate — Part 2: 4-Fluorophenol spectrometric method after
distillation
ISO 7890-3, Water quality — Determination of nitrate — Part 3: Spectrometric method using sulfosalicylic acid
ISO 7981-2, Water quality — Determination of six specified polynuclear hydrocarbons (PAH) — Part 2:
Determination of six PAH by high-performance liquid chromatography with fluorescence detection after liquid-
liquid extraction
ISO 15175:2004(E)
ISO 8165-1, Water quality — Determination of selected monovalent phenols — Part 1: Gas chromatographic
method after enrichment by extraction
ISO 8245, Water quality — Guidelines for the determination of total organic carbon (TOC) and dissolved
organic carbon (DOC)
ISO 9001:2000, Quality management systems — Requirements
ISO 9562, Water quality — Determination of adsorbable organically bound halogens (AOX)
ISO 9964-1, Water quality — Determination of sodium and potassium — Part 1: Determination of sodium by
atomic absorption spectrometry
ISO 9964-2, Water quality — Determination of sodium and potassium — Part 2: Determination of potassium
by atomic absorption spectormetry
ISO 9964-3, Water quality — Determination of sodium and potassium — Part 3: Determination of sodium and
potassium by flame emission spectrometry
ISO 10048, Water quality — Determination of nitrogen — Catalytic digestion after reduction with Devarda's
alloy
ISO 10301, Water quality — Determination of highly volatile halogenated hydrocarbons — Gas
chromatographic methods
ISO 10382, Determination of organochlorine pesticides and polychlorinated biphenyls – gas chromatographic
method with electron capture detection
ISO 10390, Soil quality — Determination of pH
ISO 10523, Water quality — Determination of pH
ISO 10573, Soil quality — Determination of water content in the unsaturated zone — Neutron depth probe
method
ISO 10693, Soil quality — Determination of carbonate content — Volumetric method
ISO 10694, Soil quality — Determination of organic and total carbon after dry combustion (elementary
analysis)
ISO 11047, Soil quality — Determination of cadmium, chromium, cobalt, copper, lead, manganese, nickel and
zinc — Flame and electrothermal atomic absorption spectrometric methods
ISO 11048, Soil quality — Determination of water-soluble and acid-soluble sulfate
ISO 11074-1, Soil quality — Vocabulary — Part 1: Terms and definitions relating to the protection and
pollution of the soil
ISO 11074-4 Soil quality — Vocabulary — Part 4: Terms and definitions relating to the rehabilitation of soils
and sites
ISO 11259, Soil quality — Simplified soil description
ISO 11260, Soil quality — Determination of effective cation exchange capacity and base saturation level using
barium chloride solution
ISO 11261, Soil quality — Determination of total nitrogen — Modified Kjeldahl method
2 © ISO 2004 – All rights reserved

ISO 15175:2004(E)
ISO 11263, Soil quality — Determination of phosphorus — Spectrometric determination of phosphorus soluble
in sodium hydrogen carbonate solution
ISO 11264, Soil quality — Determination of herbicides — Method using HPLC with UV detection
ISO 11265, Soil quality — Determination of the specific electrical conductivity
ISO 11266, Soil quality — Guidance on laboratory testing for biodegradation of organic chemicals in soil under
aerobic conditions
ISO 11271, Soil quality — Determination of redox potential — Field method
ISO 11272, Soil quality — Determination of dry bulk density
ISO 11274, Soil quality — Determination of the water retention characteristic — Laboratory methods
ISO 11275, Soil quality — Determination of unsaturated hydraulic conductivity and water-retention
characteristic — Wind's evaporation method
ISO 11277, Soil quality — Determination of particle size distribution in mineral soil material — Method by
sieving and sedimentation
ISO 11348-1, Water quality — Determination of the inhibitory effect of water samples on the light emission of
Vibrio fischeri (Luminescent bacteria test) — Part 1: Method using freshly prepared bacteria
ISO 11348-2, Water quality — Determination of the inhibitory effect of water samples on the light emission of
Vibrio fischeri (Luminescent bacteria test) — Part 2: Method using liquid-dried bacteria
ISO 11348-3 Water quality — Determination of the inhibitory effect of water samples on the light emission of
Vibrio fischeri (Luminescent bacteria test) — Part 3: Method using freeze-dried bacteria
ISO 11369, Water quality — Determination of selected plant treatment agents — Method using high
performance liquid chromatography with UV detection after solid-liquid extraction
ISO/TS 11370, Water quality — Determination of selected organic plant treatment agents — Automated
multiple development (AMD) technique
ISO 11464, Soil quality — Pretreatment of samples for physico-chemical analyses
ISO 11423-1, Water quality — Determination of benzene and some derivatives — Part 1: Head-space gas
chromatographic method
ISO 11423-2, Water quality — Determination of benzene and some derivatives — Part 2: Method using
extraction and gas chromatography
ISO 11466, Soil quality — Extraction of trace elements soluble in aqua regia
ISO 11905-1, Water quality — Determination of nitrogen — Part 1: Method using oxidative digestion with
peroxodisulfate
ISO/TR 11905-2, Water quality — Determination of nitrogen — Part 2: Determination of bound nitrogen, after
combustion and oxidation to nitrogen dioxide, using chemiluminescence detection
ISO 13536, Soil quality — Determination of the potential cation exchange capacity and exchangeable cations
using barium chloride solution buffered at pH = 8,1
ISO 13877, Soil quality — Determination of polynuclear aromatic hydrocarbons — Method using high-
performance liquid chromatography
ISO 15175:2004(E)
ISO 13878, Soil quality — Determination of total nitrogen content by dry combustion (“elemental analysis”)
ISO 14154, Soil quality — Determination of selected phenols and chlorophenols — gas chromatographic
method
ISO 14235, Soil quality — Determination of organic carbon by sulfochromic oxidation
ISO 14238, Soil quality — Biological methods — Determination of nitrogen mineralization and nitrification in
soils and the influence of chemicals on these processes
ISO 14239, Soil quality — Laboratory incubation systems for measuring the mineralization of organic
chemicals in soil under aerobic conditions
ISO 14254, Soil quality — Determination of exchangeable acidity in barium chloride extracts
ISO 14255, Soil quality — Determination of nitrate nitrogen, ammonium nitrogen and total soluble nitrogen in
air-dry soils using calcium chloride solution as extractant
ISO 14256-2, Soil quality — Determination of nitrate, nitrite and ammonium in field-moist soils by extraction
with potassium chloride solution — Part 2: Automated method
ISO 14507, Soil quality — Pretreatment of samples for determination of organic contaminants
ISO 14869-1, Soil quality — Dissolution for the determination of total element content — Part 1: Dissolution
with hydrofluoric and perchloric acids
ISO 14869-2, Soil quality — Dissolution for the determination of total element content — Part 2: Dissolution by
alkaline fusion
ISO 14870, Soil quality — Extraction of trace elements by buffered DTPA solution
+ + + + 2+ 2+ 2+ 2+ 2+
ISO 14911, Water quality — Determination of dissolved Li , Na , NH , K , Mn , Ca , Mg , Sr and Ba
using ion chromatography — Method for water and waste water
ISO 15009, Soil quality — Gas chromatogrphic determination of the content of volatile aromatic hydrocarbons,
naphthalene and volatile halogenated hydrocarbons — Purge-and-trap method with thermal desorption
ISO 15089, Water quality — Guidelines for selective immunoassays for the determination of plant treatment
and pesticide agents
ISO 15178, Soil quality — Determination of total sulfur by dry combustion
ISO 15473: 2002, Soil quality — Guidance on laboratory testing for biodegradation of organic chemicals in soil
under anaerobic conditions
ISO 15799, Soil quality — Guidance on the ecotoxicological characterization of soils and soil materials
ISO 15913, Water quality — Determination of selected phenoxyalkanoic herbicides, including bentazones and
hydroxybenzonitriles by gas chromatography and mass spectrometry after solid phase extraction and
derivatization
ISO 16703, Soil quality — Determination of content of hydrocarbon in the range C to C by gas
10 40
chromatography
ISO/IEC 17025, General requirements for the competence of testing and calibration laboratories
ISO 20279, Soil quality — Extraction of thallium and determination by electrothermal atomic absorption
spectrometry
OIML R 112:1994, High performance liquid chromatographs for measurement of pesticides and other toxic
substances
4 © ISO 2004 – All rights reserved

ISO 15175:2004(E)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 11074-1 and ISO 11074-4 and the
following apply.
3.1
soil
upper layer of the Earth's crust composed of mineral particles, organic matter, water, air and organisms
[ISO 11074-1]
3.2
contaminant
substance or agent present in the soil as a result of human activity
cf. pollutant (3.8).
NOTE There is no assumption in this definition that harm results from the presence of the contaminant.
3.3
diffuse-source input
non-point-source input
input of a substance emitted from moving sources, from sources with a large area or from many sources
NOTE 1 The sources can be for example cars, application of substances through agricultural practices, emissions from
town or region, deposition through flooding of a river.
NOTE 2 Diffuse-source input usually leads to sites that are relatively uniformly contaminated. At some sites the input
conditions may nevertheless cause a higher local input near the source or where atmospheric deposition/rain is increased.
3.4
groundwater
water which is being held in, and can usually be recovered from, an underground formation
3.5
hazard
property of a substance or material, or any action, which may cause an adverse effect on soil functions
3.6
percolating water
soil water that moves downward in the percolating space due to gravity, insofar as it is not groundwater
3.7
point-source input
input of a substance from a stationary discrete source of defined size
NOTE 1 The sources can be stack emissions, accidental spills, waste dumps, spills on industrial sites, major leaks
from sewers and other pipelines.
NOTE 2 Point-source input can cause both locally contaminated sites and relatively uniformly contaminated sites.
[ISO 11074-1]
3.8
pollutant
substance or agent present in the soil (or groundwater) which due to its properties, amount or concentration
causes adverse impacts on soil functions or soil use
NOTE Also described as those substances which due to their properties, amount or concentration cause impacts on
soil functions or soil use.
ISO 15175:2004(E)
3.9
residual contamination
amount or concentration of contaminants remaining in specific media following remediation
[ISO 11074-4]
3.10
risk
expression of the probability that an adverse effect on soil functions will occur under defined conditions, and
the magnitude of the consequences of the effect occurring
3.11
saturated zone
zone of the underground, where the space of the lithosphere is filled uninterruptedly with water at the time
under consideration
NOTE The saturated zone encompasses the groundwater zone including the zone of capillary water.
3.12
soil function
function of soil which is significant to man and the environment
NOTE Important soil functions are
 control of matter and energy cycles as compartments of an ecosystem,
 vital support for the life of plants, animals and man,
 basis for the stability of buildings and roads,
 basis for agricultural production,
 buffer inhibiting movement of water, contaminants or other agents into the groundwater,
 source of a gene pool,
 preservation of archaeological remains,
 preservation of paleoecological remains.
[ISO 11074-4]
3.13
soil material
excavated soil, dredged materials and soil treated to remove or destroy or reduce the environmental
availability of contaminants
3.14
soil water
all water of the unsaturated and saturated zone
3.15
subsoil
partially decomposed layer of rock underlying the topsoil and overlying the solid parent rock beneath
3.16
topsoil
upper part of a natural soil which is generally dark-coloured and has a higher content of organic matter and
nutrient when compared to the subsoil below
[ISO 11074-4]
6 © ISO 2004 – All rights reserved

ISO 15175:2004(E)
3.17
unsaturated zone
zone of the soil and the underground, where the space of the lithosphere is not filled uninterruptedly with
water at the time under consideration
NOTE The unsaturated zone encompasses the zone of percolating water with the zone of capillary water being
excluded.
4 General
Soils are of central importance within the water cycle because their storage and filter functions have a lasting
influence on the water balance and groundwater quality. In this context, particular attention shall be paid to the
following functions:
 mechanical filter functions (retention of suspended sludge and pollutant particles);
 chemical filter functions (sorption and mobilization of substances);
 transformation functions (degradation or transformation of substances).
Soil is understood as a porous medium consisting of three phases: the solid phase, the liquid phase and the
gaseous phase. The ratio of these phases and their respective compositions vary widely in time and space.
The assessment of contamination affecting groundwater quality requires a profound understanding of the
governing processes and reactions of potentially toxic compounds in soils. Contaminants are translocated in
all three phases of soils as a function of the properties of the chemicals and the soil. Hence strategies for
assessing risks to groundwater due to soil contamination should vary with the contaminants considered, and
should take into account those soil properties which mainly govern the soil's filter, retention, release and
transformation functions.
In addition to considering the properties of the chemicals and the soil governing the behaviour of contaminants
in soils, different ways for contaminants to enter soils shall also be evaluated when designing suitable risk
assessment strategies, with respect to contamination of groundwater. Soil and groundwater contamination
can be caused by different sources on different spatial scales, as indicated in Figure 1. On regional and larger
scales, soil contamination is caused, for example, by wet and dry atmospheric deposition and has
predominantly diffuse character on a moderate level of contamination. On a local scale, a variety of point
sources can cause all kinds and magnitudes of soil and groundwater contamination. Most point sources of
contamination may also be regarded as off-site diffuse sources of groundwater contamination. It is evident
that different contamination scenarios as a function of contamination sources and scale demand different
investigation strategies with respect to groundwater impact. At present there are no uniform principles for the
investigation and evaluation of contaminated soils and contaminated sites in relation to the protection of water
resources.
ISO 15175:2004(E)
Figure 1 — Definition of groundwater zones and examples of sources of contamination
8 © ISO 2004 – All rights reserved

ISO 15175:2004(E)
Investigation strategies may be qualitative or quantitative. Qualitative approaches mostly refer to assessment
of, for example, the potential leaching risk of chemicals through the soil towards groundwater. In contrast to
quantitative approaches, the level of actual soil contamination is not taken into account. Approaches of this
type can also be utilized, e.g. to classify larger areas with respect to their capability of protecting groundwater
resources against contamination, or as an introductory step in an assessment of an actual contaminated site.
To assess the on-site impact on groundwater resulting from specific soil contamination, quantitative
approaches based on site-specific investigation procedures including laboratory and/or field measurements
have to be carried out. Laboratory measurements can include physical, chemical and biological analysis, and
leaching tests. Assessments of this kind also shall take into account natural background concentrations of a
substance and other natural conditions affecting the impact on the groundwater. Assessments of impact on
groundwater often include a temporal aspect, since the actual impact may not be measurable at the time of
the investigation, but may happen some time in the future.
Assessments also depend on the purposes of investigations, for example:
 conservation of soil functions in order to prevent groundwater contamination;
 soil and groundwater monitoring;
 risk assessment;
 controlling remediation measures.
A listing of suitable methods are covered in the main part of this International Standard (see Clause 5). Some
examples of assessment using principles of this International Standard are provided in Annexes A and B.
Since the impact on groundwater can lead to impact on surface waters, this aspect can in some cases be
relevant in an overall impact assessment. This issue is not addressed explicitly in this International Standard.
5 Site assessment
5.1 General
A prerequisite for the evaluation of the soil-to-groundwater pathway is the determination of the relevant
physical, chemical and biological characteristics of soils and the hydrological characteristics of the site. It is
therefore normally necessary to collect data for the assessment of the contamination source with respect to
the type and degree of contamination and extent of source(s).
It is also necessary to describe the soil compartment that is influenced by the source, and the factors in this
compartment affecting the actual impact on the groundwater. Many processes influence the groundwater
impact in this soil compartment, where a number of physical, chemical and biological processes can take
place. In order to evaluate the importance of these processes in a specific assessment, it is necessary to
describe the structure of the soil compartment, e.g. the geometry, hydraulic conditions and natural chemical
and biologic processes. Input to the soil compartment includes the infiltration of water and specific
contaminants. Output is the contaminant flux to the compartment of the groundwater zone investigated. A
general description hereof is given in Figure 2 and a further description of the relevant parameters is given
in 5.2.
ISO 15175:2004(E)
Figure 2 — Schematic diagram illustrating the soil compartment covered by the assessment
procedure and processes affecting the impact of contamination on groundwater
The types of information needed to describe the relevant soil compartment include pedology, lithology of
parent material, pedology (e.g. soil unit), hydrogeology (e.g. permeability), physico-chemical conditions (e.g.
pH) and biological conditions (e.g. substrate availability). How large the actual soil compartment investigated
should be (and thus the detail of the investigation) depends on the type of assessment chosen. For example,
the volume is large if the assessment focuses on the general use of pesticides and fertilizers in an area
covering a groundwater reservoir used as a drinking water source. The area and volume of the soil
compartment investigated is considerably smaller if the assessment covers a “hot spot” on a contaminated
site with a groundwater-pumping well located on a neighbouring site.
5.2 Relevant soil processes
Contaminant transport in the unsaturated zone is governed not only by the transport of percolating water but
also by a number of biological and chemical processes. Which of these processes are to be considered
important within a given context will depend on the type of contaminants and the actual soil conditions. An
overview of soil and contaminant parameters related to contaminant transport is given in Table 1.

10 © ISO 2004 – All rights reserved

ISO 15175:2004(E)
Table 1 — Soil and contaminant parameters related to different processes in soil
Process Soil parameters Contaminant parameters Soil/contaminant
interactions
Mass transport of Hydraulic conductivity, degree of Solubility, volatility, density, Relative permeability,
contaminants saturation, porosity, pore size viscosity residual saturation,
distribution, soil water-retention wettability, surface
functions tension, capillary
pressure
Contaminant transport in
water:
Advection Pressure gradient, hydraulic Viscosity
conductivity, porosity
Dispersion/diffusion Dispersivity, pore water velocity Diffusion coefficient
Density transport Pore water velocity, soil layering Liquid density Dispersion, change in
density
Preferential flow Pore size distribution, fissure size, Viscosity, density, diffusion
macropore size, connectivity coefficient
Volatilization Water content, temperature, chemical- Vapour pressure, Henry's
phase content constant
Gas-phase transport Water content, tortuosity, pressure Diffusion coefficient
differences
Dissolution of organics Hydraulic conductivity, tortuosity, water Solubility, composition of
content chemical phase
Dissolution of inorganics Hydraulic conductivity, tortuosity, water Solubility product
content
Precipitation pH, redox, other components Solubility product,
complexation constant
Complexation pH, ligand concentration, DOC Complexation constant
Ion exchange Cation exchange capacity, ionic Valence, degree of
strength, other cations, pH hydratization
Sorption of organics pH, organic matter content, clay Octanol-water distribution Ageing
content and mineralogy, specific coefficient, sorption constant
surface area
Sorption of inorganics pH, organic matter content, clay Sorption constant Ageing
content and mineralogy, specific
surface area, non-crystalline (short-
range ordered) oxide and hydrous
oxide gels
Degradation
Abiotic Redox, pH, temperature Presence of primary
substrate, degradability,
Biotic Microorganisms, redox, substrate, pH,
toxicity to microorganisms
temperature
5.3 Impact assessment procedures
In order to complete a description of the source and the soil it is necessary to develop
 strategies for evaluation of site-specific parameters,
 sampling strategies, and
 analytical and testing strategies
for each site and/or media (soil, groundwater, soil air) that influences the impact on the groundwater.
ISO 15175:2004(E)
These strategies should be determined on the basis of
 history of the site or area,
 available data and/or results of previous investigations,
 the nature of any process-based treatment methods that have been applied to the soil,
 the intended use of the site.
To optimize the actual need for information in relation to the costs and time demanded for the investigations in
the field and laboratory, it is recommended to carry out the assessment in a stepwise procedure (see Table 2).
Table 2 — Stepwise procedure for impact assessment
Step 1
Preliminary investigation, including desktop investigation, site history, potential contaminants, available
regional data on geology and hydrogeology
Description of local geology and pedology in moderate detail and to verify the existence of contamination
Chemical analyses to identify components and concentrations
Primary impact assessment
Definition of the importance of the problem, further action (e.g. site monitoring, immediate clean-up, further
investigation or action is not necessary)
Step 2 Exploratory investigation, including supplemental field and laboratory investigations to estimate extent of
source, specific hydraulic conditions, mobility, transformation and degradation and relevant reservoir
conditions
Secondary impact assessment
Decision as to further action
Step 3
If necessary, main site investigations and testing in laboratory and field of specific details (e.g. leachability
and/or degradation), computer modelling
Tertiary impact assessment
The first step includes a preliminary study based on desktop investigations and limited field investigations with
the aim to carry out an initial impact assessment. This step includes estimation of the soil geometry, soil unit
and hydrological conditions on the basis of general knowledge of the area, possibly supplemented with some
field data concerning local conditions. The presence of contaminants of interest and their likely concentrations
are estimated on basis of site history and a few analyses of soil and water samples and/or soil-gas
measurements. The relevant transport and decomposition processes are approximated from data related to
the relevant soil conditions and contaminants retrieved from the literature. In step 1, qualitative methods as
exemplified in Annex A can be useful, as can quantitative methods described as Level 1 in B.7.
If step 1 indicates need for a more detailed assessment, the next step is carried out. The relevant
investigations consisting of supplementary sampling, chemical analysis and field tests are planned on the
basis of step 1. Step 2 typically includes sampling to estimate the extent of the source(s), and the distribution
of contaminants in the soil matrix between the different phases: the soil gas, which is bound to the soil
particles and dissolved in the soil water. The transport of contaminants in various soil types and underlying
lithologies (e.g. sand versus fractured rock) can be very different depending on their static and dynamic
characteristics (e.g. cracking soils). It is very important in step 2 to determine the dominant mechanism of
transport. For example if the transport is related to fractures in clay and rock, then the adsorption process can
be of minor importance. Alternatively, in homogeneous sand with a high organic matter content, adsorption
can be the most important process in the impact assessment. Information about the groundwater reservoir
(e.g. extent, importance for the water supply situation) in question is also relevant in this phase, to be able to
assess the severity of a potential problem. The seasonal pattern of climatic characteristics should be known in
order to evaluate seasonal trends in potential and ongoing soil and groundwater contamination. Management
practices should also be taken into account (e.g. irrigation type and quantities). In step 2, quantitative methods
as exemplified as Level 2 in B.7 may be useful.
12 © ISO 2004 – All rights reserved

ISO 15175:2004(E)
If the assessment still has to be improved after step 2, supplementary steps can be carried out. The content of
these following steps can consist of some of the same elements as in step 2, but with improved accuracy of
information available, e.g. by taking more samples to determine the influence of heterogeneity in the soil.
Sorption, degradation and leaching test can be carried out in the laboratory. Leaching and extraction tests can
be applied to assess the distribution of contaminants among the soil, water and geochemical phases, and to
assess the environmental impact (on groundwater in this context) and possible remediation actions.
Site-specific computer modelling of processes and groundwater flow can also be introduced as part of this
step. In step 3, quantitative methods as exemplified as Level 3 in B.7 may be useful.
It can be seen that the assessment is often an iterative procedure, each step being a more refined version of
the description of the problem and each leading to a more detailed basis for decision-making, as to the
necessity of remedial action in the form of site clean-up, land-use restrictions, etc.
Characterization of soil, water and the target site will require measurement of physical, chemical and biological
properties. Figure 3 indicates the broad areas in which measurement or description may be required.

Figure 3 — Overall flow chart for assessment of soil and water
5.4 Site and soil description
The assessment of the potential impacts of contaminated soil on groundwater requires general information
about the site under investigation. The most relevant parameters for a site-description are listed in Table 3.
ISO 11259 cited in Table 3 shall be applied. The scale at which this information should be collected, and the
degree of detail that is required, should be closely related to the objective of the investigation which primarily
depends on the anticipated nature and distribution of a contamination (see ISO 10381-5). In the stage of
desktop investigation (Step 1 according to Table 2), gathering information about the site does not include field
work, whereas further investigation steps may necessitate more detailed field data collection. It is important to
ISO 15175:2004(E)
bear in mind that the reliability of data interpretation and risk assessment strongly depends on a profound
knowledge of the site under consideration, hence collection of parameters indicated in Table 3 should be as
comprehensive as possible.
Table 3 — Parameters for site and soil description
Parameters Applicable
International
Standard
Landform and topography Topography, landform, land element, position, slope, ISO 11259
microtopography
Land use and vegetation Land use, human influence, vegetation ISO 11259
Geology and lithology Kind of parent material, effective soil depth ISO 11259
Surface characteristics Rock outcrops, surface coarse fragments, erosion phenomena, ISO 11259
surface sealing, surface cracks, other characteristics
Soil-water relationship Surface water balance, rainfall, evapotranspiration, ISO 11259
groundwater recharge, presence and depth of water table, site
drainage, moisture conditions
Soil type/soil profile description Soil unit in regards of the classification system used ISO 11259
Sequence and depth of diagnostic horizons, kind of boundaries
Soil colour (matrix, mottling)
Organic matter
Texture, coarse elements, presence of non-soil material,
pedofeatures
Carbonates, field-pH, electrical conductivity
Structure, voids, fracturing, inhomogeneities
Compactness and consistence
Total estimated porosity
Roots, worm channels, biological activity
5.5 Sampling
5.5.1 General
Before commencing any investigation, it is essential to define the objec
...