Bsi bs en 14996 2006 (bs 6068 5 42 2006)

untitled BRITISH STANDARD BS EN 14996 2006 BS 6068 5 42 2006 Water quality — Guidance on assuring the quality of biological and ecological assessments in the aquatic environment The European Standard[.]

BS 6068-5.42:2006

Water quality —

Guidance on assuring

the quality of biological

and ecological

assessments in the

aquatic environment

The European Standard EN 14996:2006 has the status of a

British Standard

ICS 13.060.70

National foreword

This British Standard is the official English language version of

EN 14996:2006

The UK participation in its preparation was entrusted by Technical Committee EH/3, Water quality, to Subcommittee EH/3/5, Biological methods, which has the responsibility to:

A list of organizations represented on this subcommittee can be obtained on request to its secretary

Cross-references

The British Standards which implement international or European

publications referred to in this document may be found in the BSI Catalogue

under the section entitled “International Standards Correspondence Index”, or

by using the “Search” facility of the BSI Electronic Catalogue or of British

Standards Online

This publication does not purport to include all the necessary provisions of a contract Users are responsible for its correct application

Compliance with a British Standard does not of itself confer immunity from legal obligations.

— aid enquirers to understand the text;

— present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep UK interests informed;

— monitor related international and European developments and promulgate them in the UK

Summary of pages

This document comprises a front cover, an inside front cover, the EN title page, pages 2 to 14, an inside back cover and a back cover

The BSI copyright notice displayed in this document indicates when the document was last issued

NORME EUROPÉENNE

EUROPÄISCHE NORM June 2006

ICS 13.060.70

English Version

Water quality - Guidance on assuring the quality of biological

and ecological assessments in the aquatic environment

Qualité de l'eau - Guide d'assurance qualité pour des

évaluations biologiques et écologiques dans

l'environnement aquatique

Wasserbeschaffenheit - Anleitung zur Qualitätssicherung biologischer und ökologischer Untersuchungsverfahren in

der aquatischen Umwelt

This European Standard was approved by CEN on 3 May 2006.

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 Central Secretariat 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 Central Secretariat has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, 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

C O M I T É E U R O P É E N D E N O R M A L I S A T I O N

E U R O P Ä IS C H E S K O M IT E E FÜ R N O R M U N G

Management Centre: rue de Stassart, 36 B-1050 Brussels

© 2006 CEN All rights of exploitation in any form and by any means reserved

Contents Page

Foreword 3

Introduction 4

1 Scope 5

2 Normative references 5

3 Terms and definitions 5

4 Principle 8

5 Design of biological and ecological studies 8

6 Surveys and sampling 9

7 Analysis 9

8 Performance characteristics 11

9 Validation of results 11

10 Measurement uncertainty 12

11 Interpretation and reporting 12

12 Training 12

Bibliography 14

Foreword

This document (EN 14996:2006) has been prepared by Technical Committee CEN/TC 230 “Water analysis”, the secretariat of which is held by DIN

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 2006, and conflicting national standards shall be withdrawn

at the latest by December 2006

SAFETY PRECAUTIONS — Safety issues are paramount when surveying surface waters Surveyors should conform to EU and national Health and Safety legislation and any additional guidelines appropriate for working in or near water

According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, 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

Introduction

The importance of ecology in new legislation such as the EC Water Framework Directive (WFD 2000/60/EC) means that ecological data from aquatic environments shall be of a known and verifiable quality General guidelines on quality assurance are given in the EN ISO 9000 series and, especially, EN ISO/IEC 17025 This guidance standard is designed to complement these standards by providing advice specific to the quality assurance of ecological data collected from aquatic environments The principles outlined in this standard are applicable to all field and laboratory work and to all organisations producing ecological data

According to the precise use to which this standard is to be put, it is essential for specifiers and users to agree

on any necessary variations or optional procedural details prior to use

1 Scope

This guidance standard defines activities appropriate for ensuring that the quality of ecological assessments in surface waters (including rivers, lakes, transitional and coastal waters and the open sea) and sediments meets specified requirements This standard also covers hydromorphological aspects relevant to ecological assessment While it has particular importance in relation to the assessment of ecological status in surface waters, it also applicable to other types of investigation and habitat

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

Not applicable

3 Terms and definitions

For the purposes of this document, the following terms and definitions apply

3.1

accuracy

closeness of agreement between the result of a measurement and the true value of the measurand

NOTE 1 Accuracy consists of bias (systematic error) and random error

NOTE 2 The true value is a value that would be obtained by a perfect measurement, thus true values cannot be determined and, consequently, accuracy is generally a hypothetical concept In specific cases a ‘true’ value of a sample might be derived from interlaboratory studies as the mean value of all participants This value should be regarded as a relative true value For the purpose of this standard, accuracy can also refer to the application of the correct biological name to an organism

3.2

bias

errors that are consistent rather than random in nature Average of an infinite number of measurements of the same measurand under the same conditions divided by the true value of the measurand

NOTE 1 As only a limited number of measurements can be performed bias can only be estimated

NOTE 2 Often referred to as ‘systematic error’

3.3

detection limit of discrete entities

minimum number and/or size of a specific taxon or group of organisms in a sample at which its presence can

be detected with a certain confidence

3.4

error

difference between an individual result and the average (random error)

3.5

fitness for purpose

extent to which the performance of a protocol matches the criteria that best describes the end-user's need

NOTE Fitness should normally be assessed by a validation study

3.6

metadata

summary information about data covering: how they were created, composition, limits of interpretation, quality

of data, ownership and availability

3.7

measurand

particular quantity subject to measurement

NOTE In biological investigations, this refers to the number of organisms in a sample or percentage of covering of macrophytes

3.8

performance characteristics

characteristics of a specific method or protocol, which encompass qualitative and quantitative aspects of data such as detection limit, repeatability, reproducibility, precision, uncertainty, bias, method sensitivity, measurement range, interference and recovery

3.9

phenology

study of changes in the morphology or physiology of organisms that occur over the course of a year in relation

to internal or external stimuli (e.g time of flowering in relation to climate)

3.10

precision

closeness of agreement between independent results obtained under the same conditions

NOTE Precision depends only on the distribution of random errors and does not relate to the true value or the specified value

3.11

quality

all the features and characteristics of a measurement result that bear on its ability to satisfy stated or implied needs

3.12

quality assurance

all those planned and systematic actions necessary to provide adequate confidence that a product will satisfy given requirements of quality

NOTE This includes AQC, audit, training, documentation of methods, calibration schedules, etc

3.13

quality control

operational techniques and activities that are used to fulfil requirements for quality

3.14

random error

3.16

reference collection

collection of live or preserved specimens, whose identities have been confirmed independently, that is accessible to an analyst to aid in the identification and analysis of ecological samples

NOTE A reference collection may also take the form of photographs or digital images

3.17

repeatbility (of results of measurement)

closeness of the agreement between the results of successive measurement of the same measurand carried out under the same conditions of measurement

3.18

reproducibility (of results of measurement)

closeness of the agreement between the results of measurement of the same measurand carried out under changed conditions of measurement (observer, time, location, instruments etc.)

3.19

statistical power

ability of a statistical procedure to distinguish a situation different from the null hypothesis (H0: no difference,

no effect or no change)

NOTE In statistical terms: statistical power = (1-β) in which β is the probability of failing to reject H0 when in fact H0 is false

3.20

taxon (pl taxa)

group of organisms related at a particular taxonomic level

3.21

taxonomic expert

individual recognised by his/her peers as having particular taxonomic skills or knowledge

3.22

taxonomic level

precision with which an organism is defined, for example family, genus or species

3.23

uncertainty

parameter associated with the result of a measurement that characterises the dispersion of the values that could reasonably be attributed to the measurand

NOTE Generally the parameter consists of a standard deviation For most purposes an expanded uncertainty should

be used obtained by multiplying the combined standard uncertainty by a coverage factor (k) For an approximate level of confidence of 95 %, k is 2 (n > 7, t-Statistics) The combined standard uncertainty is the result of a series of

measurements in which the contribution of all relevant sources of uncertainty (both random and systematic) are combined

3.24

validation (of a method)

confirmation, through the provision of objective evidence, that the requirements for a specific intended use or application are fulfilled

3.25

verification

confirmation of an identification, e.g by a qualified person or an independent expert

3.26

voucher specimen

sample of one or more taxa taken from a specific location at a specific time that is preserved in order to permit independent verification of their identity

4 Principle

The validity of biological and ecological investigations depends on the accuracy and precision of all activities involved in the collection and analysis of data Major variables include the characteristics of the taxonomic groups, the number of observations or measurements, their statistical distribution, the spatial or temporal representivity of samples, accuracy of identification guides, measuring devices or other methods, the skill of the surveyors or analysts in using these and the consistency of approach This standard gives a general framework for ensuring the quality of biological and ecological investigations of aquatic environments These procedures encompass study design, surveying and sampling, analysis and identification, validation, data interpretation and reporting, and training of personnel

5 Design of biological and ecological studies

5.1 General aspects

Biological and ecological assessments of aquatic environments should start with a clear statement of the qualitative and quantitative goals of the study Methods chosen should be “fit for purpose” and should take account of their statistical power, in order to ensure that necessary spatial and temporal resolution is achievable and cost-effective A written protocol for the method should be available

NOTE 1 Wherever possible, the method used should be derived from an International or European Standard

Biological and ecological analyses of aquatic environments should be performed within the context of

programmes that recognise the complexity of ecological systems, including temporal and spatial variability

Those aspects of temporal and spatial variation which should be incorporated in the sampling regime will be

determined by the objectives of the study Efforts should be made to minimise the impact of spatial and

temporal variation if they are no subjects of investigation

NOTE 2 In some cases, a pilot study may be necessary in order to optimise the design, justify the choice of method or

to provide an estimate of error and uncertainty appropriate to the system under study

5.2 Error assessment

Users of a method should be aware of all likely sources of error associated with that method As quantitative errors are additive (i.e can be combined by standard addition rules) any attempt to reduce errors is desirable Errors in identification may have an influence on the overall precision of a method, particularly when the error relates to a taxon that is abundant in a sample The relative contribution of each source to the total error should be assessed before the method is adopted Results from investigations should be accompanied by estimates or measurements of the major sources of error from sampling, sample preparation, sample analysis,