Microbiological Water Quality 

Guidelines for 

Marine and Freshwater Recreational Areas 
Published in June 2002 by the 

Ministry for the Environment 

Manatu Mo Te Taiao 

PO Box 10-362, Wellington, New Zealand 

Updated in June 2003 

ISBN: 0-478-24091-0 

ME number: 474 

This document is available under publications on the

Ministry for the Environment’s website:

www.mfe.govt.nz 
How to Use This Folder 

This folder is divided into three main parts:

• Part I gives the framework for monitoring recreational water quality 

• Part II provides the guideline values for marine, freshwater and shellfish gathering 

• Part III provides explanatory notes, which expand on the information given in Parts I and II, and give 

advice on how to implement the guidelines. 

Parts I and II are divided into sections, labelled A to F. Throughout these sections there are directions to the 

explanatory notes in Part III. Please follow up these directions if you need more information on a topic. 

Part III is divided into two sections, G and H, and provide notes on Parts I and II respectively.

The Appendices following Part III contain more extended pieces of additional information, including a 

programme for public education and awareness, and a description of the research background to how the 

guidelines have evolved.

A Glossary provides definitions for abbreviations and terms used in the guidelines, some of which are 

highly technical. 

For those readers wanting to access further information from documents referenced in these guidelines, the 

References and Further Reading contains a useful summary.

The structure of this folder enables the Ministry for the Environment and Ministry of Health to provide

updates on a regular basis. Please complete the form at the back to register your copy with the Ministry for 

the Environment. This will ensure updates are sent to the appropriate person within your organisation. 

Foreword

New Zealanders care about the quality of their 

waters. We want to swim and collect kai moana at 

our beaches and rivers without the risk of getting 

sick. Thousands of us use our beaches and rivers 

to swim, surf, sail, and collect kai moana, and we 

highly value the ability to do this. 

The Microbiological Water Quality Guidelines for 

Marine and Freshwater Recreational Areas

incorporate a risk-based approach to monitoring

water quality promoted by the World Health

Organization. The guidelines will provide 

councils with the information they need to monitor 

the state of their waters. 

These guidelines are the result of a wide 

consultative effort. Extensive consultation with

regional councils, territorial local authorities and

public health agencies since the release of the 1999 

guidelines resulted in the formation of a working 

group. The Ministry for the Environment and 

Ministry of Health have been working with this

group over the 2000–03 period to develop

guidance on public health monitoring and 

reporting, and state of the environment monitoring

and reporting.

We have deliberately formatted the guidelines so 

they can be easily revised without requiring a 

complete re-publication of the entire guidelines. If 

you would like to receive updates of these

guidelines, please complete and return the 

registration form at the back of the folder. You 

can also download the most up-to-date edition of

the guidelines from the publications area of the 

Ministry for the Environment’s website:

www.mfe.govt.nz. 

FOREWORD. 

v June 2003 
We would like to thank everyone who has been 

involved in the development of the guidelines and

acknowledge that without your input it would not 

have been possible. We look forward to your

continuing contribution in the future. 

Barry Carbon

Chief Executive 

Ministry for the Environment

Karen O Poutasi (Dr) 

Director-General of Health 

Ministry of Health

FOREWORD. 

vi June 2003 
Acknowledgements

This document has been produced and funded by

the Ministry for the Environment and the Ministry

of Health. We would like to thank the members of 

the Marine Bathing Working Group for their

contributions to the preparation of this document: 

Donald Campbell Healthcare Taranaki

Keith Hamill (formerly) Environment 

Southland 

Peter Hamill Marlborough District 

Council 

Sophie Heighway (formerly) North Shore 

City Council

Andrea Johnson Canterbury Crown Public 

Health

Erin Kearney Valley Health

Gillian Lewis Auckland Regional 

Forum

Shaun Lewis Earth matters 

Graham McBride NIWA

Adrian Meredith Environment Canterbury

Stephen Palmer Hutt Valley Health

Paul Prendergast Ministry of Health

Graham Sevicke-Jones Wellington Regional

Council 

Brian Sharman Metrowater

Rennae Shirley Auckland City Council 

Brett Stansfield Hawke’s Bay Regional 

Council 

Desmond Till Consultant

ACKNOWLEDGEMENTS. 

vii June 2003 
Contents 

Foreword v 

Acknowledgements vii 

Introduction 1 

How do these guidelines differ from previous ones? 1 

What is the aim of the guidelines? 2 

What is the status of these guidelines? 2 

What does this document cover? 2 

State of the environment reporting and links with the Environmental Performance Indicators Programme 3 

Conditions on the use of these guidelines 3 

Part I: The Framework for Monitoring Recreational Water Quality A1 

SECTION A: Why Monitor Water? A1 

A.1 Health risks A1 

A.2 State of the environment reporting A2 

SECTION B: Who Monitors and Reports? B1

B.1 Roles and responsibilities B1

B.2 Recommended framework for roles and responsibilities B1

B.3 Regional protocols B2

B.4 Abating the nuisance B3 

B.5 Legal implications B3

Part II: Guidelines for Recreational Water Quality C1

SECTION C: How Do We Develop Guideline Values? C1 

C.1 The overall approach C1 

C.2 The framework C2

SECTION D: Microbiological Guidelines for Marine Waters D1

D.1 Designation of a contact recreation area D1

D.2 Sampling beach water D1 

D.3 Grading a beach D2 

D.4 Monitored beaches: surveillance, alert and action modes D7

D.5 Marine bathing surveillance, alert and action levels D8

D.6 Conditions of using the guidelines D9 

CONTENTS. 

viii June 2003 
SECTION E: Microbiological Guidelines for Freshwaters E1

E.1 Designation of a contact recreation area E1 

E.2 Sampling rivers and lakes E1 

E.3 Grading a freshwater site E2

E.4 Monitored beaches: surveillance, alert and action modes E8

E.5 Freshwater surveillance, alert and action levels E8

E.6 Conditions of using the guidelines E10 

SECTION F: Microbiological Guidelines for Shellfish-Gathering Waters F1

F.1 The preferred indicator for waters used for shellfish gathering F1

F.2 Recreational shellfish-gathering guideline values F1

Part III: Explanatory Notes to the Guidelines G1

SECTION G: NOTES TO PART I: The Framework for Monitoring Recreational Water Quality G1

Note G(i): Respiratory illness G1

Note G(ii): Examples of health risks G2

Note G(iii): State of the Environment Reporting G3

Note G(iv): Pressure-State-Response model G3

Note G(v): Integrating public health and state of the environment data G4

Note G(vi): Merging with existing microbiological programmes G4 

Note G(vii): Different roles and responsibilities adopted around New Zealand G6

Note G(viii): The legislative basis for the Ministry’s recommendations G7

Note G(ix): Legal opinion on roles and responsibilities G9

Note G(x): The Annapolis Protocol G9 

SECTION H: NOTES TO PART II: Guidelines for Recreational Water Quality H1

Note H(i): Sampling times and periods H1

Note H(ii): Techniques for taking and analysing samples H3

Note H(iii): Establishing a Sanitary Inspection Category (SIC) H5

Note H(iv): Catchment Assessment Checklist (CAC) for marine recreational waters H7 

Note H(v): Microbiological Assessment Category (MAC) for marine recreational waters H12 

Note H(vi): Suitability for recreation grade for marine recreational waters H12

Note H(vii): Catchment Assessment Checklist for freshwater recreational areas H15

Note H(viii): Microbiological Assessment Category for freshwater recreational areas H19

Note H(ix): Suitability for recreation grade for freshwater recreational areas H20

Note H(x): Application of grades and single samples H21

Note H(xi): Interim grading H22 

Note H(xii): Modifying beach grades H22

Note H(xiii): Percentile guideline values for seawater (WHO 2001) and freshwater H24

Note H(xiv): Derivation of alert and action levels for seawater and freshwater H27 

Note H(xv): State of the environment analysis and reporting H27 

Note H(xvi): Reporting to the public H28

Note H(xvii): Management responses to exceedances for marine and freshwater H28 

CONTENTS. 

ix June 2003 
Section I: Appendices 

Appendix 1: Public Education and Awareness Programme Outline I1

Appendix 2: Developing the Guidelines I9 

Appendix 3: Signs I23 

Appendix 4: Case Study – Implementing the Marine and Freshwater Guidelines I25 

Appendix 5: Fact Sheets I31 

Abbreviations J1 

Glossary J2 

References and Further Reading J6

About the Ministry for the Environment J30

Registration Form J31

CONTENTS. 

x June 2003 
Tables 

Table D1: Microbiological Assessment Category definitions for marine waters D6 

Table D2: Suitability for recreation grade for marine sites D7

Table E1: Microbiological Assessment Category (MAC) definitions E6

Table E2: Suitability for Recreation Grade for freshwater sites E7

Table G1: Bathing-related illnesses, symptoms and pathogens, with relevant references G2

Table H1: Guideline values for microbiological quality of marine recreational waters H25

Table H2: Guideline values for microbiological quality of freshwater recreational waters H26

Table I1: Example of completed Catchment Assessment Checklist I26

Table I2: Example of a completed Catchment Assessment Checklist I28 

Figures 

Figure C1: Surveillance requirements for graded beaches C3 

Figure D1: Recreational water-quality decision tree D3

Figure E1: Recreational water-quality decision tree (duplicated) E3

Figure H1: Example of a proposed sampling strategy (marine waters) H2 

Figure H2: Sanitary Inspection Category flow chart for marine recreational waters H11

Figure H3: Sanitary Inspection Category for freshwater sites H19

CONTENTS. 

xi June 2003 

Introduction

New Zealand’s coastal waters are widely used for 

a range of recreational activities, such as bathing,

sailing, boating, various forms of surfing, water 

skiing, underwater diving and shellfish gathering. 

Maintaining and protecting the quality of this 

recreational water is therefore an important

environmental health and resource management

issue. 

How do these guidelines differ from 

previous ones? 

In the past, guidelines for assessing the public 

health risk of using recreational waters have been 

largely based on microbiological faecal indicator 

counts. The previous (1999) marine bathing 

guidelines (Recreational Water Quality 

Guidelines) were developed using the results of

international and New Zealand studies, and after 

consultation with regional and local environmental 

and health agencies. 

The guidelines presented here move away from the 

sole use of guideline values of faecal indicator 

bacteria, and instead use a combination of a 

qualitative risk grading of the catchment, 

supported by the direct measurement of

appropriate faecal indicators to assess the

suitability of a site for recreation. In addition, alert 

and action guideline levels are used for 

surveillance throughout the bathing season. 

The two components to providing a grading for an

individual beach are:

the Sanitary Inspection Category (SIC), which 

generates a measure of the susceptibility of a 

water body to faecal contamination 

• 

• historical microbiological results, which 

generate a Microbiological Assessment

Category (MAC), which provides a 

measurement of the actual water quality over 

time. 

INTRODUCTION.

1 June 2003 
These two combined give an overall Suitability for 

Recreation Grade (SFRG), which describes the 

general condition of a site at any given time, based

on both risk and indicator bacteria counts. This

grade helps to determine whether ongoing

monitoring is required, and provides the basis for 

telling people whether or not the water is suitable 

for recreational use, from a public health 

perspective. 

Throughout this document the term ‘beach’ 

refers to both marine and freshwater

recreational water sites.

What is the aim of the guidelines? 

The aim of these guidelines is to help water 

managers control the public health risk from

microbiological contamination in recreational

waters, and to provide for monitoring and 

reporting on the general health of beaches. The 

guidelines were designed to provide guidance to

water managers in implementing the Resource 

Management Act 1991 (RMA), and the Health Act 

1956 for shellfish – gathering or contact recreation.

A crucial part of this is ensuring that the public are 

informed of the health risks in time for them to

make informed decisions about whether to enter 

the water. The guidelines replace the previous 

Ministry for the Environment / Ministry of Health

Recreational Water Quality Guidelines published 

in November 1999. 

Guidance is provided for three categories of water 

use:

• 

• 

• • 

marine bathing and other contact recreation 

activities 

freshwater bathing and other contact recreation

activities 

recreational shellfish gathering in marine

waters (but not commercial shellfish 

harvesting). 

The Ministry for the Environment is specifically 

concerned with ensuring that the public has ready

access to regional or local authority water quality 

information on the potential health risks from

faecal contamination of recreational waters. The

guidelines should provide this. 

The guidelines also provide the monitoring

protocol for the state of the environment indicators 

“the percentage of monitored beaches in each 

beach grade”, and “the percentage of the season 

beaches or coastal areas were suitable for contact 

recreation or shellfish gathering”. 

What is the status of these 

guidelines? 

The guidelines have been developed over an

extensive period of consultation with regional and 

local councils and health authorities, and present a 

preferred approach to monitoring recreational 

waters. They are not legislated standards that must 

be adhered to at all times. 

What does this document cover? 

The guidelines cover the monitoring and 

interpretation of results from surveys for 

bacteriological indicators of faecal contamination 

in recreational waters. They do not cover other 

impacts on the above water uses, such as water 

clarity, chemical pollution, or marine biotoxins 

from algal blooms. The guidelines should not be

used as the basis for establishing conditions for

discharge consents, although they may be used as a 

component for decision making. 

Documents that may be of interest to anyone 

managing water for contact recreation include two 

produced by the Ministry for the Environment:

Water Quality Guidelines No 1, which covers

the management of biological growths in rivers 

used for swimming 

INTRODUCTION.

2 June 2003 
Water Quality Guidelines No 2, which covers

the management of water clarity for bathing in

freshwaters. 

• 

These guidelines take precedence over the 

ANZECC Water Quality Guidelines for Fresh and

Marine Water for microbiological water quality. 

Finally, visit the Ministry for the Environment’s 

website for further information on water-quality 

publications: www.mfe.govt.nz. 

State of the environment reporting 

and links with the Environmental 

Performance Indicators Programme 

These guidelines constitute the monitoring

protocol for recreational beaches in New Zealand. 

Although the focus of this document is on

monitoring recreational waters for public health

purposes, regional councils and the Ministry for 

the Environment also use this information to report 

on the state of the environment at a regional and 

national level. 

Indicators for recreational waters have been

developed through the Ministry’s Environmental

Performance Indicators (EPI) Programme, and will 

be reported nationally through the EPI website. 

These guidelines and the accompanying 

explanatory notes provide information on the data 

management relationship between the Ministry and

data providers, and contain guidance on data

transfer protocols. Links with other indicators are

also discussed. 

See Note G(iii) for discussion on the EPI 

programme. 

See Note G(v) for discussion on integrating state 

of the environment and public health programmes. 

Conditions on the use of these 

guidelines 

These guidelines have been prepared to support the 

management of bacteriological water quality for 

recreational use. These guidelines cannot be 

applied to water uses other than recreational use.

Guidance for wastewater discharges 

These guidelines cannot be directly used to 

determine water quality criteria for wastewater 

discharges because there is the potential for the 

relationship between indicators and pathogens to be 

altered by the treatment process. The relationship 

between indicator bacteria and disease-causing 

bacteria, viruses and protozoa in the discharge needs 

to be established.

The Ministry for the Environment has published the

Wastewater Monitoring Guidelines, which provide 

guidance on monitoring treated wastewater. 

Information on these guidelines is available on the 

Ministry’s website (www.mfe.govt.nz). Information

on the Sustainable Wastewater Management

Handbook for Smaller Communities is also available 

on the Ministry’s website. 

Applying the guidelines to water 

impacted by wastewater discharges 

These guidelines should not be directly applied to 

assess the microbiological quality of water that is 

impacted by a nearby point source discharge of

treated effluent without first confirming that they are 

appropriate. This is particularly important for 

disinfected effluent (Disinfection Review Group 

2002) and for waste stabilisation pond effluent

(Sinton et al 2002). It is important when planning

the location and degree of treatment for wastewater 

treatment plants to recognise that the guideline 

values are not necessarily a guarantee of safety. 

INTRODUCTION.

3 June 2003 
While it is correct to infer that water exceeding the 

guideline values poses an unacceptable health risk, 

the converse is not necessarily true. This is because 

effluent may be treated to a level where the indicator 

bacteria concentrations are very low, but pathogens 

such as viruses and protozoa may still be present at

substantial concentrations, effectively changing the 

indicator/pathogen ratio. 

To assess the microbiological quality of water that is 

impacted by a discharge of treated effluent, the 

relationship between indicator bacteria and key

pathogens (such as viruses and protozoa) must be 

established for that treatment.

This would require the generation of statistically 

robust data to establish that the treatment process 

produces an effluent that meets the guideline

indicator bacteria values, and is capable of 

destroying pathogenic micro-organisms. 

Treatment plants also require ongoing auditing and 

monitoring. Wastewater plants may not operate 

100% of the time (e.g. during high water flows) and 

the health status of the population at any given time 

affects the pathogens likely in wastewater. 

INTRODUCTION.

4 June 2003 
Part I:

The Framework for 

Monitoring Recreational 

Water Quality

SECTION A: 

Why Monitor Water? 

A.1 Health risks 

Water contaminated by human or animal excreta 

may contain a range of pathogenic (diseasecausing) micro-organisms, such as viruses,

bacteria and protozoa. These organisms may pose 

a health hazard when the water is used for 

recreational activities such as swimming and other 

high-contact water sports. In these activities there 

is a reasonable risk that water will be swallowed, 

inhaled (Harrington et al 1993), or come in contact 

with ears, nasal passages, mucous membranes or 

cuts in the skin, allowing pathogens to enter the 

body. 

Research is continuing into the health risks

associated with contamination of water by sewage

and excreta. Until recently scientists believed that 

gastro-enteritis was the main health effect, but it is 

now becoming clear that respiratory health effects 

are also important, and may even be more 

prevalent than gastro-enteritis. 

See Note G(i) for evidence on respiratory illness 

caused by water contamination.

In most cases the ill-health effects from exposure 

to contaminated water are minor and short-lived. 

However, there is the potential for more serious

diseases, such as hepatitis A, giardiasis, 

cryptosporidiosis, campylobacteriosis and 

salmonellosis (Philip 1991). 

Adhering to the guideline values and using the 

framework set out in this document should ensure 

that people using the water for recreation or

collecting shellfish for eating are informed of 

health risks, and can make appropriate decisions to

avoid exposing themselves to significant health

risks. 

Do these guidelines measure the level of pathogens 

in the water? In fact it is difficult and impractical 

PART I: THE FRAMEWORK FOR MONITORING

RECREATIONAL WATER QUALITY. 

June 2003 

A1
to do this directly. Instead, we measure the levels 

of ‘indicator’ micro-organisms, which indirectly

tell us about the levels of pathogens. The marine 

guidelines were developed from many studies 

relating bacteriological indicators to illness in the 

general public after bathing (see especially the 

WHO review by Prüss 1998). These studies 

include, but are not confined to, those carried out 

at seven New Zealand marine beaches in 1994–95

(McBride, Salmond, et al 1998). The freshwater 

guidelines were developed from the findings of the

Freshwater Microbiology Research Programme 

Report: Pathogen Occurrence and Human Health 

Risk Assessment Analysis, November 20021 

(McBride, et al 2002). 

The guidelines work with a defined ‘tolerable risk’ 

rather than no risk at all. For most healthy people 

water conforming to the guideline value will pose 

a minimal level of risk. However, water 

conforming to the guideline values may still pose a 

potential health risk to high-risk user groups such

as the very young, the elderly and those with 

impaired immune systems. 

See Note G(ii) for more information on health risks. 

A.2 State of the environment reporting 

Regional councils and the Ministry for the 

Environment have responsibilities under the RMA 

to monitor the state of the environment. Reporting 

on state is achieved regionally through state of the 

environment reports and nationally through

national state of the environment reporting. 

The purpose of state of the environment monitoring 

and reporting is to use environmental performance 

indicators (EPIs) to measure and monitor human 

activities and their effects on the environment. The 

Government’s objectives for the state of the 

environment monitoring and reporting are to: 

 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

1 A copy of the report can be downloaded from the Ministry for the 

Environment’s website www.mfe.govt.nz. 

systematically report on the state of New 

Zealand’s environmental assets 

systematically measure the performance of its 

environmental policies and legislation

better prioritise policy and improve 

environmental decision making. 

Over time, the information produced through

monitoring environmental performance indicators 

will: 

contribute to raising the level of knowledge

about the state of New Zealand’s environment 

increase our ability to report on environmental 

health and trends

provide the tools for effective evaluation of 

policy 

provide the information base for more 

informed policy and management decisions. 

This document serves as a monitoring protocol for

two confirmed indicators for human health and 

values for marine and freshwater environments:

the percentage of monitored beaches in each 

grade 

the percentage of the season beaches or coastal 

areas were suitable for contact recreation or 

shellfish gathering. 

‘Beaches’ refers to both marine and freshwater 

recreation sites. 

The national objectives of these indicators are to: 

quantify the human health risks at recreational 

water sites and shellfish-gathering areas 

measure the general state of recreational water 

areas 

report on the overall suitability of recreational 

water areas for bathing.

See Note G(iii) for more information on state of

the environment reporting.

PART I: THE FRAMEWORK FOR MONITORING

RECREATIONAL WATER QUALITY. 

June 2003 

A2
Integrating public health and state of the 

environment data

The purpose of the microbiological water quality 

guidelines for marine and freshwater recreational 

areas is to help control the public health risk from

microbiological contamination in recreational

waters and to provide a framework for monitoring

and reporting on the general health of beaches. 

Integrating the needs of both state of the 

environment and public health monitoring may

present some challenges, but it is achievable. 

Microbiological information is generated more

intensively to keep stock of short-term variation

that can affect the public health risk of water 

quality. This monitoring takes place on a weekly 

basis, although at times follow-up monitoring is 

required to identify the permanence of an

identified guideline exceedance. 

The purpose of state of the environment 

monitoring is to collect sufficient data to produce 

information on the general health of the 

environment. This information can then be used to 

measure how well our management practices, 

policies and laws are working, and whether

environmental outcomes are being achieved. The

beach grades generated through the combination of 

the catchment assessment and the microbiological 

assessment provide the state of the environment 

information to the public on the general condition

of the recreational area with respect to public 

health risk. The microbiological information 

collected to assess the public health risk at the 

beach on a weekly basis is aggregated over five 

years to generate the Microbiological Assessment 

Category that is used in the beach grading process. 

PART I: THE FRAMEWORK FOR MONITORING

RECREATIONAL WATER QUALITY. 

June 2003 

A3
SECTION B: 

Who Monitors and Reports? 

B.1 Roles and responsibilities 

The Microbiological Water Quality Guidelines for 

Marine and Freshwater Recreational Areas have

been developed for the agencies involved in the 

monitoring and reporting of recreational waters. 

This is primarily regional, territorial and unitary 

councils, District Health Boards and Medical

Officers of Health. 

During the development of this manual there was 

an overwhelming request from all those involved

in beach water-quality monitoring for guidance 

from the Ministry for the Environment and

Ministry of Health on the appropriate delegation of

roles and responsibilities for recreational beach

monitoring. Determining precisely which agency 

is responsible for which roles in monitoring and 

reporting beach water quality for public health

protection must be one of the first steps in

developing a sampling and reporting programme. 

Some regional, territorial and unitary councils 

have clearly defined these roles, basing their

decisions on council ‘ownership’ of the roles, and 

the available resources and areas of expertise. 

See Note G(vii) on different responsibility 

scenarios operating around the country. 

The following section outlines an approach for 

clarifying roles and responsibilities at the regional 

level by way of protocols, agreed to by the 

different agencies that have a role in monitoring 

and reporting recreational water quality. This

section also presents a recommended framework 

for the roles regional councils, territorial local 

authorities, unitary councils and health agencies 

will have with respect to recreational water-quality 

monitoring and reporting.

B.2 Recommended framework for roles 

and responsibilities 

The Ministry for the Environment and Ministry of

Health have agreed on the following recommended 

framework for roles and responsibilities in relation

to recreational waters. 

i. The regional council co-ordinates the 

monitoring and reporting strategy. 

ii. The regional council implements surveillance 

and alert-level monitoring. 

iii. The Medical Officer of Health reviews the 

effectiveness of the monitoring and reporting 

strategy. 

iv. The regional council informs the Medical 

Officer of Health and territorial authority if 

alert or action levels are reached. 

v. The Medical Officer of Health will ensure 

that the territorial authority is informed. 

vi. The territorial authority will inform the 

public when the action level is exceeded – the 

Medical Officer of Health will ensure the 

public is informed within agreed timeframes.

vii. If the action level is reached, the territorial 

authority will undertake nuisance monitoring

and cause all proper steps to be taken to abate 

or remove the nuisance. On occasion it may 

be more appropriate for the regional council 

to undertake this duty. The Medical Officer 

of Health will provide advice and ensure that 

proper steps are taken by the territorial local 

authorities and/or regional councils. 

viii. It is the responsibility of the Medical Officer 

of Health to ensure that sites with modified 

grades are audited in accordance with these 

guidelines. 

ix. The regional council will collate the 

information for state of the environment 

reporting and a review of management

policies. 

See Note G(viii) for the legislative basis for these 

recommendations. 

See Note H(xii) for an explanation of modified

beach grades. 

PART I: THE FRAMEWORK FOR MONITORING

RECREATIONAL WATER QUALITY. 

June 2003 

B1
The Medical Officer of Health has a lead 

role, given his/her responsibilities under the

Health Act, to ensure the proper steps are

taken by the territorial local authorities to 

protect public health. 

In some situations it may be more appropriate for 

the regional council to abate/remove the nuisance, 

as when the source of contamination has been

identified as being within its jurisdiction (e.g. 

discharges of farm dairy effluent). Although the 

guidelines advise investigation of the nuisance, 

they do not require that steps be undertaken to

remove it. However, taking proper steps to abate 

or remove the nuisance is a Health Act

requirement, and it is an RMA requirement to

remedy and mitigate, so removing the nuisance is a 

logical next step. 

A legal opinion on legislated roles and an outline 

of the current monitoring and reporting scenarios 

around the country provided the background for

the recommendation on roles and responsibilities. 

See Note G(ix) for details of the legal opinion. 

The Explanatory Notes also present a number of 

alternative roles and responsibilities frameworks 

that are applied by some councils around the 

country (see Note G(vii)). These illustrate that 

there are a range of options for ensuring that the 

public are able to make informed choices about 

their recreational activities. They are provided for 

agencies that do not have an effective roles and 

responsibilities framework in place and wish to use 

an alternative to the recommended framework. 

Regional councils, territorial authorities and health

authorities must decide what best suits their 

circumstances, taking into consideration what has 

previously proven to be successful. 

B.3 Regional protocols 

The Ministry for the Environment and Ministry of

Health recommend that local government and 

public health services develop regional protocols

that clearly identify a lead agency, which develops

a monitoring protocol that specifies the details of:

• 

• 

• 

• 

• 

 

the agreed roles and responsibilities protocol, 

including who is accountable2

how the programme will be implemented

what the management and communication/

education responses will be to exceedance

events. 

Each agency involved in the monitoring

programme should also be consulted to ensure 

there is agreement on how each site is assessed. 

These protocols should be based on the agencies’ 

respective legislative functions relating to

recreational water-quality monitoring and

reporting, with the aim of: 

reflecting and clarifying local/regional 

conditions and arrangements 

enhancing collaboration, operational

co-ordination and the performance of their

respective roles and responsibilities. 

Consideration must be given to the role of nonregulatory groups, such as community groups and 

or iwi. Interactions between communities, 

authorities and organisations are a key requirement 

in monitoring, reporting and resolving waterquality issues. 

2 At the time of writing, such protocols have been suggested for 

inclusion in the proposed Public Health Bill. The protocols 

outlined in the Bill relate to all matters of public health, of which 

recreational water quality is one. 

PART I: THE FRAMEWORK FOR MONITORING

RECREATIONAL WATER QUALITY. 

June 2003 

B2
When developing the protocols, consideration 

should be given to the expertise and resourcing

generally held within the regional councils, 

territorial local authorities and by the Medical 

Officers of Health. For example, Medical Officers

of Health have expertise in the implementation of

health regimes, and regional councils generally

have the technical expertise in water issues. 

These protocols should detail who is responsible

for each of the roles (i to ix) outlined in B.2, and 

copies should be held by each of the participating

agencies. Protocols may also be needed when 

reviewing an event, or to justify actions during an 

event. In extreme circumstances they may be 

necessary as supporting material for litigation.

B.4 Abating the nuisance

Investigating, identifying and remedying a 

nuisance should be based on the expertise within

the agencies and the functions of these agencies 

within their jurisdiction. How the problem is

mitigated is at the discretion of the council, 

although the course of action taken should meet 

the approval of the Medical Officer of Health. 

The guidelines do not specify that the cause of 

failure to meet the specified levels must be 

rectified. They merely require that the public is 

informed when beaches are not suitable for contact 

recreation. However, once a problem is identified,

many councils – and, indeed, the public – will

want it fixed. Some causes (e.g. broken sewers, 

illegal sewer–stormwater connections) are easier to

fix than others, but are still difficult. Aged 

stormwater systems and rural run-off will require 

long-term planning and solutions, and may never

be fully fixed. In these situations the territorial 

local authorities, regional councils and Medical 

Officer of Health may develop a strategy for

reducing or eliminating the problem. 

B.5 Legal implications 

Failure to notify the public of a known health risk, 

which then results in damage to members of the 

public, may lead to legal action being taken against 

the agency responsible (regional council, territorial 

local authority or Medical Officer of Health) by 

affected groups or individuals. 

All agencies involved in monitoring water quality 

should be aware of their legal obligation to protect 

the public health, and that failure to meet these 

obligations may result in legal action. Legal action

can be avoided by notifying the public as soon as a

health risk is identified.

PART I: THE FRAMEWORK FOR MONITORING

RECREATIONAL WATER QUALITY. 

June 2003 

B3
Part II:

Guidelines

for Recreational

Water Quality

SECTION C: 

How Do We Develop Guideline 

Values? 

C.1 The overall approach 

The principle of using guideline values is simple:

we measure the level of ‘faecal indicator 

organisms’, which do not necessarily cause disease 

themselves but signal the potential presence of

disease-causing organisms. Guideline values of

faecal indicator organisms such as enterococci 

have been used successfully for a long time in 

recreational waters. However, there are still 

questions about the effectiveness of this approach 

for monitoring and measuring water quality, and a 

number of environmental and physical factors may

influence the usefulness of faecal bacteria as

indicators. 

The main constraints to the approach used in

current guidelines are as follows: 

• 

• 

• 

 

Management actions are retrospective – they

can be deployed only after human exposure to

the hazard. 

While beaches may be designated as suitable or

unsuitable for recreational activities, there is in

fact a gradient of increasing severity, variety 

and frequency of health effects with increasing 

sewage pollution. It is therefore desirable to

promote incremental improvements or

prevention, prioritising ‘worst features’, to 

achieve cost-effective intervention. 

Although enterococci have been identified as 

having the best relationship with health effects 

in marine waters, they may also be derived

from other than faecal sources in some

conditions.3

3 Such conditions as sub-tropical temperatures and the influence of 

mangrove swamps and freshwater run-off from dense vegetation 

have been identified in parts of New Zealand.

PART II: GUIDELINES FOR RECREATIONAL

WATER QUALITY.

June 2003 

C1
• 

 

Many New Zealand recreational sites are at 

estuaries, where historical results from both

Escherichia coli (E. coli) (as the preferred 

indicator for freshwater faecal contamination) 

and enterococci are required for an assessment 

of health risk. 

Such constraints to the use of guideline values are 

not confined to New Zealand. In November 1998

a group of experts from the WHO, the 

Commission of the European Communities and the 

United States Environmental Protection Agency 

(USEPA) met in Annapolis, USA, to consider 

ways to address such anomalies and constraints. 

The experts agreed that an improved approach to

regulating recreational water that better reflected

health risk and provided enhanced scope for

effective management intervention was necessary 

– and feasible. The resulting approach has become

known as the ‘Annapolis Protocol’. Published in 

1999, it covers approaches involving both an

environmental hazard assessment and a 

microbiological water quality assessment. 

See Note G(x) for further details on the Annapolis

Protocol. 

The Ministry for the Environment responded by

establishing the Marine Bathing Working Group in

1999 as a consultation of interested parties to

investigate the application of an ‘Annapolis’ 

approach to New Zealand conditions. The 

approach has been modified after consultation and 

trial during the 2001 bathing season. It has also

been modified to incorporate updates from the 

WHO contained in their publications Bathing

Water Quality and Human Health: Protection of

the human environment water, sanitation and 

health (WHO 2001) and Guidelines for Safe 

Recreational Water Environments: Volume 1 

Coastal and Freshwaters4 (WHO 2003), and as 

such is incorporated as part of these guidelines. 

4 A copy of this report can be downloaded from the WHO website 

www.who.int. 

This approach has also been applied in the 

development of the freshwater guidelines, for 

which the Ministry for the Environment

established the Freshwater Guidelines Advisory 

Group. The freshwater guidelines were trialled

over the 2003 bathing season, and have been

updated in light of feedback. 

C.2 The framework 

The framework used in these guidelines is a 

combination of catchment risk grading and single 

samples to assess suitability for recreation. This is a 

move away from the sole use of quantitative 

‘guideline’ values of faecal indicator bacteria

towards a qualitative ranking of faecal loading in a 

recreational water environment, supported by direct 

measurement of appropriate faecal indicators. The 

framework is summarised in Figure C1. 

An explanation of all the features of this 

framework, including the Catchment Assessment

Checklist (used to derive the Sanitary Inspection

Category), the Microbiological Assessment

Category and the Sanitary Inspection Category, 

will be given when we look in Part II at setting out 

to grade a beach. For the moment we are focusing 

on the final result of this process – the Suitability 

for Recreation Beach Grade. 

This grade provides an indication of the general

condition of a beach. The risk of becoming sick 

from swimming at a beach increases as the beach 

grading shifts from Very Good to Very Poor. 

Conditions affecting water quality vary for the 

middle range of beach grades (Good, Fair and 

Poor). For example, ‘Good’ beaches usually 

comply with the guidelines, but events such as 

high rainfall increase the risk of contamination 

levels from run-off. 

Weekly monitoring should be carried out during

the bathing season for these middle-range beaches. 

For beaches where routine monitoring will be 

ongoing during the bathing season, the three-tier 

system applies, analogous to traffic lights: 

PART II: GUIDELINES FOR RECREATIONAL

WATER QUALITY.

June 2003 

C2
highly likely to be uncontaminated (green): 

‘suitable’ for bathing, but requiring water 

managers to continue surveillance (e.g. routine 

monitoring) 

• 

• 

• 

potentially contaminated (amber): 

‘potentially unsuitable’, requiring water 

managers to undertake further investigation to

assess the suitability for recreation

highly likely to be contaminated (red):

‘highly likely to be unsuitable’, requiring 

urgent action from water managers, such as 

public warnings. 

The public will be informed when swimming is 

not recommended: for the marine guidelines, when

two consecutive samples taken from the beach

exceed the action level of the microbiological 

water-quality guidelines; and for freshwater, when

one sample exceeds the action level. 

See Note H(i) for information on sampling times 

and periods. 

The grading process identifies sources of faecal 

contamination, such as sewer overflows caused by

heavy rainfall, which influence the final Suitability 

for Recreation Grade. Contamination events may 

be triggered by specific conditions (e.g. rainfall). 

Where monitoring agencies can predict such

contamination events, they may initiate 

management interventions to deter use of the site. 

Where these interventions can be demonstrated to 

be effective in discouraging use of the recreational 

site, the initial grade may be modified to reflect the 

usual water-quality conditions at that site. This is 

achieved by removing the source of the predictable 

exceedance events from the catchment assessment. 

See Note H(xii) for more information on modifying

beach grades. 

We will now go on to look at putting this 

monitoring, grading and public warning system

into practice. 

Such modification of a grade, achieved by

management practices, reflects the quality of water 

at the time of use. It does not alter the 

environmental conditions and microbiological data 

governing the initial grading.

Assessment of microbiological

data (optimum five years’ data –

100 data points or greater)

Application of the

Catchment Assessment

Checklist

Microbiological Assessment

Category

Sanitary Inspection

Category

Suitability for Recreation Beach Grade

Very Good Good Fair Poor Very Poor

Weekly surveillance and

reporting during bathing

season

Figure C1: Surveillance requirements for graded beaches 

Source: Modified from WHO, 2003.

PART II: GUIDELINES FOR RECREATIONAL

WATER QUALITY.

June 2003 

C3

SECTION D: 

Microbiological Guidelines for 

Marine Waters 

The framework in these guidelines uses both beach 

grading and guideline values. Beach grades

provide the basic means to assess suitability for 

recreation over time, using a combination of

knowledge of beach catchment characteristics and 

microbiological information gathered over 

previous years. Single sample results are 

compared against guideline values, to help water 

managers determine when management

intervention is required. The guideline values that 

have been decided on are summarised in D.5.

D.1 Designation of a contact 

recreation area 

People are generally free to swim wherever they 

like around New Zealand’s many beaches, but it

would be impossible to monitor them all. Criteria 

for identifying which beaches to monitor will vary 

from region to region, but will generally be based

on usage, available information and the resources 

available to the monitoring authority. The 

Ministry for the Environment and Ministry of

Health recommend that the beaches to be included 

in the monitoring programme be agreed by all

agencies involved in the programme and 

documented in the regional protocol. 

D.2 Sampling beach water

The following information is provided to help

develop a sampling programme for monitoring 

beaches. 

Sampling period

Samples should be collected during the bathing

season, or when the water body is used for contact

recreation. The bathing season will vary according

to location, but will generally extend from

1 November to 31 March. Sampling should take 

place between 8 am and 6 pm. 

See Note H(i) for details on sampling times and

periods. 

Bacteriological indicators, catchment 

assessment and single samples 

For marine water the preferred indicator is 

enterococci. The New Zealand Marine Bathing 

Study showed that enterococci are the indicator 

most closely correlated with health effects in New 

Zealand marine waters, confirming a pattern seen 

in a number of overseas studies (as reviewed by

Prüss 1998). Faecal coliforms and E. coli were not

as well correlated with health risks, although they 

may be used as an indicator in addition to

enterococci in environmental conditions where 

enterococci levels alone may be misleading.5

 (See

Appendix 2 for a detailed report on the 

development of indicators internationally.) 

E. coli rather than enterococci should be used as an 

indicator wherever the primary source of faecal 

contamination is a waste stabilisation pond (WSP). 

Enterococci are damaged in WSPs (Davies-Colley 

et al 1999), whereas faecal coliforms that emerge

from a pond appear to be more sunlight resistant

than those that enter it (Sinton et al 1999). Thus

WSP enterococci are inactivated in receiving water 

faster than WSP faecal coliforms (Sinton et al

2002). 

 

5 Estuarine and brackish waters may require a combination of both 

indicators, identified through the catchment assessment. 

PART II: GUIDELINES FOR RECREATIONAL

WATER QUALITY.

June 2003 

D1
Type of sampling programme 

The guidelines recommend a systematic randomsampling regime. Generally this means samples 

should be collected weekly, regardless of the 

weather. There may be exceptions if conditions

present a health and safety hazard, in which case 

samples should be collected as soon after the 

programmed time as possible. 

Sampling depth

Samples should be collected at approximately 

15 cm below the surface at a point where the depth 

of the water is approximately 0.5 metres (based on

data in McBride, Salmond, et al 1998).

See Note H(ii) for techniques for taking and

analysing samples. 

D.3 Grading a beach 

The results obtained from weekly sampling under 

a monitoring programme are only one aspect of the 

process. We also need to grade the beach we are 

monitoring. There are two components to grading 

beaches: 

the Sanitary Inspection Category (SIC), which 

generates a measure of the susceptibility of a 

water body to faecal contamination 

• 

• historical microbiological results, which 

generate a Microbiological Assessment

Category (MAC). This provides a

measurement of the actual water quality over 

time. 

The two combined give an overall Suitability for 

Recreation Grade (SFRG), which describes the 

general condition of a site at any given time, based

on both risk and indicator bacteria counts. The 

SIC, MAC and SFRG are explained below. 

Note: Whereas before the guidelines were not 

applicable where a beach received treated sewage, 

the grading system now allows an assessment of

the health risk present at a beach (via the Sanitary 

Inspection Category) after evaluating the 

effectiveness of the treatment processes. 

Assessing a beach 

The recreational water-quality decision tree 

(Figure D1) outlines the process that will lead to 

grading a beach. All beaches will have to go 

through this process, which helps to identify the 

information needed in order to grade a site. 

Collecting background information

As much information as is feasible about the site 

should be collected to make the assessment of riskcontributing factors as accurate as possible. 

Sources of information will vary from region to

region. Gathering this information may involve a 

range of agencies (health, water and sewerage 

industries; district, city, regional councils), which

will have access to different information for the 

same beach catchment. Relevant information 

includes drainage plans, site maps, previous

season’s monitoring results, and consent 

applications. 

The purpose of the decision tree is to provide a 

logical course that allows the responsible authority 

to make defensible decisions on whether or not to

grade a particular water body. 

PART II: GUIDELINES FOR RECREATIONAL

WATER QUALITY.

June 2003 

D2
Step 1

Is the water

body used for

contact

recreation?

Complete

Catchment

Assessment

Checklist

(CAC)

Step 2

Are catchment

risk factors

present?

Step 3

Is there a

wastewater

treatment plant

present?

Step 6: Determining a Grade

Microbiological Assessment Category (MAC); Sanitary Inspection Category (SIC);

Establish grading from Suitability for Recreation Grade (SFRG) table

Yes

Yes

Yes

Are there

reasons for

grading this

beach?

Low risk ungraded

(Reassess in five years or when change occurs)

Ungraded

No (Reassess if usage changes)

No No

No

Yes

No Step 5

Can you collect

microbiological

data?

No Potential risk ungraded

(Interim period agreed by TLA, RC, Health)

Yes

Step 8: Reassessment

Reassess regularly

Yes

Step 4

Is there existing

microbiological

data (five years’

data)?

Yes

Step 7:

Modify grade to reflect conditions when

people are swimming

No

Are there

strategies that

effectively discourage

people from bathing

during periods of

high risk?

Modifying a beach

grade is a management

option, applicable when

requirements in these

guidelines are met

Figure D1: Recreational water-quality decision tree 

PART II: GUIDELINES FOR RECREATIONAL

WATER QUALITY.

June 2003 

D3
The following notes describe the process and 

decisions required to complete each of the steps 

described in Figure D1. 

Step 1: Is the water body used for contact 

recreation? 

Beaches are considered either contact recreation 

areas (well used) or not contact recreation areas 

(not well used). The guidelines apply to contact 

recreation areas, and involve grading and 

monitoring. 

This does not mean water quality can be

allowed to deteriorate at ungraded beaches. 

Rather, it is expected that the guidelines will be

rigorously applied at graded beaches, while the 

monitoring required and associated costs may 

not be justified at ungraded beaches. 

Which beaches are monitored will be a local 

decision, and should be decided on a sitespecific basis by the local authorities (regional 

or local authority, or Medical Officer of Health) 

depending on the local relevance of the site.

Step 2: Are catchment risk factors 

present?

The ‘risk factors’ refer to activities in the 

catchment that may result in faecal 

contamination of a recreational water site. To

assess the catchment risk factors, the Catchment 

Assessment Checklist should be completed.

See Note H(iv) for the Catchment Assessment

Checklist for marine recreational waters. 

‘Yes’ responses to the ‘Microbiological Hazards’ 

(Part D) section of the checklist show the 

presence of catchment risk factors that affect, or 

are likely to affect, recreational water quality. 

Step 3: Is there a wastewater treatment 

plant present?

Wastewater treatment processes often effectively 

reduce microbial indicators such as enterococci but 

are less effective at removing pathogens such as 

viruses. The result may be an altered pathogen-toindicator ratio compared to that of untreated waste. 

This means that if there is a wastewater treatment

plant present, pathogens may still be present even 

when indicator levels are very low.

See Note H(iii) for Catchment Assessment

Checklist Base Conditions – discussion on risk 

assessment for tertiary treated effluent. 

A ‘Yes’ answer in this box means the 

wastewater treatment plant discharges directly 

to the recreational water, or to an area where 

discharge water may reasonably be expected to

be carried to a recreational water site by tides, 

currents or streams. 

Step 4: Is there existing microbiological

data?

Ideally there should be 100 data points

6

 or 

greater collected over the previous five years,

although it is feasible to consider grading with a 

minimum of 20 data points collected over one

full bathing season. The data should normally

be on enterococci. The grading should be

considered as interim until five years of data 

have been collected. 

Note: Follow-up samples from an alert or

action mode response should not be included in

the data used to generate an MAC (see Step 6). 

If using the software provided by the Ministry

for the Environment to generate grades, followup samples should be manually removed from 

the dataset. 

See Note H(xv) for details on the software 

available to analyse results. 

 

6 Data points are the results of samples collected. 

PART II: GUIDELINES FOR RECREATIONAL

WATER QUALITY.

June 2003 

D4
Step 5: Can you collect microbiological 

data?

If microbiological data is required, the sampling 

programme should collect at least 20 data points

over the period of greatest recreational use. 

This will normally be the summer bathing 

season, but may vary with the types of

recreational activity most common in the area. 

Step 6: Determining a grade 

In order to grade a recreational water body, the 

authority must establish:

• 

• 

the Microbiological Assessment Category

(MAC): an MAC category (ranging from A 

to D) is established from the existing or 

collected microbiological data; definitions

for the different categories are given in

Table D1. 

the Sanitary Inspection Category (SIC): this 

category is either Very High, High, 

Moderate, Low or Very Low, and is

determined for a specific water body by 

using the SIC flow chart.

See Note H(iv) for the Sanitary Inspection

Category flow chart for marine waters. 

The information for using the flow chart should 

come from the Catchment Assessment Checklist 

(CAC), Part D, and may require further

investigation to establish the principal source of 

contamination.

Determining a grade involves using both the 

MAC and the SIC (see Table D2). A grade is 

established on the basis of five years’ data. 

Thereafter recalculation of the grade may be done 

annually using the previous five years’ data. 

Step 7: Modifying a grade 

Modifying a beach grade is a management 

option, applicable when requirements in these 

guidelines have been met.

Beach grades may be modified where 

management interventions can be demonstrated 

to effectively discourage recreational use during 

occasional and predictable contamination 

events. The modified grade should reflect the 

water – quality conditions the public are usually 

exposed to, and be verified by the Medical

Officer of Health. 

See Note H(xii) for more information on

modifying beach grades.

Step 8: Reassessment

Reassess on a five-yearly basis, or sooner if

significant change occurs. Such changes will be 

reflected in new information in parts A, B, C 

and D of the Catchment Assessment Checklist. 

Examples of significant change would be:

• altered catchment characteristics or land use

• 

• 

significantly higher or lower microbiological

indicator levels

major infrastructure works affecting waterquality parameters. 

Beaches graded Very Good will almost always 

comply with the guideline values for recreation, 

and there are few sources of faecal 

contamination in the catchment. Consequently

there is a low risk of illness from bathing. 

Beaches graded Very Poor are in catchments 

with significant sources of faecal contamination, 

and they rarely pass the guidelines. The risk of 

illness from bathing at these beaches is high, 

and swimming is not recommended. For the

remaining beaches (Good, Fair and Poor) it is 

recommended that weekly monitoring be carried

out during the bathing season. The public will 

be informed when guideline values are 

exceeded and swimming is not recommended. 

The following table lists the criteria that define

the Microbiological Assessment Category 

(MAC), based on five years’ historical data.

PART II: GUIDELINES FOR RECREATIONAL

WATER QUALITY.

June 2003 

D5
Table D1: Microbiological Assessment Category definitions for marine waters 

A Sample 95 percentile ≤ 40 enterococci/100 mL 

B Sample 95 percentile 41–200 enterococci/100 mL

C Sample 95 percentile 201–500 enterococci/100 mL

D Sample 95 percentile > 500 enterococci/100 mL

Source: WHO 2001.

Note: The Hazen method is used for calculating the 95 percentiles.7

 

7 It is important to note there are several ways to calculate percentiles. 

Each uses a different formula, generating different results. The Hazen 

method has been chosen for these guidelines, as it tends to be about 

the ‘middle’ of all the options.

See Note H(v) for more information on the 

Microbiological Assessment Category for marine

recreational waters. 

The Sanitary Inspection Category (SIC) 

The SIC allows the principal microbiological

contamination from faecal sources to be identified 

and assigns a category according to risk. This 

category is then combined with the 

Microbiological Assessment Category (MAC) to

determine a Suitability for Recreation Grade for 

each site in the programme. 

Sources of human faecal contamination identified 

by the SIC may, as a result of treatment, be 

considered of low public health risk. There may, 

however, still be cultural or aesthetic objections to 

such faecal contamination. 

This category is either Very High, High, Moderate, 

Low or Very Low, and is found for a specific 

water body by use of the SIC flow chart. The 

information for using the flow chart should come

from Part D of the Catchment Assessment 

Checklist (CAC) and may require further

investigation to establish the principal source of 

contamination.

See Note H(iii) for details on how to establish a

Sanitary Inspection Category. 

Suitability for Recreation Grade (SFRG) 

SFRGs are Very Good, Good, Fair, Poor, and Very

Poor. To find the appropriate grading for the

recreational water body, locate the box in the

Suitability for Recreation Grade in Table D2 that 

coincides with both the MAC and SIC for the 

water body. 

PART II: GUIDELINES FOR RECREATIONAL

WATER QUALITY.

June 2003 

D6
Table D2: Suitability for recreation grade for marine sites 

Microbiological Assessment Category 

Indicator counts (as percentiles – see Table D1) 

Susceptibility to faecal 

influence 

A

≤ 40 enterococci/ 

100 mL

B

41–200 enterococci/ 

100 mL

C

201–500 enterococci/ 

100 mL

D

> 500 enterococci/ 

100 mL

Exceptional 

circumstances 

*** 

Very Low Very Good Very Good Follow Up** Follow Up**

Low Very Good Good Fair Follow Up** 

Moderate Follow Up* Good Fair Poor

High Follow Up* Follow Up* Poor Very Poor

Sanitary 

Inspection 

Category

Very High Follow Up* Follow Up* Follow Up* Very Poor 

Exceptional circumstances 

Notes 

* Indicates unexpected results requiring investigation (reassess SIC and MAC). If after reassessment the SFRG is still ‘follow up’, then 

assign a conservative grade (i.e. the first grade to the right of the ‘follow up’ in the same SIC row). This follows the precautionary

principle applied in public health. 

** Implies non-sewage sources of indicators, and this should be verified. If after verification the SFRG is still ‘follow up’, then assign a 

conservative grade (i.e. the first grade after ‘follow up’ in the same MAC column). 

*** Exceptional circumstances: relate to known periods of higher risk for a graded beach, such as during a sewer rupture or an outbreak of 

a potentially waterborne pathogen in the community of the recreational area catchment. Under such circumstances a grading would 

not apply until the episode has abated. 

(For example: if MAC = C and SIC = Moderate, then Suitability for Recreation Grade = Fair.)

See Note H(vi) for more information on the 

Suitability for Recreation Grade for marine

recreational waters. 

See Note H(xiii) for percentile guideline values for 

seawater. 

See Note H(xv) for information on software to use 

for grading beaches.

D.4 Monitored beaches: surveillance, alert 

and action modes 

So far we have looked at deciding which beaches 

to grade, and how to monitor a beach by taking

samples. Next we need to look at putting these 

together in a process to manage the different

scenarios that may arise. 

These guidelines propose a three-tier management

framework based on bacteriological indicator

values: 

i. surveillance – involves routine (e.g. weekly) 

sampling of bacteriological levels

ii. alert – requires investigation of the causes of 

the elevated levels and increased sampling to

enable the risks to bathers to be more 

accurately assessed 

iii. action – requires the local authority and

health authorities to warn the public that the 

beach is considered unsuitable for recreation. 

Surveillance (routine monitoring) 

Under the surveillance condition, beaches graded 

Good, Fair or Poor have the potential to be 

affected by faecal contamination events, and 

routine monitoring (e.g. weekly sampling) must 

continue (see Box 1). Guidance on when and 

where to sample can be found in section D.2, with

further information in Note H(i). 

PART II: GUIDELINES FOR RECREATIONAL

WATER QUALITY.

June 2003 

D7
Alert (amber) mode: single samples

The alert mode is triggered when a single 

bacteriological sample exceeds a predetermined 

value. Under alert mode, sampling frequency

should be increased to daily, and catchment

assessment data referred to for potential faecal 

sources. A sanitary survey should then be 

undertaken to positively identify the sources of 

contamination and the potential management

options. 

See Note H(iv) for the Sanitary Inspection

Category flow chart for marine recreational

waters. 

Action (red) mode: consecutive samples 

The action mode is triggered when two

consecutive single samples (within 24 hours) 

exceed a pre-determined value (see Box 1 for 

guideline values). Under the action mode, the 

local authority and health authorities warn the 

public, using appropriate methods, that the beach 

is unsuitable for recreation and arrange for the 

local authority to erect signs at the beach warning 

the public of a health danger. 

See Note H(xvi) for information on reporting to the 

public. 

See Note H(xvii) for management responses to

exceedances. 

D.5 Marine bathing surveillance, alert 

and action levels 

The marine bathing guidelines are summarised in

Box 1 . They are based on keeping illness risks 

associated with recreational water use to less than

about 2%. 

See Appendix 2 for details on how guideline values 

have been developed.

PART II: GUIDELINES FOR RECREATIONAL

WATER QUALITY.

June 2003 

D8
Box 1: 

Surveillance, alert and action levels for marine waters 

Surveillance/Green Mode: No single sample greater than 140 enterococci/100 mL. 

• Continue routine (e.g. weekly) monitoring.

Alert/Amber Mode: Single sample greater than 140 enterococci/100 mL.

• Increase sampling to daily (initial samples will be used to confirm if a problem exists). 

• Consult the CAC to assist in identifying possible sources.

• Undertake a sanitary survey, and identify sources of contamination.

Action/Red Mode: Two consecutive single samples (resample within 24 hours of receiving the first sample 

results, or as soon as is practicable) greater than 280 enterococci/100 mL. 

• Increase sampling to daily (initial samples will be used to confirm if a problem exists). 

• Consult the CAC to assist in identifying possible sources.

• Undertake a sanitary survey, and identify sources of contamination.

• Erect warning signs. 

• Inform public through the media that a public health problem exists.

Notes: Either of the following methods may be used to enumerate enterococci: EnterolertTM or EPA Method 1600.* For national consistency

it is recommended that accredited laboratories be used for microbiological tests (e.g. IANZ accreditation). Samples to test compliance 

should be over the bathing season appropriate to that locality (at least 1 November to 31 March) and sampling times should be restricted to 

between 0800 hours and 1800 hours.

* USEPA National Centre for Environmental Publications and Information (NCEPI), 11029 Kenwood Road, Cincinnati, OH45242, USA.

D.6 Conditions of using the guidelines 

• 

• 

• 

• 

These guidelines must not be used as a measure 

of suitability for recreation when there is a 

major outbreak of a potentially waterborne 

disease in the community, and that 

community’s sewage contributes to the 

microbiological contamination to the water. 

Such conditions constitute ‘exceptional

circumstances’. The guidelines do not apply

then because the relationship between indicator 

organisms and disease was derived when there 

were no known outbreaks of waterborne 

diseases in the community. When there is such

an outbreak, health risks may be increased 

because of a higher-than-usual ratio of pathogen 

concentration to indicators in the water. 

Implementing the guidelines emphasises the 

need and importance for traditional sanitary 

surveys, i.e. a catchment assessment. 

Compliance with the guidelines generally

indicates that a beach is suitable for 

recreation. There are exceptions however. 

For example, effluent may be treated to a 

level where the indicator bacterial levels are 

very low, but other pathogens such as viruses 

or protozoa may still be present at high levels. 

The assessment of such conditions should be 

considered during the procedure for grading a 

beach. 

It is important that water managers use these 

guidelines judiciously, and carefully

consider where they can be applied. 

These guidelines are not intended to be used as 

the basis for establishing conditions for 

discharge consents, although they may be used 

as a component for decision making. See the 

introduction of these guidelines for discussion

on what this document covers.

PART II: GUIDELINES FOR RECREATIONAL

WATER QUALITY.

June 2003 

D9

SECTION E: 

Microbiological Guidelines for 

Freshwaters 

The framework in these guidelines uses both

beach grading and guideline values. Beach 

grades provide the basic means to assess

suitability for recreation over time, using a 

combination of knowledge of beach catchment 

characteristics and microbiological information 

gathered over previous years. Single-sample 

results are compared against guideline values, to

help water managers determine when

management intervention is required. The 

guideline values that have been decided on are 

summarised in E.5. 

Throughout this document the term 

‘beach’ refers to both marine and

freshwater recreational water sites.

E.1 Designation of a contact 

recreation area 

People are generally free to swim wherever they 

like around New Zealand’s many beaches, but it

would be impossible to monitor them all. 

Criteria for identifying which beaches to 

monitor will vary from region to region, but will 

generally be based on usage, available 

information and the resources available to the 

monitoring authority. The Ministry for the 

Environment and Ministry of Health

recommend that the beaches to be included in 

the monitoring programme be agreed by all 

agencies involved in the programme and 

documented in the regional protocol. 

E.2 Sampling rivers and lakes 

The following information is provided to help

develop a sampling programme for monitoring 

rivers and beaches. 

Sampling period

Samples should be collected during the bathing

season, or when the water body is used for 

contact recreation. For rivers this may exclude 

periods of high flow, during which hazardous 

river conditions would prohibit bathing. The 

bathing season will vary according to location, 

but will generally extend from 1 November to

31 March. Sampling should take place between

8 am and 6 pm. 

See Note H(i) for details on sampling times and

periods. 

Bacteriological indicators, catchment 

assessment and single samples 

The pathogens occurring in contaminated 

freshwater are the same as those occurring in

marine waters, except that survival times in 

freshwater are likely to be longer, especially for 

protozoan cysts (e.g. Giardia and 

Cryptosporidium) and viruses. E. coli is the 

preferred indicator organism for freshwaters,

although there may be exceptions (e.g. in 

proximity to large waste stabilisation pond 

outfalls). Enterococci should not be used

because some enterococci can multiply from

natural sources, such as the decay of leaf 

material. This means that enterococci levels can 

be very high even in pristine waters, but this 

may not necessarily indicate high levels of 

pathogens. 

Type of sampling programme 

The guidelines recommend a systematic 

random-sampling regime. Generally this means 

samples should be collected weekly, regardless 

of the weather. There may be exceptions if 

conditions present a health and safety hazard, in

which case samples should be collected as soon

after the programmed time as possible. 

PART II: GUIDELINES FOR RECREATIONAL

WATER QUALITY.

June 2003 

E1
Sampling depth

Samples should be taken at approximately

30 cm below the surface, where the depth of the

water is approximately 1 metre. 

See note H(ii) for techniques for taking and 

analysing samples. 

E.3 Grading a freshwater site 

The results we obtain from microbiological 

sampling under a monitoring programme are 

only one aspect of the process. We also need to

grade the site we are monitoring. There are two 

components to grading freshwater sites:

the Sanitary Inspection Category (SIC),

which generates a measure of the 

susceptibility of a water body to faecal 

contamination 

• 

• historical microbiological results, which 

generate a Microbiological Assessment

Category (MAC). This provides a

measurement of the actual water quality over 

time. 

The two combined give an overall Suitability for 

Recreation Grade (SFRG), which describes the 

general condition of a site at any given time, 

based on both risk and indicator bacteria counts. 

The SIC, MAC and SFRG are explained below. 

Note: Whereas before the guidelines were not 

applicable where a site received treated sewage, 

the grading system now allows an assessment of

the health risk present at a site after evaluating 

the effectiveness of the treatment processes. 

Assessing a freshwater site

The recreational water-quality decision tree 

(Figure E1) and accompanying descriptions

outline the process that will lead to grading a 

site. All freshwater sites will have to go

through this process, which helps to identify the 

information needed in order to grade a site. 

Collecting background information

As much information as is feasible about the 

site should be collected to make the assessment 

of risk-contributing factors as accurate as 

possible. Sources of information will vary from

region to region. Gathering this information

may involve a range of agencies (health, water 

and sewerage industries; district, city, regional 

councils), which will have access to different

information for the same site catchment. 

Relevant information includes drainage plans, 

site maps, previous season’s monitoring results, 

and consent applications. The purpose of the 

decision tree is to provide a logical course that 

allows the responsible authority to make

defensible decisions on whether or not to grade 

a particular water body. 

The following notes describe the process and 

decisions required to complete each of the steps 

described in Figure E1. 

PART II: GUIDELINES FOR RECREATIONAL

WATER QUALITY.

June 2003 

E2
Step 1

Is the water

body used for

contact

recreation?

Complete

Catchment

Assessment

Checklist

(CAC)

Step 2

Are catchment

risk factors

present?

Step 3

Is there a

wastewater

treatment plant

present?

Step 6: Determining a Grade

Microbiological Assessment Category (MAC); Sanitary Inspection Category (SIC);

Establish grading from Suitability for Recreation Grade (SFRG) table

Yes

Yes

Yes

Are there

reasons for

grading this

beach?

Low risk ungraded

(Reassess in five years or when change occurs)

Ungraded

No (Reassess if usage changes)

No No

No

Yes

No Step 5

Can you collect

microbiological

data?

No Potential risk ungraded

(Interim period agreed by TLA, RC, Health)

Yes

Step 8: Reassessment

Reassess regularly

Yes

Step 4

Is there existing

microbiological

data (five years’

data)?

Yes

Step 7:

Modify grade to reflect conditions when

people are swimming

No

Are there

strategies that

effectively discourage

people from bathing

during periods of

high risk?

Modifying a beach

grade is a management

option, applicable when

requirements in these

guidelines are met

Figure E1: Recreational water-quality decision tree (duplicated) 

PART II: GUIDELINES FOR RECREATIONAL

WATER QUALITY.

June 2003 

E3
Step 1: Is the water body used for contact 

recreation? 

Beaches are considered either contact recreation 

areas (well used) or not contact recreation areas 

(not well used). The guidelines apply to contact 

recreation areas, and involve grading and 

monitoring. 

This does not mean water quality can be

allowed to deteriorate at ungraded beaches. 

Rather, it is expected that the guidelines will be

rigorously applied at graded beaches, while the 

monitoring required and associated costs may 

not be justified at ungraded beaches. 

Which beaches are monitored will be a local 

decision, and should be decided on a sitespecific basis by the local authorities (regional 

or local authority, or Medical Officer of Health) 

depending on the local relevance of the site.

Step 2: Are catchment risk factors 

present?

The ‘risk factors’ refer to activities in the 

catchment that may result in faecal 

contamination of a recreational water site. To

assess the catchment risk factors, the Catchment 

Assessment Checklist should be completed.

See Note H(vii) for the Catchment Assessment

Checklist for freshwater recreational areas. 

‘Yes’ responses to the ‘Microbiological Hazards’ 

(Part D) section of the checklist show the 

presence of catchment risk factors that affect, or 

are likely to affect, recreational water quality. 

Step 3: Is there a wastewater treatment 

plant present?

Wastewater treatment processes often effectively 

reduce microbial indicators such as enterococci but 

are less effective at removing pathogens such as 

viruses. The result may be an altered pathogen-toindicator ratio compared to that of untreated waste. 

This means that if there is a wastewater treatment

plant present, pathogens may still be present even 

when indicator levels are very low.

See Note H(iii) for Catchment Assessment

Checklist Base Conditions – discussion on risk 

assessment for tertiary treated effluent. 

A ‘Yes’ answer in this box means the wastewater 

treatment plant discharges directly to the

recreational water, or to an area where discharge 

water may reasonably be expected to be carried to a 

recreational water site by tides, currents or streams. 

Step 4: Is there existing microbiological

data?

Ideally there should be 100 data points

8

 or greater 

collected over the previous five years, although it

is feasible to consider grading with a minimum of 

20 data points collected over one full bathing 

season. The data should normally be on E. coli. 

The grading should be considered as interim until

five years of data have been collected. 

Note: Follow-up samples from an alert or

action mode response should not be included in

the data used to generate an MAC (see Step 6). 

If using the software provided by the Ministry

for the Environment to generate grades, followup samples should be manually removed from 

the dataset. 

See Note H(xv) for information on the software 

available to analyse results.

 

8 Data points are the results of samples collected. 

PART II: GUIDELINES FOR RECREATIONAL

WATER QUALITY.

June 2003 

E4
Step 5: Can you collect microbiological data?

If microbiological data is required, the sampling 

programme should collect at least 20 data points

over the period of greatest recreational use. 

This will normally be the summer bathing 

season, but may vary with the types of

recreational activity most common in the area. 

Step 6: Determining a grade 

In order to grade a recreational water body, the 

authority must establish:

• 

• 

the Microbiological Assessment Category

(MAC): an MAC category (ranging from A 

to D) is established from the existing or 

collected microbiological data; definitions

for the different categories are given in

Table E1. 

the Sanitary Inspection Category (SIC): this 

category is either Very High, High, 

Moderate, Low or Very Low, and is

determined for a specific water body by 

using the SIC flow chart.

See Note H(vii) for the Sanitary Inspection 

Category flow charts for rivers and lakes. 

The information for using the flow chart should 

come from the Catchment Assessment Checklist 

(CAC), Part D, and may require further

investigation to establish the principal source of 

contamination.

Determining a grade involves using both the 

MAC and the SIC (see Table E2: Suitability for 

Recreation Grade matrix). A grade is established 

on the basis of five years’ data. Thereafter 

recalculation of the grade may be done annually 

using the previous five years’ data. 

Step 7: Modifying a grade 

Modifying a beach grade is a management 

option, applicable when requirements in these 

guidelines have been met.

Beach grades may be modified where 

management interventions can be demonstrated 

to effectively discourage recreational use during 

occasional and predictable contamination 

events. The modified grade should reflect the 

water quality conditions the public are usually 

exposed to, and be verified by the Medical

Officer of Health. 

See Note H(xii) for more information on

modifying beach grades. 

Step 8: Reassessment

Reassess on a five-yearly basis, or sooner if

significant change occurs. Such changes will be 

reflected in new information in parts A, B, C 

and D of the Catchment Assessment Checklist. 

Examples of significant change would be:

• altered catchment characteristics or land use

• 

• 

significantly higher or lower microbiological

indicator levels

major infrastructure works affecting waterquality parameters. 

Beaches graded Very Good will almost always 

comply with the guideline values for recreation, 

and there are few sources of faecal 

contamination in the catchment. Consequently

there is a low risk of illness from bathing. 

Beaches graded Very Poor are in catchments 

with significant sources of faecal contamination, 

and they rarely pass the guidelines. The risk of 

illness from bathing at these beaches is high, 

and swimming is not recommended. For the

remaining beaches (Good, Fair and Poor) it is 

recommended that weekly monitoring be carried

out during the bathing season. The public will 

be informed when guideline values are 

exceeded and swimming is not recommended. 

The Microbiological Assessment Category

The following table lists the criteria that define

the MAC, based on five years’ historical data. 

PART II: GUIDELINES FOR RECREATIONAL

WATER QUALITY.

June 2003 

E5
Table E1: Microbiological Assessment Category (MAC) definitions 

A Sample 95 percentile ≤ 130 Escherichia coli per 100 mL

B Sample 95 percentile 131–260 Escherichia coli per 100 mL 

C Sample 95 percentile 261–550 Escherichia coli per 100 mL 

D Sample 95 percentile >550 Escherichia coli per 100 mL. 

Note: the Hazen method is used for calculating the percentiles.9

See Note H(viii) for more information on the Microbiological Assessment Category for freshwater recreational 

areas. 

 

9 It is important to note there are several ways to calculate 

percentiles. Each uses a different formula, generating different 

results. The Hazen method has been chosen for these guidelines,

as it tends to be about the ‘middle’ of all the options.

The Sanitary Inspection Category (SIC) 

The SIC allows the principal microbiological

contamination from faecal sources to be 

identified and assigns a category according to

risk. This category is then combined with the 

Microbiological Assessment Category (MAC) 

to determine a Suitability for Recreation Grade 

for each site in the programme. 

Sources of human faecal contamination 

identified by the SIC may, as a result of 

treatment, be considered of low public health

risk. There may, however, still be cultural or

aesthetic objections to such faecal 

contamination.

This category is either Very High, High, 

Moderate, Low or Very Low, and is found for a 

specific water body by use of the SIC flow 

chart. The information for using the flow chart 

should come from Part D of the Catchment 

Assessment Checklist (CAC) and may require 

further investigation to establish the principal

source of contamination. 

See Note H(iii) for detail on how to establish a

Sanitary Inspection Category. 

The Suitability for Recreation Grade

SFRGs are Very Good, Good, Fair, Poor and 

Very Poor. To find the appropriate grading for 

the recreational water body, locate the box in

the Suitability for Recreation Grade table (Table 

E2) that coincides with both the MAC and SIC 

for the water body. 

PART II: GUIDELINES FOR RECREATIONAL

WATER QUALITY.

June 2003 

E6
Table E2: Suitability for Recreation Grade for freshwater sites 

Microbiological Assessment Category 

Indicator counts (as percentiles – refer Table E1) 

Susceptibility to faecal 

influence 

A

≤ 130 

E. coli/100 mL

B

131–260 

E. coli/ 100 mL

C

261–550 

E. coli/ 100 mL

D

> 550 

E. coli/ 100 mL

Exceptional 

circumstances 

*** 

Very Low Very Good Very Good Follow Up** Follow Up**

Low Very Good Good Fair Follow Up** 

Moderate Follow Up* Good Fair Poor

High Follow Up* Follow Up* Poor Very Poor

Sanitary 

Inspection 

Category

Very High Follow Up* Follow Up* Follow Up* Very Poor 

Exceptional circumstances*** 

Notes 

* Indicates unexpected results requiring investigation (reassess SIC and MAC).

** Implies non-sewage sources of indicators, and this should be verified.

*** Exceptional circumstances: relate to known periods of higher risk for a graded beach, such as during a sewer rupture or an outbreak of 

a potentially waterborne pathogen in the community of the recreational area catchment. Under such circumstances a grading would 

not apply until the episode has abated. 

See Note H(ix) for more information on the Suitability for Recreation Grade for freshwater recreational areas. 

See Note H(xiii) for percentile guideline values for freshwater. 

See Note H(xv) for information on software to use for grading beaches.

PART II: GUIDELINES FOR RECREATIONAL

WATER QUALITY.

June 2003 

E7
E.4 Monitored beaches: surveillance, 

alert and action modes 

So far we have looked at deciding which 

beaches to grade, and how to monitor a beach 

by taking samples. Next we need to look at 

putting these together in a process to manage 

the different scenarios that may arise. 

These guidelines propose a three-tier 

management framework based on

bacteriological indicator values: 

i. surveillance – involves routine (e.g. 

weekly) sampling of bacteriological levels 

ii. alert – requires investigation of the causes 

of the elevated levels and increased 

sampling to enable the risks to bathers to 

be more accurately assessed 

iii. action – requires the local authority and

health authorities to warn the public that 

the beach is considered unsuitable for 

recreation. 

Surveillance (routine monitoring) 

Under the surveillance condition, beaches

graded Good, Fair or Poor have the potential to

be affected by faecal contamination events, and 

routine monitoring (e.g. weekly sampling) must 

continue (see Box 2). Guidance on when and 

where to sample can be found in section E.2, 

with further information in Note H(i). 

Alert (amber) mode: single samples

The alert mode is triggered when a single 

bacteriological sample exceeds a predetermined 

value. Under alert mode, sampling frequency

should be increased to daily, and catchment

assessment data referred to for potential faecal 

sources. A sanitary survey should then be 

undertaken to positively identify the sources of 

contamination and the potential management

options. 

See Note H(vii) for the Sanitary Inspection 

Category flow charts for rivers and lakes. 

Action (red) mode: consecutive samples 

The action mode is triggered when a single

sample exceeds a pre-determined value (see 

Box 2 for guideline values). Under the action 

mode, the local authority and health authorities 

warn the public, using appropriate methods, that 

the beach is unsuitable for recreation and 

arrange for the local authority to erect signs at

the beach warning the public of a health danger. 

See Note H(i) for discussion on sampling

requirements. 

See Note H(xvi) for information on reporting to 

the public. 

See Note H(xvii) for management responses to

exceedances. 

E.5 Freshwater surveillance, alert and 

action levels 

The surveillance, alert and action levels are 

summarised in Box 2. They are based on an

estimate that approximately 5% of 

Campylobacter infections could be attributable

to freshwater contact recreation. 

See Appendix 2 for details on how guideline 

values have been developed.

PART II: GUIDELINES FOR RECREATIONAL

WATER QUALITY.

June 2003 

E8
Box 2: 

Surveillance, alert and action levels for freshwater

Acceptable/Green Mode: No single sample greater than 260 E. coli/100 mL. 

• Continue routine (e.g. weekly) monitoring.

Alert/Amber Mode: Single sample greater than 260 E. coli/100 mL. 

• Increase sampling to daily (initial samples will be used to confirm if a problem exists). 

• Consult the CAC to assist in identifying possible location of sources of faecal contamination. 

• Undertake a sanitary survey, and report on sources of contamination.

Action/Red Mode: Single sample greater than 550 E. coli/100 mL. 

• Increase sampling to daily (initial samples will be used to confirm if a problem exists). 

• Consult the CAC to assist in identifying possible location of sources of faecal contamination. 

• Undertake a sanitary survey, and report on sources of contamination.

• Erect warning signs. 

• Inform public through the media that a public health problem exists. 

Notes: 

• ColilertTM is the method of choice to enumerate E. coli or EPA Method 1103.1, 1985 Membrane Filter Method for E. coli (this method 

gives a result for E. coli within 24 hours): USEPA ICR Microbial Laboratory Manual.* This method and the MPN Method for E. coli, 

which is also acceptable (but gives a result in 48 hours), is described in the 20th edition of Standard Methods for the Examination of 

Water and Waste Water, American Public Health Association. These methods must be used to enumerate E. coli unless an alternative 

method is validated to give equivalent results for the waters being tested. 

* USEPA National Centre for Environmental Publications and Information (NCEPI), 11029 Kenwood Road, Cincinnati, OH 45242, USA (Document No. 

EPA-821-C-97-004).

• Samples to test compliance should be over the bathing season appropriate to that locality (at least 1 November to 31 March) and 

sampling times should be restricted to between 0800 hours and 1800 hours.

PART II: GUIDELINES FOR RECREATIONAL

WATER QUALITY.

June 2003 

E9
E.6 Conditions of using the guidelines 

Use of these guidelines is conditional on the 

following. 

These guidelines must not be used as a

measure of suitability for recreation when

there is a major outbreak of a potentially

waterborne disease in the community, and 

that community’s sewage contributes to the 

microbiological contamination of the water. 

Such conditions constitute ‘exceptional

circumstances’. The guidelines do not apply 

then because the relationship between 

indicator organisms and disease was derived 

when there were no known outbreaks of

waterborne diseases in the community. 

When there is such an outbreak, health risks 

may be increased because of a higher-thanusual ratio of pathogen concentration to 

indicators in the water. 

• 

• 

• 

• 

Implementing the guidelines emphasises the 

need and importance for traditional sanitary 

surveys. 

Compliance with the guidelines generally 

indicates that a beach is suitable for 

recreation. There are exceptions however. 

For example, effluent may be treated to a 

level where the indicator bacterial levels are 

very low, but other pathogens such as 

viruses or protozoa may still be present at

high levels. The assessment of such

conditions should be considered during the 

procedure for grading a beach. 

It is important that water managers use these 

guidelines judiciously, and carefully

consider where they can be applied. 

These guidelines are not intended to be

used as the basis for establishing

conditions for discharge consents, 

although they may be used as a 

component for decision making. See the

Introduction of these guidelines for 

discussion on what this document covers. 

PART II: GUIDELINES FOR RECREATIONAL

WATER QUALITY.

June 2003 

E10
SECTION F: 

Microbiological Guidelines for 

Shellfish-Gathering Waters 

The microbiological water-quality guidelines for 

recreational shellfish gathering are as defined in

the Shellfish Quality Assurance Circular (Ministry 

of Agriculture and Forestry 1995) for areas of

approved shellfish-growing waters. These 

guidelines are used by the shellfish export sector 

and are internationally accepted as indicating that 

shellfish grown in such classified waters under 

given conditions of sanitary safety are expected to

have suitable microbiological quality for public 

consumption. 

Note: These recreational shellfish-gathering water 

quality guidelines only cover microbiological 

contamination. They do not cover marine 

biotoxins, which in certain places and locations 

can pose a significant risk to recreational shellfish

gatherers. 

F.1 The preferred indicator for waters 

used for shellfish gathering 

The guidelines use faecal coliform indicator 

organism values to denote the potential presence of

pathogenic bacteria, viruses and protozoa. 

F.2 Recreational shellfish-gathering 

guideline values 

Compliance with these guidelines alone does not 

guarantee that shellfish grown in waters of this 

microbiological quality will be safe. The 

guidelines apply to waters in a catchment where a 

prior sanitary survey has shown that there are no 

point sources of pollution of public health concern.

The guidelines are solely a management tool to

measure any change from the conditions prevailing

at the time of assessment. 

The guidelines are also useful for assessing the 

impact of pollution from surface run-off after

rainfall, and of tidal movement under storm

conditions. Such factors are used to decide when

gathering should be curtailed in commercial 

shellfish-growing areas when weather conditions

cause pollution. They are equally applicable for 

recreational shellfish-growing waters. 

The guidelines are set out in Box 3. 

PART II: GUIDELINES FOR RECREATIONAL

WATER QUALITY.

June 2003 

F1
Box 3: 

Recreational shellfish-gathering bacteriological guideline values

The median faecal coliform content of samples taken over a shellfish-gathering season shall not exceed a

Most Probable Number (MPN) of 14/100 mL, and not more than 10% of samples should exceed an MPN of 

43/100 mL (using a five-tube decimal dilution test). 

These guidelines should be applied in conjunction with a sanitary survey. There may be situations where

bacteriological levels suggest that waters are safe, but a sanitary survey may indicate that there is an

unacceptable level of risk. 

Notes: 

• The MPN method as described in Standard Methods for the Examination of Water and Wastewater; American Public Health Association 

(current edition), must be used to enumerate faecal coliforms unless an alternative method is validated to give equivalent results for the 

waters being tested.

• Sampling to test compliance shall be over the whole shellfish-gathering season.

• A sufficient number of samples should be gathered throughout the gathering season to provide reasonable statistical power in testing for

compliance for both the median limit and the 90% samples limit.

PART II: GUIDELINES FOR RECREATIONAL

WATER QUALITY.

June 2003 

F2
Part III:

Explanatory Notes

to the Guidelines

The following explanatory notes are provided to 

give more detail on some of the issues raised in

Parts I and II. 

SECTION G: NOTES TO PART I:

The Framework for Monitoring 

Recreational Water Quality 

Note G(i): Respiratory illness

Studies have increasingly found significant

relationships between respiratory illness risk and a 

bacterial indicator. This has been shown in recent 

studies in at least four different countries, but it 

may not be a new phenomenon:

• Hong Kong (Cheung et al 1990)

• 

• 

• 

England (Balarajan et al 1989; Fewtrell et al 

1992; Fleisher, Kay, Salmon et al 1996)

Australia (Corbett et al 1993) 

New Zealand (McBride, Salmond et al 1998). 

The aetiological agent(s) for this are unclear, 

although it is generally recognised that a number 

of bacterial and viral pathogens that cause

respiratory illness (e.g. members of the enterovirus 

and adenovirus group, and certain species of the 

genus Klebsiella) are shed in faecal matter. 

Infection is generally acquired by inhalation of 

aerosols containing these infectious particles

(Horwitz 1990; Melnick 1990; Tyler & Fields

1990; Grimont et al 1992), and the potential for 

transmission of viral pathogens via wavegenerated aerosols has been demonstrated (Baylor 

et al 1977). 

PART III: EXPLANATORY NOTES TO THE

GUIDELINES. 

June 2003 

G1
Note G(ii): Examples of health risks 

Contact with contaminated recreational water has 

been shown to pose a number of possible health

risks. These illnesses, symptoms and pathogens

are listed in Table G1, along with the relevant

references. 

A number of New Zealand cases of 

campylobacteriosis from the ingestion of 

contaminated drinking water have been 

demonstrated (Briesman 1987; Stehr-Green et al

1991; Ikram et al 1994; Eberhart-Phillips et al

1997), as has also been shown for giardiasis (Fraser 

& Cooke 1991). With respect to respiratory

symptoms, inhalation of aerosols has been indicated 

as a possible transmission route (Baylor et al 1977;

Tyler & Fields 1990). See also Note G(i). 

Table G1: Bathing-related illnesses, symptoms and pathogens, with relevant references 

Illness/symptoms Pathogen Reference

Campylobacteriosis – acute diarrhoea with risk of dehydration

lasting about five days, but may be longer. Usually with fever, 

headaches and nausea in the first stages. Abdominal pain can be

sufficiently severe for patients to be hospitalised with suspected 

appendicitis. 

Campylobacter jejuni Koenraad et al 1997 

Cryptosporidiosis – acute diarrhoea. Symptoms may wax and

wane but duration in healthy persons is usually less than 20 days

with spontaneous complete recovery. May be fatal in

immunocompromised patients.

Cryptosporidium parvum Sorvillo et al 1992 

Ear infection – otitis externa, skin infection of the outer ear and

otitis media, inner ear infection with exudate and earache. 

Not identified (usually

Pseudomonas aeruginosa,

Streptococcus, and 

Staphylococcus) 

Robson & Leung 1990 

Enterovirus-like illness – vomiting, diarrhoea, and abdominal

pain. 

Enteroviruses (type not 

identified) 

D’Alessio et al 1981 

Hepatitis A – long incubation with symptoms developing

gradually. Symptoms include loss of appetite, malaise, fever and

vomiting followed by jaundice. 

Hepatitis A virus Bryan et al 1974

Norwalk gastrointestinal illness – usually sudden onset with 

vomiting, diarrhoea and abdominal pain. Vomiting frequently

appears without warning and may be projectile and 

uncontrollable, while diarrhoea may be explosive. 

Small round structured

viruses (SRSVs),

including Norwalk virus

Barron et al 1982

Respiratory illness – cold and flu-like symptoms. May be 

associated with fever. 

Adenovirus and others not 

identified 

McBride, Salmond et al 

1998; Corbett et al 

1993; Fattal et al 1986 

Shigellosis – diarrhoea that may vary from relatively mild to

violent, with abdominal pains and fevers. 

Shigella sonnei Rosenberg et al 1976 

Swimmer’s ear – otitis externa, infection of the outer ear. Not identified (usually

Pseudemonas aeruginosa) 

Calderon and Mood 

1982 

Typhoid and Paratyphoid (enteric) – fever Salmonella typhi and 

Salmonella paratyphi

PHLS 1959 

PART III: EXPLANATORY NOTES TO THE

GUIDELINES. 

June 2003 

G2
Note G(iii): State of the Environment 

Reporting 

Environmental performance indicators are 

designed for use in state of the environment

monitoring programmes. They help us to: 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

systematically report on the state of New 

Zealand’s environmental assets 

systematically measure the performance of 

its environmental policies and legislation

better prioritise policy and improve 

environmental decision making. 

Over time, the information produced by State of 

the Environment reporting can:

contribute to raising the level of knowledge

about the state of New Zealand’s

environment

increase our ability to report on

environmental health and trends

provide the tools for effective evaluation of 

policy 

provide the information base for more 

informed policy and management decisions. 

This document serves as a monitoring protocol

two state of the environment performance 

indicators developed by the Ministry under the 

Environmental Performance Indicators (EPI)

Programme. Please note that beaches refer to

both freshwater and marine recreational areas, 

so each of the following indicators would be 

reported for marine and freshwater beaches:

the percentage of monitored beaches in each 

beach grade 

the percentage of the season beaches or 

coastal areas were suitable for bathing or 

shellfish gathering.

Note G(iv): Pressure-State-Response 

model 

The Pressure-State-Response (PSR) model was 

used to measure environmental performance of

management responses to develop 

environmental performance indicators. The

PSR model asks three important questions: 

What are the pressures on the environment?

What is the state of the environment?

What is being done to manage changes in

pressures or state?

Pressure indicators answer the first question by 

measuring the stresses from human activities

(and natural variations) that cause 

environmental change. State indicators answer 

the second question by measuring actual

changes or trends in the physical or biological

state of the environment. Response indicators 

answer the third question by monitoring the

effectiveness of policies or actions taken by

people to reduce, prevent or mitigate 

undesirable change in the state of the

environment.

The indicators on which these guidelines are 

based; percentage of monitored beaches in each 

beach grade, and percentage of the season 

beaches or coastal areas were suitable for 

contact recreation or shellfish gathering, are 

state indicators that provide general information 

on the public health risk presented by

recreational waters. Pressure indicators would 

measure the surrounding land use and 

discharges to water to assist identification of 

potential causes of changes in water quality. 

Response indicators would identify

management or policy changes at the regional or

national level (for example infrastructural 

improvements, land use management policies, 

national environmental standards) to manage

issues for recreational waters. 

PART III: EXPLANATORY NOTES TO THE

GUIDELINES. 

June 2003 

G3
Implementation of integrated pressure, state and 

response monitoring provides a measure of the 

entire system in question and supports detection 

of policy gaps or opportunities for management

improvements. 

Note G(v): Integrating public health and 

state of the environment data 

The purpose of the Microbiological Water 

Quality Guidelines for Marine and Freshwater 

Recreational Areas is to help control the public 

health risk from microbiological contamination 

in recreational waters, and to provide a 

framework for monitoring and reporting on the 

general health of beaches. Integrating the needs 

of both state of the environment and public

health monitoring may present some challenges, 

but it is achievable. 

Microbiological information is generated more

intensively to keep stock of short-term variation 

that can affect the public health risk of water 

quality. This monitoring takes place on a weekly

basis, although at times follow-up monitoring is

required to identify the permanence of an

identified guideline exceedance. 

The purpose of state of the environment 

monitoring is to collect sufficient data to

produce information on the general health of the 

environment. This information can then be used

to measure how well our management practices, 

policies and laws are working, and whether

environmental outcomes are being achieved. 

The beach grades generated through the 

combination of the catchment assessment and 

microbiological assessment provide state of the 

environment information to the public on the

general condition of the recreational area with

respect to public health risk. The 

microbiological information collected to assess 

the public health risk at the beach on a weekly 

basis is aggregated over five years to generate

the Microbiological Assessment Category used

in the beach grading process. 

Note G(vi): Merging with existing 

microbiological programmes 

Councils may monitor microbiological water 

quality for objectives other than public health

reporting (e.g. land-use pressure, trends). 

Merging monitoring programmes can result in

significant cost savings, though there are some

issues to be aware of. 

The following considerations should be made

when merging programmes other than for public

health reporting: 

Can the sampling requirements of both 

programmes be satisfied?

• 

• Will the sampling locations be appropriate 

for both programmes?

See Box 4 for an example of merging 

programmes. 

PART III: EXPLANATORY NOTES TO THE

GUIDELINES. 

June 2003 

G4
Box 4 

Issues with integrating programmes 

Council A’s existing microbiological monitoring programme has been specifically designed to monitor the 

effects of agricultural land-use. The sampling conditions (wet, dry) and the locations of those sites are 

important to determine trends over time and space. The monitoring requirements to meet these objectives

are: 

• monitoring sites that are representative of the catchment

• avoiding monitoring during or after storm events, to avoid skewing trends

• monthly sampling.

However, the public health programme as outlined in the Microbiological Water Quality Guidelines for 

Marine and Freshwater Recreational Areas has been designed for the protection and reporting of public 

health risk. This requires:

• monitoring at beaches that are used for contact recreation 

• sampling at locations and times that most closely represents public exposure (this may include sampling 

during rainfall events)

• weekly sampling. 

When the council attempted to satisfy the monitoring requirements of both programmes, it quickly became 

clear that there would be difficulties merging the two without the objective of one or both of the

programmes being compromised. 

Merging or adapting an existing state of the 

environment monitoring programme to report

on public health risk requires careful design to

ensure the objectives of both programmes are 

successfully achieved. The following solutions 

are suggested where monitoring objectives 

conflict. 

• 

• 

• 

Separate monitoring programmes: this is not 

the most efficient solution, but the clearest 

way to preserve the integrity of both 

monitoring programmes. 

Integrate the programmes: design a joint

programme taking advantage of overlaps,

recognising the specific sampling 

requirements of each programme. This 

approach is more complex and may involve

tagging data considered unsuitable to the 

differing objectives. 

Economise sampling efforts: use the 

catchment assessment and frequency of use

to prioritise beaches that require weekly 

sampling for public health risk evaluation.

These beaches will form the focus for 

meeting the public health objectives of the 

guidelines. The land-use pressure objectives

could then be met by a less stringent

sampling regime while maintaining

important trend information.

PART III: EXPLANATORY NOTES TO THE

GUIDELINES. 

June 2003 

G5
Note G(vii): Different roles and 

responsibilities adopted around New

Zealand 

As part of determining a sensible and pragmatic

approach to recommending an assignment of

roles and responsibilities, the Ministry for the 

Environment investigated a number of scenarios 

operating around the country.

Scenario One: Integrated approach

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

The regional council undertakes all beach 

monitoring in an area. 

When the alert level is exceeded, the 

territorial local authority carries out 

additional monitoring. Additional sampling

is funded by the Medical Officer of Health. 

A sanitary survey is carried out when in alert 

mode II. 

When the action level is exceeded the 

territorial local authority carries out 

additional monitoring. Additional sampling

is funded by the Medical Officer of Health. 

Investigation of nuisance is carried out by

the territorial local authority. 

When in action mode, public notification is 

undertaken by the Medical Officer of Health 

(includes signage). 

Scenario Two: Medical Officer of Health 

lead 

The Medical Officer of Health brings the 

regional council and territorial local 

authorities in the region together before the 

beginning of the bathing season to ascertain

the degree of monitoring programmed for 

the region. The Medical Officer of Health is

kept informed of the status of beaches 

throughout the entire season. 

The territorial local authority carries out all 

monitoring in each district. 

When the alert level is exceeded the

territorial local authority undertakes a degree

of investigation (additional sampling is 

rarely carried out). 

When the action level is exceeded signs are 

put up at beaches (sometimes permanent 

around some discharge points) and a public

communications strategy is implemented. 

An investigation into the cause of nuisance 

is carried out. 

The regional council is kept informed 

throughout the season. 

Scenario Three: Single agency

The territorial local authority carries out 

monitoring. 

The public are not alerted when action levels 

are exceeded, although an investigation is

carried out to find the cause of the problem

and abate nuisance. 

The Medical Officer of Health is available to

provide advice to the territorial local 

authority on whether to inform the public. 

Scenario Four: Regional lead

The regional council carries out all 

monitoring. 

Territorial local authorities remain informed

of water quality in their district through

regional councils. 

The Medical Officer of Health is informed 

by regional councils when the action level is

exceeded, and provides advice on the public 

health significance. 

Regional councils take additional samples 

and investigate when the action level is 

exceeded. 

The Medical Officer of Health informs the 

public when the action level is exceeded. 

PART III: EXPLANATORY NOTES TO THE

GUIDELINES. 

June 2003 

G6
Scenario Five: Double check

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

The regional council monitors beaches for 

state of the environment reporting. 

The territorial local authorities monitor 

beaches for public health purposes. 

The Medical Officer of Health provides 

advice on a sampling strategy and the public

health significance of sampling results. 

The territorial local authorities carry out 

additional sampling and investigation when 

alert levels are exceeded. 

Territorial local authorities inform the public 

when action levels are exceeded and 

investigate the nuisance. 

Note G(viii): The legislative basis for the 

Ministry’s recommendations 

The recommendations made by the Ministry for 

the Environment and the Ministry of Health are 

supported by legislation as follows. 

The regional council undertakes surveillance 

and alert-level monitoring (including resource 

consent monitoring). 

Section 35 of the Resource Management Act,

1991 requires regional councils to undertake 

monitoring to carry out their functions under the

RMA effectively. Section 35(2) requires 

regional councils to undertake “state of the 

environment” monitoring. 

Under the RMA, regional councils have 

functions in relation to the coastal marine area, 

including coastal waters, which are linked to the 

purpose of the RMA. The aspects of the 

purpose of the RMA (Part II) that are relevant to

coastal waters/marine bathing and, in particular, 

the public health aspects of beach water quality 

are: 

section 5 – sustainable management

incorporates health and safety, safeguarding 

the life-supporting capacity of water and

avoiding, remedying or mitigating any 

adverse effects of activities on the 

environment

section 6 – the preservation of the natural

character of the coastal environment, 

including the coastal marine area and the 

maintenance and enhancement of public 

access to and along the coastal marine area

are matters of national importance 

section 7 – the maintenance and

enhancement of amenity values and the 

quality of the environment are matters to

which particular regard must be had by

decision makers under the RMA.

Section 30 of the RMA ascribes functions to 

regional councils for the purpose of giving

effect to the RMA, including: 

control of land use for the purpose of 

maintaining and enhancing the quality of

coastal water 

in respect of the coastal marine area, the 

control of discharges of contaminants into

water and discharges of water into water 

the general, control of discharges of

contaminants into water and discharges of 

water into water. 

Policy 5.1.1 of the New Zealand Coastal Policy 

Statement directs regional councils that:

Rules should be made as soon as 

possible with the object of enhancing 

water quality in the coastal environment 

where that is desirable to assist in 

achieving the purpose of the Act, and in

particular where there is a high public

interest in, or use of the water. 

PART III: EXPLANATORY NOTES TO THE

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June 2003 

G7
In summary, it is consistent with the RMA to 

require regional councils to undertake

surveillance monitoring and alert-level 

monitoring of marine bathing waters. Arguably, 

the RMA requires regional councils to go

further than this and undertake stepped-up

nuisance monitoring, where necessary. 

There is no provision in the Health Act for the 

Medical Officer of Health to audit the 

monitoring carried out by regional councils. 

However, the recommendation that the Medical 

Officer of Health be satisfied with the manner in 

which the monitoring is carried out is to protect 

public health and safety. It also helps to ensure 

that the guidelines will be consistently applied

around the country. 

If alert or action levels are reached the regional 

council informs the Medical Officer of Health 

and the territorial authority. The Medical

Officer of Health ensures the territorial

authority is informed. 

Section 35(2) of the RMA requires regional

councils to “take appropriate action (having 

regard to the methods available to it under the 

RMA) where this is shown to be necessary”. 

This is linked to state of the environment

monitoring requirements. Appropriate action 

may include informing the Medical Officer of 

Health and territorial authority. 

Once the Medical Officer of Health is aware 

that alert or action levels have been exceeded, it

is consistent with the Health Act that he or she 

ensure that the territorial authority is informed. 

Under the Health Act, the Director-General of 

Health (and his or her officers) has an

overriding duty to improve, promote and protect

public health. The Medical Officers of Health 

and Health Protection Officers under the 

Director-General of Health have supervisory/ 

auditing roles in relation to public nuisances. 

While there is specific legislative authority for 

the Medical Officer of Health to direct territorial 

authorities, there is currently no such authority 

for him or her to direct regional councils.

The territorial authority informs the public, 

where necessary. The Medical Officer of 

Health ensures the public are informed. 

Territorial authorities have a duty to improve, 

promote and protect public health within their 

districts under section 23 of the Health Act. 

This extends to specific powers and duties: 

If satisfied that any nuisance, or any 

condition likely to be injurious to health

or offensive, exists in the district, the 

territorial authority is to cause all 

proper steps to be taken to secure the 

abatement of the nuisance or the removal

of the condition.

“All proper steps” arguably includes informing 

the public. Also, as outlined above, the Medical 

Officer of Health has an auditing role under the 

Health Act, and it is consistent with this that he

or she ensures that the public is informed. 

Section 57 of the RMA provides for a New 

Zealand Coastal Policy Statement (NZCPS), 

which is mandatory. By virtue of sections 55

and 57, local authorities must take such action 

as is necessary to implement the NZCPS. 

Policy 5.1.7 of the NZCPS states: 

Provision should be made to ensure that

the public is adequately warned when the 

degradation of water in the coastal 

environment has rendered the water 

unsafe for swimming, shellfish gathering

or other activities. 

Consequently, the NZCPS directs local

authorities to make provision to warn the public. 

Regional councils have functions to ensure that 

integrated management of the natural and

physical resources of a region is achieved, and 

provision could be achieved by ensuring that

territorial authorities will carry out this function.

PART III: EXPLANATORY NOTES TO THE

GUIDELINES. 

June 2003 

G8
If the action level is reached, in the first 

instance the territorial authority will undertake 

nuisance monitoring and cause all proper steps 

to be taken to abate or remove the nuisance. On

occasion it may be more appropriate for the 

regional council to undertake this duty. The 

Medical Officer of Health will provide advice 

and ensure that the territorial local authorities 

and/or regional councils take proper steps.

The Health Act requires territorial authorities to

undertake nuisance monitoring in relation to 

their districts pursuant to section 23: 

To cause inspection of its district to be

regularly made for the purpose of

ascertaining if any nuisances, or any 

conditions likely to be injurious to health

or offensive, exist in the district.

‘District’ is not defined in the Health Act, and

arguably the coastal marine area is not within a 

territorial authority’s district because of the 

definition of ‘district’ in the RMA. However, 

this definition does not expressly apply to the 

Health Act. Further, the source of the nuisance 

is likely to be within the territorial authority’s 

district (i.e. the land, as defined in the RMA),

and it is appropriate that the territorial authority 

locate the source of the nuisance. 

The RMA requirements for regional councils to 

monitor may extend to nuisance monitoring. 

For example, where the cause of the nuisance is 

found to be a consented activity or an activity 

controlled by the regional council rather than

the territorial local authority, then responsibility 

for continued monitoring and abatement rests 

with the regional council. Other situations

where it may be more appropriate for the

regional council to carry out nuisance 

monitoring include when it has been agreed by

all agencies involved before the beginning of

the bathing season, and where the territorial 

local authority is too small to cope with 

increased monitoring. The Medical Officer of 

Health may need to assist the territorial local

authorities and regional councils in determining

the most appropriate agency to investigate and 

monitor the nuisance. 

Note G(ix): Legal opinion on roles and 

responsibilities 

A legal opinion sought by the Ministry for the 

Environment found that the two major pieces of 

legislation concerned (the RMA and Health

Act) did not explicitly define responsibilities for 

beach water-quality monitoring and reporting. 

However, the proposed framework is consistent

with current legislation.

Note G(x): The Annapolis Protocol 

The Annapolis Protocol combines a monitoring

scheme of microbiological testing with broader

data collection on sources and transmission of 

pollution. It involves both an environmental

hazard assessment and a microbiological waterquality assessment. 

Councils and health authorities have been

consulted on the concept and implementation of

a risk-based approach and guideline values for 

recreational waters. The Annapolis Protocol

framework as detailed in the guidelines has been 

adapted to suit New Zealand conditions after 

trial at 30 New Zealand recreational beaches

and consideration by a Marine Bathing Working 

Group established for the purpose. The same

approach has been applied to the guidelines for

freshwater recreational use, following

consideration and trial by the Freshwater

Guidelines Advisory Group.

PART III: EXPLANATORY NOTES TO THE

GUIDELINES. 

June 2003 

G9

SECTION H: NOTES TO PART II:

Guidelines for Recreational Water 

Quality 

Note H(i): Sampling times and periods 

Season period 

The bathing season period will vary according to

location, but will generally extend from

1 November to 31 March. If a beach is used all

year round the grade and weekly monitoring 

should reflect this (i.e. should be based on data for 

a period relevant to usage). 

A Suitability for Recreation Grade (SFRG) is 

established for each beach in the programme at the 

beginning of the season. The SFRG is applicable 

for up to five years, provided there are no 

significant changes within the catchment that

might affect water quality. The grade provides an

indication of the overall condition of the site. 

Weekly sampling should continue at those beaches 

graded Good, Fair or Poor. Weekly sampling is 

required for determining the public health risk at a 

beach. Beaches graded Very Good may not 

require ongoing monitoring because of the low risk

identified. The same applies to beaches graded 

Very Poor, as they will generally be unsuitable for 

recreational use. 

Resource limitations may restrict the number of

beaches in a region that can be monitored. The 

grading system applied in these guidelines enables 

beaches to be prioritised according to their grade, 

and creates the potential to have all beaches within

a region, city or district graded over time. 

Number of samples to collect

A minimum of 20 samples should be collected 

from each site in the monitoring programme, 

usually at weekly intervals. Additional samples 

may be taken throughout the season as a result of

single-sample exceedances. While these do not 

contribute to the recommended 20 samples, they

should be recorded in the database/spreadsheet

with all other samples. 

Timing sample collection

Figure H1 shows how a sampling regime may be 

timed. In this instance it ensures that the results 

are generated in time to inform the public of the 

quality of the beach at the time of highest use (the

weekend). There may be other peak times when

the regime in Figure H1 is not appropriate and 

staff should design programmes accordingly. 

Flexibility in sample timing

In setting up a programme it is important to allow 

for the minimum number of samples to be

collected (20). This will usually require weekly 

monitoring, depending on season period (which 

may vary from region to region). As sampling is

not likely to take place during conditions which 

may present a health and safety hazard (e.g. heavy 

rainfall, storm conditions, large surf), it is 

important to design a weekly sampling programme

that has sufficient flexibility to allow sampling to

take place as soon as practical after adverse

conditions have abated. This may also better 

reflect the conditions under which people are 

swimming.

PART III: EXPLANATORY NOTES TO THE

GUIDELINES. 

June 2003 

H1
Wednesday

Sampling

11 am – 2 pm

Thursday

Result: single

> 280/100 ml

Sample

analysis

Thursday

Resample before

2 pm

Friday

Result: single

> 280/100 ml

Sample

analysis

Friday

Communication

strategy implemented

and public informed

Figure H1: Example of a proposed sampling strategy (marine waters) 

24-hour re-sampling requirement

Marine waters

For marine waters when sampling returns a result 

exceeding the action level threshold, the guidelines 

require a follow-up sample within 24 hours of

receiving the first result. The purpose of the 

follow-up sample is to ensure that the first sample 

is not an anomaly and that the problem is 

persistent before initiating a public notification 

plan. 

Ideally, resampling should take place within 

24 hours of receiving a high result. While this 

does not present a problem for urban beaches, 

logistically it may not be possible for more remote 

locations. In such instances re-sampling should

take place between 24 and 72 hours after receiving

a high result. 

If a sampling agency has remote sites it may be

possible to arrange for another organisation to

collect samples and transport them to a local 

laboratory for analysis. Health agencies, territorial 

local authorities or community organisations may 

be able assist with sampling, and could be 

particularly useful for re-sampling in remote 

locations. 

Freshwaters 

No follow-up sample is required to confirm an

exceedance of the alert-level threshold. There are 

two reasons for this: the dilution factor is likely to

be less than for marine waters resulting in more 

extreme exceedances; and potentially higher 

concentrations and a greater range of pathogens

may be present in freshwaters.

PART III: EXPLANATORY NOTES TO THE

GUIDELINES. 

June 2003 

H2
Note H(ii): Techniques for taking and 

analysing samples 

Where to sample 

Water-quality samples should be taken from the 

area where swimming occurs. In general, the 

sample will be taken at approximately 15 cm

below the surface at a point where the depth of 

water is 0.5 metres for marine water, and 30 cm

below the surface at a point where the depth of 

water is 1 metre for freshwater. 

Multiple sample sites

Sometimes it may be desirable to take multiple 

samples along a beach, particularly where a beach 

extends for some distance and one sample point is 

not representative of the whole beach. The way 

multiple samples are incorporated into results will 

vary. If samples are taken at considerable 

distances from each other, then each of the 

samples should be considered an individual sample

site. However, if multiple samples are taken from

a small beach (e.g. with the purpose of trying to 

find a potential source of contamination), then

these will need to be treated differently, and the 

highest value should be taken as the maximum for 

the whole beach. 

Sample collection techniques 

At the time of sampling, enter in a logbook (for

later transcription to a sample sheet) details of 

weather conditions (wind speed and direction, 

rainfall), water temperature, salinity, and 

observations of conditions such as turbidity or 

discoloration, and any unusual circumstances 

affecting the site (e.g. seaweed, jellyfish). 

The following steps for sampling are 

recommended.

i. Ensure that the bottle is clearly labelled for 

later sample identification.

ii. Immediately before sample collection, remove 

the bottle cap while ensuring that the inner of

the cap is protected from soiling. The 

laboratory generally supplies sterile containers 

of a suitable size. 

iii. Quickly plunge the bottle upside down to the 

required sampling depth set for the site. (For 

marine water the sample will be taken at

approximately 15–20 cm below the surface at

a point where the depth of water is 0.5 metres; 

for freshwater the sample will be taken at 

approximately 30 cm below the surface where 

the depth of the water is approximately 

1 metre.) 

iv. Tilt the bottle until the neck points slightly 

upwards, with the mouth directed towards the 

current. The bottle can be moved forward 

horizontally until filled if necessary. 

Completely fill the bottle. 

v. Rapidly bring the bottle to the surface and

pour out a small portion (leave a space of 2–3 

cm) to permit proper mixing for analysis. 

Quickly fit the cap and secure tightly. 

vi. Record the time of sample collection and 

check sample identification labelling.

vii. Place in a chilly bin containing frozen slicker 

pads. 

Sampling after wet weather 

The guidelines relate to samples taken throughout 

the total bathing season irrespective of weather 

conditions. Results influenced by rainfall should

not be excluded: people do swim shortly after a 

rainfall event, and it is important to sample when

people are likely to be swimming. This may be

particularly so for freshwater lakes and rivers. 

PART III: EXPLANATORY NOTES TO THE

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June 2003 

H3
The separation of dry-weather and wet-weather 

data is also impractical because the definition of

the two is problematic. For example, coastal water 

can be less polluted in the early stages of a wet 

spell but more polluted when the weather has 

become fine just after substantial rainfall; the 

reverse can be true in estuaries. 

Safety

The safety of field officers is vital and should be 

taken into account when selecting sample sites 

with respect to entering the water. 

Transporting samples 

The sample should be transported to the analytical 

laboratory as quickly as facilities allow, preferably 

within six hours, but no longer than 24 hours. 

When it is not possible to have the samples 

analysed by the local laboratory, a courier should

be arranged well in advance. Courier companies 

can be requested to make a pick-up from the 

council in time to courier the samples to the 

laboratory on the same day or overnight. Samples 

should be packed in chilly bins (polystyrene bins

are sufficient) with ice packs to keep them cool. 

It is particularly important that samples analysed 

for E. coli are analysed within 24 hours of 

sampling, as bacteria may begin to die or replicate, 

depending on storage conditions and the status of

the water sample. 

Documentation of the transport history and of all

those who have handled the sample should 

accompany all samples. This is known as a chain 

of custody. 

On arrival at the laboratory the samples should be

placed in a refrigerator, and analysed within two 

hours of receipt (particularly for enterococci and 

E. coli; different time factors may be applicable for

other micro-organisms). The analytical laboratory

should record the times of sample receipt and 

analysis. 

Where analysis for other micro-organisms is

required, obtain specific instructions from the 

analytical laboratory. 

Laboratory techniques

Marine studies have generally concluded that

enterococci are the indicator of choice for the

presence of faecal pollution. The recommended 

method for their detection in the Recreational 

Water Quality Guidelines are the Membrane Filter 

(MF) Test Method for Enterococci in Water as 

described in Document No. EPA-821-C-97-004, 

and EnterolertTM (note: EnterolertTM may not be

considered suitable for state of the environment 

monitoring and reporting due to inadequate 

detection limits). 

The above method has been evaluated for marine 

waters and has the advantage of giving results in

24 hours. Earlier methods gave a result within

48 hours. The value of this for monitoring

agencies is to be able to identify alert, and actionlevel exceedances more quickly. 

For similar reasons, in freshwater where E. coli is 

the indicator of choice, ColilertTM and EPA 

method 1103.1, 1985 Membrane Filter Method for 

E. coli are the preferred methods to enumerate 

Escherichia coli. Both methods give a result

within 24 hours. 

Quality control 

Laboratories conducting testing for monitoring

agencies must be able to demonstrate competence. 

Ideally this means an IANZ accredited laboratory. 

It is essential that laboratories have documented

quality assurance procedures. This does not have

to be in the form of very detailed manuals, but the 

basic procedures of the laboratory must be written

down. It needs to be quite clear what procedures

are being used and exactly how the tests are being 

carried out. All key activities must be

documented, and everyone involved in testing –

from sample collector to the person reporting the 

results – must have a thorough understanding of

PART III: EXPLANATORY NOTES TO THE

GUIDELINES. 

June 2003 

H4
their responsibilities and duties, any problems that 

could arise, and how they should be dealt with. 

All activities undertaken must be recorded so that 

it is quite clear, from the time of collection of the 

sample to the reporting of results, what actions

were taken, by whom and when. 

In showing competence, laboratories need to

consider participation in an inter-laboratory 

proficiency programme, spiked samples, split 

samples, duplicates, positive and negative controls, 

both within the laboratory and in collaborative 

tests with other laboratories. 

New method validation

New methods must be proven to provide results

equivalent in sensitivity and specificity to those of

the preferred test methods for the waters being 

tested. Statistical analysis of parallel test results 

must show strong linear correlation and no

significant difference between the methods by

paired t-test analysis. 

Note H(iii): Establishing a Sanitary 

Inspection Category (SIC) 

The following steps are required to determine an

SIC. 

i. Carry out an initial desktop analysis based on 

historical information. 

ii. Use Parts A, B and C of the Catchment 

Assessment Checklist to help identify 

relevant information about the site. 

iii. Use Part D of the Catchment Assessment 

Checklist to identify the presence of sources 

of faecal contamination likely to cause effects 

in the water body. 

iv. If more than one source is present, then 

choose the most important. Importance is

assessed in terms of the susceptibility of the 

water body to faecal influence. For example, 

a continual moderate source of faecal 

contamination may be considered more 

important than an occasional but high-load

faecal source. This may require specific 

pathogen testing to determine the source of

greater impact. 

v. Locate the number corresponding to the most 

significant impact in the SIC flow chart

(Figure H2) to determine the SIC. 

It is important to recognise there are two questions 

to be answered in Part D of the catchment 

assessment checklist. The first is “Is it present”. 

The purpose of this question is to determine the 

presence of a potential source of faecal 

contamination to the recreational site. The second

question “Is it likely to cause an effect” 

determines, after evaluation, if the potential source 

of faecal contamination actually affects the 

recreational site, thus posing a risk. 

Initial desktop assessment before sanitary

inspection 

Start the assessment of the sanitary status of a

recreational site with a review of its previous

history and, where applicable, an assessment of 

what triggers pollution events, including when and 

how the guidelines are exceeded. 

When considering historical microbiological data

to help determine causal relationships, bear in

mind the limitations – under some conditions – of 

the indicator (enterococci/faecal coliform) used. 

Additional information, such as that set out in

Parts A, B and C of the Catchment Assessment 

Checklist, may be needed to verify the cause of

elevated indicator levels, and may already be

available in the historical information.

Carrying out a sanitary inspection 

Generally, local authorities will have GIS systems 

or maps to identify the important known

discharges and conditions that could cause an

issue. The initial emphasis of any assessment 

should be on potential causes from known

discharges and existing conditions, identified using

resource information, local data and historical 

PART III: EXPLANATORY NOTES TO THE

GUIDELINES. 

June 2003 

H5
information. In addition, identifying what is not 

known is important. Gaps in the knowledge about

an area can be addressed in a catchment 

inspection, as well as by reviewing known existing 

conditions. 

To assess the immediate area and catchment data, 

an annotated map of the beach and catchment is 

required. The checklist can be used to verify that 

all aspects and areas that should be included in the 

map have been added.

Questions that require information for annotation

may include: 

• number of bathers 

• 

• 

• 

• 

• 

• 

• 

location of oxidation ponds 

duck ponds 

bird-roosting areas (daytime and night time) 

boat anchor and mooring areas 

possibility of septic tank seepage 

location of swamps and mangroves 

location of wastewater treatment and disposal

systems and effluent outfalls.

Possible contamination sources (rivers, streams, 

stormwater drains outfalls) should be included in

the map of the sanitary inspection area. Where 

available, maps of the entire catchment area 

indicating land use, topography and infrastructure 

networks (i.e. wastewater and storm drain systems 

etc.) should also be attached. 

Base conditions for establishing a Sanitary 

Inspection Category 

All beaches will have been recognised as having

contact recreational activity, so a factor for humanto-human transmission of disease during

recreational activity is not included. A single most

significant source of faecal contamination has been

used to categorise the beach. This is because a 

second source, even of similar magnitude, can only 

increase the risk by a factor of two and as such is 

of limited significance in microbiological terms. 

Other impacts not included above may produce an

‘unexpected result requiring verification’ in the 

grading matrix (Tables D2 and E2). This source 

should be identified in the ‘more detailed

investigation’ suggested in the note to Part D of

the Catchment Assessment Checklist. 

Note: The Sanitary Inspection Category (SIC) is 

based on the use of, and monitoring for, faecal

indicator bacteria to support risk assessment. As 

discussed in the introduction, where there are 

discharges of treated effluent enterococci alone

are not an appropriate indicator of public health

risk. If pathogen monitoring is carried out then 

the SIC category for tertiary treated wastewater 

discharge may be amended.

PART III: EXPLANATORY NOTES TO THE

GUIDELINES. 

June 2003 

H6
Note H(iv): Catchment Assessment Checklist (CAC) for marine recreational waters 

The purpose of the checklist is to identify potential catchment risk factors for use in establishing the 

Sanitary Inspection Category (SIC). 

Site/area name: ____________________________________________________________________________

Type of site: Open coastal beach ________ Estuarine_________ Enclosed bay ______ Other_______

Location: _________________________________________________________________________________

Map references: Latitude __________________________ Longitude ____________________________

Name of local authority (specify authority responsible) _____________________________________________

_________________________________________________________________________________________

Name of person completing checklist (for compiling report): ________________________________________

Check and tick all that apply and note findings for subsequent report.

Part A: Land use 

Type of land or human activity surrounding the recreational site. 

Land cover/geography 

Forest/bush Pasture Urban

Swamp/mangroves River/stream/irrigation Sand dunes

Hilly Flat

Urban 

Residential (population density) Commercial Industry (specify) 

Hotel Harbour Airport

Road/rail Military/prison

(restricted areas) 

Other potentially polluting

activity (please specify) 

Sanitary landfills/old dumps 

Disposal of human wastes 

(degree and type of treatment 

applied - (please specify) 

____________________________________________________________

____________________________________________________________

____________________________________________________________

____________________________________________________________

PART III: EXPLANATORY NOTES TO THE

GUIDELINES. 

June 2003 

H7
Part B: Rural land use 

Indicate the presence of the following for agricultural land use. 

Sheep Dairy/beef Horses

Pigs Deer

Poultry Feral

Is there disposal of animal 

wastes? (please specify) 

____________________________________________________________

____________________________________________________________

____________________________________________________________

Part C: Water uses 

Indicate the presence of the following for the marine area. 

Marina Fish boat berths

Permanent boat moorings Harbour 

Temporary boat moorings Ferry berth 

Additional influencing factors 

Size of bathing area: 

Area _____ m2

Length ______m

Mean width ______m

Is there a beach? 

Average area _____ m2

Length ______m

Width at low tide ______m

Width at high tide ______m

Are there lagoons used for bathing?

Is the beach subject to above average seasonal/holiday loading?

Direction of prevailing onshore winds _______

Direction of prevailing water currents _______

Shoreline configuration/geomorphology/erosion gullies: ________________

_____________________________________________________________

Presence of sandbars 

Presence of surf: average wave heights _______

Total rainfall

Total annual: _______ mm

Seasonal patterns: ______________________________________________

PART III: EXPLANATORY NOTES TO THE

GUIDELINES. 

June 2003 

H8
Part D: Microbiological hazards

Sewage and animal waste 

Is the water quality in the recreational area affected, or likely to be affected

by:

Is it 

present?

Is it likely 

to cause an effect?

1 discharge of untreated human effluent onto or adjacent to a recreational

area 

2 stormwater outlets with potential sewage contamination / combined

stormwater outlet onto or adjacent to a recreational area 

3 urban stormwater that is protected from sewage ingress 

4 on-site or other private sewage disposal systems (e.g. septic tank or

package plant) 

5 communal sewage disposal or primary or secondary treatment facilities 

6 communal sewage disposal with tertiary treatment facilities

7 intensive agricultural use in immediate catchment and potential for runoff from untreated animal effluent (e.g. dairying, piggeries, milking 

sheds) 

8 the incidence and density of bird life (particularly where lagoons or 

estuarine conditions exist)

9 water craft mooring or use (for boats, proximity, densities and pumpouts). 

Yes No

Is there a river or stream (including a piped stream) discharging into the 

recreational area?

If ‘Yes’ complete Questions 10–15 to determine an effect. 

PART III: EXPLANATORY NOTES TO THE

GUIDELINES. 

June 2003 

H9
River/stream discharge influences 

Is the water quality of any river or stream discharging into the recreational 

area affected or likely to be affected by:

Is it 

present?

Is it likely to

cause an effect?

10 discharge of untreated human effluent, primary or secondary

wastewater treatment plant discharge, on-site or other private sewage

disposal systems (e.g. septic tank) 

11 stormwater outlets with potential sewage contamination/combined 

stormwater outlet 

12 communal sewage disposal with tertiary treatment facilities

13 high-intensity agricultural/rural activities, incidence and density of

feral animal/bird population

14 focal points of drainage, as run-off from low-intensity

agriculture/urban/rural catchment

15 potential for run-off from feral animals (e.g. forest or bush).

Other influences 

Is it

present?

Is it likely to cause 

an effect?

16 tidal movements or onshore winds that are likely to carry water 

polluted by untreated / primary / secondary treated effluent or onsite

waste treatment systems into the recreational area 

17 tidal movements or onshore winds that are likely to carry water 

polluted by tertiary treated wastewater into the recreational area. 

Further considerations 

Yes No

Does rainfall trigger contamination events?

Does microbiological water quality data exceed the national guidelines 

(280 single-sample exceedance) on any occasion?

Is there additional information implying risk (such as notified illness related

to recreational water activities)?

Note: If the box is ticked indicating the presence of any of the above microbiological hazards, the answer as to

whether it is causing an effect may be obvious (e.g. discharge of human or animal effluent onto or adjacent to a

recreational area). If it is unclear whether it is causing an effect, a more detailed investigation may be required 

to establish relative importance and magnitude of the effect. 

PART III: EXPLANATORY NOTES TO THE

GUIDELINES. 

June 2003 

H10
Effluent, wastewater

stormwater (direct to

recreational water)

Effluent, combined

sewer discharges (CSO);

sewer overflows

Receives untreated/1° or 2° treated discharge

to beach or adjacent area

On-site waste treatment systems

CAC reference: 1, 4, 5, 16

Very high

Treated tertiary wastewater discharge to beach

or adjacent area

CAC reference: 6,17

High

Urban stormwater; marinas or moorings (boats); direct run-off

from intensive agriculture

CAC reference: 2, 7, 9

High

Urban stormwater not contaminated by sewage

CAC reference: 3, 8

Moderate

Receives untreated/1o or 2 o wastewater treatment discharge;

on-site waste treatment systems

CAC reference: 10

High

River/stream discharge

Receives tertiary treated discharge, combined sewerdischarges, sewer

overflows, intensive use in agricultural/rural catchment, significant feral

bird/animal population

CAC reference: 11, 12, 13

Moderate

Run-off from low-intensity agricultural/urban/rural catchment

CAC reference: 14 Low

Bush, forest, etc

CAC reference: 15 Very low

No significant source Very low

Figure H2: Sanitary Inspection Category flow chart for marine recreational waters 

PART III: EXPLANATORY NOTES TO THE

GUIDELINES. 

June 2003 

H11
Note H(v): Microbiological Assessment 

Category (MAC) for marine recreational 

waters 

The Microbiological Assessment Category is 

calculated on the basis of five years of historical

data (at least 100 data points). Data collected

during or immediately following rainfall, as part

of routine sampling, should be included in the 

calculation of the MAC. The purpose of the 

MAC is to give an indication of general water 

quality over an extended period, to allow for 

variations in climatic conditions. The MAC is 

used in conjunction with the Sanitary Inspection

Category (SIC) to determine the Suitability for 

Recreation Grade, and to confirm that the 

selected SIC is accurate, based on historical 

water-quality results. 

Note: Follow-up samples from an alert or

action mode response should not be included in

the data used to generate an MAC. If using the 

software provided by the Ministry for the 

Environment to generate grades, follow-up

samples will need to be removed from the 

dataset prior to importing.

See Section D.3 for MAC definitions. 

Change in indicators 

If a change between indicators is made, there 

may be limited amounts of data available in the 

initial years of implementation. To overcome 

this, correction factors appropriate to local 

conditions can be applied to historical records. 

Such conversion factors would normally be 

based on the results of local analyses. 

For many locations there will be a large amount 

of historical data available that can be used for

preliminary recreational water environment 

classification. If this data includes analysis for 

enterococci, there will be no problem using the 

data. However, many recreational water

environment managers will have data based 

only on coliform and faecal coliform counts. 

Although there is no exact relationship between

enterococci and E. coli counts, a relationship 

expressed by the following equation (WHO

2001) may help in interpreting historical data: 

log10(faecal coliform) = 

1.028 + 0.601log10(enterococci) 

Even more helpful are the following simpler

forms of this equation, relating enterococci to

faecal coliforms and vice versa: 

faecal coliform = 10.67(enterococci)

0.601 

enterococci = 0.0195(faecal coliform)

1.67

Using the first formula, a count of 70 

enterococci equates to 137.1 faecal coliforms. 

Using the second formula, a count of 100 faecal 

coliforms/100 mL equates to 42.7 enterococci/

100 mL. 

However, this equivalence is not exact as it is 

based on the relationship between faecal 

coliform and faecal streptococcal/enterococci 

counts in United Kingdom bathing waters after 

censoring zero values. If possible, local 

recreational-water environment managers 

should define the relationship that exists in their 

own waters. 

Note H(vi): Suitability for recreation 

grade for marine recreational waters 

Explanation of grades 

Beaches are graded by considering 

microbiological monitoring results from

previous years in combination with the factors 

in the catchment that may contribute faecal 

contamination to the beach. It is a riskassociated grading of the beach, meaning that it 

provides an indication of what the likely 

condition of the beach will be on any day. The 

following general explanation provides a 

description of each of the beach grades. 

PART III: EXPLANATORY NOTES TO THE

GUIDELINES. 

June 2003 

H12
Very good

Water-quality tests and assessment of potential 

contamination sources indicate beaches within 

this category are considered to have very good

water quality (see Table D2 for details). There 

may be some run-off from low-intensity 

agricultural/urban/rural catchments, but there 

are likely to be no significant sources of faecal 

contamination.

Recommendation: Considered satisfactory for 

swimming at all times, and therefore may not

require monitoring on a regular basis. 

Good

Water-quality tests and assessment of potential 

contamination sources indicate beaches within 

this category are considered to have generally

good water quality (see Table D2 for details). 

On occasions (such as after high rainfall) there 

may be an increased risk of contamination from

run-off. Such sites receive run-off from one or 

more of the following sources and may contain 

animal or human faecal material: 

• 

• 

• 

• 

• 

• 

• 

• 

• 

river discharges impacted by tertiary treated 

wastewater, combined sewer overflows, 

intensive agricultural/rural catchments, feral

bird/animal populations 

river discharges impacted by; run-off from

low-intensity agricultural/urban/rural 

catchment 

stormwater not contaminated by sewage. 

Recommendation: Satisfactory for swimming

most of the time. Exceptions may include 

following rainfall. Such beaches are monitored 

regularly throughout the summer season and

warning signs will be erected if water quality 

deteriorates. 

Fair 

Water-quality tests and assessment of potential 

contamination sources indicate beaches within 

this category are considered to have generally

fair water quality (see Table D2 for details). 

Events such as high rainfall increase the risk of 

contamination levels from run-off. Such sites 

receive run-off from one or more of the

following sources and may contain animal or 

human faecal material: 

river discharges impacted by tertiary treated 

wastewater, combined sewer overflows, 

intensive agricultural/rural catchments, feral

bird/animal populations 

river discharges impacted by run-off from

low-intensity agricultural/urban/rural 

catchment 

stormwater not contaminated by sewage. 

Recommendation: Generally satisfactory for 

swimming, though there are many potential

sources of faecal material. Caution should be 

taken during periods of high rainfall, and

swimming avoided if water is discoloured. Sites 

are monitored weekly and warning signs 

erected if water quality deteriorates. 

Poor 

Water-quality tests and assessment of potential 

contamination sources indicate beaches within 

this category are considered to have generally

poor water quality (see Table D2 for details). 

These sites receive run-off from one or more of

the following sources and may contain animal 

or human faecal material: 

tertiary treated wastewater 

urban stormwater, marinas or moorings, 

intensive agriculture 

river discharges containing untreated /

primary / secondary treated wastewater or 

on-site waste treatment systems 

PART III: EXPLANATORY NOTES TO THE

GUIDELINES. 

June 2003 

H13
• • 

• 

• 

• 

• 

river discharges impacted by tertiary treated 

wastewater, combined sewer overflows, 

intensive agricultural/rural catchments, feral

bird/animal populations. 

Recommendation: Generally not okay for 

swimming, as indicated by historical results. 

Swimming should be avoided, particularly by

the very young, the very old and those with 

compromised immunity. Permanent warning

signs may be erected at these sites, although 

councils may monitor these sites weekly and 

post temporary warnings. 

Very poor 

Water-quality tests and assessment of potential 

contamination sources indicate beaches within 

this category are considered to have very poor

water quality (see Table D2 for details). These 

sites receive run-off from one or more of the

following sources and may contain animal or 

human faecal material: 

untreated/primary/secondary treated 

wastewater 

on-site waste treatment systems 

tertiary treated wastewater 

urban stormwater, marinas or moorings, 

intensive agriculture 

river discharges containing untreated/

primary/secondary treated wastewater or 

on-site waste treatment systems. 

Recommendation: Avoid swimming, as there 

are direct discharges of faecal material. 

Permanent signage will be erected at the beach 

stating that swimming is not recommended. 

PART III: EXPLANATORY NOTES TO THE

GUIDELINES. 

June 2003 

H14
Note H(vii): Catchment Assessment Checklist for freshwater recreational areas 

The purpose of the checklist is to identify potential catchment risk factors of faecal contamination for

freshwater recreational water quality. 

Site/area name: ____________________________________________________________________________

Type of site: Lake ____________________________ River/Stream _________________________________

Location: _________________________________________________________________________________

Map references: Latitude_______________________ Longitude____________________________________

Name of local authority (specify authority responsible) _____________________________________________

_________________________________________________________________________________________

Name of person completing checklist (for compiling report):______________________________________

Check and tick all that apply and note findings for subsequent report.

Part A: Land use 

Type of land or human activity affecting the recreational site. 

Land cover/geography 

Forest/bush Pasture Urban 

Wetlands River/stream/irrigation

Hilly Flat

Urban 

Residential (population density) Commercial 

Military/prison (restricted areas) Industry (please specify) _____________________

Sanitary landfills/old dumps Other potentially polluting activity (please specify) 

_________________________________________

Disposal of human or animal wastes 

(degree and type of treatment applied – 

please specify) 

____________________________________________________

____________________________________________________

____________________________________________________

PART III: EXPLANATORY NOTES TO THE

GUIDELINES. 

June 2003 

H15
Part B: Rural land use 

Indicate the presence of the following for agricultural land use. 

Sheep Dairy Beef 

Pigs Deer Horses

Poultry Feral

Is there disposal of animal 

wastes? (Please specify) 

__________________________________________________________

__________________________________________________________

__________________________________________________________

Part C: Water uses 

Indicate the presence of the following for the recreational site. 

Marina Boat ramp

Permanent boat moorings Jetty/wharf 

Additional influencing factors 

Size of bathing /recreational area: 

Area______________________m2

Length ____________________ m

Mean width ________________ m

Is the site subject to seasonal/holiday loading? Yes / No

Direction of prevailing winds _______________________________________________________________

Shoreline configuration/geomorphology/erosion gullies: _________________________________________

_______________________________________________________________________________________

Total rainfall: 

Total annual: ______________ mm

Location of rainfall monitoring station: ___________________________________

Shoreline configuration/geomorphology/erosion gullies: _________________________________________

_______________________________________________________________________________________

PART III: EXPLANATORY NOTES TO THE

GUIDELINES. 

June 2003 

H16
Part D: Microbiological hazards

Sewage and animal wastes 

Is the water quality in the recreational area affected, or likely to be

affected by:

Is it 

present?

Is it likely to

cause an effect?

1 discharge of untreated human effluent onto or upstream to a 

recreational area 

2 stormwater outlets with potential sewage contamination /

combined stormwater outlet onto or upstream to a recreational

area 

3 urban stormwater that is protected from sewage ingress 

4 on-site or other private sewage disposal systems (e.g. septic tank

or package plant)

5 communal sewage disposal or primary or secondary treatment

facilities 

6 communal sewage disposal with tertiary treatment facilities

7 intensive agricultural use in immediate catchment and potential 

for run-off from untreated animal effluent (e.g. dairying, 

piggeries, milking sheds etc.) 

8 focal points of drainage, as run-off from low-intensity

agriculture/urban/rural catchment 

9 unrestricted stock access to waterways 

10 the incidence and density of birdlife 

11 water craft mooring or use 

12 potential for run-off from feral animals (e.g. forest or bush).

Indirect influences

Yes No

Is there a stream (including a piped stream or tributary) or drain or 

wetland discharging into or upstream to the recreational area?

PART III: EXPLANATORY NOTES TO THE

GUIDELINES. 

June 2003 

H17
If ‘Yes’ please answer Questions 13–18. 

Is the water quality of that stream, drain or wetland affected or likely 

to be affected by:

Is it 

present?

Is it likely to

cause an effect?

13 discharge of untreated human effluent, primary or secondary

wastewater treatment plant discharge, on-site or other private 

sewage disposal systems (e.g. septic tank) 

14 stormwater outlets with potential sewage contamination /

combined stormwater outlet 

15 communal sewage disposal with tertiary treatment facilities

16 high-intensity agricultural/rural activities, incidence and density 

of feral animal/bird population

17 focal points of drainage, as run-off from low-intensity

agriculture/urban/rural catchment 

18 potential for run-off from feral animals (e.g. forest or bush).

Further considerations Yes No

Does rainfall trigger contamination events?

Does microbiological water-quality data exceed the national 

guidelines (550 E. coli per 100 mL single sample exceedance) on any 

occasion?

Is there additional information implying risk (such as notified illness 

related to recreational water activities)?

Note: If the answer to any of the above microbiological hazard questions is ticked as present, the answer as to 

whether or not it is causing an effect may be obvious (i.e. discharge of untreated human effluent into or upstream

to a recreational area). If, however, it is unclear that it is causing an effect, a more detailed investigation may

be required to establish the relative importance of the effect. 

PART III: EXPLANATORY NOTES TO THE

GUIDELINES. 

June 2003 

H18
Direct discharge to

recreational water

Wastewater, stormwater

animals and birds

Effluent wastewater,

combined sewer

discharges (CSO);

sewer overflows

Receives untreated/1° /2° treated discharge

to beach or adjacent area

On-site waste treatment systems

CAC reference: 1, 4,5

Very high

Treated tertiary wastewater discharge to beach

or adjacent area

CAC reference:6

High

Urban stormwater; direct run-off from intensive agriculture

unrestricted stock access, dense bird populations

CAC reference: 2, 7,9, 10

High

Urban stormwater not contaminated bysewage

Low intensity agriculture, marina or boat moorings

CAC reference: 3,8, 11

Moderate

Receives untreated, 1

o

 or 2 o wastewater treatment discharge,

on-site waste treatment systems

CAC reference:13

High

Indirect discharge to

adjacent shoreline

River/stream discharge

Receives tertiary treated discharge, combined sewerdischarges, sewer

overflows, intensive use in agricultural/rural catchment, significant feral

bird/animal population, unrestricted stock access to streams

CAC reference:14, 15, 16

Moderate

Run-off from low-intensity agricultural/urban/rural catchment

CAC reference:17

Low

Bush, forest, etc

CAC reference:18

Very low

No significant source Very low

Feral animals including those in bush and forest areas

CAC reference:12

Low

Figure H3: Sanitary Inspection Category for freshwater sites 

Note H(viii): Microbiological Assessment 

Category for freshwater recreational 

areas 

The Microbiological Assessment Category is 

calculated on the basis of five years of historical

data (at least 100 data points). Data collected

during or immediately following rainfall, as part

of routine sampling, should be included in the 

calculation of the MAC. The purpose of the 

MAC is to give an indication of general water 

quality over an extended period, to allow for 

variations in climatic conditions. The MAC is 

used in conjunction with the Sanitary Inspection

Category (SIC) to determine the Suitability for 

Recreation Grade, and to confirm that the 

selected SIC is accurate, based on historical 

water-quality results. 

Note: Follow-up samples from an alert or

action mode response should not be included in

the data used to generate an MAC. If using the 

software provided by the Ministry for the 

Environment to generate grades, follow-up will 

need to be removed from the dataset prior to 

importing.

Note: See Section E.3 for MAC definitions for 

freshwater. 

PART III: EXPLANATORY NOTES TO THE

GUIDELINES. 

June 2003 

H19
Note H(ix): Suitability for recreation 

grade for freshwater recreational areas 

Explanation of grades 

Beaches are graded by considering 

microbiological monitoring results from

previous years in combination with the factors 

in the catchment that may contribute faecal 

contamination to the beach. It is a riskassociated grading of the beach, meaning that it 

provides an indication of what the likely 

condition of the beach will be on any day. The 

following general explanation provides a 

description of each of the beach grades. 

Very good

Water-quality tests and assessment of potential 

contamination sources indicate beaches within 

this category are considered to have very good

water-quality (see Table E2 for details). This 

indicates there may be some indirect run-off 

from low intensity agricultural/urban/rural/bush 

catchments, but there are likely to be no 

significant sources of faecal contamination. 

Recommendation: Considered satisfactory for 

swimming at all times, and therefore may not

require monitoring on a regular basis. 

Good

Water-quality tests and assessment of potential 

contamination sources indicate beaches within 

this category are considered to have generally

good water-quality (see Table E2 for details). 

On occasions (such as after high rainfall) there 

may be an increased risk of contamination from

run-off. Such sites receive run-off from one or 

more of the following sources and may contain 

animal or human faecal material: 

• 

• 

• 

• 

• 

• 

• 

• 

river discharges impacted by tertiary treated 

wastewater, combined sewer overflows, 

sewer overflows, intensive agricultural/rural 

catchments, significant feral bird/animal

populations

river discharges impacted by; run-off from lowintensity agricultural/urban/rural catchment

direct discharges from stormwater not

contaminated by sewage, boat moorings or

marinas

direct discharges from low-intensity

agriculture. 

Recommendation: Satisfactory for swimming

most of the time. Exceptions may include 

following rainfall. Such beaches are monitored 

regularly throughout the summer season and

warning signs will be erected if water quality 

deteriorates. 

Fair 

Water-quality tests and assessment of potential 

contamination sources indicate beaches within 

this category are considered to have generally

fair water-quality (see Table E2 for details). 

However, events such as high rainfall increase 

the risk of contamination levels from run-off. 

Such sites receive run-off from one or more of

the following sources and may contain animal 

or human faecal material: 

river discharges impacted by tertiary treated 

wastewater, combined sewer overflows, 

sewer overflows, intensive agricultural/rural 

catchments, significant feral bird/animal

populations

river discharges impacted by; run-off from lowintensity agricultural/urban/rural catchment

direct discharges from stormwater not

contaminated by sewage, boat moorings or

marinas

direct discharges from low-intensity

agriculture. 

Recommendation: Generally satisfactory for 

swimming, though there are many potential

sources of faecal material. Caution should be 

taken during periods of high rainfall, and

swimming avoided if water is discoloured. Sites 

are monitored weekly and warning signs 

erected if water quality deteriorates. 

PART III: EXPLANATORY NOTES TO THE

GUIDELINES. 

June 2003 

H20
Poor 

Water-quality tests and assessment of potential 

contamination sources indicate beaches within 

this category are considered to have generally

poor water-quality (see Table E2 for details). 

These sites receive run-off from one or more of

the following sources and may contain animal 

or human faecal material: 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

tertiary treated wastewater 

urban stormwater, intensive agriculture, 

unrestricted stock access, dense bird 

populations

low-intensity agriculture, marinas or boat 

moorings, urban stormwater not

contaminated by sewage 

river discharges containing untreated/

primary/secondary treated wastewater or 

on-site waste treatment systems 

river discharges impacted by tertiary treated 

wastewater, combined sewer overflows, 

intensive agricultural/rural catchments, feral

bird/animal populations. 

Recommendation: Generally not okay for 

swimming, as indicated by historical results. 

Swimming should be avoided, particularly by

the very young, the very old and those with 

compromised immunity. Permanent warning

signs may be erected at these sites, although 

councils may monitor these sites weekly and 

post temporary warnings. 

Very poor 

Water-quality tests and assessment of potential 

contamination sources indicate beaches within 

this category are considered to have very poor

water-quality (see Table E2 for details). These 

sites receive run-off from one or more of the

following sources and may contain animal or 

human faecal material: 

untreated/primary/secondary treated 

wastewater 

on-site waste treatment systems 

tertiary treated wastewater 

urban stormwater, intensive agriculture, 

unrestricted stock access, dense bird 

populations

river discharges containing untreated/

primary/secondary treated wastewater or 

on-site waste treatment systems. 

Recommendation: Avoid swimming, as there 

are direct discharges of faecal material. 

Permanent signage will be erected at the beach 

stating that swimming is not recommended. 

Note H(x): Application of grades and 

single samples 

The risk of becoming sick from swimming at a 

beach is inferred from the associated grade. 

Beaches graded Very Good almost always pass 

the Microbiological Water Quality Guidelines, 

and there are few sources of faecal contamination 

in the catchment. Consequently, the risk of

becoming sick is low. Beaches graded Very Poor 

are within catchments with significant sources of

faecal contamination, and they rarely pass the 

guidelines. The risk of becoming sick at these 

beaches is high and swimming is not 

recommended. Unless there is a change in the

catchment characteristics of beaches graded Very 

Poor, monitoring is not justified. 

For the remaining grades of beaches (Good, 

Fair, Poor), water quality deteriorates and the 

risk of illness from swimming increases down

the gradient from Good to Poor. The conditions

affecting water quality vary (e.g. Good beaches 

usually pass the guidelines, but occasions such

as high rainfall increase the risk of

contamination from run-off). 

For these beaches it is recommended that 

weekly monitoring be carried out during the 

bathing season. The public will be informed 

when swimming is not recommended (when a 

sample taken from the beach exceeds the actionlevel single-sample criteria of the 

Microbiological Water Quality Guidelines).

PART III: EXPLANATORY NOTES TO THE

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June 2003 

H21
Note H(xi): Interim grading 

An interim grade is provisional, and dependent

on annual review as additional information

becomes available until five years of data is 

obtained. An interim grade is mainly for 

management purposes, although it may be 

communicated to the public if it is clearly 

defined as interim only.

An interim grade can be derived using less than 

the recommended five years’ data where at least 

20 data points over the period of greatest

recreational use are available. This period will 

normally be the summer bathing season, but

may vary with the types of recreational activity 

most common in the area. 

Circumstances under which an interim grade

might be applied include:

where the data available is incomplete, 

either with respect to the MAC, or the SIC, 

or both

• 

• where there is reason to believe that the 

existing grading no longer accords with

changed circumstances, but the data required

for completing the grading is insufficient. 

Note H(xii): Modifying beach grades 

Modifying a beach’s SFRG is justified where 

occasional and predictable contamination events 

are identified, and interventions can be

demonstrated to be effective in discouraging

recreational use. Sites with a modified SFRG 

should be labelled, and their condition and the 

effectiveness of management interventions

assessed annually. 

Modifying an SFRG is particularly relevant to

mid-range beaches (Good, Fair and Poor) and 

where there is disagreement between the SIC

and MAC (i.e. a ‘Follow Up’). The process for 

modifying a beach grade is as follows. 

i. Determine whether contamination events 

are occasional and predictable (i.e. 

triggered by an event such as heavy 

rainfall). 

ii. Implement and evaluate the effectiveness 

of management interventions to discourage 

recreational use during known high-risk 

periods. 

iii. Reassess the SIC, removing the source of 

predictable contamination events (provided 

interventions are effective). 

iv. Reassess the MAC (where there is 

sufficient data), excluding results caused 

by the trigger event. 

v. Modify the beach grade according to the 

revised SIC and MAC.

Data requirements for modifying an SFRG 

To reassess the MAC, rainfall-related data 

should be identified and removed from the 

dataset. This requires all rainfall data to be

marked for easy identification in subsequent

years. If removing rainfall data decreases the 

size of the dataset below the 100 required to

generate a MAC, it cannot be modified. 

Sampling in the subsequent season may be 

sufficient to generate the required number of 

samples to reassess the MAC. If not, councils 

should design a programme to meet this 

requirement, or stick with modifying the SFRG 

based on the revised SIC category only. Once 

sufficient data has been collected the MAC can

be reassessed and the SFRG modified 

accordingly. 

The following example illustrates how to

modify a grade.

PART III: EXPLANATORY NOTES TO THE

GUIDELINES. 

June 2003 

H22
Box 5 

Example of modifying a beach grade 

Initial assessment of the site resulted in a SIC of High (primary impact = ‘stormwater outlets with potential

sewage contamination’) and a MAC of C (95 percentile = 315), giving an SFRG of Poor. 

The stormwater overflows are caused by heavy rainfall, and are therefore predictable events. Signs were 

introduced to warn against swimming for up two days following rainfall. Site monitoring over the following

season found public warnings to be effective in deterring use of the site for up to two days following rainfall. 

As a result, sewage impacted stormwater was replaced as the primary impact on the site with stormwater

protected from sewage ingress. This improved the SIC from High to Moderate and gave a modified SFRG

of Fair (but unsuitable for two days after heavy rainfall). 

Water-quality sampling confirmed that after two days microbiological levels returned to pre-rainfall levels. 

After removing rainfall data, there were insufficient results to generate a MAC. A sampling strategy was 

designed for the following season to collect sufficient samples to meet the 100 data points needed. 

Reanalysis of water-quality data using water quality to which people were exposed revealed a 95 percentile 

of 126, improving the MAC from C to B. 

The modified grade for the site becomes Good (but unsuitable for two days after heavy rainfall), given 

the modification of both the SIC and MAC.

Note: Remediation of stormwater overflows would result in an SFRG of Good, based on the outcome of the 

modified grade. 

Demonstrating effectiveness of management 

interventions

Management interventions may range from

warning signs to public notices in newspapers. 

They should aim to reduce beach usage under 

specific conditions that are known to cause 

contamination, e.g. after heavy rainfall. It is 

critical that the effectiveness of these 

interventions be demonstrated before a beach’s 

SFRG can be modified. This requires 

management interventions to be in place for at

least one bathing season before a site’s grade 

can be modified. 

The effectiveness of management interventions 

can be assessed by measuring the decrease in 

beach use following their implementation. An 

80% reduction in recreational use is required for 

management interventions to be considered 

effective. Head counts are available from surf 

clubs to provide baseline information. If no surf 

club is present, councils or health agencies should 

collect their own information on beach usage. 

Before modified grades are finalised, the 

monitoring authority should consult other

councils and the Medical Officer of Health in

their area to gain agreement on the outcome of 

the regrading. Given their public health

protection role, the Medical Officer of Health in 

particular should concur that:

there is sufficient documentation to support 

the original Suitability for Recreation Grade 

• 

• 

• 

there is evidence that management 

interventions have been effective 

the modified grade is appropriate for the site. 

PART III: EXPLANATORY NOTES TO THE

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June 2003 

H23
What information to report?

Where site grades have been modified, regional

and local councils will report the modified grade 

to the public. The modified grade provides

information on the condition of the site, 

including when it is not suitable for recreational 

use (i.e. Good – except for two days following

rainfall). While the ‘actual’ water quality at the 

site hasn’t been improved by removing the 

source of contamination, the risk has been

mitigated through effective management

interventions. 

The Ministry for the Environment is interested

in reporting the original SFRGs, as these reflect 

the actual water quality and potential for faecal 

contamination. Reporting the original SFRG 

will enable the Ministry to pick up

improvements to the overall condition of 

beaches as a result of infrastructural or landuse 

changes over time. 

Note H(xiii): Percentile guideline values 

for seawater (WHO 2001) and freshwater 

Seawater

For marine waters, only faecal streptococci

(enterococci) showed a dose–response 

relationship for both gastrointestinal illness 

(Kay et al 1994) and Acute Febrile Respiratory 

Infection (AFRI) (Fleisher, Kay, Salmon et al 

1996). A recent reanalysis of this data (Kay 

et al 2001) using a range of contemporary

statistical tools has confirmed that the 

relationships originally reported are robust to

alternative statistical approaches. 

The guideline values for microbiological quality 

given in Table H1 are derived from the key

studies described in the previous paragraph.

The cut-off or bounding values (40, 200, 500)

are expressed in terms of the 95th percentile of 

numbers of faecal streptococci per 100 mL, and

represent readily understood levels of risk, 

based on the exposure conditions of the key

studies. 

For the purposes of water-quality monitoring, 

the terms ‘faecal streptococci’, ‘intestinal 

enterococci’ and ‘enterococci’ are considered to 

be synonymous (Figueras et al 2000). Exposure

to recreational waters with these measured

indicators refers to body contact that is likely to

involve head immersion, such as swimming, 

surfing, white-water canoeing, scuba diving and

dinghy-boat sailing. 

PART III: EXPLANATORY NOTES TO THE

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June 2003 

H24
Table H1: Guideline values for microbiological quality of marine recreational waters

95th percentile value of

enterococci/100 mL 

(rounded values)

Basis of derivation Estimated risk 

≤ 40 This value is below the NOAEL in most 

epidemiological studies. 

< 1% GI illness risk, < 0.3% AFRI risk. This relates to an 

excess illness of less than one incidence in every 

100 exposures. The AFRI burden would be negligible. 

41–200 The 200/100 mL value is above the

threshold of illness transmission 

reported in most epidemiological studies 

that have attempted to define a NOAEL

or LOAEL for GI illness and AFRI.

1–5% GI illness risk, 0.3–< 1.9% AFRI illness risk. The

upper 95th percentile value of 200 relates to an average 

probability of one case of gastroenteritis in 20 exposures.

The AFRI illness rate at this water quality would be 19 per

1000 exposures, or approximately 1 in 50 exposures. 

201–500 This level represents a substantial 

elevation in the probability of all 

adverse health outcomes for which 

dose–response data is available. 

5–10% GI illness risk, 1.9–3.9% AFRI illness risk. This range 

of 95th percentiles represents a probability of 1 in 10 to 1 in 

20 of gastroenteritis for a single exposure. Exposures in this 

category also suggest a risk of AFRI in the range of 19–39

per 1000 exposures, or a range of approximately 1 in 50 to 

1 in 25 exposures. 

> 500 Above this level there may be a 

significant risk of high levels of minor 

illness transmission.

> 10% GI illness risk, > 3.9% AFRI illness risk. There is a 

greater than 10% chance of illness per single exposure. The 

AFRI illness rate at the 95th percentile point of 500 

enterococci per 100 mL would be 39 per 1000 exposures, or

approximately 1 in 25 exposures. 

Source: Adapted from WHO 2001.

Notes: 

1 AFRI = acute febrile respiratory illness; GI = gastrointestinal; LOAEL = lowest observed-adverse-effect level; NOAEL = no-observedadverse-effect level. 

2 The ‘exposure’ in the key studies was a minimum of 10 minutes’ bathing involving three immersions. It is envisaged that this is 

equivalent to many immersion activities of similar duration, but it may underestimate risk for longer periods of water contact or for

activities involving higher risks of water ingestion (see also note 7). 

3 The ‘estimated risk’ refers to the excess risk of illness (relative to a group of non-bathers) among a group of bathers who have been 

exposed to faecally contaminated recreational water under conditions similar to those in the key studies. 

4 The functional form used in the dose–response curve assumes no excess illness outside the range of the data (i.e. at concentrations above 

158 faecal streptococci/100 mL). Thus, the estimates of illness rate reported above are likely to be underestimates of the actual disease 

incidence attributable to recreational-water exposure.

5 This table would produce protection of ‘healthy adult bathers’ exposed to marine waters in temperate north European waters.

6 It does not relate to children, the elderly or immunocompromised people, who would have lower immunity and might require a greater

degree of protection. There is no available data with which to quantify this, and no correction factors are therefore applied.

7 Epidemiological data on freshwaters or exposures other than bathing (e.g. high-exposure activities such as surfing, dinghy-boat sailing 

or white-water canoeing) are currently inadequate to present a parallel analysis for defined reference risks. Thus, a single 

microbiological value is proposed, at this time, for all recreational uses of water, because insufficient evidence exists at present to do 

otherwise. However, it is recommended that the severity and frequency of exposure encountered by special interest groups (such as 

bodysurfers, board riders, windsurfers, sub-aqua divers, canoeists and dinghy sailors) be taken into account. 

8 Where disinfection is used to reduce the density of indicator bacteria in effluents and discharges, the presumed relationship between 

faecal streptococci (as indicators of faecal contamination) and pathogen presence may be altered. This alteration is, at present, poorly

understood. In water receiving such effluents and discharges, faecal streptococci counts may not provide an accurate estimate of the risk 

of suffering from mild gastrointestinal symptoms or AFRI. 

9 Risk attributable to exposure to recreational water is calculated after the method given by Wyer et al (1999), in which a log 10 standard

deviation of 0.8103 was assumed. If the true standard deviation for a beach were less than 0.8103, then reliance on faecal streptococci 

would tend to overestimate the health risk for people exposed above the threshold level, and vice versa.

10 Note that the values presented in this table do not take account of health outcomes other than gastroenteritis and AFRI. Where other

outcomes are of public health concern, then the risks should be assessed and appropriate action taken.

11 Guideline values should be applied to water used recreationally and at the times of recreational use. This implies care in the design of 

monitoring programmes to ensure that representative samples are obtained. It also implies that data from periods of high risk may be

ignored if effective measures were in place to discourage recreational exposure. 

PART III: EXPLANATORY NOTES TO THE

GUIDELINES. 

June 2003 

H25
Freshwater 

The marine water guideline values have been

derived from epidemiological studies, but this

type of study is seldom carried out for 

freshwater and has not been conducted for New

Zealand. Instead values are based on a 

quantitative risk assessment for Campylobacter

infection using the results obtained in a recent

nationwide study (McBride, Till, Ryan et al 

2002). Campylobacteriosis accounts for more 

than half of New Zealand’s burden of notifiable 

disease, and for this reason it was selected as the 

end point for this analysis. Also in that study a 

reasonable correlation was found between 

concentrations of Campylobacter and of E. coli. 

Table H2: Guideline values for microbiological quality of freshwater recreational waters 

95th percentile value 

of E. coli/100 mL

(rounded values)

Basis of derivation Estimated risk of Campylobacter infection 

≤ 130 This value is the NCRL for 

Campylobacter infection.

< 0.1% occurrence. 

This relates to less than one case of Campylobacter infection 

in every 1000 exposures. 

131–260 The 260/100 mL value is above the

threshold of Campylobacter infection 

(above the NCRL). 

0.1–1% occurrence. 

The upper 95th percentile value of 260 relates to an average 

probability of one case of Campylobacter infection in every 

100 exposures. 

261–550 This level represents a substantial 

elevation in the probability of 

Campylobacter infection compared to 

the New Zealand background rate. 

1–5% occurrence. 

This range of 95th percentiles represents a probability of 1 in 

100 to 5 in 100 of Campylobacter infection.

> 550 Above this level there may be a 

significant risk of high levels of 

Campylobacter infection.

> 5% occurrence.

The upper 95th percentile value of 550 represents a greater 

than 1 in 20 chance of Campylobacter infection.

Notes: 

1 NCRL = no-calculated-risk level. This is based on the 55th percentile of E. coli distributions because the calculated community

Campylobacter risk at a given recreational site starts to rise above zero at this percentile. (See the all-data-for-all-catchments case 

Tables A3.3.2 and A3.7.3 in the Freshwater Microbiology Research Programme Report (FMRPR), Pathogen Occurrence and Human 

Health Risk Assessment Analysis (McBride et al 2002).)

2 The routes of infection include both ingestion and inhalation from contact recreation with mode (most likely value) for duration = half 

hour, and volume ingested/inhaled =50 mL (Monte Carlo modelling of health risk, FMRPR). This may underestimate risk for longer

periods of water contact or for activities involving higher risk of water ingestion (e.g. higher exposure activities such as dinghy-boat 

sailing or white-water canoeing). It is recommended that the severity and frequency of exposure encountered by special interest groups 

be taken into account.

3 The “estimated risk” refers to the community risk at a given recreational site (1000 people at the same beach each day) of 

Campylobacter infection (Table A3.7.3 in the FMRPR) from exposure to faecally contaminated recreational water similar to the 25 sites 

in the Freshwater Microbiological Research Programme. 

4 These risks does not relate to children, the elderly or immunocompromised people, who would have lower immunity and might require a 

greater degree of protection. There is no available data with which to quantify this, and no correction factors are therefore applied.

5 Where disinfection is used to reduce the density of indicator bacteria in effluents or discharges, the presumed relationship between 

E. coli (as indicators of faecal contamination) and pathogen presence may be altered. This alteration is, at present, poorly understood. 

In waters receiving such effluents and discharges, E. coli may not provide an accurate estimate of the risk of infection. 

6 Note that the values presented in this table do not take account of health outcomes other than the risk of Campylobacter infection. 

Where other outcomes are of public health concern, the risks should be assessed and appropriate action taken.

7 Guideline values should be also applied to waters at the time of recreational use. This implies care in the design of monitoring 

programmes to ensure representative samples are obtained. It may also imply that data from periods of high risk may be ignored if 

effective measures are in place to discourage recreational exposure.

PART III: EXPLANATORY NOTES TO THE

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H26
Note H(xiv): Derivation of alert and 

action levels for seawater and freshwater 

The alert and action levels are management

tools, ensuring that risks are kept below illness 

risks of about 2% per 1000 swimmers. They 

represent, respectively, 80% and 90% one-sided

upper tolerance limits, assuming that the waters 

are borderline for compliance with previous

guidelines and a stated variability applies 

(measured as the standard deviation of

logarithms). 

See Appendix 2: Developing the Guidelines. 

Note H(xv): State of the environment 

analysis and reporting 

Monitoring and reporting the state of the 

environment

This section discusses the Ministry’s 

Environmental Monitoring and Reporting

system, which uses environmental performance 

indicators to report on the state of the

environment. The Microbiological Water 

Quality Guidelines for Marine and Freshwater 

Recreational Areas serve as the monitoring 

protocol for the marine and freshwater 

recreation indicators. In this document the 

monitoring approach, analysis and data

management procedures are described to ensure

the generation of robust information for 

reporting of the indicators. 

Good-quality information is increasingly 

important for central and local government to

meet public expectations, be accountable and 

demonstrate performance. Information is used

to produce State of the Environment reports; to

review national legislation, regional and district

plans; to assess compliance of resource 

consents; for environmental education, and for 

the strategic and annual planning process. 

Partnerships for monitoring and reporting

The Ministry for the Environment has been

working with Regional, City and District 

Councils, Medical Officers of Health and the

Ministry of Health to develop approaches for 

monitoring and reporting the state of

recreational beaches. 

Should the Ministry for the Environment want

to use the information generated for National

State of the Environment reporting then the 

Ministry would work in partnership with

Councils to agree on the principles for 

information sharing.

Software 

The Ministry for the Environment has 

developed software to assist councils with the 

process of grading beaches, and calculating the 

two state of the environment indicators. The

software (Bathewatch.exe) follows the same

format as the guidelines and uses historical data 

and information from the Catchment 

Assessment Checklist to calculate the 

Microbiological Assessment Category and the 

Sanitary Inspection Category. The MAC and

SIC are used to generate a Suitability for 

Recreation Grade and percentage compliance 

with the guidelines for the site. 

The software and a user guide can be 

downloaded from the Ministry’s website: 

www.mfe.govt.nz. 

PART III: EXPLANATORY NOTES TO THE

GUIDELINES. 

June 2003 

H27
Data storage and archiving 

Most councils store their data as Excel files. 

The user guide for the Bathewatch software

specifies the data file format requirements for 

loading data into the software. For the MAC

component of the SFRG assessment, the data

collected from field observations must be stored

in a comma-delimited value (*.csv) file format. 

The data must be stored in this specific file 

format or it will fail to load properly. It is a 

simple process to convert files from an Excel 

format into a *.csv format. The procedure is

detailed in the Bathewatch user guide. 

It is expected that councils will archive their 

monitoring data using the council’s normal

computer back-up system. The council may 

wish to consider burning the data onto a CD or 

an otherwise secure file. 

Note H(xvi): Reporting to the public 

Public health reporting

If exceedances of alert and/or action levels are 

recorded during weekly monitoring of

recreational beaches, the appropriate responses 

should be undertaken, as described in section 

D.4 of the guidelines and Note H(xvii) of these 

notes. 

State of the Environment reporting 

The two beach water quality indicators can be 

reported using the data generated by councils. For:

• 

• 

the percentage of monitored beaches in each 

beach grade 

the indicator provides a measure of the general

state of bathing beaches by combining the risk 

of contamination from the catchment with the 

microbiological monitoring at the beach. It 

reports the overall suitability of beaches for 

bathing. Beaches will be classified into one of

five grades (from very good to very poor). 

And for: 

the percentage of the season beaches or 

coastal areas are suitable for bathing or

shellfish gathering

the indicator will give an indication of the 

amount of time in a season the water quality 

was considered suitable for bathing or shellfish

gathering. It provides a measure of the variation 

of microbiological quality of bathing waters 

within a bathing season. 

Indicator fit with the pressure-stateresponse model 

The Ministry for the Environment has used the 

pressure-state-response (PSR) model for

developing environmental performance 

indicators – refer to Note G(iii): State of the 

Environment Reporting, page G3.

The indicators on which these guidelines are 

based - percentage of monitored beaches in each 

beach grade, and percentage of the season 

beaches or coastal areas were suitable for 

contact recreation or shellfish gathering - are

state indicators that provide general information 

on the public health risk presented by

recreational waters. Pressure indicators would 

measure the surrounding land use and 

discharges to water to assist identification of 

potential causes of changes in water quality. 

Response indicators would identify

management or policy changes (e.g.

infrastructural improvements, land-use 

management policies, national environmental

standards) to manage issues for recreational

waters. 

Note H(xvii): Management responses to 

exceedances for marine and freshwater 

The planned responses to exceedances of the 

guidelines should be considered and

documented when establishing a regional

monitoring protocol, and communicated to all

PART III: EXPLANATORY NOTES TO THE

GUIDELINES. 

June 2003 

H28
agencies that will have a role to play (e.g. 

regional councils, territorial local authorities 

and health agencies). Documentation should 

clearly state who is responsible for carrying out 

what actions in response to exceedances. If the 

response varies from site to site, depending on

the overall grade, this should also be clearly 

stated. 

See Section B for details on who monitors and

reports. 

Single-sample exceedances

The point of having single-sample limits is to

identify variations in water quality within the 

bathing season that pose an immediate risk to 

human health. 

There are two levels of response to singlesample exceedances. 

Alert mode 

The first is alert (or amber) mode, and is 

triggered when a single sample is greater than

140 enterococci per 100 mL for marine waters 

and 260 E. coli per 100 mL for freshwaters. In

this situation, sampling should be increased to

daily to improve the information base and

identify whether or not the problem is ongoing. 

A catchment assessment should be carried out to 

identify all possible sources of contamination. 

The monitoring authority should inform the 

Medical Officer of Health and the other 

council(s) (either regional or local, depending 

on who is doing the monitoring). 

Action mode

The second level of response to a single-sample 

exceedance is action (or red) mode. In the case 

of marine waters this is triggered when two

consecutive samples are greater than

280 enterococci per 100 mL, and for 

freshwaters when a single sample exceeds

550 mL E. coli per 100 mL. In this instance the 

monitoring authority informs the Medical 

Officer of Health and the other council(s) of the 

problem. Sampling is increased to daily and a 

catchment assessment carried out to identify the 

source of the contamination. The public should

be notified of the health risks using appropriate 

methods identified in the regional monitoring

plan. Discussion between the regional council, 

territorial local authority and Medical Officer of 

Health should take place to ascertain who is 

responsible for fixing the problem.

The Ministry for the Environment and Ministry of

Health have developed sign templates in

consultation with councils and health agencies to 

use in response to exceedance events and at highrisk sites. (See Appendix 3 for these sign 

templates.) 

High-risk sites 

High-risk sites are those sites graded Poor or 

Very Poor, and will generally have direct 

discharges, such as sewer outfalls, impacting on

them. While the guidelines and notes provide 

details on assessing these sites and recommend 

that permanent signs be erected to warn the

public of the health risks (see Appendix 3 for 

sign templates), there is no discussion on

remediation work. The agencies responsible for 

managing the infrastructure or land use 

affecting water quality, and those responsible 

for monitoring the sites and public health

protection, may wish to discuss and document

the remediation work required, and the 

timeframes, budgets, etc, for achieving this. 

Communicating health risks 

Communicating health risk is required after 

exceedance of the action level of the guidelines, as 

monitoring has identified increased levels of faecal 

material, which mean the site is unsuitable for 

recreational use. In order to protect public health, 

local authorities are required to notify the public of

those health risks until the problem has been 

remedied. 

PART III: EXPLANATORY NOTES TO THE

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H29
When to issue warnings 

The guidelines identify an action level, at which 

point use of a recreational site is considered 

unsuitable for contact recreation. For marine 

waters this is when two consecutive samples 

taken are greater than 280 enterococci per 

100 mL, and for freshwaters when a single 

sample exceeds 550 E. coli per 100 mL. 

Warnings should be issued as soon as possible 

after the results from the sample are available. If 

contamination is obvious and likely to be 

ongoing, it is not necessary to wait for results 

from samples before issuing a health warning. 

Other agencies involved in monitoring and

reporting should be notified of exceedances 

before notifying the public of health risks. 

Who to contact

The regional monitoring plan will clearly define

lines of communication and responsibilities, 

such as whose role it is to notify the public. 

Results should be communicated as soon as

possible to the agency responsible for public 

notifications. 

What messages to convey 

There are several messages to consider when 

issuing warnings, other than that there is a 

health risk. These are: 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

there is a health risk

the council is investigating the cause of the 

problem (i.e. the council is on to it) 

a list of alternative beaches to visit in the 

region 

an announcement when the problem has 

been fixed. 

How to deliver the message 

There are many ways to communicate 

information to the public. A number of factors

will determine the methods chosen to deliver the 

warnings, including:

the urgency of the message 

how well informed the community is 

the demographic make-up of the community. 

The public awareness and education section 

provides more detail on establishing the best 

methods of delivering messages to the public

(see Appendix 1), but the most widely used

methods for health warnings are:

signs 

newspaper articles 

radio 

notices in local shops 

websites 

0800 numbers.

Signs 

The Ministry for the Environment and Ministry 

of Health have developed sign templates in

consultation with regional councils, local 

authorities and public health agencies. These 

are provided in Appendix 3. 

Fact sheets 

Fact sheets have been written to help

communicate information about the guidelines 

and monitoring programmes. These generic fact 

sheets can be used for media releases, handing 

out at public at meetings, etc. See Appendix 5 

for fact sheets on different topics. 

Summary 

The most important messages to get across are: 

the health risk

the council is responding quickly to the 

event. 

It is also important to convey the unpredictable 

nature of this type of problem and the

difficulties in isolating the cause. 

PART III: EXPLANATORY NOTES TO THE

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June 2003 

H30
Once the problem has been fixed, the public 

should be notified. This will be apparent from

the removal of signs, but should be highlighted

through use of the media, community meetings, 

and contact with user groups, etc. 

The public education and awareness programme 

outline (Appendix 1) provides more information

on engaging public support for the monitoring

programme. 

Management interventions for modified 

grades

Management interventions will vary in type

according to the nature of the predictable event 

leading to the modification and the target 

audience. Interventions may range from

permanent warning signs on beaches, to public 

meetings (see Appendix 1: Public Education 

and Awareness Programme Outline). The 

ability to demonstrate the effectiveness of 

interventions in discouraging the public from

using the site during periods of high risk is

critical. This is what will lead to a modified 

grade. How this is assessed will vary, but must 

be verified by the Medical Officer of Health. 

See Note H(xii) for details on modifying grades.

PART III: EXPLANATORY NOTES TO THE

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Section I: Appendices

Appendix 1: Public 

Education and Awareness 

Programme Outline

The need to incorporate guidance on developing

a public education and awareness programme as 

part of the Microbiological Water Quality 

Guidelines for Marine and Freshwater

Recreational Areas was identified through

feedback from councils and health authorities. 

Communicating risk, changing attitudes and

behaviours towards monitoring programmes and

water-quality issues, and inter-agency 

communication were among the main drivers 

for developing this appendix. 

The goal of the Guidelines is to protect human 

health. In many cases, there is no ‘quick fix’ to 

bacteriological contamination of recreational 

waters, so one of the goals becomes risk 

communication. Relevant information must be 

communicated in an effective, efficient and 

timely way to the public, allowing them to make

informed choices about whether to swim. 

Implementing a public education and awareness 

programme will help the public better 

understand what the guidelines mean to them, 

how they can minimise their chances of 

becoming sick as a result of swimming, and 

what – if anything – they can do to help

improve their local water quality. 

Designing and implementing your own 

programme 

This appendix aims to provide councils and

health agencies with a broad template for 

designing and implementing their own public

education and awareness programme, to help

achieve the broad aim of the guidelines: 

to ensure that the public are informed of

the microbiological health risks in time 

for them to make informed decisions

about whether or not to enter the water. 

APPENDIX 1: PUBLIC EDUCATION AND 

AWARENESS PROGRAMME OUTLINE. 

June 2003 

I1 
Local variation and differences in the learning 

methods of the different stakeholder groups 

(e.g. informed versus uninformed) will to some 

extent determine the best means of delivering a 

message or forum for consultation. Taking the 

process in ‘bite-sized chunks’ and providing

local context is a good basis for local 

programmes. 

For additional information on designing, 

implementing and evaluating an environmental

education programme, contact the education 

officer within your organisation or visit the 

Sustainable Management Fund website

(ww.smf.govt.nz) and download a copy of 

Environmental Education: A guide for 

programme providers – how to develop, 

implement and evaluate strategies and 

programmes. 

Objectives

While the objective of the Guidelines may be

met through risk communication in response to

contamination events, mitigating contamination 

events requires a more detailed approach. 

Longer-term goals to clean up where poor water

quality exists and where the community10

demands good water quality will inevitably 

require some action from individuals. In order 

to facilitate a change in attitudes and behaviours 

from the community, they need to be aware of 

their impact on water quality and what they can

do to minimise those impacts. 

Therefore, the two objectives of a public 

education and awareness programme are: 

 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

10 For the purposes of any public education and awareness

programme, ‘the community’ is defined as people, or groups of 

people such as businesses, councils, public health agencies, iwi,

landowners, etc.

to protect human health through the 

efficient, effective and timely 

communication of the health risks associated

with using recreational waters 

to prevent, and where necessary isolate and 

remedy, bacteriological contamination of

recreational waters. 

Other objectives of this type of programme will 

be to: 

develop a base level of understanding of the

issues within the community

gain public support for the monitoring

programme 

build confidence in the authority carrying

out the monitoring

accentuate the positive areas and use them as 

a selling point for the region

build an image of responsibility for the 

council 

inform beach users of the immediate health 

risk 

manage community concern and public

outrage 

maintain a responsible image 

encourage and facilitate community 

ownership and participation. 

What is public education and awareness? 

The following hierarchy defines public 

awareness and education: 

i. information: pamphlets, posters, etc. 

ii. communication: public meetings, 

submissions, call centres, etc. 

iii. education: consultation, developing

knowledge, awareness, attitudes, values 

and skills that contribute to maintaining

and improving the environment (Ministry 

for the Environment 1999). 

APPENDIX 1: PUBLIC EDUCATION AND 

AWARENESS PROGRAMME OUTLINE. 

June 2003 

I2 
The level at which councils and health agencies 

enter into a programme will depend on their 

statutory functions and their agreed role in

implementing the guidelines. It will also

depend on what level of participation or action 

the community expects. For example, one

community may wish to be directly involved in

a local monitoring programme, while others

may be content to see weekly results published

in the local paper. 

Whatever the intention, this should be clear 

from the outset, and care taken not to raise 

expectations beyond this, as it will inevitably 

result in community backlash and mistrust in the 

council or health agency. 

What is the environmental issue? 

New Zealand has an extensive coastline and

freshwater recreational area, which is used for a 

wide variety of recreational activities. Primarily 

usage is highest during the summer months 

(November to March), but there may be areas of 

the country or user groups that use recreational 

sites all year round. While water quality at New 

Zealand’s recreational beaches and freshwater 

sites is good most of the time, there are 

occasions when water may become

contaminated with bacteria or viruses that cause 

respiratory or gastrointestinal illnesses, or skin

infections. Susceptibility to illness is increased

in those who have a compromised immune 

system, the very young and the elderly, and in

severe cases may result in hospitalisation.

At the local/regional level specific 

environmental issues may vary. Consultation 

with local communities will help to identify 

these issues. 

Who are the stakeholders? 

It is important when designing an education

strategy to identify the key stakeholders and 

how they use the beach in question. This will 

vary across the country and within each region

or district, and may depend on the type of

recreational site. There will also be variability 

over time within each user group; for example, 

there may be walkers who use the beach every 

day throughout the year, and those that only 

visit two or three times a season. 

The main point is that baseline levels of

awareness between and within stakeholder 

groups will vary considerably, as will the way in

which they want/need to be involved in the 

programme. It is important to recognise this 

when designing a programme and to ensure the 

programme can be delivered at a variety of 

levels to suit the needs of those involved. 

The following is a list of potential stakeholders, 

divided into those within monitoring agencies 

and those within the wider community. 

Within council 

Council staff 

Council staff will inevitably have contact with

the public, particularly after a pollution event

when signs are posted advising against 

swimming. Frontline staff in particular should

be trained appropriately to deal with possible 

irate members of the public, and be informed 

when they might expect such calls. Field staff 

may also come into contact with members of the 

public who are angry with the council for 

closing a beach. It is vital these staff are

prepared for such encounters, and that the 

information they give the public is consistent 

with what other staff are communicating. 

APPENDIX 1: PUBLIC EDUCATION AND 

AWARENESS PROGRAMME OUTLINE. 

June 2003 

I3 
Councillors and potential councillors 

It is important that councillors and potential 

councillors are aware of the issues surrounding 

beach water quality as they have a great deal of 

influence on what priority programmes are 

given. They are also directly affected by bad 

press and will need to be prepared should a 

pollution event result in media coverage. 

Outside the council 

Beach users 

This group includes a variety of users that will

vary locally. It is important to identify all user 

groups and how best to involve them in the

programme, or at least how to communicate 

information. Some potential user groups are:

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

local clubs (e.g. surf life-saving, Lions, 

waterski, sea scouts, walkers, kayakers) 

national and international groups (e.g. 

triathletes, boaties) 

schools 

parent networks

iwi 

Pacific peoples’ groups 

other community groups 

ratepayers (including community boards). 

These groups may be unaware of water-quality 

issues. They are also directly affected by poor 

water quality, beach closures and health 

impacts. The level of understanding and 

awareness should be established and 

programmes set accordingly. It is important 

that beach/river users are brought up to speed on

the issue and kept informed throughout the 

monitoring season. 

Local community (non-beach users)

Not everyone in the local community is 

interested in going to the beach. However, 

everyone will be affected by publicity about

poor water quality at bathing beaches in their 

region. For example, homeowners may suffer a

drop in property values and local businesses

may notice a drop in trade. As with beach users 

it is important the local community is informed

about the issue, and kept informed throughout 

the monitoring season. 

Environmental interest groups

Environmental groups may have a greater level 

of understanding of the issues, so

communicating with them at the same level as 

the above groups may be redundant or even

detrimental. Instead, support from these groups

should be sought. Environmental groups have 

the ability to sway the opinion of the general 

public, and if supportive of the council’s 

programme may be a real asset. 

Media 

The way the media interpret and report events

will inevitably influence the community. 

Efforts should be made to ensure the message 

being reported by the media is accurate and 

factual, and that the positive aspects of the 

monitoring programme are highlighted. 

Business 

This includes: 

retail outlets, cafes, dairies, etc 

tourism operators (including the Tourism

Board)

dive clubs. 

APPENDIX 1: PUBLIC EDUCATION AND 

AWARENESS PROGRAMME OUTLINE. 

June 2003 

I4 
Local businesses can be dramatically affected 

when a water-quality problem is identified. 

They can also be very influential in the 

community. Keeping them informed and 

getting their support for the monitoring

programme at all stages is essential. 

Encouraging tourist operators to use clean 

beaches as a selling point will benefit the whole 

region, and provide an incentive to clean up 

beaches that experience water-quality problems. 

Public health agencies, hospitals, GPs and

laboratories 

These groups need to be made aware that gastric 

and respiratory illnesses as well as skin 

infections can be caused through contact with

bacteriologically contaminated bathing water. 

These agencies have a lot of contact with the

public, so they are able to disseminate 

information effectively. This can be done

through posters, fact sheets, and advice from 

staff. 

What are the key outcomes sought? 

If the objective of a public education and 

awareness programme is to encourage public 

participation, then the key outcomes of a 

programme should be developed in consultation 

with the community and be prepared to deliver 

what is jointly agreed. Developing outcomes in

consultation with local communities will ensure 

they relate closely to regional or local issues. 

On the other hand, if the intention is purely to

communicate the results of your monitoring and 

to alert the public to specific contamination

events, then consultation would be

inappropriate, as it would raise false 

expectations and inevitably result in backlash. 

Some key outcomes of a public education and 

awareness programme might be: 

increased understanding within the 

community of what the monitoring

programme is about including:

• 

• 

• 

– how, when, where and why monitoring is 

done 

– what the indicator bacteria are and what 

their presence means 

– costs and other resourcing issues 

– how the results will be used

– the scale of the issue: put it into a local, 

national and international context 

– sources of contamination and problem

areas (e.g. stormwater, ageing 

infrastructure)

– causes of contamination are not always 

predictable 

– even if a beach is ‘clean’, councils will 

monitor anyway to identify unexpected

risks 

participation in ‘care’ groups 

a decrease in the number of swimmingrelated illnesses. 

What methods should you use and what 

materials do you need? 

The methods and materials used to get the 

message across will vary locally and with each

stakeholder group. Consultation with the 

community will help to identify the level at 

which various groups wish to be involved and 

how they prefer to receive material and 

information. Consulting within the council will 

also help to identify existing programmes that 

can be tapped into to avoid reinventing the 

wheel and creating confusion.

The urgency of the message/information will

also determine the methods used; e.g. if there is

a contamination event and the message is a 

public health warning. 

APPENDIX 1: PUBLIC EDUCATION AND 

AWARENESS PROGRAMME OUTLINE. 

June 2003 

I5 
See Note H(xvii) for information on issuing

health warnings. 

The following are a variety of methods that can 

be used to deliver a range of materials:

media – press (local and regional papers, 

magazines), radio 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

internet 

fact sheets (see Appendix 5) 

pamphlets 

community meetings

school visits

notices in local businesses 

notices/pamphlets in medical centres and 

hospital waiting rooms 

presentations to council committee meetings

meetings with specific user groups 

establishing ‘care’ groups 

signs at beaches (see Appendix 3) 

0800 numbers

getting influential community members on

board. 

Practical considerations for delivering 

the programme 

Identifying up front the practical aspects of how 

the programme will be delivered will avoid

confusion and frustration when it comes time to

implementing it. The following factors should

be considered in advance of implementing the 

programme. 

Who? 

Clearly define who is responsible for delivering 

the programme. This is critical. Identify which

agency will be responsible and the roles of

individuals/officers within each organisation. 

The roles and responsibilities set out in

Section B of Part I will help to identify which

agencies and officers should be involved in a 

public education and awareness programme.

Clearly defined lines of communication within

monitoring agencies, between agencies

(regional council, territorial local authority and 

Medical Officer of Health) and to the public 

should be documented in the monitoring plan. 

This will include identifying the agency and

officer responsible for notifying the public of

health risks. 

When? 

Determining the timing for the programme is

also very important, especially when

communicating information about

contamination events, which requires an

immediate response. Starting the programme

with sufficient time to lead in to the bathing

season may also be useful. Timing of

programmes will vary considerably across the 

country and will need to be decided locally. 

As there is likely to be a number of agencies

involved in the programme, it is important to 

define exactly when each of those agencies 

becomes involved and how. 

Where? 

Defining the extent of the programme will also

affect how it is delivered and will depend on

which agency is implementing the programme. 

Local authorities that co-ordinate programmes 

regionally may also wish to co-ordinate the 

public education and awareness programme. 

More specifically, this will affect what venues 

are used for public meetings, etc. 

APPENDIX 1: PUBLIC EDUCATION AND 

AWARENESS PROGRAMME OUTLINE. 

June 2003 

I6 
How will you monitor implementation 

and effectiveness? 

It is important before beginning a programme

such as this to establish a base level of 

awareness. This will enable progress to 

measured using this pre-programme 

information. User-group surveys, household 

surveys and council staff surveys are some of 

the methods that can be used to achieve this.

It is also important to review the programme on

a regular basis. It will take time before changes 

in attitudes and behaviours are noticed, so a 

long-term plan for review is essential. Again,

annual surveys are useful for this purpose.

Summary 

An open, honest and transparent policy with the 

public is essential if the council is to gain

support for their monitoring and remediation

programmes. Authorities who have adopted this 

approach have received additional funding for 

infrastructure upgrades and increased 

community and media backing. 

A number of councils have implemented 

programmes that utilise the community 

resource, such as training community volunteers 

to monitor water quality. Volunteers are trained 

and perform some monitoring functions. This

approach has proven to be successful in raising 

levels of awareness and understanding of the

issues surrounding beach water quality and in

gaining support for monitoring programmes.

For further information on designing and 

implementing environmental education 

programmes, refer to the Ministry for the

Environment’s Environmental Education: A 

guide for programme providers – how to

develop, implement and evaluate environmental 

education programmes (1999).

APPENDIX 1: PUBLIC EDUCATION AND 

AWARENESS PROGRAMME OUTLINE. 

June 2003 

I7 
APPENDIX 1: PUBLIC EDUCATION AND 

AWARENESS PROGRAMME OUTLINE. 

June 2003 

I8 
Appendix 2:

Developing the Guidelines

In this appendix: 

section 1 summarises the two basic approaches 

that have been taken internationally and in

New Zealand to the relation between

recreational water users’ health risks and the 

degree of faecal contamination of the water, 

either by human or animal waste residues 

• 

• 

• 

section 2 explains how the results of these 

studies have been incorporated into these 

Guidelines 

section 3 discusses some implementation 

issues. 

Two basic approaches 

Microbiological water-quality guidelines for 

recreational areas may be developed from two 

main strands of enquiry into health effects: 

epidemiological studies or quantitative risk 

assessment. In the former the focus is on direct 

measurement of health effects while in the latter 

the focus is first on pathogen concentrations, with

health effects then being inferred using known 

dose-response relationships. Both types of study

have been used to develop these guidelines:

epidemiological for the marine waters and

quantitative risk assessment for the freshwaters. 

The main reason for choosing to base marine water 

guidelines on the epidemiological approach is that 

there is a wealth of results from such studies (Prüss

1998), including some for New Zealand (McBride, 

Salmond et al 1998). On the other hand very few

such studies are available for freshwaters, and 

those that are available are nearly all confined to 

lakes, not rivers. However, we are now in

possession of a large amount of data for pathogens

and indicators in freshwaters and this has 

facilitated a quantitative risk assessment approach. 

Accordingly, the guidelines for freshwaters are 

based on this approach. 

APPENDIX 2: DEVELOPING THE GUIDELINES.

I9 June 2003 
It is important to note that the wealth of results 

from international studies now available point

overwhelmingly to an association between illness 

risk to recreational water users and the 

concentration of suitable faecal indicators (as 

reviewed by Prüss 1998). They show that careful

studies are needed to reveal the relationship, 

particularly because many of the illnesses 

concerned are mild and no records are kept of their 

occurrence (i.e. they are not ‘notifiable’).11 

Furthermore, these illnesses include both

gastrointestinal and respiratory categories (when 

sought, respiratory illness effects have often been

found; e.g. Fattal et al 1986; Corbett et al 1993; 

Fleisher, Kay, Salmon et al 1996; McBride, 

Salmond et al 1998).12 While some studies fail to

detect an association (e.g. New Jersey Department 

of Health 1989), this appears to be caused either by

a lack of sufficient statistical power or a lack of an 

‘exposure gradient’; i.e. a sufficient range of

contamination in the waters studied (as was the 

case in the New Jersey study). 

Epidemiological studies

In these studies one aims to discover the illness 

record of a number of water users who used a 

recreational site on a particular day – a day on

which water-quality samples were also taken. This 

calls for an intensive effort in interviewing beach 

users on the sampling day, and following them up 

some days later to obtain a record of health effects; 

i.e. a record of self-diagnosis is obtained (medical 

records are not available for examination because 

most swimming-associated illnesses are mild and

not notifiable). Associations between health 

effects and the swimmers versus non-swimmers 

are sought, to get an estimate of any swimmingassociated, pollution-related effects. 

 

11 More severe illnesses (e.g. typhoid) do occur among swimmers at 

grossly polluted beaches (e.g. in Egypt, El-Sharkawi & Hassan 

1979; Cabelli 1983a). 

12 Ear, nose, throat and skin symptoms are also found, often being 

attributed to bather-to-bather transmission, rather than to microorganisms of faecal origin.

The group of people interviewed may be those 

who have decided of their own volition to attend

the beach, without knowing that a study was in 

progress, in which case it is an uncontrolled 

prospective study. On the other hand people may

be recruited into the study and taken to a particular 

beach where they may swim, in which case it is a 

controlled cohort study. Most epidemiological 

studies have been of the former kind, but more 

recent efforts have used the controlled approach. 

Results from controlled cohort studies have 

recently been endorsed by the World Health 

Organization and are being incorporated into their 

international guidance (WHO 2003). Accordingly, 

these New Zealand guidelines are also based on 

that approach, marking a distinct change from

previous editions of the New Zealand guidelines 

(1992, 1998, 1999). 

Nevertheless, comprehending the history of the 

development of these studies may be helpful, as 

given in the following sections. 

US studies 

Concerns about health risks to bathers in

contaminated water in America in the 1940s led to 

the US Public Health Service conducting a series 

of uncontrolled prospective follow-up

epidemiological studies at river, lake and coastal 

sites from 1948 to 1950 (Stevenson 1953). This 

was a large study that reported two statistically 

significant associations between swimmers’ health 

risk and water quality, measured as concentration

of total coliforms. These two findings were for 

beaches on Lake Michigan, at Chicago, and for the

Ohio River at Dayton, Kentucky (none were found

for the two marine sites, in New York City). 

APPENDIX 2: DEVELOPING THE GUIDELINES.

I10 June 2003 
The study design consisted of three major 

elements: 

• 

• 

• 

• 

• 

• 

 

approaching people at the beach to see whether 

they would agree to being questioned a few

days later about their health

making water-quality measurements at the 

beach on the same day as beach-goers are 

approached

within a few days, questioning those who

agreed to the follow-up as to any subsequent

illness, as well as a host of other possibly 

confounding factors (such as other swimming, 

foods eaten, animal contact and household 

sickness). 

Elements of the design of studies used to develop 

guidelines have been questioned over the years 

(e.g. Cabelli et al 1975; Moore 1975). This has 

included the following objections:

‘swimming’ did not necessarily include head

immersion

total coliforms are not very effective indexes of

faecal pollution 

non-swimmers were not at the beach. 

Such flaws were addressed in major further studies 

carried out in the US in the late 1970s and early 

1980s for both marine waters (Cabelli 1983a) and 

freshwaters (Dufour 1984), with the motivation of 

providing public policy agencies with a 

relationship between “swimming-associated,

pollution-related illness risk” and typical 

concentrations of faecal indicators (Cabelli et al 

1975). The idea was that those agencies could use 

an ‘acceptable’ health risk to derive limits for 

faecal indicator concentrations. These researchers 

never did advocate any acceptable particular 

values of these risks. Motivation for the other 

studies was similar. Some workers have actually

recommended guidelines or standards (Grabow

et al 1989; Wyer et al 1999). 

Other marine water epidemiological studies have 

been carried out in the USA, at New Jersey 

beaches (New Jersey Department of Health 1989) 

and at Santa Monica Bay, near stormwater outfalls 

(Haile et al 1996). The latter study did discover 

health effects related to proximity to the outfalls. 

UK studies 

Meanwhile, in the UK a view had held sway since 

the late 1950s that swimmers’ health risk had no

relationship to degree of faecal contamination, 

unless beaches were “aesthetically revolting” 

(MRC 1959) or “aesthetically very unsatisfactory” 

(PHLS 1959). That view was challenged 

increasingly over the years as being untenable (e.g. 

Kay & McDonald 1986a; 1986b): it was derived 

from a retrospective case control study for two

severe and notifiable illnesses, and generalised to 

all illnesses (many of which are not notifiable, and

so lack any substantial data). Accordingly, some

prospective uncontrolled studies have also been 

carried out in the UK also (Pike 1994).13

Another UK group has proposed that such studies

are better carried out using a recruited, controlled 

cohort approach (Jones et al 1991). This cohort is 

randomly split into swimming and non-swimming

parts. All eat the same foods. The swimmers are 

directed where to swim and for how long

(immersing the head three times). Many waterquality measurements are made at the assigned

swimming points. The follow-up consists of both 

self-reporting and clinical examinations. 

13 This report reviews two sets of UK studies: controlled studies at 

four beaches (subsequently reported by Kay et al 1994 and by 

Fleisher, Kay, Salmon et al 1996), and uncontrolled studies at 

another eight beaches (partly reported by Balarajan et al 1989 and 

Alexander et al 1992). A full open-literature paper on the eightbeach study has not been sighted.

APPENDIX 2: DEVELOPING THE GUIDELINES.

I11 June 2003 
The findings of these careful studies (endorsed by

Telford 1996) have reported that faecal 

streptococci were related to adverse 

gastrointestinal health effects (threshold 32 per 

100 mL, Kay et al 1994) and to acute febrile

respiratory illness (threshold 60 per 100 mL, 

Fleisher, Kay, Salmon et al 1996). (This definition 

of respiratory illness requires an accompanying 

fever, and so is more stringent than that used in 

other studies, such as the one carried out in New 

Zealand by McBride, Salmond et al 1998.)

Note that the analysis of these UK studies postulates 

the existence of a threshold effect (a value of water 

quality below which there is no illness risk to

swimmers whatsoever and above which there is). 

Analyses of other studies (e.g. Cabelli 1983a;

Dufour 1984) have used continuous relationships 

between water quality and swimmers’ health. This 

is more consistent with the mixture of ages and 

health status of usual beach-goers: while an 

individual may have a particular threshold, it is

unlikely that a whole population would share the 

same value. For that reason the UK analysis notes 

that the threshold should not be considered as an 

“absolute” value, noting that it may be set to a lower 

value were the study to have included a larger 

number of people (Wyer et al 1999). 

Other relevant UK marine water studies are Brown

et al 1987; Balarajan et al 1989 (see also its 

discussion by Hall & Rodrigues 1992); Alexander 

et al 1992 and Fewtrell et al 1994. Freshwater 

studies for canoeists and rafters have been reported

by Fewtrell et al (1992, 1994) and by Lee et al 

(1997). 

New Zealand studies 

Prospective epidemiological studies were carried 

out at seven New Zealand beaches in the 1995/96

bathing season (McBride, Salmond et al 1998). 

This was particularly driven by concerns in the 

Auckland region about possible health effects at 

marine beaches. 

Prior to statistical analysis each beach was placed 

into one of three categories: (i) impacted by human 

wastes, (ii) impacted by animal wastes, or (iii) 

pristine. 

An association between enterococci concentration 

and respiratory illness symptoms among those 

entering the water was identified.

14 This included 

“paddlers”, who entered the water but did not

immerse their heads (e.g. tending small children). 

Relative risks in the highest enterococci quartile 

were rather high: 4.5 for the paddlers and 3.3 for

long-duration swimmers. The unexpectedly 

limited range of beach contamination during the 

survey precluded the possibility of developing a 

detailed statistical model of health risk versus 

indicator density, as had been hoped.15 No

substantial differences in illness risks were found

between the two types of impacted beach, but the 

health risks for both were separable from that at 

pristine beaches. 

Studies in other countries 

Other relevant epidemiological studies have been

conducted in the following countries (an asterisk *

denotes a retrospective study): 

• 

• 

• 

• 

 

Australia: Corbett et al 1993; Harrington et al 

1993

Canada: EHD 1980; Seyfried et al 1985a and 

1985b; Lightfoot 1989

Egypt: Cabelli 1983a; El-Sharkawi & Hassan 

1979* 

France: Foulon et al 1983; Ferley et al 1989* 

14 Some statistically significant associations with faecal coliform and 

E. coli concentrations were also noted. However their strength was 

lower because they tended not to rise through the quartiles of that 

indicator’s concentrations (whereas enterococci did so rise) and 

their relative risks were also lower than for enterococci.

15 The enterococci quartiles cut-offs were 1.5, 3.75 and 13 enterococci 

per 100 mL.

APPENDIX 2: DEVELOPING THE GUIDELINES.

I12 June 2003 
• 

• 

• 

• 

• 

• 

 

Holland: Medema et al 1995, 1997

Hong Kong: Holmes 1989; Cheung et al 1990; 

Kueh et al 1995 

Israel: Fattal et al 1986, 1987, 1991

New Zealand: Bandaranayake et al 1993;16

McBride, Salmond et al 1998 

Spain: Mujeriego et al 1982*; Mariño et al 

1995b 

South Africa: Von Schirnding et al 1992; 1993

Comparing controlled and uncontrolled studies 

Most of the studies listed above are of the 

uncontrolled type, so it is appropriate to consider 

which of the two main approaches to

epidemiological studies is the better. 

The first consideration is to note that there is no

optimal way of conducting epidemiological

surveys – each approach has its drawbacks (Lacey 

and Pike 1989). Clearly some are better than 

others, and flaws in older studies have been

identified and remedied in later studies, such that a 

reasonably consistent body of evidence has now 

been gathered (Prüss 1998). In spite of the 

uncertainties involved in epidemiological studies 

with low attack rates, it is often still considered to

be the best line of approach (cf. a risk calculation

approach), where feasible (Ware 1990). This view

is in spite of the fact that funds that would be spent 

on extensive interviewing in the epidemiological 

approach could be spent on a wider range of

indicators and pathogens in a risk-calculation 

approach. 

16 This reports a preliminary trial at two beaches.

The controlled cohort prospective approach offers

the most accurate methodology, minimising bias 

and providing for a balanced matching of

swimmers and non-swimmers (Fleisher 1990b; 

Fleisher, Jones, Kay & Morano 1993). However, 

its use does require pre-publicity, which may cause 

enhanced self-reporting rates (Wheeler &

Alexander 1992). Also, the cohort used (healthy 

adult volunteers) is not typical of the usual beachgoing population (which includes many ages and 

variable health status), and the type of swimming

activity may not be typical either – especially for 

high wave-energy New Zealand beaches where 

boogey boarding and body surfing are so popular. 

(This is important, because close-to-shore waters 

are often the more polluted.) 

The uncontrolled cohort prospective approach 

offers the advantages of minimal pre-publicity and 

of using the actual population using the beach. It

suffers from difficulties in assigning water quality 

to particular swimmers (according to where they 

swam) and in having a somewhat unbalanced set 

of swimmers and non-swimmers. 

The view taken in these guidelines is that, given

the endorsement of the WHO (2003), the results of 

the carefully conducted controlled cohort UK 

studies will be used as a basis for marine beach

grading. Note that the illness rates reported by

these studies, both for swimmers and for nonswimmers, tend to be higher than for uncontrolled

studies. 

APPENDIX 2: DEVELOPING THE GUIDELINES.

I13 June 2003 
The quantitative risk assessment approach 

Some early work leading to the setting of waterquality microbiological standards and guidelines 

was based on a risk calculation approach. For

example, Streeter (1951) calculated an individual’s

risk of contracting typhoid fever or “diarrhoeaenteritis” assuming a concentration of 1000 total 

coliforms per 100 mL. For 90 consecutive daily 

exposures to this concentration the calculated risks 

were 1:950 and 1:50 for the two illnesses, 

respectively. Also, Furfari (1968) reports how 

shellfish standards have been calculated.

17

Recent developments in this approach have noted a 

number of shortcomings (see especially Haas et al

1999). In particular:

• 

• 

• 

 

water users experience a range of 

concentrations of pathogens and indicators

from one day to the next, and even within a day

they also have variable rates of ingestion or

inhalation of water, and for varying times 

dose-response relationships (between illness 

risk and indicator density) have been lacking. 

With the advent of powerful computer technology

these issues can now be addressed relatively easily, 

using ‘Monte Carlo’ mathematical modelling. 

This is known as the Quantitative Risk Assessment 

(QRA) approach. Historical data is used to assign

statistical distributions to the ingestion/inhalation

rates, duration of exposure, and the concentration 

of pathogens in the water. Then a random sample 

is taken from each distribution to calculate the 

dose, which is then turned into infection or illness 

probabilities, or into cases, using a dose-response 

curve. This sampling is done many times over to

simulate a large population being exposed to beach 

water that may, on some occasions, be 

contaminated. 

17 By requiring that no more than 50% of 1 mL samples were positive 

for coliforms, that being equivalent to an MPN of about 70 per 

100 mL.

When this is done for a population of people at a 

given beach (not dispersed over many beaches) the

end result is that on a majority of occasions there 

are no cases of infection, but on a few occasions

(when the contamination is unusually high and

recreational water contact actually occurs) a

number of infections, and hence illness, could

occur. 

The greatest weakness of this approach is the

paucity of dose-response information. However, a 

surprising amount is now available – as reviewed

by Teunis et al (1996) for gastrointestinal

pathogens; McBride et al (2002) also include a 

review of material for adenovirus respiratory

pathogens, only some of which is covered by Haas

et al (1999). 

The New Zealand study 

The QRA approach has been reported in some 

detail for New Zealand freshwater recreational 

waters, as a consequence of a large national study

at 22 river and three lake sites, in which five

indicators and six pathogens were sampled 

fortnightly for 15 months in the period 1998–2000

(McBride et al 2002). The main reason for 

adopting the QRA approach was that 

epidemiological studies – either controlled or

uncontrolled – were held to be unfeasible. While

McBride et al (1996) concluded that a controlled 

cohort study would in fact be feasible, two 

subsequent considerations ruled it out. First was 

the difficulty in recruiting suitable cohorts within

proper ethical requirements, and second was the 

paucity of available data on pathogens and 

indicators in New Zealand freshwaters. Given that 

there were many indications that freshwaters were 

rather more contaminated than marine beaches, it 

seemed prudent to attempt to plug this gap and to

use the results in a QRA approach. 

APPENDIX 2: DEVELOPING THE GUIDELINES.

I14 June 2003 
That study produced a wealth of information on

the distribution of pathogens and indicators. In

particular it found that Campylobacter was present 

in 60% of all samples, and that human enterovirus

and/or human adenovirus were present in 54% of

samples. Concentrations and occurrences of

Salmonellae, Giardia cysts and Cryptosporidium

oocysts were low. Catchments impacted 

predominantly by birds were the most

contaminated, followed by those in which the 

dominant impact was from dairying or sheep

farming. The degree of contamination was 

strongly related to the turbidity of the water. 

In essence the study confirmed the continued use 

of E. coli as a faecal health-risk indicator, at least 

so far as Campylobacter is concerned.18 

Unfortunately correlations between this indicator

and the two virus groups examined (human 

enterovirus and human adenovirus) were very

poor, as was the case for all other indicators

examined – somatic coliphage, FRNA phage and 

C. perfingens spores. Also, correlation between 

the enterovirus and adenovirus groups was poor

(enterovirus has also been used as a general virus 

indicator). 

Accordingly, in the health-risk modelling 

particular attention was paid to Campylobacter

infection as well as enterovirus and adenovirus

infections.

19 Of the two virus groups, 

dose-response information suggests strongly that 

adenovirus is much the more infective, with risk 

profiles for a given beach being very similar to that

for Campylobacter infections. 

 

18 Campylobacteriosis illness forms more than half of all reported 

notifiable illnesses in New Zealand, in recent times being around 

300 cases per 100,000 population per annum (see the New Zealand 

Public Health Reports, published by ESR).

19 The endpoint of this analsyis was taken as infection, not illness, 

principally because once infection rates are controlled to low levels, 

so too will be the illness rate. Also there are some severe practical 

difficulties in determining the probability of illness (given infection 

has occurred) as a function of dose (Teunis et al 1999).

Deriving the guidelines 

The following sections describe the basis of the 

guidelines for marine water and then for 

freshwater, both for the grading of beaches and for 

their ongoing surveillance. In each case a 

subsection describes the changes from previous

guidelines. 

General considerations

Since 1999 the WHO has favoured using 

95 percentiles of microbiological concentrations

for grading beaches via a Microbiological

Assessment Category (first proposed in the

Annapolis Protocol, WHO 1999). That approach

is adopted here; i.e. these 2003 guidelines 

incorporate a risk-based approach to monitoring

recreational waters, in addition to single samples 

as used in previous guidelines. The purpose of 

incorporating risk assessment is to overcome the 

constraints of these previous guidelines, as 

discussed in Section C.

Taking risk into consideration when assessing a 

site is achieved via a grading process, combining 

historical microbiological results and sanitary

inspection information to give an overall 

Suitability for Recreation Grade. This grade 

provides an assessment of the condition of a site at 

any given time, while single samples are used to 

identify any immediate health risk. 

The WHO provides no guidance for surveillance 

values; their derivation is explained below. 

See Note G(x) for discussion on the Annapolis

Protocol. 

APPENDIX 2: DEVELOPING THE GUIDELINES.

I15 June 2003 
Marine waters

Beach grading

Results of the UK controlled epidemiological trials 

have been used to develop a four-category scale, as 

shown in Table H1. The essential results are those 

for gastrointestinal illness (as reported by Kay et al 

1994; Wyer et al 1999), but also accompanied by

the results for respiratory illness reported by

Fleisher, Kay, Salmon et al (1996). In essence 

95 percentile enterococci values have been

identified relating to cut-off gastrointestinal risks 

of 1%, 5%, and 10%. The associated respiratory 

illness risk cut-offs are 0.3%, 1.9% and 3.9%.

20 

Readers are directed to these publications for 

details of the modelling approach used to derive 

these values. 

Beach surveillance 

Neither the WHO (2003) nor the authors of the UK 

studies on which the WHO guidance is based give 

any guidance for deriving surveillance values. 

Accordingly, we have used results from previous 

uncontrolled epidemiological studies, in particular 

those of Cabelli (1983a), also used in previous

versions of the guidelines. While this could be 

argued to be somewhat dislocated, it has the

advantage of maintaining good continuity with

past practice. 

 20 Note that these are risks of acute febrile respiratory illness (AFRI). 

In the New Zealand study (McBride, Salmond et al 1998), and in 

other studies, a less strict definition of respiratory illness has been 

used – essentially not requiring fever as an accompanying symptom. 

This was a deliberate choice in the New Zealand study, given our 

incidence of asthma. Accordingly, the risks of more respiratory 

illness would be higher than these AFRI results indicate. 

These values are obtained by assuming that the 

distribution of enterococci is lognormal, the 

standard deviation of the logarithms of enterococci

concentration is 0.7 (a reasonable average of

available data) and the enterococci concentration is

at the previous limit of a median of 35 per 100 mL

(corresponding, under Cabelli’s model, to a 

swimming-associated risk of 19 per 1000 bathing

events). Then the alert (amber) and action (red) 

limits are taken as the 80% and 90% upper onesided tolerance limits for that distribution.21 These 

figures may be simply calculated as 136 and 276 

enterococci per 100 mL.

22 Having regard to the 

uncertainty in estimating the standard deviation (of 

the logarithms) it seems appropriate to round these 

figures to 140 and 280 enterococci per 100 mL. 

It is important to note that while this calculation is 

based on the assumption that waters are marginal 

for compliance with the median value, this does 

not mean that the alert and action limits will only 

be exceeded once the health risk rises above 19 per 

1000 swimming events. In fact the alert and action 

limits begin to be exceeded when the true median 

concentration is someway below 19 per 1000

events. The unfortunate fact is that we can only 

associate particular risks with average or median 

values of enterococci; it is impossible to associate 

risks with any particular enterococci value. All 

that can be said is that if the alert and action levels

are not exceeded then the illness risks are some 

way below 19 per 1000 recreational events. 

21 In the one-sided case, tolerance limits and confidence limits are 

operationally identical; this is not so in a two-sided case.

22 The 80 percentile and 90 percentile abscissae of the unit normal 

distribution are 0.8416 and 1.2816 respectively. So the one-sided 

80% upper tolerance limit is 35x100.8416x0.7

 = 135.9. Similarly the 

90% upper tolerance limit is 35x101.2816x0.7

 = 276.2.

APPENDIX 2: DEVELOPING THE GUIDELINES.

I16 June 2003 
Changes from previous guidelines 

The previous guidelines were based on Cabelli’s 

uncontrolled study, as implemented by the

USEPA. That is a median enterococci 

concentration of 35 per 100 mL, corresponding to

a swimming-associated illness risk of 19 per 1000

swimmers. Also the alert and action limits have

been rounded from 136 and 277 enterococci per

100 mL to 140 and 280 enterococci per 100 mL. 

Background to the changes 

It is of interest to note that the previous guidelines 

were not based on an explicit adoption of an 

‘acceptable illness risk’ of 19 per 1000 bathers. 

What in fact happened is that the USEPA first

proposed that criteria be based on a maximum

acceptable illness risk of six per 1000 bathers (in 

the Federal Register 1984), corresponding to a 

geometric mean (or median) concentration of three

enterococci per 100 mL. Submissions on the 

proposal noted this limit was so low as to be

impractical (i.e. unattainable) in near-shore coastal 

environments. The counter-argument was made 

that the previous limit (geometric mean 200 faecal 

coliforms per 100 mL) had appeared to work

satisfactorily, so why not use corresponding limits 

of enterococci? This argument was accepted by 

the USEPA, which used ratios of faecal coliforms 

versus enterococci to establish correspondences 

between faecal coliforms and the new preferred 

enterococci indicator (Favero 1985; USEPA 

1986a), i.e. 200 faecal coliforms per 100 mL

corresponded to 35 enterococci per 100 mL in

coastal waters. Using Cabelli’s relationship, this 

corresponds to an illness risk of 19 per 1000 

bathing events. 

That is, the ‘acceptable’ illness risks were not 

chosen a priori23 but were calculated, once it was 

decided that risks corresponding to the previous

criteria (200 faecal coliforms per 100 mL, as a 

geometric mean) should be adopted. 

 

23 It would be very odd if they had been, since 19 is not a number that 

the public might generally adopt as being ‘acceptable’. 

In contrast, these new guidelines are based on an

explicit choice of acceptable risks. 

Freshwaters 

Beach grading

For consistency with the marine grading system, 

the same basic structure is used for the

Microbiological Assessment Category, i.e. a fourcategory scale. However, the risk cut-offs have 

been set at lower values: 0.1%, 1% and 5%. There

are two reasons for adopting these lower values. 

First, they are based on Campylobacter infection

only: we simply lack credible information to

develop risk figures for other illnesses. However, 

as this particular infection is important in the New 

Zealand setting these risks have been taken as a 

suitably precautionary approach. Second, the 

upper level (5%) represents a doubling of the 

background infection rate and this has been viewed

as a tolerable upper limit. 

These risks have been calculated in the New 

Zealand QRA study (McBride, Till, Ryan et al 

2002) for Campylobacter infection, results for 

which as given in Table H2. 

The derivation of that table’s figures relied on the

moderate correlations found in the New Zealand

study between Campylobacter and E. coli

concentrations. The values of calculated 

Campylobacter concentrations corresponding to

the risk cut-offs were obtained. These 

corresponded to Campylobacter percentiles of

55%, 70% and 80–85%.24 The corresponding 

percentiles of E. coli were then read from its 

distribution, being 131, 261 and about 550 E. coli

per 100 mL. These values were then rounded to

the values in Table H2 (viz, 130, 260, 550 E. coli

respectively). 

24 Using the results for all beaches and all times in Table A3.7.3 of 

McBride et al (2002).

APPENDIX 2: DEVELOPING THE GUIDELINES.

I17 June 2003 
Beach surveillance 

In the absence of better information, the alert and 

action levels have been taken as the second and 

third E. coli cut-offs for beach grading. 

Changes from previous guidelines 

The previous guidelines were based on the Dufour 

(1984) study, as implemented by the USEPA. That

is a median E. coli concentration of 126 per 100 mL, 

corresponding to a swimming-associated illness risk 

of 8 per 100 bathers. Also, the alert and action limits 

have been rounded from 273 and 410 E. coli per

100 mL to 260 and 550 E. coli per 100 mL. 

Background to the changes 

Once again, the previous guidelines were not based 

on an explicit adoption of an ‘acceptable illness 

risk’ of 8 per 100 bathers. The reasoning was 

entirely similar to that given above for marine 

waters, in which 200 faecal coliforms per 100 mL

was found to be equivalent to 126 E. coli per 

100 mL. That is, the ‘acceptable’ illness risks 

were not chosen a priori but were calculated, once 

it was decided that risks corresponding to the 

previous criteria (200 faecal coliforms per 100 mL, 

as a geometric mean) should be adopted. 

In contrast, these new guidelines are based on an

explicit choice of acceptable risks. 

Implementation issues 

Change in sampling depth 

The provisional guidelines (Department of Health

1992) required sampling at adult chest depth, the 

reason being that this was the sampling depth used 

by the two studies on which the guidelines were 

based (Cabelli 1983a; Dufour 1984). This has now 

been changed to sampling at 0.5 m. This was partly

driven by a concern expressed by some New 

Zealand sampling teams about the safety of 

sampling in New Zealand’s high-energy coastal

waters. But it was also done in the light of other 

studies. Controlled-cohort studies in the UK have 

shown very clearly that swimming-associated 

illness risks are related to water quality measured at

and only at the swimming location (Fleisher, Jones, 

Kay, Stanwell-Smith et al 1993; Kay et al 1994). 

The 1998 guidelines advocated sampling at 0.5 m. 

This considered children, who use shallower-depth 

water and may be more susceptible to illness than 

adults, and that adults are also exposed to 

shallower water. The technical justification for the 

change in sampling depth is as follows. 

In the New Zealand study, bathers were exposed to 

a variety of depths. Water samples were taken at

both chest and knee depths. Using a median of

35/100 mL and taking into consideration both

gastrointestinal and respiratory illnesses (not

considered in studies on which the 1992 

provisional guidelines were based), the maximum

level of risk to swimmers at a depth of 0.5 m

(previously applied to chest depth) remained at 

19/1000. Therefore the risk level of 19/1000 

relates to the number (35/100 mL) of indicator

bacteria measured at any given depth. 

However, concentrations of indicator bacteria at

0.5 m are nearly always found to be more than at 

chest depth (and considerably more than water 

beyond breaking waves). In fact the New Zealand 

study found that, on average, the values found at 

chest depth were about 50% lower than those 

found at 0.5 m.

Single category for bathing areas 

The provisional guidelines followed the USEPA 

(1986b) in using four separate categories for 

maximum limits for indicator bacteria. These four 

categories correspond to four levels of beach usage 

(infrequent use, light use, moderate use and 

designated bathing beaches). This was based on 

the notion of minimising community risk rather

than of minimising individual risk, a factor often 

criticised (Fleisher 1991). The adjustment of the 

limits to one category of use is based on the 

principle that the level of risk at a beach is 

independent of its popularity. 

APPENDIX 2: DEVELOPING THE GUIDELINES.

I18 June 2003 
Difference between faecal streptococci and 

enterococci 

The faecal streptococcus group consists of a number 

of species of the genus Streptococcus, such as

S. faecalis, S. faecium, S. avium, S. bovis, S. equinus

and S. gallinarum. They have all been isolated from

the faeces of warm-blooded animals, and S. avium 

and S. gallinarum occur in poultry. S. bovis and 

S. equinus are residents of the bovine and equine 

intestinal tracts and, although detectable in their 

faeces, do not survive well outside the animal host 

and die off rapidly once exposed to aquatic 

environments. The faecal streptococci have been 

used in many of the European, UK and Australian 

studies of water pollution. 

The enterococcus group is a subgroup of the faecal 

streptococci that includes S. faecalis, S. faecium, 

S. gallinarum and S. avium. Procedures for the 

isolation and identification of the enterococcus 

group from aquatic environments have been well

validated as identifying this group as a valuable

indicator for determining the extent of faecal 

contamination of recreational marine waters. 

Studies at marine and freshwater bathing beaches 

have indicated that swimming-associated 

gastroenteritis and respiratory illness can be related

directly to the quality of the bathing water, and that

enterococci are the most efficient bacterial indicator 

for marine water quality (Cabelli, Dufour, et al 

1983; Dufour 1984; McBride, Salmond et al 1998). 

The enterococci have been used predominantly in

American studies of water pollution, but also in 

Europe. Studies in New Zealand using enterococci

as the indicator of choice form the basis of the

current recreational water-quality guidelines for the 

marine environment.

Urban and rural run-off

Rural and urban run-off can contain both human

and animal faeces. The catchment type will reflect 

the likely proportions of each. Animals can carry 

pathogens that may be passed on to humans 

(zoonoses) such as Giardia, Salmonella, 

Campylobacter, Cryptosporidium (Donnison and

Ross 1999) and verotoxic E. coli (E. coli 0157). In

times of high rainfall the pathogens present in

animal faeces can be transferred into waterways 

via stormwater drains or overland flow. 

The results of some studies (Calderon et al 1991, 

as interpreted by McBride 1993; McBride, 

Salmond et al 1998) indicate that illness risks 

posed by animal versus human faecal material 

should be considered to be equivalent, although

the first Hong Kong study results are less clear 

(Cheung et al 1990). 

For urban catchments, at least, indicators at beaches 

could be elevated by inflow (wrong connections) 

and infiltration of stormwater into the sewer system, 

leading to sewer overflows which then contaminate 

stormwater conduits (streams, channels, direct

pipes, etc). These contamination events are 

probably dependent on rain intensity and may be 

able to be quantified. Also, animal faecal matter, 

soil and vegetative indicator inputs and other 

undefined sources can contaminate stormwater itself

(without sewer overflow). Directly leaking sewers 

(termed ‘exfiltration’) can occur in any weather, 

contributing significantly to infiltration when it does 

rain or when groundwater levels rise. 

Stormwater from unreticulated (but not necessarily

‘rural’) areas may contain faecal indicators from

direct surface run-off containing animal or bird 

faecal matter and vegetative inputs, direct stock 

access to waterways, direct stormwater delivery to 

the coastal marine area, and indirectly via streams, 

all of which are believed to constitute a risk to

human health. 

Only one study (Haile et al 1996) has been

conducted in waters impacted by direct urban runoff (storm drains). The rates of illnesses presented 

were similar to those of other studies conducted in

waters contaminated with domestic sewage. 

However, Ferguson et al (1996) found that 

increased levels of faecal coliforms, faecal 

streptococci, Clostridium perfringens spores, 

Giardia and Cryptosporidium occurred in an urban 

estuary after rainfall. Gibson et al 1998 found that 

APPENDIX 2: DEVELOPING THE GUIDELINES.

I19 June 2003 
combined sewer overflows contributed increased 

Cryptosporidium and Giardia in both dry and 

(particularly) wet weather. Data from a study by

Grohmann et al (1993) suggests that stormwater 

was a source of virus contamination in river and

coastal water systems. It is therefore very likely 

that increased indicator levels identified at a beach 

following rainfall are indicating increased 

pathogen levels, and increased risk. 

During the epidemiological study in New Zealand 

(see below), insufficient questionnaires were filled

out immediately following rainfall events because 

people were not swimming at those times. 

However, the microbiological analyses were still 

conducted and the data shows that indicator levels 

go up at times of rainfall as a result of subsequent

run-off. 

The original claim from Cabelli was that rural point

sources probably do not pose as great a risk as 

sources of human wastes. The advent of findings of 

Giardia, Cryptosporidium and Campylobacter, and 

the reinterpretation of the Connecticut rural 

swimming-pond study (McBride 1993), confounds 

this. Furthermore, the 1995 New Zealand marine 

beaches study (McBride, Salmond et al 1998) 

showed no statistically significant difference 

between beaches with urban versus rural impacts;

indeed, the illness risks actually measured for those 

two impacts were very similar.

Illness:indicator relationships

Many more studies have been conducted for marine 

waters than for freshwaters. For marine waters the 

indicator of choice has usually been faecal

streptococci (especially in the UK, Europe and 

Australia) and its subset, enterococci (especially in 

the US and New Zealand). For freshwaters, E. coli

is usually the indicator of choice. 

The essential idea behind the use of bacterial 

faecal indicators is that they may best represent 

overall pathogenicity of the water, as they may be

well correlated to some pathogens but poorly 

correlated to others (e.g. protozoa and viruses). 

This lack of correlation has been shown in many

studies (e.g. Elliott and Colwell 1985; Grabow

et al 1989; Ashbolt et al 1993; Ferguson et al

1996). It must always be remembered that only a 

portion of the pathogens are ever measured, and 

some (e.g. Norwalk-like viruses) cannot be 

enumerated routinely. 

Both the controlled and uncontrolled cohort 

approaches have identified significant (in the 

statistical and social senses of that word) 

increasing relationships between the risk of illness 

to swimmers in water containing faecal residues 

and the concentration of one or more bacterial 

faecal indicators. While many of the illnesscausing organisms are not bacterial (e.g. viruses 

and protozoan cysts) and may not be well

correlated to the bacterial indicator(s), the general

form of this relationship is found among many

studies (as reviewed recently by Prüss 1998). 

Symptoms are reported to increase with increased 

exposure to water and to aerosols (spray from

breaking waves). Studies have increasingly found 

significant relationships between respiratory

illness risk and a bacterial indicator (Balarajan et al

1989; Cheung et al 1990; Fewtrell et al 1992; 

Corbett et al 1993; Fleisher, Kay, Salmon et al 

1996; McBride, Salmond et al 1998), as well as 

gastrointestinal illness. Skin rash, and eye and ear 

complaints seem to be related more to the presence 

of other bathers (bather-to-bather transmission

occurs) than to degree of faecal contamination. 

Children may be more susceptible to illness than 

adults, although they do tend to swim in waters

that are shallower and are hence more polluted. 

Interpreting human health risk 

Investigations on the possible relationship between 

water contamination and human health risk (e.g. of

swimmers) have to account for various

uncertainties. These arise because we only have a 

small number of samples from which to

characterise the degree of contamination of the 

water the swimmers use, and we have health status 

APPENDIX 2: DEVELOPING THE GUIDELINES.

I20 June 2003 
information from only a tiny part of the whole 

population of swimmers.

25 If we took the 

measured relationship to be the true relationship, 

these uncertainties would be ignored and our 

relationship would have a high chance of being

incorrect. Statistical methods allow us to account

for these uncertainties. 

It is traditional to use ‘null hypothesis tests’ to

account for uncertainties. These test the 

hypothesis that there is no association between the

indicator concentration and the swimmers’ risk of

illness.26 If the association (measured by a 

correlation coefficient or by a regression 

coefficient) indicated by the data is in some sense 

strong enough,27

 one concludes that the null

hypothesis should be rejected and that a 

‘statistically significant’ result has been found. In

this case, the true association is estimated by that 

found in the sample data. The level of uncertainty 

in this estimate is indicated by an interval (usually 

the 95% confidence interval) within which we 

might usually expect the underlying true value to

lie, 95% of the time. 

On the other hand, failing to reject the hypothesis 

simply means that the observed data is not

inconsistent with the null hypothesis. It does not

mean that we can regard the null hypothesis as 

being true, i.e. that there is no association at all. 

There may well be an association, but our sample 

data is held to be insufficient to reliably infer 

either this or its magnitude. This can be either 

because there is too much variability in the data, or 

that insufficient data was collected given its degree 

of variability. Increasing the size of the sample 

data set may identify an association – unless the 

variability continues. 

 

 

25 As well as some non-swimmers, who are used as controls, it is the 

difference in illness risk between swimmers and non-swimmers that 

we are interested in. 

26 That is, one posits a ‘null’ hypothesis – that the correlation is 

exactly zero. 

27 The computed p-value would be less than half of the a priori 

significance level (usually denoted by α). The p-value is the 

probability of getting a correlation at least as extreme as has been 

obtained, if the null hypothesis were true.

A cautionary note: the form of words used by

some authors to interpret a negative result for a 

null hypothesis test can be ambiguous (McBride, 

Loftis et al 1993). For example, in reporting on a 

study of bathers’ illness risks in a freshwater pond

contaminated by animal faecal material (Calderon 

et al 1991), a null hypothesis test (only just) failed

to reach ‘statistical significance’. This led the 

authors to state that there was “no association” 

between swimmers’ illness risk and animal faecal 

contamination.

This conclusion had quite dramatic consequences 

because it was thought to support the idea that 

bathers’ illness risks from exposure to animal

faecal residues are much lower than for exposure

to human faecal residues, and perhaps did not even 

exist (as is implied by the phrase “no association”). 

But if more swimmers had been included it is

entirely plausible that the test result would have 

been statistically significant (McBride, Loftis, et al 

1993).28

In fact the measured relationship was quite large, 

but the data’s variability and limited size meant 

that the associated null hypothesis test failed to

attain statistical significance. In other words, 

failure to attain statistical significance does not 

necessarily imply that the relationship tested lacks 

practical significance. The actual results found 

can be used, with results from other studies, in

some kind of meta-analysis.

29

28 Technically, the ‘power of the test’ increases with the number of 

data used, making it more likely that a null hypothesis will be 

rejected. 

29 Meta-analysis refers to pooling data from a number of studies to 

reanalyse the relationship.

APPENDIX 2: DEVELOPING THE GUIDELINES.

I21 June 2003 
APPENDIX 2: DEVELOPING THE GUIDELINES.

I22 June 2003 
Appendix 3:

Signs

Temporary health warning sign 

These signs should be erected at entrances to sites 

as soon as possible following contamination

events. Dimensions for these signs may vary, but

they should be clearly visible from site access 

points. 

APPENDIX 3: SIGNS.

I23 June 2003 
Permanent health warning sign 

These signs should be erected at sites where faecal 

material is known to be contaminating the water on 

an ongoing basis. Generally these sites will either 

not be graded, or will be graded as Very Poor and 

are therefore unlikely to be monitored regularly 

until improvements are made. 

Dimensions for these signs may vary, but they

should be clearly visible at all times. 

APPENDIX 3: SIGNS.

I24 June 2003 
Appendix 4:

Case Study –

Implementing the Marine 

and Freshwater Guidelines

Jacobs Estuary, Southland 

Environment Southland co-ordinates recreational 

water-quality monitoring in the Southland region. 

The following case study focuses on one of

13 marine recreational sites monitored in the 

region, details the process for developing a grade

for the site, and defines the resulting surveillance 

monitoring regime and responses. 

Microbiological Assessment Category (MAC)

Jacobs Estuary has been monitored for at least five 

years, so there is sufficient data to generate a 

MAC. Using the Hazen method recommended in 

the guidelines, the 95th percentile for this site is 

99. Repeat or follow-up samples are not included 

when calculating the MAC. 

Referring to the Microbiological Assessment 

Category Definitions the MAC for Jacobs Estuary

is B. 

Sanitary Inspection Category 

The following table presents the findings after 

working through the Catchment Assessment 

Checklist and the resulting Sanitary Inspection 

Category.

APPENDIX 4: CASE STUDY – IMPLEMENTING 

THE MARINE AND FRESHWATER GUIDELINES. 

June 2003 

I25
Table I1: Example of completed Catchment Assessment Checklist 

Site name Jacobs Estuary 

Map reference D46:260168 

Type of site (open coast/estuarine/enclosed bay) Estuary 

Is the BEACH water quality affected by: Microbial hazards 

1 direct discharge of sewage or animal wastes N 

2 stormwater contaminated by sewage N 

3 urban stormwater protected from sewage ingress Y 

4 private sewage disposal systems discharge N 

5 commercial sewage disposal with 1o or 2o treatment N 

6 commercial sewage disposal with 3o treatment N 

7 agricultural use and potential for direct run-off Y 

8 dense birdlife near the beach Y 

9 rivers or streams near the beach Y 

10 water craft mooring or use of area N 

Are RIVERS INFLUENCING THE BEACH affected by: 

11 discharges of human or animal effluent to river N 

12 urban stormwater contaminated by sewage N 

13 intensity of agriculture impacting rivers High 

14 dense forest or bush (feral animals) N 

Other influences 

15 Does water quality change with currents, tide or wind? N 

16 Does rainfall trigger contamination? Y 

17 Does microbial water data ever exceed guidelines? Y 

18 Have illnesses been notified from this area? N 

Land use

Land cover 

Forest/pasture/urban Urban

Swamps/streams/dunes Stream

Hilly/flat Hilly 

Urban land use

Type of urban surrounds (residential, commercial, harbour, etc) R, C, H 

Estimate population density (No. per km2) 75 (excluding Aparima) 

Landfills present N 

Disposal of human waste N past illegal overflows 

Rural land use 

Type of agriculture (sheep, dairy, beef, horses, pigs, deer, poultry, feral) D, S, B 

Disposal of animal waste (dairy?) Y via Aparima 

Additional information 

Length of bathing area (m) 200 

Length of beach (m) – 

Distance from nearest stream (km) 2 

Subject to seasonal loading of pollution N 

Direction of prevailing water currents Tide 

Presence of surf N 

Annual rainfall (mm) 1120 

APPENDIX 4: CASE STUDY – IMPLEMENTING 

THE MARINE AND FRESHWATER GUIDELINES. 

June 2003 

I26
The primary source of potential contaminants to

the bathing site in Jacobs Estuary is the Aparima 

River. The land adjoining the Aparima River has 

moderately intensive agriculture with an increasing

amount of dairy farming in the catchment. This

corresponds to a ‘moderate’ risk. Stormwater 

drains enter Jacobs Estuary, but these are distant 

from the bathing sites and were not considered to

be significant influences. A sewage overflow was 

discovered on the western side of Jacobs Estuary 

in 2001, but this did not appear to influence 

monitoring results and has since been rectified. 

The Regional Council confirmed its catchment 

assessment of the site with the relevant territorial 

local authority and the Medical Officer of Health. 

The resulting Sanitary Inspection Category 

(moderate) was referenced from the Sanitary

Inspection Flowchart. 

Suitability for Recreation Grade 

The suitability for recreation of this marine bathing

water site was determined by integrating the site’s 

Sanitary Inspection Category with the site’s 

Microbial Assessment Category according to the 

Suitability for Recreation Grade matrix. The 

resulting grade for this site is Good. 

The factors that contributed to the SFRG for this 

site can be summarised as follows.

Site ID 13 

Site name Jacobs Estuary 

Map reference D46:260 168 

SIC Moderate 

MAC B (95 percentile = 99) 

SFRG Good 

Monitoring frequency Weekly

Boyes Beach, Bay of Plenty 

Environment Bay of Plenty monitors marine and

freshwater recreational areas throughout the Bay of 

Plenty region. This case study examines a 

freshwater site graded using these guidelines, 

including how each component is assessed and 

brought together to achieve an overall grade for the 

site. 

Microbiological Assessment Category (MAC)

Boyes Beach has been monitored for two years, 

giving insufficient data to generate a final grade. 

However, there is sufficient data to generate an

interim grade. An interim grade is used primarily 

for management purposes and must be reviewed

annually as new data becomes available, until five

years’ data has been collected. 

The 95th percentile for this site, generated using

the Hazen Method is 207. Therefore the resulting 

Microbiological Assessment Category is B. 

Sanitary Inspection Category 

The results of the catchment assessment are 

summarised in the following table. 

APPENDIX 4: CASE STUDY – IMPLEMENTING 

THE MARINE AND FRESHWATER GUIDELINES. 

June 2003 

I27
Table I2: Example of a completed Catchment Assessment Checklist 

Site name Boyes Beach 

Map reference U16:0380-3240 

Type of site (lake / river / stream) Lake

Is the BEACH water quality affected by: Microbiological hazards 

1 direct discharge of sewage or animal wastes N 

2 stormwater contaminated by sewage N 

3 urban stormwater protected from sewage ingress N 

4 discharges from private sewage disposal systems Y 

5 communal sewage disposal with 1o or 2o treatment N 

6 communal sewage disposal with 3o treatment N 

7 intensive agriculture and potential for run-off of effluent N 

8 focal points of drainage as run-off N 

9 unrestricted stock access to waterways N 

10 incidence and density of birdlife Y 

11 water craft mooring or use N 

12 potential for run-off from feral animals Y 

Are rivers, streams or drains influencing the site affected by: 

13 discharges of 1o or 2o treated human effluent Y 

14 stormwater outlets with potential sewage contamination N

15 communal sewage disposal with 3o treatment N 

16 high intensity agriculture, feral animal/bird populations N 

17 focal points of drainage from low intensity land use N 

18 potential for run-off from feral animals Y 

Other influences 

15 Does water quality change with currents, tide or wind? N 

16 Does rainfall trigger contamination? Y 

17 Does microbial water data ever exceed guidelines? Y 

18 Have illnesses been notified from this area? Y 

Land use

Land cover 

Forest/pasture/urban F, P 

Wetlands/streams/dunes W, S 

Hilly/flat H 

Urban land use

Type of urban surrounds (residential, commercial, harbour, etc.) R 

Estimate population density (no. per km2) 1000

Landfills present N 

Disposal of human waste Y – septic tanks

Rural land use 

Type of agriculture (sheep, dairy, beef, horses, pigs, deer, poultry, feral) S, D, B 

Disposal of animal waste (dairy?) N 

Additional information 

Length of bathing area (m) 400 

Length of beach (m) 20 

Distance from nearest stream (km) 10 metres

Subject to seasonal loading of pollution Y 

Direction of prevailing water/winds W / SW

Shoreline configuration / geomorphology / erosion gullies Flat – sandy beach 

Annual rainfall (mm) 1250 mm 

APPENDIX 4: CASE STUDY – IMPLEMENTING 

THE MARINE AND FRESHWATER GUIDELINES. 

June 2003 

I28
The primary source of potential contamination for 

Boyes Beach is septic tanks. In addition to the 

residential on-site disposal systems there is a toilet 

block to the rear of the beach, which is another

source of faecal contamination, particularly during 

the holiday season when the area experiences 

seasonal population growth. 

The land surrounding Boyes Beach is a mixture of 

low-density urban and low-intensity agriculture, 

including beef, deer and sheep. Stock have 

unrestricted access to waterways that discharge 

onto the beach, although these are not considered 

significant impacts due to low stock densities. 

There is also some forest area around the lake with

the potential for run-off from feral animals. 

However, this was also not considered a 

significant source of faecal contamination. 

Using the Sanitary Inspection Flow Chart for 

Freshwater Sites, the Sanitary Inspection Category 

(SIC) for Boyes Beach is Very High. 

Suitability for Recreation Grade 

The Suitability for Recreation Grade (SFRG) for 

this site is determined by integrating the site’s 

Sanitary Inspection Category and Microbiological

Assessment Category according to the Suitability 

for Recreation Grade Matrix for Freshwater. The

resulting grade for this site is Follow Up. This is 

due to the disagreement between the MAC and the 

SIC. 

Investigation of both the MAC and SIC is

recommended. The grade for this site is also 

interim as there are fewer than 100 data points and

less than five years’ data. This is likely to be the 

cause of the disagreement between the MAC and 

the SIC also. 

Factors that contributed to the SFRG for this site 

can be summarised as follows. 

Site name Boyes Beach 

Map reference U16:0380-3240 

SIC Very High 

MAC B (95 percentile = 207) 

SFRG Follow Up (Interim)

Recommendation Continue to monitor weekly

during peak usage until five 

years’ data has been collected

and an SFRG can be assigned. 

APPENDIX 4: CASE STUDY – IMPLEMENTING 

THE MARINE AND FRESHWATER GUIDELINES. 

June 2003 

I29
APPENDIX 4: CASE STUDY – IMPLEMENTING 

THE MARINE AND FRESHWATER GUIDELINES. 

June 2003 

I30
Appendix 5:

Fact Sheets 

In this appendix we have provided a series of fact

sheets about recreational water-quality monitoring. 

Please feel free to photocopy and distribute these 

to anyone wanting more information about this

issue. 

APPENDIX 5: FACT SHEETS.

Published by the Ministry for the Environment.

June 2003 

I31
Beaches and rivers are important 

Every weekend thousands of people flock to

beaches, lakes and rivers around the country and 

take the plunge. The numbers soar during the 

summer holidays. Whether it is swimming,

diving, surfing or sailing, when the sun shines

Kiwis head for the beach. 

A part of New Zealand culture 

The Hillary Commission’s 1991 Life in New 

Zealand Survey looked at recreational water use 

and found that in the 15–18-year age groups:

28% had been swimming in the past four

weeks 

• 

• 

• 

• 

31% had been to the beach in the past four

weeks 

23% of males and 8% of females had been

either surfing or wind surfing in the past four 

weeks 

20% had been involved in water-based leisure 

or activities in the past four weeks. 

This represents only a small slice of New 

Zealand’s population but is a strong indicator of

how our beaches are a significant part of Kiwi 

culture. 

Mostly clean, but ...

New Zealand’s ‘clean green image’ extends to our 

oceans, lakes and rivers. The perception many of 

us have that our coasts and freshwaters are some of

the cleanest in the world is well founded. We 

don’t have the severity of problems facing nations 

such as the United Kingdom or the US. But we do 

have some problems. 

Some of our stormwater and sewerage systems are 

approaching 100 years old. Combined sewerage

and stormwater pipes can sometimes pump 

untreated human effluent into lakes, rivers and the 

sea, especially in urban areas. Stormwater (urban

run-off) collects waste from streets, lawns and 

parks and deposits it in waterways. This run-off 

often contains animal waste. Run-off from

farmland (rural run-off) collects waste from farm

animals, which also ends up in rivers and finally in

the sea or lakes. Animal and human waste 

contains disease-causing organisms that may 

survive in the marine environment, posing a risk to

human health. 

What is being done about it?

Councils monitor water quality according to

guidelines developed by the Health and

Environment Ministries. The purpose of

monitoring is to identify risks to public health

from disease-causing organisms, and to inform the 

public of these risks. This information allows 

people to make informed decisions about where, 

when and how they use the aquatic environment

for recreational activities. 

Aside from monitoring water quality, many

councils have long-term plans in place to deal with 

ageing sewerage and stormwater systems and carry 

out routine inspections of these systems. Regular

inspection ensures the systems are maintained to as 

high a standard as possible so that the waters

receiving the discharge meet acceptable health 

criteria. But it is important to realise there has 

always been a health risk while in contact with

waters that receive stormwater, rural run-off and

sewage. 

APPENDIX 5: FACT SHEETS.

Published by the Ministry for the Environment.

June 2003 

I32
Health impacts of contaminated 

recreational water

There are a number of disease-causing bugs (called 

pathogens) that once discharged into the marine 

and freshwater environments can survive for some

time. Every time we come into contact with

waters that have been contaminated with human 

and animal faeces, we expose ourselves to these 

bugs and risk getting sick. Pristine waters are 

unlikely to present a health risk from these 

pathogens. 

What does ‘risk’ mean?

The risk is of getting sick when swimming, surfing

or otherwise being exposed to freshwater or

seawater. The guidelines that New Zealand 

councils use are based on fixed levels of risk, 

which in turn are based on overseas guidelines 

(which have been confirmed by New Zealand

studies). Overseas investigations have settled on a 

maximum acceptable level of risk for marine

waters of 19 in every 1000 bathers contracting an 

illness. For freshwaters the accepted level of risk

is 8 in every 1000 bathers contracting an illness. 

Even when beaches and rivers meet the guidelines

there will still be a health risk associated with

recreational activities in the sea. Because 

scientists are not directly measuring the pathogens, 

it is not possible to say there is zero risk to public 

health, especially where there are known inputs of

human and animal faeces. 

If tested waters exceed the acceptable level of risk, 

the public is advised that the area is unsuitable for 

recreational activities. 

What does ‘illness’ refer to? 

Illnesses related to contact with recreational waters 

were initially thought to be confined to

gastrointestinal illness such as salmonellosis. 

More recently Giardia, Campylobacter and 

Cryptosporidium have also been shown to cause 

gastrointestinal illness. These pathogens cause 

diarrhoea and sometimes vomiting associated with 

‘tummy bug’ symptoms. Recent studies indicate 

that respiratory illnesses, such as those that cause 

cold and flu-like symptoms, can also result from

swimming in sewage-contaminated water. Skin,

eye and ear infections can also be caught through 

contact with marine and fresh waters. 

Illnesses related to toxic substances – such as 

heavy metals or PCBs – are not measurable with

indicator bacteria and are not covered in this fact

sheet. 

Risk factors 

Stormwater, and treated and untreated sewage 

discharged directly into our oceans, rivers and 

lakes, can contain a variety of micro-organisms 

that can cause disease. Therefore there may be a 

greater risk of getting sick under certain 

conditions, such as: 

• two to three days after rainfall 

• 

• 

during full immersion in water that may be

contaminated with sewage or run-off 

high exposure to shallow water where there 

may be higher concentrations of pathogens. 

There may also be a greater risk to those with

reduced immunity, the elderly and the very young. 

When do the guidelines not apply?

In most communities the effluent produced will 

contain pathogens all year round, and the 

guidelines councils use are designed for use under 

such conditions. However, when there is an

outbreak of a potentially waterborne disease in the 

community, and where that community’s sewage 

is discharged directly into or close to recreational 

waters without adequate treatment, the guidelines 

that councils use are not suitable. Under these 

circumstances an area may be deemed suitable for 

recreational use based on the indicator bacteria, 

when in fact the levels of pathogens are elevated to 

a point where there is an unacceptable risk to 

public health. 

APPENDIX 5: FACT SHEETS.

Published by the Ministry for the Environment.

June 2003 

I33
What are councils doing? 

Councils around the country monitor water quality 

to minimise the risk to public health. They do this 

by measuring the number of enterococci (indicator 

bacteria) in our water. They do not measure 

pathogens directly because the science to do this 

cost effectively and reliably isn’t yet available. 

In addition to measuring indicator bacteria, 

councils look at the area surrounding the beach or

river and identify potential sources of 

contamination. This helps councils assess the 

potential risk of contamination, so they can ‘grade’

recreational sites for their suitability for 

recreational use. 

Where do I get more information? 

Councils monitor water quality and will have

detailed information on specific beaches. 

There may be an 0800 number to call for this

information.

• 

• 

• 

• 

Local papers and radio stations may also 

provide information in their community 

bulletins. 

Signs at monitored beaches will have details 

about where to get more information (0800

number, radio stations, etc.) and will indicate if 

the beach is suitable for recreational use. 

Some council websites have information about 

monitoring programmes locally. 

APPENDIX 5: FACT SHEETS.

Published by the Ministry for the Environment.

June 2003 

I34
The water-quality monitoring 

programme

Regional, city and district councils have been 

monitoring water quality at beaches for many

years. The guidelines now used by the councils

are the Microbiological Water Quality Guidelines 

for Marine and Freshwater Recreational Areas

published by the Ministry for the Environment and 

the Ministry of Health in 2002. These guidelines 

aim to establish national consistency in

recreational water quality and public awareness of 

when there is a health risk.

Which beaches are being monitored?

The councils decide which freshwater and marine

sites they will monitor before the bathing season

begins. How councils decide this varies from

region to region. Contact your local city or

regional council to find out which sites in your 

region are monitored.

When are beaches monitored?

Beaches and rivers are monitored by the council on 

a weekly basis throughout the bathing season. The 

bathing season is generally from 1 November to 31

March, although this may vary depending on the 

local climate. 

What do councils ‘do’ when they monitor 

water quality?

There are two parts to the council’s monitoring

programme. Firstly, an overall grade for the site is 

worked out based on previous years’ monitoring

results and an assessment of potential sources of 

contamination from the surrounding area. This

grade gives an idea of the general condition of the 

site on any given day.

In addition to the overall grade, councils monitor 

recreational waters on a weekly basis during the 

bathing season. Samples are collected from

monitored sites and tested for bacteria that indicate 

whether disease-causing micro-organisms, or 

pathogens, are present. The councils use the

‘traffic light’ approach of the guidelines to decide

whether the beaches and rivers are suitable for 

swimming.

Surveillance monitoring is carried out when levels 

of indicator bacteria are low. Sites in surveillance 

mode are monitored weekly. The purpose of 

surveillance monitoring is to routinely check that 

water quality is at a level that doesn’t pose an

unacceptable risk to public health. 

The alert or ‘amber’ level acts as a trigger for 

councils to collect samples more frequently. The 

guidelines also recommend that when in this mode 

councils investigate whether there is a source of 

contamination causing the higher indicator levels

at the beach or river. 

For marine waters, when a sample taken during 

either surveillance monitoring or while in alert 

mode exceeds the action or ‘red’ mode indicator

level, a second sample is taken immediately. If 

this also exceeds the action-level threshold the 

public are informed that the beach is not suitable 

for swimming.

For freshwater, if a sample taken during either 

surveillance monitoring or while in alert mode

exceeds the action or ‘red’ mode indicator level, a 

second sample is not required to confirm the result. 

This is due to the potential for greater pathogen

levels and their survival in freshwater. Illnesses 

may range from a skin infection, to a cold, to

gastrointestinal disease. In action mode, sampling 

may increase to daily if the cause is unknown. The 

guidelines specify that a catchment assessment 

should be carried out in the surrounding 

catchment. This involves the council checking the 

sewerage and stormwater systems for leaks, illegal 

connections and other causes of contamination of

the site. A catchment assessment can also involve

investigating further up the catchment to identify 

contaminating activities or discharges. 

APPENDIX 5: FACT SHEETS.

Published by the Ministry for the Environment.

June 2003 

I35
How do I know if it is OK to swim?

Councils have communication strategies as part of

their monitoring programmes to ensure the public 

are informed of a health risk at a beach or river as 

soon as possible. If you are concerned about water

quality at beaches or rivers in your area, contact 

your local council for more information.

The bugs

In New Zealand we are becoming increasingly 

aware of the potential health risks associated with 

swimming (and other related activities) in marine

and fresh waters. Although this problem is not as

severe as in many other countries, it is important

that we manage the problem in the interests of

public health. 

When monitoring water quality at New Zealand 

beaches and rivers, water managers and scientists 

are interested in the number of disease-causing 

pathogens present. It is impractical to measure the

pathogens directly, so indicator bacteria are used to

alert water managers to possible health risks

presented by the pathogens. 

What are indicator bacteria? 

In the case of the recreational water-quality 

guidelines, the indicator bacteria are enterococci 

for marine waters and E. coli for freshwaters. 

These bacteria occur naturally in the gut of humans

and animals, including mammals, birds, fish and 

reptiles. The indicator bacteria themselves do not 

pose a significant risk to human health. Rather, 

they indicate the presence of faecal material, which 

contains disease-causing pathogens. It is the

number of enterococci or E. coli per 100 mL of

water that is measured and on which the guideline 

levels are based. 

What are pathogens?

Pathogens are microscopic organisms that cause 

disease in humans and animals. There are many 

different kinds. Some of the more widely known 

are Campylobacter, Salmonella, Giardia, 

Cryptosporidium, and viruses that cause diarrhoea

and cold and flu-like symptoms. These pathogens 

are present in faeces and may enter our waterways 

through untreated sewage discharges, and from

leaky sewerage pipes, septic tanks, stormwater and

rural run-off. 

When do the guidelines not apply?

In most communities the effluent produced will 

contain pathogens all year round, and the 

guidelines councils use are designed for use under 

such conditions. However, when there is an

outbreak of a potentially waterborne disease in the 

community, and where that community’s sewage 

is discharged directly into or close to recreational 

waters without adequate treatment, the guidelines 

councils use are not suitable. If the guidelines are 

used under these circumstances a beach or river 

may be deemed suitable for recreational use based 

on the indicator bacteria, when in fact the levels of 

pathogens are raised to a point where there is an 

unacceptable risk to public health. 

Indicator bacteria tell us about the likelihood of 

there being pathogens present in the water. We 

don’t use indicator bacteria to measure the 

likelihood of there being toxic contaminants or

harmful poisons such as heavy metals, polyaromatic carbons or PCBs. 

APPENDIX 5: FACT SHEETS.

Published by the Ministry for the Environment.

June 2003 

I36
The sources of contamination in 

waters used for recreation

This fact sheet discusses the sources of bacteria 

and pathogens in waters used for recreation that 

pose a risk to human and animal health. 

Sewage 

Sewage from many communities is collected via a 

network of pipes and pumped to a central facility, 

where it is treated before being discharged to the 

environment. Sewage consists mostly of water, 

but also contains organic material and microorganisms. There are a number of factors that can 

cause sewage to enter the environment before 

completing its journey through the treatment

facility. The main ones include: 

• 

• 

• 

• 

• 

broken or leaky pipes – these can be caused by

ageing pipes, construction activities or road 

works 

overflows, during heavy rainfall – the 

treatment facility may not be able to cope with

the volumes of water and sewage entering the 

system, so pumps are turned off and sewage is 

discharged directly to the environment. This is 

made worse where houses have stormwater 

illegally connected to wastewater. Also, some

older sewerage systems do not have completely

separated sewage and stormwater pipes. 

During high rainfall, stormwater (urban runoff) can enter the sewerage system and cause

sewage to overflow into the stormwater pipes. 

Sewage is then discharged directly to the 

environment

emergency overflows – these can also occur 

periodically during maintenance of sewerage

systems. 

There are also other sources of sewage. 

Some older properties, especially baches, are 

still connected to a septic tank. Where these 

have deteriorated they leak contaminated water 

into the groundwater system. This 

contaminated water then ends up in waterways 

and eventually at the beach. 

Some boaties discharge their waste directly 

into the sea, without treatment. The Ministry

for the Environment’s booklet, Dealing with

Sewage Safely and Responsibly on Your Boat,

deals with discharges from all marine vessels. 

The cost of upgrading much of the country’s

ageing pipes to cope with our increasing 

population is estimated to be several billion 

dollars. It is anticipated that these upgrades will be

spread over several decades. 

Stormwater 

Rainwater collected from roofs, driveways, roads, 

carparks and other sealed surfaces is piped directly 

to rivers, lakes and the marine environment

without treatment. During its travels stormwater 

collects a number of nasties along the way. This

includes waste from domestic animals, which 

collects on footpaths, gutters and lawns. This 

contaminated water is washed into the stormwater 

system during rainfall and ultimately ends up on

our beaches. Animal waste collected in 

stormwater contains disease-causing organisms 

that can affect human health. These pathogens can 

cause colds, flu, respiratory illness, gastrointestinal 

illness and skin, eye and ear infections. 

Rural run-off 

Farm run-off can add significantly to the 

contamination of waterways. Apart from farm

oxidation ponds, which have been shown to

contain high levels of bacteria and pathogens, a 

large amount of animal waste ends up on the 

paddock. Depending on a number of factors – 

including distance to the nearest stream, rainfall 

intensity and stock numbers – faecal material ends 

up in rivers and streams, which ultimately

discharge to the sea. Where stock have access to 

streams and rivers for drinking water, excrement 

may be deposited directly into the water. 

APPENDIX 5: FACT SHEETS.

Published by the Ministry for the Environment.

June 2003 

I37
APPENDIX 5: FACT SHEETS.

Published by the Ministry for the Environment.

June 2003 

I38
Abbreviations

CAC Catchment Assessment Checklist 

EHO Environmental Health Officer

IANZ International Accreditation New

Zealand 

MAC Microbiological Assessment Category

NZCPS New Zealand Coastal Policy Statement 

RMA Resource Management Act 1991

SFRG Suitability for Recreation Grade 

SIC Sanitary Inspection Category 

ABBREVIATIONS.

J1 June 2003 
Glossary

Word/term Definition

Agricultural land

use 

Land use involving cultivation of

land or raising of livestock. 

Agricultural 

run-off 

Surface water after rainfall from an 

area of agricultural land use. 

Animal waste Animal faecal material. 

Bacteriological 

indicators 

Micro-organisms selected as 

indicators of faecal material. 

Bathers Those who enter the water, and

either partially or fully immerse 

themselves. 

Bathing season Generally the bathing season 

extends between 1 November and 

31 March. However, this may vary

according to local climatic

conditions. 

Beach The shore or any access point to the 

sea, a freshwater lake or river used

for recreational purposes 

Bird-roosting 

areas

Where birds congregate routinely. 

Bush Fallow areas, predominantly 

covered with native or exotic bush 

or scrub. 

Catchment That area of land from which runoff 

or direct discharges may affect 

water-quality at a recreational water

site. 

Category One of five possible outcomes 

based on historical microbiological 

results and potential risk of faecal

contamination. 

Central tendency The degree of clustering of the 

values of a statistical distribution

that is usually measured by the 

arithmetic mean, mode, or median.

Coastal water Seawater within the outer limits of

the territorial sea. Includes

seawater with a substantial

freshwater component; and

seawater in estuaries, fiords, inlets, 

harbours or embayments (RMA). 

Combined sewer

overflows 

Where stormwater and sewer

overflows are combined. 

Communal 

sewage disposal 

Where a number of houses have a 

combined sewage disposal system. 

GLOSSARY. 

J2 June 2003 
Word/term Definition

Contact 

recreation 

Recreational activities that bring 

people physically in contact with

water, involving a risk of

involuntary ingestion or inhalation

of water (see also Bathers). 

Contamination Reduction in water quality by faecal 

material, resulting in a breach of

guideline values. 

Cryptosporidiosis Diarrhoeal disease caused by

oocysts of the protozoa 

Cryptosporidium parvum.

Direct discharges Piped or channelled discharge of

wastewater concentrated at a given 

point (point source). 

Effluent The liquid effluent from sewage 

treatment processes (sometimes

called wastewater). 

Enterococci Members of the Streptococcus

group of bacteria characterised as 

faecal in origin. 

Enterolert Trade name of test kit for detecting 

enterococci. 

Environmental 

hazard

assessment 

Assessment of risk of potential 

sources of faecal contamination

within a catchment. 

Escherichia coli

(E. coli) 

Member of the Enterobacteriaceae 

group of bacteria. 

Exceedance When indicator levels from samples

taken at a recreational site exceed

those recommended in these 

guidelines. 

Exceptional 

circumstances

Circumstances under which the 

result of the grading matrix

indicates an inconsistency between

the Sanitary Inspection Category 

and the Microbiological 

Assessment Category, requiring

further investigation or analysis. 

Feral animal A wild, untamed animal. 

Follow-up sample Second sample taken to confirm an 

initial high result; usually within

24–72 hours depending on

accessibility / sample turnaround

time, etc. 

Forest Area predominantly covered by

exotic or native trees. 

Word/term Definition

Freshwater All water except coastal water and 

geothermal water (RMA). 

Gastroenteritis Stomach condition causing

diarrhoea. 

Giardiasis Clinical condition caused by

infection with cysts of Giardia 

intestinalis.

Graded beaches Beaches identified by a grade

according to their suitability for

recreational use, as per these

guidelines. 

Hazen method Method for calculating percentile 

numerical values. 

High-contact 

water sports 

Recreational activities that bring 

people physically in contact with

water, involving a risk of

involuntary ingestion of water (e.g. 

swimming, surfing, water skiing, 

windsurfing). 

Human waste Faecal material.

Median Central value when values are 

arranged in order of magnitude. 

Membrane filter

test 

Test to capture bacteria on a filter

by means of filtration.

Microbial 

indicators 

Bacteria used as indicators of faecal

contamination. 

Micro-organisms Collective term for bacteria, viruses 

and protozoa. 

Middle-range 

beaches

Beaches with a Suitability for 

Recreation Grade of good, fair or

poor. 

Multiple-sample

sites 

When more than one sample is

taken along a beach, either because

the beach extends for some 

distance, or to investigate potential 

causes of exceedances. 

Non-point-source 

discharge 

Diffuse pollution sources (without a 

single point of origin, or not 

introduced into a receiving stream 

from a specific outlet). The 

pollutants are generally carried off 

the land by stormwater 

(http://www.epa.gov/OCEPAterms/ 

nterms.html). 

On-site waste 

treatment 

Septic tank. 

GLOSSARY. 

J3 June 2003 
Word/term Definition

Pathenogenic 

micro-organisms 

Micro-organisms that can cause 

disease. 

Pathogens Pathenogenic micro-organisms.

Point-source 

discharge 

Piped or channelled discharge of

waste water concentrated at a given 

point. 

Potential 

contamination 

source 

Any feature of the catchment that

may contribute human or animal 

waste that affects the 

microbiological condition of a 

recreational site.

Primary treatment The first major stage of treatment

following preliminary treatment in

a wastewater works, usually 

involving removal of settleable 

solids.

Principal source 

(of 

contamination) 

The source of faecal contamination 

that has the greatest effect on

recreational water quality.

Private sewage 

disposal system 

Septic tank, long drop (pit privy). 

Protozoa Single-celled micro-organisms.

Rainfall event A rainfall event is one that has an

effect on beach water quality. This 

may be described in mm of rainfall 

over time. The definition of rainfall 

events will vary within and between 

catchments. Factors such as land

use, vegetation cover and catchment 

size will affect the quality and

quantity of water that impacts on a 

beach. Water managers in each 

region will need to determine what 

qualifies as a rainfall event in their 

region, or maybe even in

catchments in their region. 

Historical data may help to 

determine the levels of rainfall

required to impact on a region’s 

beaches. Note: data specific to dryweather sampling is likely to reflect

the most favourable indication of a 

health risk. 

Recreational use See contact recreation. 

Respiratory

illness 

Cold and flu-like symptoms; may

be associated with fever. 

Word/term Definition

Risk The public health risk when

considering beach water quality is

the probability of illness occurring. 

The best available means of 

predicting the probability of illness 

occurring at a beach is given by the 

number of particular indicator

bacteria present in the water. 

Risk factors Potential sources of faecal 

contamination. 

Salmonellosis Disease caused by infection with

members of the Salmonellae group 

of bacteria. 

Sanitary landfills Landfills (tips) where sewage

sludge is disposed. 

Sanitary survey Survey to detect potential sources

of faecal pollution within a

catchment. 

Secondary

treatment 

The treatment of waste water,

usually after removal of suspended 

solids, by bacteria under aerobic 

conditions during which organic 

matter in solution is oxidised or

incorporated into cells, which may 

be removed by settlement. This 

may be achieved by biological 

filtration or by the activated-sludge 

process. Sometimes called ‘aerobic 

biological treatment’. 

Septic tank A type of sedimentation tank in 

which the sludge is retained 

sufficiently long for the organic 

content to undergo anaerobic 

digestion. (When efficient, this 

equates to secondary treatment.)

Sewage The liquid wastes of a community, 

including toilet wastes, sullage and 

trade wastes. May include

stormwater infiltration.

Sewerage A system of pipes to convey

sewage to the place of disposal or

treatment. The term ‘sewerage’ is

analogous to ‘sewer reticulation’ or 

‘drainage system’. 

GLOSSARY. 

J4 June 2003 
Word/term Definition

Tertiary treatment The further treatment of 

biologically treated waste water by

removing suspended matter to 

enable the effluent to comply with a 

standard more stringent than 30:20 

(not containing more than 30 mg/L 

suspended solids and with a 

biological oxygen demand (BOD) 

not exceeding 20 mg/L) before 

discharge to a receiving water. 

Also termed ‘polishing’. 

Note: this is not equivalent to

disinfection. A system should be

described as secondary treatment + 

disinfection, but not tertiary

treatment. 

Treated effluent Effluent that has been through at 

least primary treatment (see also 

Primary treatment, Secondary

treatment, and Tertiary treatment). 

Ungraded 

beaches

Beaches that are not used for

contact recreation and therefore

have not been through the grading 

process. 

Word/term Definition

Wastewater

treatment plant 

A facility for treating effluent

before discharging it into the 

environment (see also Treated 

effluent). 

Water manager A generic term used for any

person(s) or organisation(s) that 

make(s) decisions regarding water 

use or quality, including those that 

monitor for state of the environment 

reporting and for public health 

protection. 

Water quality The bacteriological condition of a 

water body as it relates to human

health, measured using indicator 

bacteria. 

Waterborne 

pathogen 

Disease-causing micro-organisms

capable of being transmitted by

water.

GLOSSARY. 

J5 June 2003 
References and

Further Reading

The following documents are ordered 

alphabetically by author, then by date, with

accompanying commentary. 

A librarian can easily obtain most of the items in

this list. For those more difficult to access,

supplemental information is given on their 

availability. 

Abbott S, Caughley B, Scott G. 1998. Evaluation 

of Enterolert® for the enumeration of enterococci 

in the marine environment. New Zealand Journal

of Marine and Freshwater Research 32: 505–13. 

Reports comparative evaluation of Enterolert® versus 

membrane filtration on 343 marine samples from the

Wellington area. Found sensitivity of 99.8% and specificity of 

97% (2.4% false positives and 0.3% false negatives). 

Alexander LM, Heaven A, Morris R. 1992.

Symptomatology of children in contact with sea 

water contaminated with sewage. Journal of 

Epidemiology and Community Health 46: 340–4. 

A prospective study of parents of children between 6 and 11 

years was conducted at Blackpool beach (UK) in 1990, 

resulting in 703 cases of matched data. Concluded that 

“children who came into contact with contaminated sea water 

are likely to develop symptoms as a result”. 

Anderson SA, Turner SJ, Lewis GD. 1997. 

Enterococci in the New Zealand environment: 

implications for water quality monitoring. Water

Science and Technology 35(11–12): 325–31. 

A considerable part of the enterococci load in urban and rural 

catchments and waterways (typically 102

–103 cfu/100 mL)

comes from non-human sources. They may multiply within 

some non-faecal environments (e.g. on degrading seaweed). 

Ashbolt NJ, Grohmann GS, Kueh CSW. 1993. 

Significance of specific bacterial pathogens in the

assessment of polluted receiving waters of Sydney, 

Australia. Water Science and Technology 27(3–4):

449–52. 

Primary sewage released from Sydney’s ocean outfalls and 

tertiary chlorinated sewage discharged to rivers were studied 

for two years. Diverting the ocean discharge from a cliff-edge 

release to deepwater ocean release 3 km offshore resulted in 

significant reductions of bacteria in water, but not in near-shore 

sediments. Campylobacters were found in rivers but not in 

effluents or seawater, being associated with rural land. 

REFERENCES AND FURTHER READING.

J6 June 2003 
Balarajan R, Soni Raleigh V, Yuen P, Wheeler D, 

Machin D, Cartwright R. 1989. Health risks 

associated with bathing in sea water. British

Medical Journal 303: 1444–5. 

Reports a three-week prospective cohort study at Ramsgate 

Beach (Kent, UK) using 1,883 persons, including 839 nonbathers as a control. The waters occasionally failed EC 

standards (but this is not quantified). Relative risk of 

gastrointestinal symptoms (age- and gender-adjusted) was 

elevated among the bathers (i.e. swimmers and waders). 

Relative risks of eye/ear/nose/throat and respiratory illness 

among surfers and divers were statistically significant.

Bandaranayake DR, Salmond CE, Cooper AB, 

McBride GB, Lewis GD, Hatton C, Turner SJ, 

Till DG. 1993. Health Effects from Sea Bathing:

A report on the preliminary study carried out at

two Auckland beaches over the 1992/93 summer. 

Ministry for the Environment, Wellington. 

Reports on the New Zealand 1992/93 preliminary trials. 

Includes the paper, the questionnaire, and a sample size 

calculation (power analysis) for the planned final study.

Barron RC, Murphy F, Greenberg HB, Davis CE, 

Bregman DJ, Gary GW, Hughes JM,

Schonberger LB. 1982. Norwalk gastrointestinal 

illness: an outbreak associated with swimming in a 

recreational lake and secondary person-to-person

transmission. American Journal of Epidemiology 

115(2): 163–72. 

Incubation period for 121 first-in-their-household persons 

becoming ill at a Michigan recreational park was 4–77 hours. 

A history of swimming in the park’s lake was elicited with 

significantly greater frequency of illness compared to those 

who did not swim (odds ratio 4.8, 95% CI = 1.8–12.7). 

Serological studies identified Norwalk virus as the aetiological 

agent. Water appeared to meet current bacterial guidelines. 

Baylor ER, Baylor MB, Blanchard DC, 

Syzdek LD, Appel C. 1977. Virus transfer from

surf to wind. Science 198: 575–80. 

Documents this mode of pathogen transfer.

Brieseman MA. 1987. Town water supply as the 

cause of an outbreak of Campylobacter infection.

New Zealand Medical Journal 100: 212–13. 

An outbreak of 19 cases in Ashburton was attributed to the 

local water supply being contaminated after heavy rain during a 

period in which water treatment was temporarily not operating.

Brown JM, Campbell EA, Rickards AD, 

Wheeler D. 1987. Sewage pollution of bathing

water. The Lancet (21 November): 1208–9. 

Reports a Greenpeace study on two southern England resorts, 

one polluted the other not, interviewing 190 people. Found that 

“bathers who immersed their heads in seawater polluted by 

sewage were more likely to complain of gastrointestinal

symptoms than those who did not immerse their heads or those 

who bathed at a non-polluted resort”.

Bryan JA, Lehmann JD, Setiady IF, Hatch MH. 

1974. An outbreak of Hepatitis-A associated with 

recreational lake water. American Journal of

Epidemiology 99(2): 145–54. 

In a 15-day period in September 1969, 14 cases of viral 

hepatitis-A developed in members of a boy scout troop who had 

been camping on an island in a lake recreation area about four 

weeks earlier. Exposure to contaminated lake water was

indicated. 

Cabelli VJ, Levin MA, Dufour AP, McCabe LJ. 

1975. The development of criteria for recreational 

waters. In: ALH Gameson (ed). Discharge of 

Sewage from Sea Outfalls. Oxford and New York,

Pergamon Press, 63–73. 

Foreshadows the full trials reported in Cabelli (1983a). 

Explains how the design was aimed at improving perceived 

shortcomings in the 1940s study reported by Stevenson (1953),

including: ‘swimming’ to require head-immersion, multiple 

exposures to be avoided, non-bather controls to be beach 

attenders, include more candidate indicators. Notes that studies 

need to be large enough to obtain “significant results”.

Cabelli VJ. 1977. Indicators of recreational water 

quality. In: AW Hoadley and BJ Dukta (eds) 

Bacterial Indicators/Health Hazards Associated

with Water. ASTM STP 635, American Society 

for Testing and Materials, Washington: 222–38. 

An early review of Cabelli’s approach. Points to the need to 

develop a scientific basis for standards applicable to waters 

containing faecal wastes of lower animals (from waterfowl, 

wild animals, farm run-off and urban stormwater). Reports 

results from New York component of the full study reported by

Cabelli (1983a). 

Cabelli VJ. 1978. New standards for enteric 

bacteria. In: R Mitchell (ed) Water Pollution

Microbiology, Vol 2. Wiley, New York: 233–71. 

Covers risk assessment, drinking water, swimming pool water,

recreational waters and shellfish-growing waters. Reviews 

each area up to the mid-1970s. 

REFERENCES AND FURTHER READING.

J7 June 2003 
Cabelli VJ. 1979. Evaluation of recreational 

water quality, the EPA approach. In: A James and

L Evison (eds) Biological Indicators of Water 

Quality. Wiley, Chichester, 14-1–14-23. 

Discusses EPA’s use of “criteria”, “guidelines” and 

“standards”: a criterion is a relationship (e.g. between indicator

density and illness risk); a guideline is a suggested upper limit, 

derived from the criterion; and a standard is a guideline with the 

force of law. The beach studies underway were designed to 

provide criteria.

Cabelli VJ, Dufour AP, Levin MA, McCabe LJ, 

Haberman PW. 1979. Relationship of 

microbiological indicators to health effects at

marine bathing beaches. American Journal of

Public Health 69(7): 690–6. 

Reports results of second year for the New York part of the full 

study reported by Cabelli (1983a). 

Cabelli VJ, Dufour AP, McCabe LJ, Levin MA. 

1982. Swimming-associated gastroenteritis and 

water quality. American Journal of Epidemiology

115: 606–16. 

Reports main results of Cabelli (1983a). Concludes that 

“swimming in even marginally polluted marine bathing water is

a significant route of transmission for the observed 

gastroenteritis”. 

Cabelli VJ. 1983a. Health Effects Criteria for 

Marine Recreational Waters. Report EPA 600/1-

80-031, USEPA Cincinnati, OH (first published 

1980). NTIS access #: PB 83-259994. 

Major prospective epidemiological study at coastal beaches in 

New York and Boston, and a brackish beach at Lake

Ponchartrain (Louisiana), involving 26,686 persons. Beaches 

were impacted by (mostly) chlorinated effluents. Most notable 

result was a relationship between swimming-associated illness 

risk and (the logarithm of) enterococci concentration. The 

illness was HCGI (highly credible gastro-intestinal illness, 

essentially vomiting or GI accompanied by fever). Analysis 

methods used data grouping followed by linear regression,

rather than the more modern “generalized linear models” (e.g.

logistic regression); appropriate software was not then 

available. Also includes a 1976–78 study in Alexandria, Egypt. 

Some beaches were very polluted (enterococci up to 104

 per

100 mL). Egyptian participants included 12,532 locals and 

10,707 visitors (from Cairo). Only E. coli and enterococci were

measured, both showing strong associations with highly

credible gastrointestinal illness. For equivalent enterococci 

concentrations illness risks were lower than found in the US 

studies, attributed to local immunity (Cairo visitors appeared to 

be less immune). Four cases of typhoid were found among 

swimmers at the polluted beach. 

Cabelli VJ. 1983b. Public health and water 

quality significance of viral diseases transmitted by

drinking water and recreational water. Water 

Science & Technology 15(5):1–15. 

Presents predictions of gastrointestinal illness at beaches using 

the relationships derived in Cabelli (1983a). Notes the 

inapplicability of the model to beaches with small immediate 

waste sources, and local outbreaks. 

Cabelli VJ, Dufour AP, McCabe LJ, Levin MA. 

1983. A marine recreational water quality 

criterion consistent with indicator concepts and

risk analysis. Journal of the Water Pollution

Control Federation 55: 1306–14. 

Presents the health effects enterococci indicator relationship 

derived in Cabelli (1983a). Companion paper to Cabelli et al 

(1982).

Cabelli VJ. 1989. Swimming-associated illness 

and recreational water quality criteria. Water 

Science and Technology 21(2): 13–21. 

Presents the application of results in Cabelli (1983a) by USEPA 

(1986b). Contains an error in the intercept term (‘0.02’ in 

Table E1 should be ‘0.2’). States the expectation that 

contamination of water with faecal wastes from lower animals 

would carry a much lower risk of illness than from humans. 

Calderon RL, Mood EW. 1982. An

epidemiological assessment of water quality and 

‘swimmer’s ear’. Archives of Environmental 

Health 37(5): 300–5. 

A retrospective study of otitis externa in 1980 on 29 cases and 

controls finding that swimming and length of time spent in the 

water were associated positively with cases of otitis externa. 

No significant correlation of the illness with water quality was 

found (faecal coliforms, enterococci, Pseudomonas 

aeruginosa). 

Calderon RL, Mood EW, Dufour AP. 1991. 

Health effects of swimmers and nonpoint sources 

of contaminated water. International Journal of

Environmental Health Research 1: 21–31. 

Reports a diary illness study of users of freshwater ponds 

impacted only by animal wastes. Gastrointestinal illness was 

related to the number of swimmers and to staphylococcal 

counts. “Swimmer illness was not associated with high 

densities of common faecal indicator bacteria ...”. 

REFERENCES AND FURTHER READING.

J8 June 2003 
Carrie MS. 1973. Coliforms and water quality 

legislation. Soil and Water 10(2): 20–3. 

Gives some explanation of how the standards in the 1971 Water

and Soil Conservation Amendment Act (No. 2) came to pass.

Cheung WHS, Chang KCK, Hung RPS, 

Kleevens JWL. 1990. Health effects of beach 

water pollution in Hong Kong. Epidemiology and 

Infection 105: 139–62. 

Reports on a 1987 prospective study at nine Hong Kong

beaches using 18,741 useable responses. E. coli was found to 

be the best indicator of health effects (gastrointesteritis and skin 

symptom rates) among swimmers. Overall symptom rates for

gastrointestinal, ear, eye, skin, respiratory, fever and total 

illness was (statistically) significantly higher for swimmers than 

for non-swimmers. Low gastrointestinal illness rates were 

observed at the two beaches impacted by animal wastes. 

Concludes that illness associated with swimming is a public 

health problem in Hong Kong. While this study reported low 

gastro-intestinal swimming-associated rates at the two beaches 

influenced by livestock (pig) wastes, respiratory illness and 

skin infections rates were elevated such that the total illness 

rate was very similar to the other beaches.

Cheung WHS, Chang KCK, Hung RPS. 1991. 

Variations in microbial indicator densities in beach 

waters and health-related assessment of bathing 

water quality. Epidemiology and Infection 106:

329–44. 

Describes daily and hourly variations in microbial indicators. 

E. coli was influenced by tide, by staphylococci and by the 

number of bathers. Average staphylococci: E. coli ratio was 

0.04:3. Staphylococci serve as an indicator of bather density

and risk of cross-contamination between bathers. Recommends 

weekend sampling for compliance assessment. 

Chung H, Jaykus L-A, Lovelace G, Sobsey MD. 

1998. Bacteriophages and bacteria as indicators of 

enteric viruses in oysters and their harvest waters. 

Water Science and Technology 38(12): 37–44. 

Concentrations of male-specific (F+) coliphages, Bacteroides 

fragilis phages, Salmonella phages and several indicator

bacteria in wastewater, estuarine receiving water and its oysters 

were examined at 2–4-week intervals for 14 months. The levels 

of most indicators were higher in oysters and water when 

oysters were virus-positive. F+ coliphages and C. perfringens 

were the only indicators significantly associated with the 

presence of enteric viruses in oysters.

Conover WJ. 1980. Practical Nonparametric 

Statistics. 2nd ed. Wiley, New York. 

The best introduction to this class of methods, whereby data 

ranks are used in place of their actual magnitudes (e.g. medians 

and percentiles). 

Corbett SJ, Rubin GL, Curry GK, Kleinbaum DG, 

et al 1993. The health effects of swimming at 

Sydney beaches. American Journal of Public

Health 83(12): 1701–6. 

Reports follow-up study of 2,839 beach-goers in 1989/90; 683 

reported experiencing symptoms in the 10 days following initial 

interview, of whom 435 reported respiratory symptoms. A 

linear relationship between water pollution and all reported 

symptoms (except gastrointestinal) was shown. 

Cornax R, Morinigo MA, Balebona C, Castro D, 

Borrego JJ. 1991. Significance of several 

bacteriophage groups as indicators of sewage 

pollution in marine waters. Water Research 25:

673–8. 

From a two-beach study this documents a poor correlation 

between FRNA phages and pathogen occurrence and 

persistence. Concludes that faecal streptococci and E. coli

“C bacteriophages” are the most appropriate indicators of 

remote pollution in marine waters. 

Dadswell JV. 1993. Microbiological quality of

coastal water and its health effects. International 

Journal of Environmental Health Research 3:

32–46. 

Reviews health-related marine microbiology, both natural and 

pollution-related organisms.

D’Alessio D, Minot TE, Allen CI, Tsiatis AA, 

Nelson DB. 1981. A study of the proportions of

swimmers among well controls and children with

enterovirus-like illness shedding or not shedding

an enterovirus. American Journal of Epidemiology

113(5): 533–41. 

A retrospective study of children visiting a paediatric clinic in 

Madison, Wisconsin, in 1977: 679 well children and 296 with 

enteroviral-like symptoms. Exclusive beach swimmers had 

significantly (p < 0.0005) relative risk (odds ratio estimate 

3.41) of enterovirus illness. The highest relative risk (10.63) of 

enterovirus illness occurred in children less than four years old 

who were exclusive beach swimmers.

REFERENCES AND FURTHER READING.

J9 June 2003 
Davies-Colley RJ, Bell RG, Donnison AM. 1994. 

Sunlight inactivation of enterococci and fecal 

coliforms in sewage effluent diluted in seawater. 

Applied and Environmental Microbiology 60:

2049–58. 

Two parameters are required to describe the inactivation (loss of

culturability): a shoulder constant and a rate constant. Depthdependent inactivation rate for both indicators matched the 

attenuation profile of UV-A radiation at about 360 nm

(attributable to inactivation maxima in the 318–340 and > 400 nm

ranges, Sinton et al 1994). Inactivation by UV-B (290–320 nm, 

which penetrates less into seawater) is of lesser importance. 

Davies-Colley RJ, Donnison AM, Speed DJ. 

1997. Sunlight wavelengths inactivating faecal 

indicator micro-organisms in waste stabilisation

ponds. Water Science and Technology 35(11–12):

219–25. 

UVB, UVA and blue-green (< 550 nm) radiation all contributed 

to inactivation of enterococci and (possibly) FRNA phage,

consistent with a photo-oxidation mechanism. In contrast,

E. coli and (possibly) FDNA phage were inactivated mainly by 

UVB in these freshwaters. Results suggest E. coli may be a 

better freshwater indicator than enterococci. 

Davies-Colley RJ, Donnison AM, Speed DJ, 

Ross CM, Nagels JW. 1999. Inactivation of 

faecal indicator microorganisms in waste 

stabilisation ponds: Interactions of environmental 

factors with sunlight. Water Res 33: 1220–30.

Sunlight exposure is considered to be the most important cause 

of “natural” disinfection in waste stabilisation ponds (WSPs). 

The influence of dissolved oxygen (DO), pH, and particulate 

and dissolved constituents in WSP effluent, on sunlight 

inactivation of faecal micro-organisms, using small reactors 

operated under controlled physico-chemical conditions was 

examined. Inactivation of both enterococci and F-RNA phages 

increased strongly as DO was increased, and also depended on 

light-absorbing pond-water constituents, but pH was not 

influential over the range investigated (7.5 to 10). Inactivation 

of E. coli increased strongly when pH increased above 8.5, as 

well as being strongly dependent on DO. Inactivation of 

F-DNA phage was independent of the factors investigated. 

These results are consistent with the F-DNA phages being 

inactivated as a result of direct DNA damage by UVB in

sunlight, whereas the other three microbiological indicators are 

inactivated as a result of photo-oxidative damage, although the 

target of damage is apparently different. Our findings of

diverse influences of physico-chemical conditions suggest 

difficulties in interpreting data for a single micro-organism to 

indicate WSP effluent quality. However, sunlight remains the 

factor of overriding importance, and disinfection in WSPs may

be enhanced by increasing sunlight exposure.

Deely J, Hodges S, McIntosh J, Bassett D. 1997. 

Enterococcal numbers measured in waters of 

marine, lake, and river swimming sites of the Bay

of Plenty, New Zealand. New Zealand Journal of

Marine and Freshwater Research 31: 89–101. 

Reports enterococci numbers for 32 coastal beaches, 23 lake 

beaches and 31 river swimming holes, using medians of five 

samples. Most marine, lake and up-river sites had low 

enterococci counts, complying with current guidelines, but midriver and lowland river reaches tended to breach those 

guidelines.

Department of Health. 1992. Provisional 

Microbiological Water Quality Guidelines for 

Recreational and Shellfish-gathering Waters in

New Zealand. Department of Health, Public

Health Services, Wellington. 

Previous guidelines, issued in response to a number of 

authorities beginning to use the USEPA (1986b) criteria. These 

guidelines attempted to interpret those criteria in terms of New 

Zealand conditions.

Disinfection Review Group. 2002. Pilot Study: 

Pilot plant investigations, surrogate study results 

and recommendations. Final report to Watercare 

Services Ltd, Auckland, June. 

Reports on an extensive set of trials examining inactivation 

rates of a number of faecal indicators and pathogens in a pilot 

plant mimicking the processes to be used in the upgraded 

Mangere Wastewater Treatment Plant. Demonstrates 

decreasing correlations between indicators and pathogens

(enteroviruses) as the level of treatment is increased. 

Donnison AM, Cooper RN. 1990. Enumeration

of faecal coliforms and Escherichia coli in New 

Zealand receiving waters and effluents. 

Environmental Technology 11: 1123–7. 

Describes mTEC membrane filtration method for enumeration 

of faecal coliforms and E. coli (as a subsequent step). 

Compares the method favourably to alternatives (MPN and 

mFC).

Donnison AM. 1992. Enumeration of enterococci

in New Zealand waters and effluents. 

Environmental Technology 13: 771–8. 

Compares an in-house MPN method to the USEPA Membrane 

Filter Method, suggesting it as a desirable method for 

enumerating enterococci in effluents (particularly if they are 

minimally treated).

REFERENCES AND FURTHER READING.

J10 June 2003 
Donnison AM, Ross CM. 1995. Somatic and 

F-specific coliphages in New Zealand waste

treatment lagoons. Water Research 29(4):

1105–10. 

Concludes that the FRNA:FDNA coliphage ratio may

distinguish between animal and human faecal material. 

Donnison AM, Ross CM. 1999. Animal and

human faecal pollution in New Zealand. New 

Zealand Journal of Marine and Freshwater 

Research 33: 119–28. 

Sentinel freshwater mussels were placed in rivers impacted by

faecal pollution. E. coli were recovered from all sites

(including a forest control site) but were highest at sites 

impacted by treated sewage, meat-processing wastes or dairy 

farm inputs. The pathogens measured (Campylobacter jejuni, 

E. coli, Salmonella typhimurium, Yersinia enterocolitica) were 

recovered from mussels – except at the control site. Untreated 

wastewaters (sheep, beef, human sewage) all indicated the 

presence of these pathogens, mostly in more than half the 

samples. Thermophilic Campylobacters “are likely to remain 

after secondary treatment of either meat plant waste water or

sewage”. 

Dufour AP. 1984. Health Effects Criteria for 

Fresh Recreational Waters. Report EPA 600/1-

84.004, USEPA Cincinnati, OH. NTIS access #:

PB 85-150878. 

Major prospective epidemiological study at lake beaches in 

Tulsa, Oklahoma, and Erie, Pennsylvania, involving 34,598 

persons. Most notable result was a relationship between

“swimming-associated pollution-related illness risk” and (the 

logarithm of) E. coli and enterococci concentrations. The 

association with E. coli was the stronger of the two. The illness 

was HCGI (highly credible gastro-intestinal illness, being GI 

accompanied by fever). Analysis methods used data grouping 

followed by linear regression, rather than the more modern

“generalized linear models” (e.g. logistic regression); 

appropriate software was not available. Also reports results of 

Egyptian studies, but these were not included in their final 

analysis. 

Dutka BJ. 1979. Microbiological indicators,

problems and potential of new microbial indicators

of water quality. In: A James and L Evison (eds) 

Biological Indicators of Water Quality. Wiley and 

Sons, London. 

Reviews alternatives, each of which may signal contamination. 

Eberhart-Phillips J, Walker N, Garrett N, Bell D, 

Sinclair D, Rainger W, Bates M. 1997. 

Campylobacteriosis in New Zealand: results of a 

case-control study. Journal of Epidemiology and 

Community Health 51: 686–91. 

Reports a study on 621 people with notified illness between 

June 1994 and February 1995 in Auckland, Hamilton, 

Wellington and Christchurch. Found undercooked chicken to 

be a strong risk factor. Rainwater as a source at home was a 

lesser factor. Recreational water use appears not to have been 

in the questionnaire.

EEC. 1976. Council Directive of 8 December 

1975 concerning the quality of bathing water 

(76/160/EEC). Official Journal of the European

Communities. No. L31/1–7. Available at: 

http://europa.eu.int/water/waterbathing/directiv.html. 

Documents the EEC bathing water directive. Imperative 

standards require 95% of fortnightly samples to not exceed 

10,000 total coliforms per 100 mL or 2000 faecal coliforms per 

100 mL. If inspection shows that other substances may be 

present, or that water quality has deteriorated, then there should 

be zero Salmonella per litre and zero enterovirus per 10 litres in 

95% of samples (sampling frequency unspecified). Guideline 

values require 80% of fortnightly samples to not exceed 500 

total coliforms per 100 mL or 100 faecal coliforms per 100 mL. 

If inspection shows that the substances may be present, or that 

water quality has deteriorated, then 80% of samples should not 

exceed 100 faecal streptococci per 100 mL (sampling frequency

unspecified). There are other limits on pH, colour, mineral oils,

surface-active substances, phenols, transparency, dissolved 

oxygen, tarry residues and floatables (fortnightly sampling 

being required for colour, mineral oils, surface-active 

substances, phenols, transparency, tarry residues and 

floatables). The following should be checked if there is a 

tendency toward eutrophication: ammonia and Kjeldahl 

nitrogen. If inspection shows that other substances may be 

present, or that water quality has deteriorated, then sampling is 

required for pesticides, heavy metals, cyanides, nitrates and 

phosphates.

EEC. 1979. Council Directive of 30 October

1979 on the quality required of shellfish waters. 

Official Journal of the European Communities. 

No. L 281/47–49 plus annex. Details, with

amendment 391L0692, at: http://europa.eu.int/eurlex/en/lif/dat/1979/en_379L0923.html. 

REFERENCES AND FURTHER READING.

J11 June 2003 
EHD. 1980. A Study of Disease Incidence and

Recreational Water Quality in the Great Lakes. 

Phase I. Report 81-EHD-67. Environmental

Health Directorate, Health Protection Branch, 

Health and Welfare, Ottawa, Canada (prepared by

The University of Toronto). 

A prospective study using 6,166 interviews, of whom 65% 

were swimmers at lake beaches. Swimmers were found to have 

higher morbidity risks. Main feature was evidence of bather-tobather transmission of infections (strongest association was 

with Staphylococci). 

El-Sharkawi F, Hassan MNER. 1979. The

relation between the state of pollution in 

Alexandria swimming beaches and the occurrence

of typhoid among bathers. Bulletin of the High

Institute of Public Health of Alexandria IX: 

337–51. (Reprinted by the Alexandria University 

Press, 1980.) Report obtainable from G McBride, 

NIWA, Hamilton, New Zealand.

Reports on a 1976 retrospective study of hospital inpatients. 

Concludes that “there is a significant risk of contracting 

Typhoid from bathing in the polluted water and the mostly

affected were the young age group”. Sewer outfalls discharged 

raw material directly to some beaches. 

Elliot EL, Colwell RR. 1985. Indicator organisms 

for estuarine and marine waters. FEMS 

Microbiology Reviews 32: 61–79. 

Documents finding the presence of pathogens in waters and 

shellfish when faecal coliforms are either absent or in low 

numbers.

Elliott AH. 1998. Prediction of illness risk near 

ocean outfalls using frequency distributions of 

bacterial concentrations. Water Research 32(10):

3182–7. 

Presents a method for combining temporal concentration 

frequency distribution with a concentration–response relation to 

obtain an averaged illness rate, applied to North Shore 

(Auckland).

Ellis JC, Lacey RF. 1980. Sampling: defining the 

task and planning the scheme. Water Pollution 

Control 79: 452–67; discussion: 482–4. 

Wide review of sampling programme design. Discusses 

statistics of assessing compliance with percentile standards, 

where the percentile refers to a percentage of time (not of

samples). 

EU. 1994. Proposal for a Council Directive

concerning the quality of bathing water. Official 

Journal of the European Communities. No. 

C 112/3–10. Available at: http://europa.eu.int/eurlex/en/com/dat/1994/en_594PC0036.html. 

Clarifies method of compliance assessment and proposes 

revised quality requirements based on E. coli, faecal 

streptococci, enteroviruses (bacteriophages mentioned, but no 

limits are proposed). Compliance is to be assessed using lookup tables (e.g. for an imperative standard, 95% percentile are 

assessed by allowing no exceedances in 19 samples, one 

exceedance in between 20 and 39 samples, etc). The

imperative 95% percentile limits for E. coli and faecal 

streptococci are 2000 and 400 per 100 mL respectively, and for

enteroviruses it remains at 0 pfu/10 L.

Fattal B, Vasl RJ, Katzenelson E, Shuval HI. 

1983. Survival of bacterial indicator organisms 

and enteric viruses in the Mediterranean coastal 

waters off Tel-Aviv. Water Research 17:

397–402. 

Reports ‘die-away’ studies on coliforms and enteric viruses 

offshore from Tel Aviv. Concentrations of total coliforms, 

faecal coliforms and faecal streptococci were correlated with 

enterovirus concentrations (though not all correlations were

statistically significant). Faecal streptococci displayed a similar 

die-away rate to enteroviruses; the other bacteria reduced more

quickly. About 76% of positive enterovirus samples were 

found at beaches within ‘safe’ levels, as indicated. 

Fattal B, Peleg-Olevsky E, Yoshpe-Purer Y, 

Shuval HI. 1986. The association between 

morbidity among bathers and microbial quality of

seawater. Water Science and Technology 18(11):

59–69. 

Reports a prospective epidemiological study at three Tel Aviv 

coastal beaches in 1983, comprising 2,231 persons (23% below 

four years of age). Strongest finding was symptoms of enteric 

morbidity among swimmers, particularly the 0–4-year-olds,

related to elevated levels of enterococci, E. coli and 

staphylococci (not faecal coliforms). Swimmers had more 

morbidity of all types of symptoms (enteric, respiratory, others)

than non-swimmers.

Fattal B, Peleg-Olevsky E, Agursky T, Shuval HI. 

1987. The association between seawater pollution 

as measured by bacterial indicators and morbidity 

among bathers at Mediterranean bathing beaches 

of Israel. Chemosphere 16(2/3): 565–70. 

A briefer description of the 1983 study than that given by Fattal 

et al (1986).

REFERENCES AND FURTHER READING.

J12 June 2003 
Fattal B, Peleg-Olevsky E, Cabelli VJ. 1991. 

Bathers as a possible source of contamination for 

swimming-associated illness at marine bathing 

beaches. International Journal of Environmental 

Health Research 1: 204–14. 

Further analysis of the 1983 study. Notes that the best 

association between an indicator and swimmers’ illness is with 

Staphylococcus aureus (rather than enterococcus or E. coli), 

suggesting bather-to-bather contamination as a dominant 

mechanism.

Favero MS. 1985. Microbiological indicators of

health risks associated with swimming. American

Journal of Public Health 75(9): 1051–3. 

Reviews the history of this topic up to 1985 (Seyfried et al’s

papers were in this issue). Notes that faecal coliforms may now 

be regarded as “relatively useless for judging the safety of 

natural bathing waters”. Notes also the USEPA promulgated a 

proposal that the criteria be set at 20 enterococci per 100 mL or

77 E. coli per 100 mL for freshwaters or only three enterococci 

per 100 mL for marine waters (Federal Register May 1984,

49(102): 21987–8). These limits were revised upward after

feedback from professionals, many of whom suggested that the 

proposed limits were too stringent (Federal Register February

1986, 51(45): 8012–16).

Fayer R, Graczyk TK, Lewis EJ, Trout JM, 

Farley CA. 1998. Survival of infectious 

Cryptosporidium parvum oocysts in seawater and 

Eastern oysters (Crassostrea viginica) in the

Chesapeake Bay. Applied and Environmental 

Microbiology 64(3): 1070–4. 

Oocysts placed in artificial seawater were infectious for up to 

12 weeks. Oysters sampled from natural waters contained 

infectious oocysts and can serve as mechanical vectors of this 

organism.

Ferguson CM, Coote BG, Ashbolt NJ,

Stevenson AM. 1996. Relationships between 

indicators, pathogens and water quality in an

estuarine system. Water Research 30(9): 2045–54.

Water and sediment sampling for a range of indicators and 

pathogens is reported for an urban estuary in Sydney, Australia. 

Significant increases of faecal coliforms, faecal streptococci, 

Clostridium perfringens spores, F-RNA bacteriophage,

Aeromonas spp., Giardia and Cryptosporidium spp. occurred in 

the water after rain, but only faecal coliforms showed 

significant increases in the sediments. Isolations of enteric 

viruses were sporadic and not exclusively related to wet

weather events. C. perfringens was identified as the most 

useful indicator of faecal pollution. 

Ferley JP, Zmirou D, Balducci F, Baleux B, 

Fera P, Larbaigt G, Jacq E, Moissonnier B,

Blineau A, Boudot J. 1989. Epidemiological 

significance of microbiological pollution criteria

for river recreational waters. International Journal 

of Epidemiology 18: 198–205. 

Reports a retrospective 1986 follow-up study in the Ardèche 

basin using 5737 tourists in eight holiday camps. Found a 

relative risk of 2.3 (95% CI = 1.7–3.2) for “objective” 

gastrointestinal cases (requires vomiting or diarrhoea). Faecal 

streptococci were best correlated to morbidity, with threshold 

20 per 100 mL.

Fewtrell L, Godfree AF, Jones F, Kay D, 

Salmon RL, Wyer MD. 1992. Health effects of 

white-water canoeing. The Lancet 339: 1587–9. 

Reports a prospective cohort study using 516 canoeists on two 

channels with different degrees of pollution: arithmetic mean 

enterovirus 198 and 0 pfu/L and geometric mean faecal

coliforms 285 and 22/dL for streams A and B. Between five 

and seven days after exposure canoeists using stream A had 

significantly higher incidences of gastrointestinal and upper

respiratory symptoms than either canoeists using stream B or 

non-exposed controls (spectators).

Fewtrell L, Kay D, Salmon RL, Wyer MD, 

Newman G, Bowering G. 1994. The health

effects of low-contact water activities in fresh and 

estuarine waters. Journal of the Institution of 

Water and Environmental Management 8: 97–101. 

Four studies were carried out at separate locations (two 

freshwater and two estuarine) using about 1000 participants in 

marathons and canoeing. Geometric mean faecal coliforms

ranged from 62 to 4613 per 100 mL. Comparison of exposed 

and unexposed groups five – seven days after exposure showed 

minimal health effects for the low water-contact sports. 

Figueras MJ, Polo F, Inza I, Guarro J. 1997. Past, 

present and future perspectives of the EU bathing

water directive. Marine Pollution Bulletin 34(3):

148–56. 

Reviews reasons put forward for changes to the 1976 standards 

(EEC 1976) and recent proposals. 

REFERENCES AND FURTHER READING.

J13 June 2003 
Figueras MJ, Robertson W, Pike EB, Ashbolt NJ,

Borrego JJ. 2000. Sanitary inspection and 

microbiological water quality. In: J Bartram,

G Rees (eds). Monitoring Bathing Waters: A 

practical guide to the design and implementation

of assessments and monitoring programmes. 

London, E & FN Spons, 113–67. Published on

behalf of the World Health Organization,

Commission of the European Communities and 

US Environmental Protection Agency. 

Fleisher JM, McFadden RT. 1980. Obtaining 

precise estimates in coliform enumeration. Water 

Research 14: 477–83. 

Argues for increasing precision in coliform enumerations by 

replication of sampling.

Fleisher JM. 1985. Implications of coliform

variability in the assessment of the sanitary quality 

of recreational waters. Journal of Hygiene 

(Cambridge) 94: 193–200. 

Reanalysed New York coliform compliance data, showing the 

impact of lack of precision. Within-day variations were

identified. 

Fleisher JM. 1990a. Conducting recreational 

water quality surveys: Some problems and

suggested remedies. Marine Pollution Bulletin

21(2): 562–7. 

Discusses need to account for measurement error and temporal 

within-day variability of microbiological examinations. Argues 

it is better to maximise replications instead of sample dates. 

Fleisher JM. 1990b. The effects of measurement 

error on previously reported mathematical

relationships between indicator organism density

and swimming associated illness: a quantitative 

estimate of the resulting bias. International 

Journal of Epidemiology 19(4): 1100–6. 

Uses computer simulations to demonstrate the effect of

measurement error on indicator–health risk relationships. 

Underestimation of health risks was shown. Recommendations 

for future study designs were made.

Fleisher JM. 1991. A re-analysis of data 

supporting US federal bacteriological water quality 

criteria governing marine recreational waters. 

Research Journal WPCF 63(3): 259–65. 

Criticises the USEPA criteria for including brackish water 

(Lake Ponchartrain, Louisiana), and reanalyses the data using 

logistic regression. Some aspects of the reanalysis are also 

open to question in our opinion (especially the weight put on 

Boston data beyond their range).

Fleisher JM. 1992. US Federal bacteriological 

water quality standards: a re-analysis. In: D Kay 

(ed) Recreational Water Quality Management. 

Vol. 1, Coastal Waters. New York, Ellis 

Horwood, 113–28. 

Criticises the USEPA criterion’s basis for incorporating three 

different relationships (for the three beaches) developed by the 

author, using logistic regression.

Fleisher JM, Jones F, Kay D, Morano R. 1993. 

Setting recreational water quality criteria. In: 

D Kay and R Hanbury (eds). Recreational Water 

Quality Management. Vol. 2. Fresh Water. New

York, Ellis Horwood, 123–36. 

Identifies sources of bias probably incorporated in previous 

epidemiological studies, and promotes methods to minimise 

them. 

Fleisher JM, Jones F, Kay D, Stanwell-Smith R, 

Wyer MD, Morano R. 1993. Water and nonwater related risk factors for gastroenteritis among 

bathers exposed to sewage contaminated marine 

waters. International Journal of Epidemiology 22: 

698–708. 

Finds three faults in previous epidemiological studies, being 

failures to: account for within-day and spatial variability at

beaches, relate indicator concentration to an individual bather, 

and rigorously control non-water-related risk factors. Results 

of two “intervention follow-up studies” (controlled-cohort 

trials) are reported. These were at Langland Bay (109 bathers 

and 124 non-bathers) and Moreton Beach (97 bathers and 154 

non-bathers). Faecal streptococci (and not faecal coliforms) 

were associated with bathers’ gastrointestinal illness, and only 

for chest-depth samples (two shallower sampling depths were

used): “excess risk among bathers did not occur until exposure 

to waters containing 40–59 faecal streptococci/100 mL”.

REFERENCES AND FURTHER READING.

J14 June 2003 
Fleisher JM, Kay D, Salmon RL, Jones F,

Wyer MD, Godfree AF. 1996. Marine waters 

contaminated with domestic sewage, non-enteric 

illnesses associated with bather exposure in the 

United Kingdom. American Journal of Public

Health 86(9): 1228–34. 

Reports on results from all four UK controlled-cohort studies 

using 1216 healthy adult volunteers (average age about 

32 years). Intensive water-quality monitoring was used to 

assign possible health-risk indicators (all bacteria) to individual 

bathers. Faecal streptococci exposure (threshold 60 per 

100 mL) was predictive of acute febrile respiratory illness 

(which must include fever), while faecal coliform exposure 

(threshold 100 per 100 mL) was predictive of ear ailments. 

Bathers were at higher risk for eye ailments. 

Fleisher JM, Kay D, Wyer MD, Merrett H. 1996. 

The enterovirus test in the assessment of

recreational water-associated gastroenteritis. 

Water Research 30(10): 2341–6. 

Uses polychotomous logistic regression on 2066 parallel faecal 

streptococci and enterovirus enumerations from 416 UK 

locations. Found that the actual viruses enumerated by the 

assay are not aetiologically related to recreational waterassociated gastroenteritis. Suggest that enterovirus assay may

be of limited use in assessing marine recreational water quality. 

Fleisher JM, Kay D, Wyer MD, Godfree AF. 

1998. Estimates of the severity of illnesses 

associated with bathing in marine recreational 

waters contaminated with domestic sewage. 

International Journal of Epidemiology 27: 722–6. 

Reviews findings of the four UK controlled-cohort trials. 

Concludes that “illness associated with bathing in marine 

waters contaminated with domestic sewage can no longer be 

viewed as minor, and indeed can have a substantial impact on 

the public health”. 

Foulon G, Maurin J, Quoi N, Martin-Boyer G. 

1983. Relationship between the microbial quality 

of water and health effects. Revue Francaise des

Sciences de L’Eau 2: 127–43. 

Beach interviews of 4,921 persons at five coastal beaches were

followed by an answer card (only 1532 persons did so). The 

study indicates that an answer card system should be avoided. 

See also the review by Shuval (1986).

Fraser GG, Cooke KR. 1991. Epidemic giardiasis 

and municipal water supply. American Journal of

Public Health 81(6): 760–2. 

Compares reported rates of giardiasis in Dunedin (New 

Zealand) for two 10-month periods. The city had two water

supplies, one “unfiltered” (microstrained, 23 μm) and the other

a modern plant with dual filters (anthracite and silica sand). 

Found incidence rate-ratio of 3.3 (90% CI = 1.1, 10.1,

49 cases). A parallel case-control study found an odds ratio of 

1.8 (90% CI = 0.5, 6.5). These results do not achieve 

“statistical significance” at the 95% level, but are suggestive of 

transmission of Giardia via water.

Furfari SA. 1968. History of the 70 MPN/100 mL

standard. Memo, Northeast Marine Health 

Services Laboratory, USA.

Documents the history of the 70 MPN per 100 mL shellfishgathering water standard, as used by the US Public Health 

Service. The calculation was based on a requirement that no 

more than 50% of 1 mL portions were positive for coliforms, 

equivalent to an MPN of about 70 per 100 mL. (Available only

from G McBride, NIWA, Hamilton, New Zealand.) 

Gameson ALH, Gould DJ. 1975. Effects of solar 

radiation on the mortality of some terrestrial 

bacteria in sea water. In: ALH Gameson (ed) 

Discharge of Sewage from Sea Outfalls.

Pergamon Press, Oxford and New York, 209–19. 

Rate of die-off of coliforms in water is much greater in daylight 

than in the dark. Die-off of E. coli was slower than that of total 

coliforms. Reports seminal work on this topic.

Gameson ALH. 1979. EEC directive on quality 

of bathing water. Water Pollution Control 78(2):

206–14. 

Notes some practical difficulties in implementing the EEC 

Directive (EEC 1976).

Geldreich EE. 1978. Bacterial populations and 

indicator concepts in feces, sewage, stormwater 

and solid wastes. In: G Berg (ed) Indicators of

Viruses in Water and Food. Ann Arbor Science, 

Ann Arbor, Mich., 51–97. 

Substantial review of literature up to the late 1970s. 

REFERENCES AND FURTHER READING.

J15 June 2003 
Gibson CJ, Stadterman KL, States S, Sykora J. 

1998. Combined sewer overflows: a source of

Cryptosporidium and Giardia. Water Science and

Technology 38(12): 67–72. 

Combined overflows were found to contribute both parasites in 

dry and (particularly) wet weather.

Gilbert RO. 1987. Statistical Methods for 

Environmental Pollution Monitoring. Van 

Nostrand Reinhold, New York. 

This is an excellent book on many aspects of statistical 

interpretation of pollution data. Particularly strong on the lognormal distribution, which is often followed by microbiological 

particles. 

Godfree A, Jones F, Kay D. 1990. Recreational 

water quality: the management of environmental 

health risks associated with sewage discharges. 

Marine Pollution Bulletin 9: 414–22. 

Reviews past studies and claims the 1986 USEPA “standards” 

do not have a firm scientific foundation.

Goodman SN. 1993. p values, hypothesis tests, 

and likelihood: implications for epidemiology of a 

neglected historical debate. American Journal of

Epidemiology 137(5): 485–96. 

Discusses valid and invalid conclusions from significance tests 

and hypothesis tests.

Grabow WOK, Idema GK, Coubrough P,

Bateman BW. 1989. Selection of indicator

systems for human viruses in polluted seawater 

and shellfish. Water Science and Technology

21(3): 111–17. 

Analysed 610 samples of sewage, polluted seawater and 

shellfish. Ratios of indicators:viruses varied considerably.

Recommends sample medians of 100 faecal coliforms per 

100 mL, 40 faecal streptococci per 100 mL, 50 coliphages per 

100 mL, 0 human viruses per 10 L.

Green DH, Lewis GD. 1999. Comparative 

detection of enteric viruses in wastewaters, 

sediments and oysters by reverse transcriptionPCR and cell culture. Water Research 33(5): 

1195–200. 

Reports results from eight occasions over a 12-month period 

around Auckland’s Mangere treatment plant. Enteroviruses 

were found up to 276 pfu per L in the final effluent, being 

highest in winter and spring (four samples were less than 

detection limit). They were also present in most sediment 

samples and in three oyster samples. Rotavirus was present in 

most final effluent and oyster samples, and in one sediment 

sample. Hepatitis A virus was confirmed in seven sediment 

samples, but not in any final effluent or oyster samples. 

Grimes DJ. 1991. Ecology of estuarine bacteria 

capable of causing human disease: a review. 

Estuaries 14(4): 345–60. 

Reviews current knowledge concerning A. cinetobacter,

Aeromonas, Clostridium, Enterobacter, Flavobacterium,

Legionella, Listeria, Pleisiomonas, Pseudomonas and Vibrio. 

Grimont F, Grimont PAD, Richard C. 1992. The 

genus Klebsiella. In: A Balows et al (eds) The 

Prokaryotes, 2nd ed. Springer-Verlag, New York, 

2673–4. 

Discusses Klebsiella species as infectious particles. 

Grohmann GS, Ashbolt NJ, Genova MS, Logan G,

Cox P, Kueh CSW. 1993. Detection of viruses in

coastal and river water systems in Sydney, 

Australia. Water Science and Technology 27(3–4):

457–61. 

Isolated enteroviruses, adenoviruses and reoviruses. Data 

suggest “long-term survival of viruses in sediments and/or

contamination from other sources such as storm water 

discharge”. Since the use of deep ocean outfalls there was a 

decrease in the number of positive seawater samples close to 

the beaches, whereas in stormwater drains viral presence

remained constant.

Haas CN, Rose JB, Gerba CP. 1999. Quantitative 

Microbial Risk Assessment. Wiley, New York.

Authoritative reference for this new field of risk modelling, and 

associated techniques. 

REFERENCES AND FURTHER READING.

J16 June 2003 
Haile RW, Alamillo J, Barrett K, Cressey R,

Dermond J, Ervin C, Glasser A, Harawa N,

Harmon P, Harper J, McGee C, Millikan RC, 

Nides M, Witte JS. 1996. An Epidemiological 

Study of Possible Adverse Health Effects of 

Swimming in Santa Monica Bay. Santa Monica 

Bay Restoration Project. Final Report, 7 May

(summary dated October 1996). 

Reports a large-scale epidemiological study of head-immersing 

bathers aimed at evaluating the possible adverse health effects 

of urban run-off. Some 11,793 successful follow-up interviews 

were completed with beach attenders, and daily ankle-depth 

water samples were analysed for faecal coliforms, enterococci 

and E. coli. Findings include: (i) an increased risk of illness 

(about 1%) associated with swimming near flowing storm drain 

outlets (based on groups swimming at and 400 yards from

drains); (ii) an increased risk of illness associated with 

swimming in areas with high densities of bacterial indicators; 

(iii) the total coliform to faecal coliform ratio was one of the 

better indicators for predicting health risk; (iv) illnesses were 

reported more often on days when samples were positive for 

enteric viruses. 

Hall AJ, Rodrigues LC. 1992. Health risks 

associated with bathing in sea water. British

Medical Journal 302: 572. 

A letter to the editor faulting Balarajan et al (1991) for lack of 

detail on a number of issues (pre-publicity, influence of nonownership of telephones, forms of immersion, accounting for

possible confounders). In reply (same page) the authors

clarified aspects of these questions (e.g. explaining how they

minimised pre-publicity so as to avoid enhanced self-reporting 

of symptoms). They noted that their main finding was a “doseresponse effect of different forms of contact with sea water:

those bathing activities that entailed more immersion usually 

resulted in more symptoms being reported”. 

Harrington JF, Wilcox DN, Giles PS, Ashbolt NJ,

Evans JC, Kirton HC. 1993. The health of

Sydney surfers: an epidemiological study. Water 

Science and Technology 27(3–4): 175–81. 

Reports a 90-day, six-beach study wherein 2003 recruits 

returned 4011 questionnaires incorporating 43,175 swimming 

events. Overall, swimmers reported illness 1.63 times more 

often than non-swimmers. Relative risks for total illness in 

males rose from 1.79 in high-frequency beach swimmers, to 

2.26 when their swims at non-ocean sites were included. No 

firm health-based risk threshold was reported.

Henshilwood K, Green J, Lees DN. 1993. 

Monitoring the marine environment for small

round structured viruses (SRSVs): a new approach

to combating the transmission of these viruses by

molluscan shellfish. Water Science and

Technology 38(12): 51–6. 

Shellfish were measured every 1–2 weeks over a 14-month 

period for SRSVs. Concentrations were highest in winter,

when oyster-associated gastrointestinal illness is at its peak. 

Sequence analysis identified 11 SRSV strains. Virus 

monitoring of shellfish is now possible.

Holmes PR. 1989. Research into health risks at 

bathing beaches in Hong Kong. Journal of the 

Institution of Water and Environmental 

Management 3: 488–95. 

Partial presentation of results of the 1987 Hong Kong study

(see Cheung et al 1990).

Horwitz MS. 1990. Adenoviruses. In: BN Fields 

et al (eds) Virology, 2nd ed. Raven Press, New

York, 1723–43. 

Describes this virus, which can cause significant respiratory

illness. 

IAWPRC. 1991. Bacteriophages as model viruses

in water quality control. In: AH Havelaar (ed)

Study Group on Health Related Water 

Microbiology. Water Research 25: 529–45. 

Reviews possible use of F-specific RNA phages and phages of 

Bacteroides fragilis as virus surrogates. Usefulness of somatic 

coliphages is compromised by their ability to multiply in

freshwater. 

Ikram R, Chambers S, Mitchell P, Brieseman MA, 

Ikram OH. 1994. A case control study to 

determine risk factors for Campylobacter infection 

in Christchurch in the summer of 1992–93. New 

Zealand Medical Journal 107: 430–2. 

A study aimed at determining the risk factors for acquiring 

Campylobacter infection in Christchurch in the 1992/93 

summer found eating undercooked chicken away from home is 

a major factor, but also drinking water from a non-urban 

supply.

REFERENCES AND FURTHER READING.

J17 June 2003 
Jones F, Kay D. 1989. Bathing waters and health

studies. Water Services 93: 87–9. 

Raises questions about the Cabelli studies (between-site range 

of illness rates, use of telephone survey rather than medical 

follow-up, lack of control of length of swim, lack of 

information on alternative modes of infection). Opined that 

USA results may not be transferable to UK. 

Jones F, Kay D, Stanwell-Smith R, Wyer M.

1990. An appraisal of the potential health impacts 

of sewage disposal to UK coastal waters. Journal 

of the Institution of Water and Environmental 

Management 4: 295–303. 

Claims that North American epidemiological studies are not 

scientifically robust, leaving a “research vacuum”, such that 

UK studies should proceed (pilot controlled cohort studies had 

been carried out in 1989 at Langland Bay in Wales).

Jones F, Kay D, Stanwell-Smith R, Wyer M.

1991. Results of the first pilot-scale controlled

cohort epidemiological investigation into possible 

health effects of bathing in sea water at Langland 

Bay, Swansea. Journal of the Institution of Water 

and Environmental Management 5: 91–8. 

Reviews the 1989 controlled-cohort pilot study. Notes that 

responses to their detailed medical questionnaire resulted in 

higher reported attack rates of perceived illness for both bathers 

and non-bathers. Some statistically significant results were

reported for perceived illness, which were not confirmed by 

clinical tests. Concludes full-scale studies are desirable.

Jones N, Graham J. 1995. Outbreak of 

gastroenteritis associated with oysters: a Norwalklike virus most likely cause. The New Zealand 

Public Health Report 2(3): 25–7. 

Thirty-six of 95 people attending a Christmas party in 

December 1994 developed a gastrointestinal illness. 

Epidemiological and microbiological investigation indicated 

that oysters contaminated with a Norwalk-like virus were the 

most likely cause of infection. The oysters were all probably

from a Bay of Islands farm.

Kay D. 1988. Coastal bathing water: the 

application of water quality standards to Welsh

beaches. Applied Geography 8: 117–34. 

Compares relative utility of European and North American 

standards to Welsh beach data. Equates faecal coliforms to 

E. coli.

Kay D, McDonald A. 1986a. Coastal bathing 

water quality. Journal of Shoreline Management

2: 259–83. 

Notes the need for very large samples to identify statistically 

significant relationships. Criticises the PHLS (1959) and MRC 

(1959) findings as inferences going far beyond the data 

gathered (which was for two severe notifiable illnesses). 

Kay D, McDonald A. 1986b. The relevance of

epidemiological research in the British context. 

European Water and Sewage 90: 321–8. 

Documents the UK shift away from the views expressed by 

MRC (1959) and PHLS (1959). Notes that statistically

significant transmission of minor illnesses could be expected 

even at beaches that comply with the EEC standards. 

Kay D, Wyer M, McDonald A, Woods N. 1990. 

The application of water-quality standards to UK

bathing waters. Journal of the Institute of Water 

and Environmental Management 4: 436–41. 

Analyses data for 425 sampling locations. Ranks EEC, US 

EPA and Canadian standards for stringency. Equates faecal 

coliforms to E. coli. 

Kay D, Fleisher JM, Jones F, Salmon RL, 

Wyer MD, Godfree AF, Zelenauch-Jacquotte Z, 

Shore R. 1994. Predicting the likelihood of

gastro-enteritis from sea bathing: results from

randomised exposure. Lancet 344: 905–9. 

Reports controlled-cohort trials at four UK beaches with 1216 

adults, including 548 who entered the water, immersing the 

head three times. Adverse (gastrointestinal) health effects were

identified when faecal streptococci (at chest depth) exceeded 

32 per 100 mL (being the median of the highest faecal 

streptococci band which failed to attain statistical significance). 

Equation used is Logn odd (of gastroenteritis) = √(FS-32) – 

2.3561. Medical follow-up was included. Some 65.7% of 

gastrointestinal cases had onset dates 7–21 days after exposure. 

Non-bather gastrointestinal illness rate was 9.7%. 

Kay D, Fleisher J, Wyer MD, Salmon RL. 2001. 

Re-analysis of the seabathing data from the UK

randomised trials. A report to DETR,

Aberystwyth, University of Wales, Centre for 

Research into Environment and Health.

REFERENCES AND FURTHER READING.

J18 June 2003 
Koenraad PMF, Rombouts FM, Notermans SHW. 

1997. Epidemiological aspects of thermophilic 

Campylobacter in water-related environments: a 

review. Water Environment Research 69(1): 

52–63. 

Risk analysis indicates that the contribution of contaminated 

recreational water to human infections may be greater than 

previously assumed. “The contribution of viable but nonculturable Campylobacter cells in the contamination cycle has 

been found to be negligible.” 

Kueh CS, Tam T-Y, Lee T, Wong SL, Lloyd OL, 

Yu ITS, Wong TW, Tam JS, Bassett DCJ. 1995. 

Epidemiological study of swimming-associated 

illnesses relating to bathing-beach water quality. 

Water Science and Technology 31(5–6): 1–4. 

Reports results from a 1992 study at two beaches with 18,122 

swimmers, following on from that in 1987 (Cheung et al 1990). 

Only swimmer’s gastrointestinal symptoms were found to be 

associated with pollution level, not with faecal coliforms or E.

coli, but with Clostridium perfringens, Aeromonas spp. and 

Vibrio cholerae (non-O1). The study did not measure faecal 

streptococci or enterococci.

Lacey RF, Pike EB. 1989. Water recreation and 

risk. Journal of the Institution of Water and

Environmental Management 3: 13–18. 

Discusses the role of society in regulating voluntary risks,

difficulties of measuring risks via epidemiological studies, 

questionable predictive power of bacterial indicators, and 

identifying a satisfactory rationale for standards for recreational 

waters. Concludes that there is no completely satisfactory way 

of providing guidance on recreational risk.

Lacey RF, Gunby A, Hay SV. 1995. Methods of 

Assessing Compliance with Standards for the 

Quality of Bathing Waters. Final report to the 

Department of the Environment. Report No. DoE 

3837/1, Water Research Centre, Medmenham,

Marlow, Bucks, England.

Addresses statistical issues in deciding whether bathing sites 

conform to the imperative (I) values in EU Directive (which are 

based on 95% of samples).

Lee JV, Dawson SR, Ward S, Surman SB,

Neal KR. 1997. Bacteriophages are a better 

indicator of illness rates than bacteria amongst

users of a white water course fed by a lowland 

river. Water Science and Technology 35(11–12): 

165–70. 

Reports results from 473 questionnaires from canoeists and 

rafters. Logistic regression identified F-specific RNA 

bacteriophages as the best microbiological parameter associated 

with the risk of gastrointestinal illness. No pattern was found 

with other illnesses (including respiratory). Regular users of 

the course had lower risks of illness. The level of 

contamination was very high (median enterococci = 102 per

100 mL).

Leeming R, Ball A, Ashbolt N, Nichols P. 1996. 

Using faecal sterols from humans and animals to 

distinguish faecal pollution in receiving waters. 

Water Research 30(12): 2893–900. 

Analysed up to seven replicates for faecal samples: hen, 

seagull, duck, magpie, Rosella, swan, pig, human. Species 

chosen from those common to both urban and rural catchments. 

Cats and pigs were the only animals with similar faecal sterol 

profiles to humans. Sterol fingerprints are sufficiently

distinctive to be of diagnostic value in determining the origin of 

faecal pollution. 

Le Guyader F, Miossec L, Haugarreau L, 

Dubois E, Kopecka H, Pommepuy M. 1998. 

RT-PCR evaluation of viral contamination in five 

shellfish beds over a 12-month period. Water

Science and Technology 38(12): 45–50. 

Five shellfish beds were surveyed for 12 months. Of the 

104 samples, 66% contained at least one virus. The two sites 

regularly contaminated by faecal coliforms had the highest 

percentage of viruses, but HAV was detected at only one site. 

Sampling sites meeting the criteria for commercialisation 

showed occasional viral contamination and viruses were

detected in sites with no faecal coliform contamination. 

Lewis GD, Loutit MW, Austin FJ. 1985. Human

enteroviruses in marine sediments near a sewage

outfall on the Otago coast. New Zealand Journal

of Marine and Freshwater Research 19: 187–92. 

Sediment and beach sand samples were collected from around a 

sewer outfall and tested for presence of enteroviruses and faecal 

coliforms. Enteroviruses were recovered from five of 

14 samples collected on three occasions and were recovered 

from two samples in which faecal coliforms were low. 

REFERENCES AND FURTHER READING.

J19 June 2003 
Lewis GD, Austin FJ, Loutit MW, Sharples K. 

1986. Enterovirus removal from sewage: the 

effectiveness of four different treatment plants. 

Water Research 20: 1291–7. 

Human enterovirus removal from four sewage plants (oxidation 

pond, two trickling filters, sedimentation/chlorination) showed 

insignificant removal through the plants and poor correlation 

with faecal coliforms, suspended solids, pH or conductivity. 

More viruses were present in summer. Maximum concentration 

was 2570 pfu per L.

Lewis GD, Loutit MW, Austin FJ. 1986. 

Enteroviruses in mussels and marine sediments 

and deputation of naturally accumulated viruses by

green-lipped mussels (Perna canaliculus). New

Zealand Journal of Marine and Freshwater 

Research 20: 431–7. 

A 16-month survey assessing the distribution of human 

enteroviruses in sediments and mussels near two sewage 

outfalls on the North Taranaki coast. Enteroviruses were 

present in high numbers near the New Plymouth outfall 

(maximum 32,000 pfu (100 g)–1 of wet mussel tissue and 59 pfu 

(100 g)–1of wet sediment material). Viruses were recovered

occasionally from sediments and mussels near the Waitara 

Borough outfall. Attempts to depurate the New Plymouth 

mussels over eight days were unsuccessful.

Lewis GD. 1995. F-specific bacteriophage as an 

indicator of human viruses in natural waters and

sewage effluents in northern New Zealand. Water 

Science and Technology 31(5–6): 231–4. 

While F-phage matched pathogen behaviour in several respects,

its low abundance in marine waters, uncertainty as to source 

and detection irregularities pose problems for its use as an

indicator.

Lightfoot NE. 1989. A prospective study of

swimming related illness at six freshwater beaches 

in Southern Ontario. Unpublished PhD thesis, 

University of Toronto. 

A Cabelli-type study, but “highly credible” gastrointestinal 

illness was not included in the analysis (the author disagreed 

with the inclusion of fever in its definition). It was concluded 

that there was “no evidence to suggest that bacterial count 

contributed to the prediction of illness in swimmers” (abstract) 

and that “only tenuous correlations exist, at best” (p. 141). A 

logistic regression model was fitted to the data, finding that 

interviewer and contact person were significant confounders.

Liston J. 1994. Association of Vibrionaceae, 

natural toxins and parasites with fecal indicators. 

In: CR Hackney and MD Pearson (eds)

Environmental Indicators and Shellfish Safety. 

Chapman & Hall, New York. 

Notes strong evidence for vibrios being indigenous to estuaries. 

No useful correlation between vibrios or Plesiomonas and 

faecal indicators has been found for shellfish. Natural toxins 

are, and should be, completely independent of testing for faecal 

contamination. Association between parasites (Giardia and 

Cryptosporidium) is “moot until there is substantial evidence of 

actual parasite infection by one of these organisms or any other

(e.g. Entamoeba histolytica) parasite where the vehicle is

molluscan shellfish”. 

Loutit M. 1985. The fate of certain bacteria and

heavy metals in sewage discharged through an

ocean outfall. Proceedings of the Australasian

Conference on Coastal and Ocean Engineering,

Vol. 1, Christchurch, December, pp. 211–19. 

Sponsored by Institution of Engineers, Australia, 

Institution of Professional Engineers, New 

Zealand, National Water and Soil Conservation

Organisation. 

Bacteria could be detected in sediments up to 8 km from

Dunedin’s Lawyer’s Head outfall. On occasion E. coli could be 

detected in the sediments but not in the water.

Mariño FJ, Moiñigo MA, Martinez-Manzanares E, 

Borrego JJ. 1995a. Microbiological

epidemiological study of selected marine beaches 

in Malaga (Spain). Water Science and Technology

31(5–6): 5–9. 

Reports a three-year study at two beaches. Skin infections were

found to be associated with levels of Pseudomonas aeruginosa, 

Candida albicans and Aeromonas hydrophilia. The study had 

very small numbers of non-exposed individuals, making the 

attainment of statistical significance difficult. 

Mariño FJ, Moiñigo MA, Martinez-Manzanares E, 

Borrego JJ. 1995b. Application of the recreational 

water quality standard guidelines. Water Science 

and Technology 31(5–6): 27–31. 

Examines applicability of WHO/UNEP and EC bathing water 

directive using data from their epidemiological study. 

Concludes the best indicators are faecal coliforms, E. coli and 

coliphages (at low pollution level) and faecal streptococci and 

coliphages (at high pollution level).

REFERENCES AND FURTHER READING.

J20 June 2003 
McBride GB. 1990. Background Notes for the 

Development of Guidelines for Microbiological 

Receiving Water Standards for New Zealand. 

Water Quality Centre Publication No. 18. DSIR, 

Hamilton. Report available from the librarian, 

NIWA, Hamilton.

Documents historical development of microbiological standards 

for New Zealand, and issues to be addressed in the forthcoming 

Resource Management Act’s implementation.

McBride GB. 1993. Discussion of ‘Health effects 

of swimmers and nonpoint sources of

contaminated water’, by Calderon et al. 

International Journal of Environmental Health

Research 3: 115–16. 

Disagrees with the claim by Calderon et al (1991) that there 

was “no association” between swimmers’ health risk and the 

concentration of animal faecal material. Notes that reported 

rates appear to be in fact rather high. 

McBride GB, Bandaranayake DR, Salmond CE, 

Turner SJ, Lewis GD, Till D, Hatton C,

Cooper AB. 1993. Faecal indicator density and 

illness risk to swimmers in coastal waters: a 

preliminary study for New Zealand. Proceedings 

of the Annual Conference of the New Zealand

Water and Wastes Association, Havelock North, 

1–3 September 1993. 

Reports results of preliminary trials (1992/93) carried out at 

Auckland beaches only. Enterococci emerged as a statistically 

significant indicator for HCGI (highly credible gastrointestinal 

illness). Sample size was too small to reach firm conclusions 

about how this might have related to pollution levels. Minor

corrections (hand-annotated on the original) have been made in 

the version of this paper appearing in Bandaranayake et al 

1993.

McBride GB, Loftis JC, Adkins NC. 1993. What 

do significance tests really tell us about the 

environment? Environmental Management 17(4):

423–32. Errata in 18: 317. 

Notes that an individual p-value may not be instructive about 

patterns and associations in the environment, particularly

because one seldom has confidence that a null hypothesis could 

in fact be true. 

McBride GB, Salmond CE, Bandaranayake DR,

Turner SJ, Lewis GD, Till DG. 1998. Health

effects of marine bathing in New Zealand. 

International Journal of Environmental Health

Research 8: 173–89. 

Reports New Zealand national prospective study performed at 

seven beaches in the 1995 summer using 1577 beach-users who 

entered the water, and 2307 who did not. On each of the 

107 interview days multiple samples of the beach water were 

examined for three faecal indicators (faecal coliforms, E. coli, 

enterococci). Log-linear modelling showed that enterococci 

was most strongly and consistently associated with illness risk 

for the exposed groups, particularly for respiratory illness 

among paddlers and long-duration swimmers. Crude risk 

differences for these two groups were 7 and 33 per 1000 

individuals, rising to 62 and 87 per 1000 individuals for the 

highest enterococci quartile. No substantial differences in 

illness risks were found between the human and animal waste 

impacted beaches, though both were markedly different from

the control beaches. 

McBride GB, Thorn C, Salmond C. 1996. 

Feasibility of Bathing-health Effects Study for New 

Zealand Freshwaters. Ministry for the 

Environment Report No. 202.

Examines patterns of freshwater recreation at lower North 

Island sites. Concluded that an epidemiological study was 

feasible only if of the controlled type. 

McBride GB, Till DG, Salmond CE. 1998. 

National study of health effects of marine bathing 

and implications for new guidelines. Proceedings 

of the 40th Annual Conference and Expo of the 

New Zealand Water & Wastes Association, 

Museum of New Zealand, Wellington, 23–25

September, 251–5.

Implications of the national study (McBride, Salmond et al 

1998) for the review of microbiological water quality 

guidelines are discussed, particularly in terms of the ‘singlesample maxima’ and sampling depth.

REFERENCES AND FURTHER READING.

J21 June 2003 
McBride G, Till D, Ryan T, Ball A, Lewis G, 

Palmer S, Weinstein P. 2002. Freshwater 

Microbiological Research Programme: Pathogen

Occurrence and Human Health Risk Assessment 

Analysis. Ministry for the Environment.

A study of New Zealand freshwater recreational sites. The 

main outcomes were that: (i) Campylobacter and human 

adenoviruses are the pathogens most likely to cause human 

waterborne illness; (ii) an estimated 4% of notified 

campylobacteriosis in New Zealand could be attributable to 

water contact recreation; (iii) E. coli as an indicator of increased 

Campylobacter infection is in the range of 200–500 E. coli per

100 mL; (iv) other pathogens examined could not be related to 

E. coli concentrations in fresh waters; (v) pathogens are more

likely to be present and in greater numbers in turbid waters. 

The report can be downloaded from www.mfe.govt.nz. 

Medema GJ, Asperen IA van, Havelaar AH. 1997. 

Assessment of the exposure of swimmers to

microbiological contaminants in fresh waters. 

Water Science and Technology 35(11–12):

157–63. 

Reports on a follow-up study using 1,313 participants in seven 

triathlons in 1993/94. All sites were influenced by sewage 

effluents and most by agricultural run-off. The risk of 

gastrointestinal infection correlated well with concentration of 

thermotolerant coliforms and E. coli, but not with other

variables (faecal enterococci, Staphylococcus aureus, F-specific 

RNA phages, enteroviruses , thermophilic Campylobacter, 

Salmonella, Aeromonas, Pleisiomonas shigelloides, 

Pseudomonas aeruginosa). Note that the abstract says more 

than the paper on epidemiological parts, but an accompanying 

poster paper reported illness results from 827 of the triathletes, 

with 773 non-swimming controls (in a run-bike-run event). 

Thresholds of 220 cfp per 100 mL (thermotolerant coliforms)

and 355 cfp per 100 mL (E. coli) were reported.

Medema GJ, Asperen IA van, KlokmanHouweling JM, Nooitgedagt A, de Laar MJW van, 

Havelaar AH. 1995. The relationship between 

health effects in triathletes and microbiological 

quality of freshwater. Water Science and 

Technology 31(5–6): 19–26. 

Reports on a follow-up pilot study of 314 triathletes and 81 runbike-run controls. The triathletes showed elevated illness rates,

indicating that a full study is feasible. Geometric mean E. coli

and enterococci were 170 and 13 per 100 mL, respectively.

Medema GJ, Teunis PFM, Havelaar AH, Haas CN. 

1996. Assessment of dose-response relationship of

Campylobacter jejuni. International Journal of

Food Microbiology 30: 101–11.

Reports the best-fit beta-Poisson dose response model for a 

common strain of Campylobacter jejuni (Penner serotype 27).

Melnick JL. 1990. Enteroviruses: polioviruses, 

coxsackieviruses, echoviruses, and newer

enteroviruses. In: BN Fields et al (eds) Virology, 

2nd ed. Raven Press, New York, 549–606. 

Good review of virology.

Miles MA. 1973. An investigation into the 

possible relationship between bathing and ear 

complaints in Taupo. New Zealand Sanitarian

28(2): 75. 

Propose that further examination be made into ear complaints 

among swimmers at Taupo.

Ministry for the Environment. 1992. ME91. 

Water Quality Guidelines No. 1. Ministry for the

Environment, Wellington. 

Guidelines for the control of undesirable biological growths in 

water. 

Ministry for the Environment. 1994. ME142. 

Water Quality Guidelines No. 2. Ministry for the

Environment, Wellington. 

Guidelines for management of water colour and clarity.

Ministry for the Environment. 1996. Feasibility 

of Bathing-health Effects Study for New Zealand 

Freshwaters. Prepared by GB McBride, C Thorn 

and C Salmond. Ministry for the Environment,

Wellington. 

Considers possibilities for freshwater epidemiological study of 

swimmers’ health risk, and concludes that only a controlledcohort design is likely to be fruitful. Includes a survey of the 

degree of recreational use of freshwaters at sites in Hawke’s 

Bay, Wairarapa and Manawatu. Implies that hundreds of

thousands of New Zealanders swim at freshwater sites annually,

but in a very dispersed manner (there are seldom more than 

100 people at a ‘site’).

REFERENCES AND FURTHER READING.

J22 June 2003 
Ministry for the Environment. 1999. 

Environmental Education: A guide for programme 

providers – how to develop, implement and 

evaluate strategies and programmes. Ministry for 

the Environment, Wellington.

A guide to assist with preparing and implementing effective 

environmental education programmes, tailored to meet the 

needs of individual organisations.

Ministry of Agriculture and Forestry. 1995.

Shellfish Quality Assurance Circular. Ministry of

Agriculture, Wellington. 

Moore B. 1975. The case against microbial 

standards for bathing beaches. In: ALH Gameson 

(ed) Discharge of Sewage from Sea Outfalls. 

Pergamon Press, Oxford and New York, 103–9. 

Argues against standards, noting that a health-effects versus 

indicator relationship had not yet been developed, and that total 

or faecal coliforms are not appropriate. 

Moore B. 1977. The EEC bathing water directive. 

Marine Pollution Bulletin 8: 269–72. 

Expresses dissatisfaction with the 1976 EEC Directive (EU 

1976), with concern about competition for public funds. Notes 

the effect of the Directive is to give high priority to 

“epidemiological studies that will provide a quantitative 

dimension to the postulated health risks of bathing in sewage 

contaminated seawater”. 

Moriñgo MA, Wheeler D, Berry C, Jones C,

Muñoz MA, Cornax R, Borrego JJ. 1992. 

Evaluation of different bacteriophage groups as 

faecal indicators in contaminated natural waters in 

southern England. Water Research 26(3): 267–71. 

River and seawater affected by faecal discharges were analysed 

to evaluate the reliability of coliphages and F-specific RNA 

bacteriophages as indicators of the microbiological quality of 

waters. FRNA phages showed no direct relationship with 

levels of faecal pollution and were never detected in samples 

with few enteroviruses, whereas coliphages were detected. 

Coliphages could be considered an optimal indicator. 

Morris R. 1991. The EC bathing water virological 

standard: is it realistic? Water Science and 

Technology 24(2): 49–52. 

Notes that only culturable enteroviruses and rotaviruses have 

available enumeration methods, and that sampling frequency is 

generally not sufficient to give effect to the requirement that 

95% of samples be free of enteroviruses. Nevertheless 

concludes that the present imperative standard should remain.

MRC. 1959. Sewage Contamination of Bathing

Beaches in England and Wales. Medical Research 

Council Memorandum (UK) No. 37. 

Interpreted the PHLS (1959) study results as: “With the 

exception of a few aesthetically revolting beaches around the 

coast of England and Wales, the risk to health of bathing in 

sewage-contaminated sea-water can, for all practical purposes,

be ignored.”

Mujeriego R, Bravo JM, Feliu MT. 1982.

Recreation in coastal waters: public health

implications. Vier Journée Études Pollutions. 

Cannes, Centre Internationale d’Exploration

Scientifique de la Mer (CIESM): 585–94. 

Reports on a follow-up epidemiological study of 24 beaches at 

Málaga and Tarragona, using 20,219 responses. Ailments 

found were skin infections (2%), ear and eye infections (1.5%) 

and intestinal infection (< 1%). According to Shuval (1986) the 

study does supply “some suggestive evidence as to the value of 

enterococci as an indicator of marine pollution”, but suffers

from a lack of controls and appropriate water quality data. 

New Jersey Department of Health. 1989. Ocean 

Health Study: A study of the relationship between 

illness and ocean beach water quality in New 

Jersey.

A 1988 prospective study using 16,089 (10% under age 10) at 

nine coastal and two lake beaches impacted by chlorinated 

effluents. Swimmers consistently reported higher symptom

rates than non-swimmers (excess of 12.2 cases per 1000). 

Water quality was very good and attempts to relate the excess 

illness rates with pollution levels failed. 

NTAC. 1968. Water Quality Criteria. Report of

the National Technical Advisory Committee to the 

Federal Water Pollution Control Administration.

The first federal compilation of quality ‘criteria’, sometimes 

called the “Green Book”. It was compiled by five separate 

committees, which each recommended different definitions of

how one would judge compliance.

REFERENCES AND FURTHER READING.

J23 June 2003 
Nuzzi R, Burhans R. 1997. The use of

enterococcus and coliform in characterising 

bathing-beach waters. Environmental Health

(July/August): 16–21. 

Reports water quality studies at New York beaches for total and 

faecal coliforms (still used in New York for bathing waters) and 

enterococci. Found that enterococcus correlated well with both 

sets of coliforms, but would result in more beach closures. 

Philip R. 1991. Risk Assessment and 

Microbiological Hazards Associated with 

Recreational Water Sports. Reviews in Medical 

Microbiology 2: 208–14. 

PHLS. 1959. Sewage contamination of coastal

bathing waters in England and Wales: a 

bacteriological and epidemiological study. 

Journal of Hygiene (Cambridge) 57: 435–72. 

Reports on a retrospective study of enteric fever and 

poliomyelitis (both notifiable). Concludes “that bathing in 

sewage polluted sea water carries only a negligible risk to 

health, even on beaches that are aesthetically very 

unsatisfactory ...”. This is sometimes quoted as Moore (1959); 

Dr Brendan Moore was the main author.

Pike EB. 1993. Recreational use of coastal 

waters: development of health-related standards. 

Journal of the Institution of Water and

Environmental Management: 163–69. 

Compares USA/UK/EU approaches to setting standards, noting 

that all are primarily directed at bathing. Statistical issues in 

defining central and extreme values of indicator variables are 

discussed, in particular the use of single sample maxima is 

problematical. Notes that only the USEPA criteria had been 

developed from epidemiological studies (up to 1993).

Pike EB. 1994. Health effects of sea bathing

(WMI 9021) – Phase III. Final Report to the 

Department of the Environment. Report No. DoE 

3412/2, Water Research Centre, Medmenham,

England. Available from Water Research Centre. 

Summarises results from the two sets of UK studies in the early

1990s. These were on 16,569 holidaymakers at 10 beaches 

using an uncontrolled prospective cohort design, and on 1112 

healthy adult volunteers at four beaches, using a controlled 

cohort design. Holidaymakers entering the sea perceived all 

symptoms more frequently than those who did not, the relative 

increases being related to degree of water contact and age, 

being greatest in surfers and in 15–24-year-olds. Relative 

increases in frequencies of eye, ear nose and throat, respiratory 

and skin symptoms were not strongly related to microbiological 

water quality. Relative increases in diarrhoea in those entering 

the water were related to total coliform counts and 

enteroviruses. In the volunteer study, the incidence in bathers 

of symptoms suggesting gastroenteritis was related to counts of 

faecal streptococci at chest depth. No relationship was evident 

between self-recording of symptoms and results of clinical 

examinations. Overall conclusions from both types of study are 

in agreement with the results of earlier studies. 

Prüss A. 1998. Review of epidemiological studies

on health effects from exposure to recreational 

water. International Journal of Epidemiology 27: 

1–9. 

Reviews 22 epidemiological studies conducted for freshwater

and coastal water. Most reported a dose-related increase of 

health risk in swimmers with an increase in indicator bacteria 

count in recreational waters. Relative risks for swimmers

versus non-swimmers are typically in the range 1.0 to 3.0. 

Enterococci and faecal streptococci were opined to be the best 

indicators for seawater and E. coli for freshwater. Reviews 

Bradford Hill’s nine criteria for causation in environmental 

studies, as applied to gastrointestinal symptoms. Passes seven 

of them: strength of association (yes), consistency (yes),

specificity of association (no), temporality (yes), biological 

gradient (yes), plausibility (yes), coherence (yes), experiment 

(no), analogy (yes).

Robertson WJ. 1993. Guidelines for the

protection of human health on bathing beaches.

Journal of the Canadian Institute of Public Health 

Inspectors (Spring): 14–17. 

Reviews national recreational water data and proposes that 

E. coli and the enterococcus group are currently the best 

available indicators for fresh and marine waters respectively. 

Proposed limits similar to those of USEPA 1986a.

Robson WLM, Leung AKC. 1990. Swimming

and ear infection. Journal of the Royal Society of 

Health 199–200. 

Reviews the association of ear infection with swimming. 

Chlorinated water or stagnant ponds may pose a risk for otitis 

media or otitis externa. 

REFERENCES AND FURTHER READING.

J24 June 2003 
Rosenberg ML, Hazlet KK, Schaefer J, Wells JG, 

Pruneda RC. 1976. Shigellosis from swimming. 

Journal of the American Medical Association 

236(16): 1849–52. 

In August 1974, 31 of 45 cases of Shigella sonnei infection in 

Dubuque (Iowa) were traced to swimming in the Mississippi 

River (in an eight-mile stretch). Significant associations

between illness and swimming were also reported by a

retrospective survey of 60 families who had camped at a park 

beside the river. The attack rate for swimmers was 18%. Mean 

faecal coliform content was 17,500 per 100 mL. 

Salas HJ. 1986. History and application of

microbiological water quality standards in the 

marine environment. Water Science & Technology

18: 47–57. 

Reviews many countries standards up to the mid-1980s.

Proposes that standards are best expressed as an average 

concentration, and a ‘maximum value’ that is not to be 

exceeded for more than a high percentage of the time (e.g. 

90%).

Seyfried PL, Tobin RS, Brown NE, Ness PF. 

1985a. A prospective study of swimming-related 

illness. I. Swimming-associated health risk. 

American Journal of Public Health 75(9):

1068–70. 

Reports on a 1980 prospective study on 10 Ontario river and 

lake beaches (see EHD 1980), using 4537 interviews. Crude 

morbidity rates were 69.6 per 1000 swimmers and 29.5 per

1000 non-swimmers. Swimmers experienced respiratory

ailments most frequently, followed by gastrointestinal, eye, ear, 

skin and allergenic symptoms. 

Seyfried PL, Tobin RS, Brown NE, Ness PF. 

1985b. A prospective study of swimming-related 

illness. II. Morbidity and the microbiological 

quality of water. American Journal of Public 

Health 75(9): 1071–6. 

Reports results for faecal coliforms, faecal streptococci, 

heterotrophic bacteria, Pseudomonas aeruginosa, and total 

staphylococci. Logistic modelling showed morbidity among 

swimmers to be related to staphylococcal counts, faecal 

coliforms and, less strongly, to faecal streptococci. 

Shuval HI. 1986. Thalassogenic diseases. UNEP 

Regional Seas Reports and Studies No. 79, UNEP.

(Greek: thalass = sea, genesis = source.) Comprehensive 

review of many studies. Concludes that after years of debate 

there is now firm evidence that bathing in sewage-polluted 

waters causes an excess of gastrointestinal disease, the rates of

which correlate generally with enterococci or E. coli

concentrations. 

Simmonds RS, Loutit MW, Austin FJ. 1983. 

Enteric viruses in New Zealand wastewaters. New 

Zealand Journal of Science 26: 437–41. 

Forty-seven samples from three treatment plants were tested for 

human enteroviruses. Nine different viruses were detected in

36 samples ranging up to 4000 pfu/L. Chlorine reduced

numbers, but they were still detectable in 11 of 16 chlorinated 

samples. 

Sinton LW, Davies-Colley RJ, Bell RG. 1994. 

Inactivation of enterococci and fecal coliforms

from sewage and meatworks effluents in seawater 

chambers. Applied and Environmental

Microbiology 60: 2040–8. 

Inactivation of faecal coliforms (FC) and enterococci (Ent) 

from sewage and meatworks effluents was measured in

experiments (meatworks FC > sewage FC > meatworks Ent > 

sewage Ent). Decay coefficient (1st-order) for FC was two to

four times that for Ent, and was slower at lower temperatures. 

Factors other than insolation were implicated (by betweenexperiment variations). Most inactivation appeared to be in the 

318–340 nm and > 400 nm ranges.

Sinton LW, Donnison AM, Hastie CM. 1993a. 

Faecal streptococci as faecal pollution indicators: a

review. Part I: Taxonomy and enumeration. New 

Zealand Journal of Marine and Freshwater 

Research 27: 101–15. 

Notes that there is no universally accepted method for isolating 

faecal streptococci. 

REFERENCES AND FURTHER READING.

J25 June 2003 
Sinton LW, Donnison AM, Hastie CM. 1993b. 

Faecal streptococci as faecal pollution indicators: a

review. Part II: Sanitary significance, survival, 

and use. New Zealand Journal of Marine and 

Freshwater Research 27: 117–37. 

Faecal streptococci (or the subset enterococci) are more

resistant to sunlight-induced inactivation than faecal coliforms. 

Notes adoption of USEPA criteria, using enterococci for marine 

and freshwaters (and E. coli for freshwaters) should be adopted 

with caution in New Zealand. Also notes the general failure of 

the faecal streptococci:faecal coliform ratio as a measure of

human:animal contributions to a faecal load. 

Sinton LW, Finlay RK, Hannah DJ. 1998. 

Distinguishing human from animal faecal 

contamination: a review. New Zealand Journal of

Marine and Freshwater Research 32: 323–48. 

Notes that reliable evidence is lacking on the relative health 

risks posed by exposure to either human or animal faeces. 

Notes that New Zealand’s high grazing animal:human ratio 

makes “it seem prudent to assume that human and animal faecal 

pollution both constitute a risk to human health”. Reviews 

methods for distinguishing animal and human faecal residues, 

noting that DNA-based techniques (e.g. PCR) may assist. 

Sinton LW, Finlay RK, Lynch PA. 1999. 

Sunlight inactivation of fecal bacteriophages and 

bacteria in sewage-polluted seawater. Applied and 

Environmental Microbiology. 

Sunlight inactivation in seawater water of faecal indicators 

from sewage was measured in outdoor experiments over a twoyear period. The ranking (from the greatest to least inactivation) 

was faecal coliforms > F-RNA phages > somatic coliphages. 

These results suggest that, in seawater, somatic coliphages are 

likely to be the best enteric virus indicators. This inactivation 

ranking was also evident in a two-day experiment, which 

included enterococci. Although enterococci were initially more 

sunlight resistant than faecal coliforms, the two indicators fell 

to counts of < 1/100 mL at around the same time on day two.

Sinton LW, Hall CH, Lynch PA, 

Davies-Colley RJ. 2002. Sunlight inactivation of 

fecal indicator bacteria and bacteriophages from

waste stabilization pond effluent in fresh and 

saline water. Applied and Environmental

Microbiology 68: 3. 

An important paper on the topic of receiving waters affected by 

pond discharges. Experiments demonstrate that enterococci 

survive longer than faecal coliforms in freshwater / raw sewage 

mixtures, but the opposite pattern was observed for pond 

effluents. Enterococci appear to suffer photo-oxidative damage 

in ponds, rendering them susceptible to further such damage 

after discharge, suggesting that they are unsuitable as indicators 

of pond effluents to natural waters.

Sorvillo FJ, Fujioka F, Nahlen B, Tormey P, 

Kebebjian RS, Mascola L. 1992. Swimmingassociated Cryptosporidiosis. American Journal of

Public Health 82(5): 742–44. 

An example of a swimming-pool outbreak of this disease.

Stehr-Green JK, Nicholls C, McEwan S, Payne A, 

Mitchell P. 1991. Waterborne outbreak of 

Campylobacter jejuni in Christchurch: the 

importance of a combined epidemiologic and 

microbiologic investigation. New Zealand

Medical Journal 104: 356–8. 

Two cases at a camp and convention centre near Christchurch 

had water supply strongly suggested as the source of infection.

Stevenson AH. 1953. Studies of bathing water

quality and health. American Journal of Public 

Health 43: 529–38. 

Reports findings from US Public Health Service studies in 

1948–50 at freshwater sites on lake Michigan at Chicago, the 

Ohio River at Dayton Ohio (and Tacoma Park pool at Dayton),

and New York tidal waters (New Rochelle and Mamaroneck). 

Used prospective study with 22,164 persons. ‘Swimming’

didn’t require head immersion. Found illness in swimmers was 

appreciably higher than in non-swimmers. Also found two 

statistically significant results for illness related to degree of 

pollution (assessed using total coliforms), between low and 

high contamination days at one of the Chicago beaches and 

between the Ohio swimmers. 

REFERENCES AND FURTHER READING.

J26 June 2003 
Streeter HW. 1951. Bacterial Quality Objectives 

for the Ohio River: A guide for the evaluation of

sanitary conditions of waters used for potable 

supplies and recreational uses. Ohio River Valley

Water Sanitation Commission, Cincinnati, OH. 

Presents calculations on the risk of contracting typhoid fever for

someone who bathes every day for 90 days in water containing 

1000 total coliforms per 100 mL. This gave a risk of 1:950, or

1:50 for “diarrhea-enteritis”. This result was used in early 

standards (Waters Pollution Regulations 1963).

Telford SR. 1996. Annotation: marine waters and 

non-enteric illness: matching the degree of

analytical rigour to the biology of the infection 

process. American Journal of Public Health

86(9): 1203–04. 

A comment on the article by Fleisher and others appearing in 

the same issue. Notes that their paper represents a “vast 

methodological improvement over previous studies”,

particularly that of Stevenson (1953). Notes that causation 

studies are now desirable.

Teunis PFM, Havelaar AH. 2000. The beta 

Poisson dose-response model is not a single-hit 

model. Risk Analysis 20(4): 513–20.

Cogent account of the validity of a standard dose response 

model at low doses, and methods for accounting for uncertainty 

in that model (via Bayesian posterior intervals). 

Teunis PFM, Nagelkerke NJD, Haas CN 1999.

Dose response models for infectious 

gastroenteritis. Risk Analysis 19(6): 1251–60.

Identifies some difficulties in modelling the probability of 

illness given infection for a range of doses – much less 

straightforward than modelling infection given dose.

Teunis PFM, van der Heijden OG, 

van der Giessen JWB, Havelaar AH. 1996. The 

Dose-response Relation in Human Volunteers for 

Gastro-intestinal Pathogens. RIVM Report 

No. 284 550 002. Antonie van 

Leeuwenhoeklaan 9, PO Box 1, NL-3720 BA

Bilthoven, The Netherlands.

In-depth review of the available data on clinical trials for a 

range of gastro-intestinal pathogens. Identifies the most 

satisfactory models (exponential or beta-Poisson) for each case.

Turner SJ, Lewis GD. 1995. Comparison of

F-specific bacteriophage, enterococci, and faecal 

coliform densities through a wastewater treatment

plant employing oxidation ponds. Water Science 

and Technology 31(5–6): 85–9. 

A 12-month study suggests that enterococci may be the best 

indicator for oxidation pond systems. Did not include E. coli. 

Turner SJ, Lewis GD, Bellamy AR. 1997. 

Detection of sewage-derived Escherichia coli in a 

rural stream using multiplex PCR and automated

DNA detection. Water Science and Technology

35(11–12): 85–9. 

A DNA marker shows promise in identifying E. coli isolates of

human origin. Field trials upstream and downstream of sewage 

ponds appear to confirm this.

Tyler KL, Fields BN. 1990. Pathogenesis of viral 

infections. In: BN Fields et al (eds) Virology, 2nd

ed. Raven Press, New York, 191–240. 

Includes discussion of inhalation of aerosols as a means of 

acquiring infectious viral disease.

Tyrrell SA, Rippey SR, Watkins WD. 1995. 

Inactivation of bacterial and viral indicators in

secondary sewage effluents, using chlorine and

ozone. Water Science and Technology 29(11): 

2483–90. 

Chlorine reduced faecal coliforms and enterococci > 100-fold, 

but for bacteriophages < 10-fold. In contrast, ozonation gave 

> 100-fold reduction of the phages, but not so much for

vegetative bacteria. Concludes faecal coliforms are inadequate 

for predicting viral response to chlorine or ozone.

USEPA. 1985. Test Methods for Escherichia coli

and Enterococci in Water by the Membrane

Filtration Procedure. Report EPA 600/4-85-076. 

United States Environmental Protection Agency, 

Cincinnati, OH.

Details the test methods to be used at that time when applying 

the EPA guidelines to recreational waters. 

USEPA. 1986a. Ambient Water Quality for 

Bacteria 1986. Report EPA 440/5-84-002. 

USEPA Office of Water Regulations and

Standards, Washington, DC 20460. 

Gives explanatory material about the derivation of the criteria, 

using the results of Cabelli (1983a) and Dufour (1984). 

REFERENCES AND FURTHER READING.

J27 June 2003 
USEPA. 1986b. Quality Criteria for Water 1986: 

Bacteria. Report EPA 440/5-86-001. USEPA

Office of Water Regulations and Standards,

Washington, DC 20460. 

Promulgates “criteria” (i.e. recommended state standards) based 

on the work of Cabelli (1983a) and Dufour (1984). 

USEPA. Standard Methods for the Examination

of Water and Waste Water. 20th ed, American 

Public Health Association.

Von Schirnding YER, Kfir R, Cabelli VJ, 

Franklin L, Joubert G. 1992. Morbidity among 

bathers exposed to polluted seawater. South

African Medical Journal 81(6): 543–6. 

Reports on the first phase of a 1990/91 prospective follow-up 

study at two beaches in Cape Town, using 733 people. Found 

an excess of gastrointestinal, respiratory and skin symptoms

among swimmers, relative to non-swimmers. Results were

suggestive of a relationship between swimmers’ illness and 

water quality. 

Von Schirnding YER, Strauss N, Robertson P, 

Kfir R, Fattal B, Mathee A, Franck M, Cabelli VJ. 

1993. Bather morbidity from recreational 

exposure to sea water. Water Science and

Technology 27(3–4): 183–6. 

Reports on the full study carried out at two Cape Town beaches 

in the early 1990s, using 5551 people. Symptom rates for

gastrointestinal, respiratory and skin effects were substantially 

higher at the polluted beach, although they did not reach 

statistical significance. Does not use the more advanced 

statistical methods.

Ward RC, Loftis JC, McBride GB. 1990. Design

of Water Quality Monitoring Systems. Van 

Nostrand Reinhold, New York. 

Documents important features of design. Includes case studies.

Ware JH. 1990. The role of epidemiology in the 

assessment of societal risk: a statistician’s 

perspective. Chance: New Directions for Statistics 

and Computing: 41–7. 

Tracks the development of new statistical methods for design 

and analysis of chronic diseases. Argues that, in spite of

inherent uncertainties, epidemiology plays an essential role in 

risk assessment. 

Wheeler D, Alexander LM. 1992. Assessing the 

health risks of sea bathing. Journal of the 

Institution of Water and Environmental 

Management 6: 459–67 (with discussion). 

Reviews the UK-controlled cohort and uncontrolled cohort

studies. Questions the effect of necessary pre-publicity of

possible self-reporting of health effects in healthy-adult 

controlled-cohort trials. Concludes that using “captive 

volunteer” populations of healthy adults has technical merit, but 

that “there is no epidemiologically defensible way of linking 

the output of such methods to the results of more conventional 

techniques for assessing risks in marine waters”. Notes that the 

Langland Bay pilot controlled cohort study volunteers’ rate of 

self-reporting of symptoms was very high and correlated poorly

with clinical examinations. 

WHO. 1986. Correlation between Coastal Water 

Quality and Health Effects. Report ICP/CEH OO1 

m06. World Health Organization, Copenhagen. 

Reviews known information, and proposes protocol for

carrying out prospective epidemiological studies (with input 

from Prof. Cabelli, and Drs Fattal and Geldreich). Updated in 

(uncited) documents ICP/CEH 083/10 (1989) and 

EUR/ICP/CEH/103(S) (1991).

WHO. 1998. Guidelines for Safe Recreationalwater Environments: Coastal and fresh-waters. 

Draft. Report EOS/DRAFT/98.14. World Health 

Organization, Geneva. 

Proposes 95 percentile guideline values for faecal streptococci 

(per 100 mL): 10 – NOAEL (No Observed Adverse Effect 

Level); 50 – LOAEL (Lowest Observed Adverse Effect Level); 

200 – value is above threshold and LOAEL in most studies; 

1000 – derived from limited evidence concerning typhoid fever.

WHO. 1999. Health-Based Monitoring of

Recreational Waters: The feasibility of a new 

approach (The ‘Annapolis Protocol’). World 

Health Organization, Geneva.

WHO. 2001. Bathing Water Quality and Human

Health: Protection of the human environment

water, sanitation and health. Report 

WHO/SDE/WSH/01.2. World Health 

Organization, Geneva. 

Details of the application of the Annapolis Approach. 

Percentile values of enterococci for risk based on exposure 

conditions.

REFERENCES AND FURTHER READING.

J28 June 2003 
WHO. 2003. Guidelines for Safe Recreational 

Water Environments: Volume 1 Coastal and

Freshwaters. World Health Organization, Geneva. 

Provides a review and assessment of the health hazards 

encountered during recreational use of coastal and freshwater

environments. A wide range of hazards are addressed,

including water quality. 

Wilkinson J, Jenkins A, Wyer M, Kay D. 1995.

Modelling faecal coliform dynamics in streams 

and rivers. Water Research 29(3): 847–55. 

Field experiments and modelling have been used to account for

sediment entrainment and release of bacteria, as governed by

stream flow. 

Wittman RJ, Flick GJ. 1995. Microbial 

contamination of shellfish: prevalence, risk to

human health, and control strategies. Annual 

Review of Public Health 16: 123–40. 

In the US the largest number of disease cases are of unknown 

aetiology. The greatest percentage of known death (95%) is 

caused by non-cholera vibrio. People with underlying health 

conditions are the group most at risk. 

Wyer MD, Fleisher JM, Gough J, Kay D,

Merrett H. 1995. An investigation into parametric 

relationships between enterovirus and faecal 

indicator organisms in the coastal waters of

England and Wales. Water Research 29(8): 

1863–8. 

Examined a large combined dataset. The amount of variance in 

enterovirus concentration explained by bacterial concentrations 

was only 15–16%.

Wyer MD, Kay D, Fleisher JM, Salmon RL, 

Jones F, Godfree AF, Jackson G, Rogers A. 1999. 

An experimental health-related classification for 

marine waters. Water Research 33(3): 715–22. 

Proposes a health-related bathing water standard system (based 

on gastrointestinal illness avoidance) using faecal streptococci 

in units per 100 mL. Water quality is: ‘good’ if more than 50% 

of the FS distribution above 32 is below 73; ‘moderate’ if more

than 50% of the FS distribution above 32 is above 73; ‘poor’ if 

more than 50% of the FS distribution above 32 is above 137; 

‘very poor’ if more than 75% of the FS distribution above 32 is 

above 137.

REFERENCES AND FURTHER READING.

J29 June 2003 
About the Ministry for the Environment 

The Ministry for the Environment works with others to identify New Zealand’s environmental problems and get

action on solutions. Our focus is on the effects people’s everyday activities have on the environment, so our 

work programmes cover both the natural world and the places where people live and work. 

We advise the Government on New Zealand’s environmental laws, policies, standards and guidelines, monitor 

how they are working in practice, and take any action needed to improve them. Through reporting on the state 

of our environment, we help raise community awareness and provide the information needed by decision

makers. We also play our part in international action on global environmental issues. 

On behalf of the Minister for the Environment, who has duties under various laws, we report on local

government performance on environmental matters and on the work of the Environmental Risk Management

Authority and the Energy Efficiency and Conservation Authority. 

Besides the Environment Act 1986 under which it was set up, the Ministry is responsible for administering the 

Soil Conservation and Rivers Control Act 1941, the Resource Management Act 1991, the Ozone Layer 

Protection Act 1996, and the Hazardous Substances and New Organisms Act 1996. 

Head Office 

Grand Annexe Building 

84 Boulcott Street 

PO Box 10-362

Wellington, New Zealand 

Phone (04) 917 7400, fax (04) 917 7523

Internet www.mfe.govt.nz 

Northern Regions Office 

8–10 Whitaker Place 

PO Box 8270 

Auckland

Phone (09) 913 1640, fax (09) 913 1649

South Island Office 

Level 4 

Price Waterhouse Centre 

119 Armagh Street

PO Box 1345 

Christchurch

Phone (03) 963 0940, fax (03) 963 2050

ABOUT THE MINISTRY FOR THE

ENVIRONMENT.

June 2003 

J30
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