minimum requirements for water monitoring at …

MINIMUM REQUIREMENTS

FOR WATER MONITORING AT WASTE

MANAGEMENT FACILITIES

DEPARTMENT OF WATER AFFAIRS AND FORESTRY

Second Edition 1998

MINIMUM REQUIREMENTS FOR WATER MONITORING AT

WASTE MANAGEMENT FACILITIES

Department of Water Affairs and ForestryRepublic of South Africa

Second Edition 1998

_______________________________________________________________________________________Minimum Requirements for Water Monitoring at Waste Management Facilities, Second Edition 1998 i

Published by

Department of Water Affairs and ForestryPrivate Bag X313

PRETORIA0001

Republic of South AfricaTel: (012) 388 7500

Printed and bound by CTP Book Printers, Cape

First Edition 1994Second Edition 1998

ISBN 0-620-22994-2

Copyright reserved

No Part of this document may be reproduced in any manner

without full acknowledgementOf the source

________________________________

This report should be cited as:

Department of Water Affairs and Forestry, Second Edition, 1998. Waste Management Series.Minimum Requirements for Water Monitoring as Waste Management Facilities.

Project Leader:L. Bredenhann, Department of Water Affairs and Forestry, South Africa

Project Co-ordinator:Prof. F.D.I. Hodgson, Institute for Groudwater Studies, South Africa

Editor:K. Langmore

_______________________________________________________________________________________Minimum Requirements for Water Monitoring at Waste Management Facilities, Second Edition 1998 ii

This document forms part of the Waste Management Series, produced by the Department of WaterAffairs and Forestry. Thus far, the series comprises:

Document 1: Minimum Requirements for the Handling, Classification and Disposal of HazardousWaste, sets out the waste classification system. In this, wastes are placed in two classes,General or Hazardous, according to their inherent toxicological properties. Hazardouswastes are further subdivided, according to the risk that they may pose at disposal, using ahazard rating. In this way, a less hazardous waste is distinguished from an extremelyhazardous waste. Wastes with a hazard rating of 1 or 2 are very or extremely hazardous,while wastes with a hazard rating of 3 or 4 are of moderate or low hazard. Therequirements for pre-treatment and disposal are appropriately set in accordance with thewaste classification. Hazardous waste prevention and minimization are briefly addressed,because of their importance, as is handling, transportation and storage.

Document 2: Minimum Requirements for Waste Disposal by Landfill, addresses landfill classification,and the siting, investigation, design, operation and monitoring of landfill sites. In thelandfill classification system, a landfill is classified in terms of waste class, size ofoperation, and potential for significant leachate generation, all of which influence the riskit poses to the environment. Graded requirements are then set for all aspects of landfilling,including public participation.

Document 3: Minimum Requirements for Water Monitoring as Waste Management Facilities,addresses the monitoring of water at and around waste disposal facilities.

The Department intends extending the Waste Management Series. At the time of writing, the NationalWaste Management Strategy was being formulated, as a joint venture between the Department of WaterAffairs and Forestry, the Department of Environmental Affairs and Tourism, and funded by the DanishCooperation for Environment and Development (DANCED). Initially, three baseline study documents weredrafted by South African consultants to provide data regarding waste generation, community waste and litter,and waste disposal sites in South Africa. These will form part of the series. Further work being carried outby Danish and South African consultants, assisted by Departmental staff will generate strategy documentswhich will also form part of the series.

Other documents envisaged for the series include Minimum Requirements for waste disposal site auditing,and the training of operators and managers of waste management facilities.

PREFACE

_______________________________________________________________________________________Minimum Requirements for Water Monitoring at Waste Management Facilities, Second Edition 1998 iii

PREFACE

This document has become necessary in view ofthe deteriorating groundwater quality at manywaste management facilities in South Africa. Interms of the Reconstruction and DevelopmentProgramme of the Government, supply of water ofacceptable quality is one of the cornerstones.Knowledge of water quality distribution andprotection of our water resources can only beaccomplished through a comprehensive andstandardized monitoring programme. It is theintention for this document to provide theframework within which this can be accomplished.

The Department of Water Affairs and Forestryconsiders monitoring as a requirement forEnvironmental Impact Assessment, which in turnis an important component in the IntegratedEnvironmental Management Procedure for theestablishment of waste management facilities.

This document is a practical manual on“minimum” requirements for monitoring at wastemanagement facilities. The term “minimum”refers to the lower limit that must be compliedwith. “Monitoring” refers to the meaningfulmeasurement of a variable(s) on a once-off basisduring initial impact assessments, or on a routinebasis thereafter.

It is likely that the minimum monitoringrequirements stipulated in this document will besurpassed in many instances. The waste managershould bear in mind that at all waste sites, the normshould be “to conduct sufficient investigations andmonitoring, to understand the short-, medium- andlong-term impact that waste management mayhave on the groundwater regime”.

This document is one of a series. The other twodocuments in this waste management series dealwith the management and disposal of General andHazardous waste.

Monitoring procedures to be followed arerecommended in this document. These proceduresare not necessarily the only ones acceptable, butexperience has shown that they work well.

Deviations from recommended procedures shouldbe cleared with the Department of Water Affairsand Forestry.

Implementation of the Minimum MonitoringRequirements is possible under existing legislation.Co-operation between companies that handle wasteand relevant governmental departments isessential. Public involvement and participation iscrucial in acceptance and implementation of theserequirements.

Appeal against compliance with the minimummonitoring requirements, based on sufficientmotivation, will be considered in instances ofspecific merit. Application, after a risk assessmenthas been made, may be made to the Department ofWater Affairs and Forestry.

In conclusion, the comment received on theseminimum requirements is highly valued, as itsinclusion has improved and augmented thecontents of the document. I therefore wish tothank all those who have contributed by submittingcomment. Further written comment on the SecondEdition will be very welcome.

PROFESSOR KADER ASMAL M.P.MINISTER OF WATER AFFAIRSAND FORESTRY

SYNOPSIS

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SYNOPSIS

Groundwater is a limited and strategic resource inSouth Africa. It must therefore be protected fromundue contamination. Protection of water resourcesrequires systematic and organized monitoring. Thisdocument “Minimum Requirements for WaterMonitoring at Waste Management Facilities”, is anattempt to:

• Standardize monitoring procedures.• Provide specifications for monitoring design.• Provide mechanisms for communication

between waste management companies andauthorities.

In the compilation of this document, the uniquenature of the South African situation has beenconsidered. Throughout this document, theemphasis is on what could reasonably be achieved,without compromising on information that wouldlead to early detection of water pollution.

All procedures recommended in this document areessentially standard practice in South Africa. WasteManagement Companies should therefore befamiliar with the necessary procedures andrequirements and should not have seriousdifficulties in complying with such monitoring. Ininstances where the Department has issued wastemanagement permits, such as for general andhazardous waste, the reporting mechanism to theDepartment has been established. In othersituations, such as mining for instance, reporting isthrough existing mechanisms, such as theirEnvironmental Management Programme Report(EMPR).

The installation of groundwater monitoring systemsrequires specialized knowledge, and consultationwith an appropriately qualified geohydrologist is arequirement.

TABLE OF CONTENTS

_______________________________________________________________________________________Minimum Requirements for Water Monitoring at Waste Management Facilities, Second Edition 1998 v

Table of Contents

PREFACE iiiSYNOPSIS ivGLOSSARY FOR DOCUMENT TITLE ixACKNOWLEDGEMENTS x

Section 1: BACKGROUND INFORMATION 1 - 1

1.1 Introduction 1 - 1

Section 2: POLICY AND STRATEGY FOR GROUNDWATER QUALITY MANAGEMENT 2 - 2

2.1 Mission and policy goals 2 - 22.2 Groundwater Quality Management Policies 2 - 12.3 Aquifer Classification 2 - 2

Section 3: SOUTH AFRICAN AQUIFERS 3 - 1

3.1 Aquifer types 3 - 13.1.1 Porous aquifers (Primary aquifers) 3 - 13.1.2 Fracture aquifers (Secondary aquifers) 3 - 13.1.3 Dolomitic aquifers 3 - 2

3.2 Groundwater utilization 3 - 23.3 Aquifer yield 3 - 33.4 Aquifer vulnerability 3 - 3

Section 4: SEQUENTIAL STEPS FOR THE DESIGN OF A MONITORING SYSTEM 4 - 1

Section 5: RISK ASSESSMENT 5 - 1

5.1 Goals for Risk Assessment 5 - 15.2 Dominant issues 5 - 1

5.2.1 Potential for groundwater usage 5 - 15.2.2 Aquifer Vulnerability 5 - 15.2.3 Toxicity of the waste 5 - 25.2.4 Quantity of waste 5 - 25.2.5 Potential for leachate-generation 5 - 25.2.6 Liner Design 5 - 2

Section 6: FACILITIES FOR MONITORING 6 - 16.1 Introduction 6 - 16.2 Early Warning Systems 6 - 26.3 Regional Monitoring Systems 6 - 2

Monitoring boreholes 6 - 4In porous flow aquifers 6 - 4In fracture flow aquifers 6 - 4Borehole design 6 - 4Borehole type 6 - 5Hole diameter 6 - 5

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_______________________________________________________________________________________Minimum Requirements for Water Monitoring at Waste Management Facilities, Second Edition 1998 vi

Hole depth 6 - 5Casing, screens and filters 6 - 5Borehole protection 6 - 6Groundwater levels. 6 - 6Piezometer tubes 6 - 6Water sampling and preservation 6 - 6Pumping and/or packer tests 6 - 6Fountains, wells, dams, pans, streams and rivers 6 - 7Water/salt balances 6 - 7

6.4 Monitoring Networks 6 - 7

Section 7: ANALYTICAL VARIABLES 7 - 1

7.1 Comprehensive analysis 7 - 17.2 Indicator analysis 7 - 1

Section 8: DATA STORAGE, PROCESSING, INTERPRETATION AND REPORTING 8 - 1

8.1 Introduction 8 - 18.2 Data Storage 8 - 18.3 Processing and Interpretation 8 - 18.4 Reporting to the Department 8 - 1

Section 9: IMPLEMENTATION AND MANAGEMENT 9 -1

9.1 Introduction 9 - 19.2 Public participation 9 - 19.3 Company level 9 - 19.4 Local authority level 9 - 19.5 Departmental level 9 - 2

Section 10: SUGGESTED READING MATTER 10 - 1

Appendix A: RISK ASSESSMENT PROCEDURES AA - 1

WASP (Waste-aquifer separation procedure) AA - 1Numerical modelling AA - 2

Appendix B: BOREHOLE WATER SAMPLING AB - 1

Stratified Borehole Water Sampling AB - 1Composite Borehole Water Sampling AB - 1Recommendations AB - 2

Appendix C: SAMPLE FREQUENCY AND PRESERVATION AC - 1

Sample bottles and filters AC - 1Sample Frequency AC - 1Groundwater AC - 1Surface water AC - 1Sample Preservation AC - 1

TABLE OF CONTENTS

_______________________________________________________________________________________ Minimum Requirements for Water Monitoring at Waste Management Facilities, Second Edition 1998 vii

Appendix D: ANALYTICAL PROCEDURES AD - 1 SABS AD - 1 Prepackaged analytical procedures AD - 2 Automated equipment AD - 2 Practical tips AD - 2 pH AD - 2 Electrical conductivity AD - 3 Alkalinity and acidity AD - 3 Macro cations AD - 3 Heavy metals AD - 3 Anions AD - 3 Organic compounds AD - 3 Analytical costs AD - 4 Appendix E: DATA INTERPRETATION WITH WASTEMANAGER AE - 1 Piper and Expanded Durov Diagrams AE - 1 Appendix F: SUMMARY OF REQUIREMENTS AF - 1 Minimum requirement AF - 1 Monitoring AF - 1 Waste Management Facility AF - 1 Expertise Required AF - 1 Monitoring Network AF - 1 Aquifer Classification AF - 1 Risk Assessment AF - 1 Rainfall AF - 1 Evaporation potential AF - 1 Run-off AF - 1 Rehabilitation AF - 1 Borehole data AF - 2 Borehole type AF - 2 Hole diameter AF - 2 Hole depth AF - 2

Casing, screens and filters AF - 2 Piezometer tubes AF - 2 Borehole protection AF - 2 Groundwater levels. AF - 2 Pumping and/or packer tests AF - 2 Fountains, wells, dams, pans, streams and rivers AF - 2 Water/salt balances AF - 2 Monitoring Networks AF - 3 Water sampling AF - 3

Sample bottles and filters AF - 3 Sample Preservation AF - 3 Sample Frequency AF - 3 Surface water AF - 3 Analytical variables AF - 3 Reporting to the Department AF - 3 The following actions are recommended AF - 3 Public participation AF - 3

TABLE OF CONTENTS

_______________________________________________________________________________________Minimum Requirements for Water Monitoring at Waste Management Facilities, Second Edition 1998 viii

Company level AF - 3Local authority level AF - 4Departmental level AF - 4

GLOSSARY FOR DOCUMENT TITLE

_______________________________________________________________________________________Minimum Requirements for Water Monitoring at Waste Management Facilities, Second Edition 1998 ix

GLOSSARY FOR DOCUMENT TITLE

Several terms, mainly relating to the title of thisdocument, need clarification.

Minimum requirementThe lower limit which must be complied with.The right to appeal against compliance with theprescribed minimum requirements, based uponsufficient motivation, exists.

MonitoringThe meaningful measurement of a variable(s) on aonce-off basis during initial impact assessments,or on routine basis.

Compliance monitoringMonitoring done in compliance with permitconditions.

Geohydrological investigationInvestigation of the groundwater system on aonce-off basis, probably as part of a wider impactassessment, or routine monitoring.

Waste Management FacilityAll wastes or products stored on a temporary orpermanent basis, that could impact on surface orgroundwater quality, by leaching into or comingin contact with water, are referred to a “WasteManagement Facilities”. See also the WasteManagement Documents, “Minimum require-ments for waste disposal sites” and “Minimumrequirements for the handling and disposal ofhazardous waste”.

Managerial informationInformation generated during monitoring at awaste management facility for the purpose ofdefining a management strategy, for measuringperformance or for use in mitigation.

Monitoring facilities for recording variables, thusfacilitating the comprehensive description of thearea monitored, in terms of time, space andvariables recorded. Monitoring networks mustextend beyond zones of impact.

ACKNOWLEDGEMENTS

_______________________________________________________________________________________Minimum Requirements for Water Monitoring at Waste Management Facilities, Second Edition 1998 x

ACKNOWLEDGEMENTS

Apart from having received contributions from representatives on the Steering Committee and theirorganizations, this document has been circulated as widely as possible, to ensure general acceptance withinthe waste and geohydrological community. All contributions received are hereby gratefully acknowledged.

STEERING COMMITTEE MEMBERS

Mr L. Bredenhann*** Department of Water Affairs and Forestry (Chairman/Project Leader)Prof F. Hodgson*** Institute of Groundwater Studies (Co-ordinating Consultant)Mr T. Aab** Department of Water Affairs and Forestry: Head OfficeDr H.A. Abbott*** Department of Water Affairs and Forestry: Head OfficeDr D Baldwin** Environmental and Chemical ConsultantsMr J. Ball*** Jarrod Ball and Associates ccMs S. Barkhuizen** Department of Environmental Affairs and Tourism: Free State RegionMs D. Borg** National Waste Management Strategy (Observer)Mr A Botha* Association of Regional Services Councils (ARSC)Mr J. Botha** Department of Environmental Affairs and Tourism: Northern ProvinceMs C. Bosman** Department of Water Affairs and Forestry: Head OfficeMr D. Brink** SAICE/Jones and WagnerMr P. Davies*** Institute of Waste ManagementMr F. Druyts** Department of Water Affairs and Forestry: Head OfficeMr G. du Plessis* Municipal Executive of SAMr L. Eischsädt*** Department of Water Affairs and Forestry: Western Cape RegionMs D. Fischer** Department of Agriculture, Conservation and Environment: GautengMr P. Fourie* Department of Mineral and Energy Affairs: Head OfficeDr O. Fourie*** Ockie Fourie ToxicologistsMrs L. Garlipp* Department of Water Affairs and Forestry: Law AdministrationMr E. Grond*** Department of Environmental Affairs and TourismMr M.L. Hawke** South African Chamber of BusinessProf F. Hodgson** Institute of Groundwater StudiesMr I. Hopewell*** Institute of Waste ManagementMr C.S.W. Joubert*** Department of Water Affairs and Forestry: Natal RegionMr M. Keet* Department of Water Affairs and Forestry: Highveld RegionDr T.S. Kok*** Department of Water Affairs and Forestry: Ground WaterMr K. Legge*** Department of Water Affairs and Forestry: Civil DesignMr G. le Roux*** Department of Water Affairs and Forestry: Head OfficeMr A.B. Lucas*** Department of Water Affairs and Forestry: Eastern Cape RegionMr T. Mahola** Department of Environmental Affairs and Tourism: Free StateMr T. Mphahlele** Department of Environmental Affairs and Tourism: MpumalangaMr M. Marler** Development Bank of South AfricaMr D. Mofokeng** Department of Environmental Affairs and Tourism: Free StateMs W. Moolman** Department of Water Affairs and Forestry: Head OfficeMs R. Munnik** Department of Water Affairs and Forestry: Gauteng RegionMr A. Mzamo** Department of Water Affairs and Forestry: Head OfficeMr H. Neetling** Pretoria Metropolitan CouncilMs L. Nielson** National Waste Management Strategy (Observer)Ms G. Nosilela-Twala** Department of Water Affairs and Forestry: Head OfficeMr P. Novella** Cape Metropolitan Council / IWM Landfill Interest Group

ACKNOWLEDGEMENTS

_______________________________________________________________________________________Minimum Requirements for Water Monitoring at Waste Management Facilities, Second Edition 1998 xi

Mr B. Oelofse** Department of Water Affairs and Forestry: Northern Province RegionMr J Parkin** SA Local Government Association (SALGA) / Durban Solid WasteMr R. Parsons* Council for Scientific and Industrial ResearchMr T. Pather** Department of Water Affairs and Forestry: Gauteng RegionMr T. Pule** Department of Health: Head OfficeMr R. Rimmer* Institute for Waste ManagementMr A.G. Reynders* Water Research CommissionMr J. Singh* Development Bank of South AfricaMr D. Steyn* Department of Water Affairs and Forestry: Gauteng RegionDr J. van der Merwe*** Department of Water Affairs and Forestry: Free State RegionMr J. Streit** Department of Water Affairs and Forestry: Northern Cape RegionMr C. Theron** Gauteng Province Metropolitan CouncilMr B. Tladi** Parks Board Environmental AffairsMr J. Toudal** National Waste Management Strategy (Observer)Mr H. van Tonder* ESKOMMr F.S. Vivier* Department of Health and Population Development: Head OfficeDr. H Wiechers** Wiechers Environmental Consultancy cc

* Member of Steering Committee, First Edition only** Member of Steering Committee, Second Edition only*** Member of Steering Committee, First and Second Editions

Representatives of the following organizations were invited to form part of the Second Edition SteeringCommittee. However, they were either unable to attend or elected, at this stage, to partake on a strategic levelthrough the project steering committee of the National Waste Management Strategy of South Africa:

Chamber of MinesChemical and Allied Industries Association (CAIA)COSATUEnvironmental Justice Network Forum (EJNF) . Earth Life Africa (ELA)Parks Board Environmental AffairsSouth African National Civics Organization (SANCO)

1: BACKGROUND INFORMATION

_______________________________________________________________________________________Minimum Requirements for Water Monitoring at Waste Management Facilities, Second Edition 1998 1-1

Section 1

BACKGROUND INFORMATION

1.1 Introduction

Monitoring the effect that waste managementfacilities have on the water quality of surface andgroundwater resources is a complex and multi-disciplinary task. Numerous methodologies existfor monitoring of this kind. Facilities required fora specific situation will depend on the:

• Type of waste• Amount of waste• Potential for leachate formation• Vulnerability of groundwater resources• Potential for groundwater usage

South African groundwater systems differ inmany ways from those overseas. Monitoringmethodologies and requirements that have beendeveloped overseas do not necessarily apply to theSouth African situation. This could lead toconfusion and result in unnecessary expenditure.To ensure co-ordinated and meaningful waterquality monitoring in South Africa, a re-evaluation of the situation has become necessary.

The departure point in this document is on “whatcould reasonably be achieved”, considering theuniqueness of the South African situation in thegeneral and specific sense. The principle of“batneec” (best available technology, not entailingexcessive cost) is subscribed to throughout thisdocument. Consideration is also given to existingpolicy documents by governmental departments.Examples of the latter are the EnvironmentalConservation Act, Act 73 of 1989, dealing withgeneral and hazardous waste and activities underthe EIA regulations, the EMPR (EnvironmentalManagement Programme Report)

of the mining industry, the Water Services Act,Act 108 of 1997 and the National Water Bill of1998.

It stands to reason that the contents of thisdocument will have to be upgraded as new policydocuments become available, or as monitoringtechniques improve. For that reason, thisdocument has been structured in a modularfashion and sections can easily be upgraded orreplaced.

Many of the requirements as specified in thisdocument deviate from those stipulated in classictextbooks. These deviations do not contradictwell-established methodologies, but modificationshave been introduced in accordance to the“batneec” principle of South African conditions.This should not deter those who want to followmore stringent procedures from doing so.

This is a grass roots level document. Apart fromlisting monitoring requirements, the intention is toexplain:

• Groundwater behavior• Reasoning behind monitoring• Principle of risk assessment• Installation of a monitoring

system• Principles of water sampling• Principles of indicator variables• Principles of data evaluation.

Much of the information contained in thisdocument is therefore of an informatory nature.Only items that have been printed in Italics areactual minimum requirements or definitionswhich relate to requirements.

2: POLICY AND STRATEGY FOR GROUNDWATER QUALITY MANAGEMENT IN THE RSA


Section 2

POLICY AND STRATEGY FOR GROUNDWATER QUALITYMANAGEMENT IN THE RSA

2.1 Mission and policy goals

The Department’s water quality managementpolicy serves both surface and groundwaterresources. The special nature of groundwaterdictates a more specific resolution of the missionand strategic objectives of the resource. TheDepartment has thus adopted the followingmission for groundwater quality management:

To ensure that groundwater quality ismanaged in an integrated and sustainablemanner that provides adequate protection tothe resource and secures the supply ofacceptable quality for all recognized users.

The emphasis that is placed on the protection ofthe groundwater quality management mission issignificant and reflects the recognition of thevulnerability of the resource. This mission isunderpinned by three policy goals. These are asfollows:

• To minimize, at source, the impact ofdevelopment on groundwater quality by theimposition of regulating controls andincentives.

• To manage such impacts as do inevitablyoccur in such a manner to at least ensurefitness for use of groundwater by recognizedbeneficial users.

• To restore groundwater quality, wherepracticable to at least fitness for use byrecognized beneficial users.

The three policy goals, when achieved together,will on the one hand achieve fitness for use and onthe other ensure that degradation of groundwaterquality which can reasonably be prevented doesnot occur.

The groundwater quality management goals canonly be achieved if management of groundwater

quality is integrated with surface water qualitymanagement. Water quality management is inturn an integral part of water resourcemanagement.

2.2 Groundwater Quality Manage-ment Policies

The Department intends implementing adifferentiated approach to the protection ofgroundwater quality. This means, in practice,that the relatively stringency and acceptable risklevels for impact minimization measures that willbe required for potentially polluting sources willdepend on the nature of the affected resource.

The approach will be based on the country’sgroundwater resources firstly in terms ofimportance and secondly in terms of vulnerability.This classification will provide the basis for theimplementation of differentiated source-basedregulatory controls.

Groundwater resources which represent the onlysource of water for communities will beafforded special status and will enjoy the highestlevel of protection.

In order to conserve limited manpower andcapacity, regulatory controls will be focused onthose activities that represent the most significantthreat to the groundwater resources of the country.These activities include:

• Groundwater abstraction and dewatering.• Disturbance and damage to aquifers.• Waste disposal from urban, commercial

farming, industrial and mining sectors.• Diffuse sources of pollution associated with

urban and rural development specificallyaround boreholes.

• Underground storage tanks.

In those instances where groundwater qualitydeterioration is inevitable, such as where mines

2: POLICY AND STRATEGY FOR GROUNDWATER QUALITY MANAGEMENT IN THE RSA


locally depress groundwater levels or affect waterquality, the Department will only allow suchimpacts if the proponent has exhausted allreasonable options to avoid the impact and wherethe rights of the other water users will not beaffected.

The Department will only intervene directly tocontrol abstraction and dewatering whereappropriate. The utilization of groundwater forprivate domestic consumption and agriculturalpurposes will not specifically be controlled unlesscommunity interests are at stake.

2.3 Aquifer Classification

In order to apply its policy of differentialprotection to aquifers, the Department hasdeveloped a classification scheme for SouthAfrican Aquifers.

This scheme recognizes:

• The high value of sole-source aquifers inSouth Africa.

• The need for a pragmatic approach whichallows for site-specific factors to beconsidered.

It is important to note that the concepts of Major,Minor and Poor Aquifers are relative and thatyield is not quantified. Within any specific area,all three classes of aquifers should therefore, intheory, be present. In the siting of new wastefacilities, a geohydrological map will be requiredto distinguish between aquifer regions. Aproposed new waste site must be within a PoorAquifer Region.

This classification system is included below:

Solesourceaquifer

An aquifer which is used to supply50% or more of urban domesticwater for a given area, for whichthere are no reasonably availablealternative sources should thisaquifer be impacted upon ordepleted.

Majoraquiferregion

High-yielding aquifer of acceptablequality water

Minoraquiferregion

Moderately yielding aquifer ofacceptable quality or high yieldingaquifer of poor quality, or aquiferwhich will never be utilized forwater supply and which will notcontaminate other aquifers.

Pooraquiferregion

Insignificantly yielding aquifer ofgood quality or moderately yieldingaquifer of poor quality, or aquiferwhich will never be utilized forwater supply and which will notcontaminate other aquifers.

Specialaquiferregion

An aquifer designated as such by theMinister of Water Affairs, after dueprocess

It is a requirement that all future waste facilitiesbe sited on Poor Aquifer Regions. In the eventthat this is not possible, a risk assessment andextensive motivation should be submitted to theDepartment of consideration.

3: SOUTH AFRICAN AQUIFERS


Section 3

SOUTH AFRICAN AQUIFERS

A basic understanding of the nature and oc-currence of groundwater in South Africa aquifersis a prerequisite for the design of monitoringsystems at waste management facilities. Thischapter provides a general introduction on thetopic.

3.1 Aquifer types

Definition: An aquifer is an undergroundformation, capable of yielding sustainableamounts of water for the potential user(s) thereof.No upper or lower limit is placed on the aquiferyield. In the wider definition, an aquifer onlybecomes a groundwater resource once it is tapped.

Three types of aquifers are generally recognized,namely porous flow aquifers, fracture flowaquifers and dolomitic (karst) aquifers.

3.1.1 Porous aquifers (Primary aquifers)

Only about 10% of the South African aquifers areof the type where porous flow is the dominantflow mechanism. In these instances, flow isaround grains of sand and clay, which make upthe aquifer. Examples of such aquifers are:

• Coastal sands, gravels and other uncon-solidated material along the South Africancoast, such as those along the west coast atPort Nolloth, Doringbaai, Lambertsbaai,Langebaan, Atlantis, Cape Flats, Gansbaai,Bredesdorp, Stilbaai, Alexandria, Kenton OnSea, Boesmansriviermond, Kidds Beach andRichards Bay (Kok, 1991).

• Sands and gravels along stream beds, such asthose along the Crocodile and Caledon Rivers,at De Aar, De Doorns, Rawsonville, Pieters-burg, Messina and Makatini Flats.

Typical characteristics of porous flow aquifersare:

• They are usually shallow unconfined systemsand the groundwater surface in the aquifer isat atmospheric pressure.

• They mostly consist of unconsolidatedmaterial, usually less than 30 metres thick.

• They contain 1 – 20% water by aquifervolume.

• Recharge is commonly a relatively largepercentage of the rainfall and may amount tobetween 15 – 30% of the annual total.

• Geohydrological characteristics of the aquiferdo not vary greatly over short distances.

• Contaminant transport through porous flowaquifers is comparatively slow because of thehigh effective porosity.

• Significant attenuation of pollutants couldoccur within the clayey portion (matrix) of theaquifer, where present.

• Borehole yield from porous flow aquifers ismainly a function of the clay percentagewithin the aquifer. The higher the percentageclay, the lower the yield.

3.1.2 Fracture aquifers (Secondaryaquifers)

The term, fracture flow, has generally becomeaccepted amongst geohydrologists, for thedescription of groundwater movement through avariety of secondary structures in rock.Geologically, these structures may be defined asjoints, cracks, fractures and faults. In undergroundmines, water-bearing fractures are also calledfissures.

The degree of fracturing of rocks in South Africais a function of the tectonic history of the rocks, aswell as the rock composition. Competent rocks,such as dolerite and quartzite, for instance,fracture more readily than incompetent or ductilerocks, such as dolomite and shale.

The degree of fracturing in an aquifer is notnecessarily a measure of the degree to which theaquifer can transmit water. Many of the fracturesare tight, because of compression forces actingwithin the earth’s crust. Usually, at depths deeper



than 60 metres below surface, less than 1% of thefractures transmit significant amounts of water.Exceptions occur within quartzintic rocks, wheresignificant yields are possible at greater depths.

Typical characteristics of fracture flow aquifersare:

• These are present as either unconfined orconfined aquifers. In the latter instance, theaquifer is overlain by sediments or rock of aconfining nature, thus limiting direct rechargefrom rainfall.

• They are shallow systems, usually less than60 metres thick, with a maximum of 200metres in exceptional instances.

• Although deeper fracture flow systems doexist, the quality of the water within thesesystems is generally not acceptable for humanconsumption.

• They contain between 0,001 – 0,1% water byaquifer volume.

• Recharge from rainfall is generally low andtotals between 1 -–5% of the annual rainfall.

• Characteristics of the aquifer vary greatlyover short distances.

• Contaminant transport through fracture flowaquifers is comparatively fast.

• There is hardly any attenuation of pollutantsin the fractures.

• Borehole yields from fracture flow aquifersvary greatly within a few metres.

A combination of fracture flow and porous flowmechanisms often exists in a single aquifer. Twoexamples of aquifers of this type are sandstoneand weathered granite.

Sandstone has an inherent permeability of its own,and water can, to a lesser or greater extent, flowaround the grains within the sandstone, dependingon their degree of cementation. All sandstones inSouth Africa are fractured. These fractures areusually the dominant flow mechanism within thesandstones. When a pollutant enters a sandstoneaquifer, the fractures within the sandstone willtherefore be the dominant mechanism along whichthe contaminant will be transported.

Granite is an igneous rock and, like all otherigneous rocks, impermeable to groundwater flow

in its unfractured and fresh state. However,granite weathers comparatively easily.Weathering usually starts along fractures in thegranite, eventually affecting large areas within thegranitic mass. When weathered, crystals withinthe rock disengage and water can flow aroundindividual crystals within the granite. Dependingon the degree of weathering, the groundwater flowmechanism within a granite mass may thereforedominantly be fracture flow or porous flow.

3.1.3 Dolomitic aquifers

Dolomite is a crystalline rock, unstable in acidenvironments. Dissolution channels that developalong fractures within dolomite may extend tosurface and give rise to a typical karst topography,which has a very significant influence uponrecharge characteristics of the aquifer. Dolomiticaquifers that are not protected by overlyinggeological formations are particularly vulnerableto pollution because of their thin soil cover andhigh transmissive characteristics.

3.2 Groundwater utilization

Groundwater is utilized extensively by smallercommunities in South Africa. At least 140communities are wholly dependent on ground-water as their source of supply, emphasizing theneed for aquifer protection.

Conjunctive use of groundwater as asupplementary water source to surface watersupplies is the case in at least another 160instances. The largest of these schemes aregroundwater supply from the West Rand dolomiteinto the Rand Water Board water supply andgroundwater from the Crocodile River alluvialdeposits.

Nearly all farmers are totally dependent ongroundwater for their drinking-water supply. Inmost farming operations, groundwater forms anintegral part of stock-farming, garden irrigationand, in some instances, irrigation of crops.

Groundwater is an important resource that is notcurrently fully utilized. Its importance willincrease with time.



3.3 Aquifer yield

Yields from boreholes in South Africa may –typically be classified according to their potentialfor use and the following index is suggested:

Index Range Potential UseLow Yield <1l /sec Stock, Garden, DomesticMedium

Yield1 – 5 l/sec Limited development

potentialHigh Yield 6 – 20 l/sec Small CommunityVery High

Yield>20l/sec Large-scale water supply

In terms of the South Africa aquifer classificationsystem (Chapter 2), the high yield and very highyield categories in the above table wouldundoubtedly fall within the ‘Major aquifer’category. Medium yield corresponds to the‘Minor aquifer’ category and low yield wouldnormally fall within the ‘Poor aquifer’ class.

However, vast areas of South Africa haveboreholes that yield less than 1 l/sec on average.Large areas underlain by Karoo sediments andmost other sedimentary basins in South Africa fallinto this class. Also in this yield category areunweathered igneous and metamorphic rocks. Inthese areas, the physical limits for aquiferclassification will therefore move down and a‘Poor aquifer’ will typically yield less than 0,01l/s, for instance. It is important to realize that thecurrent aquifer classification system for SouthAfrican aquifers does not specify yields forspecific categories. Local conditions andvariations in aquifer yield will determine thelimits for aquifer classification.

Yields in excess of 5 l/sec are generally hard tocome by in South Africa. Boreholes with suchhigh yields have usually been sited scientificallyand are located on very favourable structures,such as faults or along dolerite dykes.

Dolomitic rocks, particularly where solutionchannels exist, usually yield vast amounts ofwater. Such yields may exceed 100 l/sec in manyinstances. In the gold-mining industry, forinstance, where dolomitic water is abstracted,yields are in excess of 500 l/sec.

Examples of favourable yield characteristics forthe major aquifer types in South Africa areprovided below:

Aquifer Typical yield (onestandard deviation)

Alluvial deposits 3 – 8 l/secCoastal sands 3 – 16 l/secKaroo sediments 1 – 3 l/secKaroo dyke contacts 3 – 6 l/secTable Mountain Sandstone 1 – 10 l/secDolomite (karst) 20 – 50 l /secGranite (weathered) 5 – 10 l/sec

The above values are for favourable yieldconditions from boreholes sited scientifically.These values should not be used for planning ordesign purposes, since the actual aquifer yielddepends on local conditions.

In view of the limited thickness of South Africaaquifers, their long-term potential yield is afunction of the amount of water recharged to thegroundwater from rainfall, from impoundmentsand, in rare instances, from streams. Rechargequantities generally range between 1 -–5% of theannual rainfall. Higher recharge percentages areusually the case where a thin soil cover is present,such as on dolomitic and certain unconfinedaquifers.

3.4 Aquifer vulnerability

South African aquifers are extremely vulnerableto pollution, because:

• Almost all usable groundwater in SouthAfrica occurs within 60 metres of the surface.

• Recharge to South African aquifers occursfreely through infiltration from rainfall, pondsand from seepage through dumps.

• Fracture flow systems, which constitute about90% of our aquifers, are capable oftransmitting contaminants at rates of between10 1000 times faster than porous flowsystems.

• Pollution within aquifers follows preferentialflow-paths usually emanating into streams.The water-table gradient, fractures andgeology dictate these flow-paths.

4: SEQUENTIAL STEPS FOR THE DESIGN OF A MONITORING SYSTEM


Section 4

SEQUENTIAL STEPS FOR THE DESIGN OF AMONITORING SYSTEM

The design of monitoring systems for wastemanagement facilities should follow a certainsequence of events. The following is a summaryof actions recommended in the following chaptersand appendices in this document:

(i) Obtain information on disposal practices,volumes and type of waste.

(ii) Obtain available information on thetopography, stream flow, fountains, dams,geology, existing boreholes, wells andexcavations (see Chapter 6 of the Mini-mum Requirements for Waste Disposalby Landfill). Sample surface andgroundwater for chemical analyses todetermine the presence of pollutants, ifany, at existing points. Obtain informationon other human activities that could beaffected by the disposal of the waste.Delineate possible pollution plumes atexisting waste sites.

(iii) Perform a risk assessment and decide onthe level of the impact study and themonitoring facilities that will be required(see Chapter 5 and Appendix A).

(iv) Perform geophysical investigations tolocate groundwater barriers and aquifers(see Chapter 6 of the Minimum Require-ments for Waste Disposal by Landfill).

(v) Drill boreholes at positions as determinedby (i), (ii), (iii) and (iv). Recordgeological and geohydrological inform-ation from boreholes. If necessary,perform tests such as hydraulic con-ductivity, aquifer yield and water qualityprofiling in boreholes. Studycharacteristics of rainwater penetrationinto waste. Install, if required, early

warning devices underneath new disposalsites (see Chapter 6).

(vi) Perform water sampling from holes.Analyse for elements typically foundwithin the natural and waste environments(see Appendices B, C and D).

(vii) Document data or enter it into thecomputerized database, Waste Manager,for processing and interpretation.Interpret data, extract tables and graphs,identify and investigate anomalies (seeAppendix E).

(viii) Present report, database and recommendmethods and frequency of sampling to theclient. Specify equipment to samplewater from boreholes.

(ix) Include information in the application fora waste management permit in the case ofgeneral or hazardous waste. In the case ofmining, include information in the EMPR.In other instances, submit information tothe Department.

(x) Train on-site personnel in the use of thedatabase, the sampling equipment and inthe interpretation of the data. Providefacilities for the client to report to theDepartment in terms of their permitconditions.

Where actual conditions are at variance with thatassumed here or of a complex nature and do notconform to a specific situation, it may beadvisable to discuss the matter with a seniorrepresentative of the Department.

5: RISK ASSESSMENT


Section 5

RISK ASSESSMENT

It is a minimum requirement that a riskassessment, to determine the risk of waterbecoming polluted, be performed at all waste sitesbefore the installation of a monitoring system.This serves to ensure that the design of themonitoring system is adequate. The prescribedmethodology for risk assessment is included inAppendix A.

In the case of disposal facilities that have beencited and developed in accordance with theMinimum Requirements for Waste Disposal byLandfill, most or all of the information required tocarried out a risk assessment should be readily athand. In the case of older sites that do not pre-scribe to the minimum requirements, certainadditional exploratory work may have to beundertaken.

5.1 Goals for Risk Assessment

A groundwater pollution risk assessment servestwo valuable purposes:

• It provides a numerical value or visual aidwith respect to the groundwater pollutionpotential for a particular waste managementfacility. Existing or potential sites evaluatedby these means can therefore be ranked interms of suitability or remedial priorities.

• Monitoring facilities can be prescribedaccording to the results of the risk assessment.Particularly, the density and locality ofmonitoring points should be in relation to therating obtained from the risk assessmentprocedures.

5.2 Dominant issues

Assessment of the risk for a waste managementfacility to pollute the groundwater regime is thefirst step in the design of a suitable groundwatermonitoring system. This risk differs from site tosite and monitoring facilities have to be adapted

accordingly. The dominant issues in riskassessment are:

• Potential for groundwater usage.• Aquifer vulnerability.• Toxicity and other properties of the waste.• Quantities of waste.• Potential for leachate generation.

5.2.1 Potential for groundwater usage

The potential for groundwater utilization from aspecific aquifer may change with time. Agroundwater resource that presently seemsunimportant may, in future, be a valuable asset.In the siting of any waste management facility,aquifers within a specific area should be rankedand those least likely to be of future use must firstbe considered for waste disposal.

5.2.2 Aquifer vulnerability

Aquifer vulnerability relates to a number offactors, the most important of which are:

• Climate, precipitation and surface water run-off.

• Nature and composition of the unsaturatedzone, in the case of unconfined aquifers.

• Aquifer characteristics, such as hydraulic con-ductivity, water quality and regional ground-water flow directions and degrees of confine-ment in the case of confined aquifers.

• Liner design, leachate management and otherprecautionary or control measures.

Many examples of aquifer degradation from wastedisposal already exist in South Africa. Thedolomitic aquifer in the south-western Gautengand the Karoo aquifers in parts of the NorthernFree State and Mpumalanga are but two examplesof areas where groundwater quality degradationhad to be allowed in exchange for development.From this, it can be seen that developmentinevitably leads to groundwater qualitydeterioration.

A policy of differentiated protection is inevitablefor South African aquifers.

5: RISK ASSESSMENT


Differential protection can only be implementedafter an impact study and a risk assessment hasbeen made.

5.2.3 Toxicity of the waste

The potential for different wastes to pollute waterresources differs greatly, depending on thecomposition of the waste and its potential fordegradation with time. South African legislationbroadly classifies waste under two categories,namely general and hazardous waste. Betweenthese two categories lies a continuum, with atransition from what could be described as non-toxic to toxic. When referring to a level oftoxicity, then the constituent itself must beconsidered and also the potential user of thewater, e.g. human, animal, aquatic life, orirrigation. The Department gives more infor-mation on waste classification and its toxicity inthe other two documents of this series.

5.2.4 Quantity of waste

Toxicity and quantity of waste go hand in hand.Experience has shown that it is easier to disposeof, manage and contain small quantities of wastethan large quantities.

The risk for groundwater pollution is usuallygreater at large waste disposal facilities, where itis often impossible to prevent groundwaterpollution because of the nature and scale ofoperations.

5.2.5 Potential for leachategeneration

It is theoretically possible, by using syntheticliners, to completely contain leachate from awaste site. This is, however, mostly impracticaland very costly. It is also now generally acceptedthat all liners leak to a lesser or greater (or tosome) extent. In reality, therefore, leachate that isgenerated in a disposal site may eventually reachthe groundwater regime. This should be takeninto account in the risk assessment (see MinimumRequirements for Waste Disposal by Landfill,Chapter 8 – Design).

5.2.6 Liner Design

Leachate generation is often considered as anessential component of the degradation of wastes.All hazardous waste disposal sites and certaingeneral waste sites, need to be equipped with theappropriate liner design and leachate managementsystem (see Minimum Requirements for WasteDisposal by Landfill, Chapter 8). A riskassessment is again essential when determiningthe degree to which leachate generation needs tobe controlled at a particular site.

6: FACILITIES FOR MONITORING


Section 6

FACILITIES FOR MONITORING

6.1 Introduction

The main purpose and endeavours of a monitoringsystem, concerned with the control of pollutionand the migration of hazardous liquids, are to:

• Provide reliable and irrefutable data on thequality and chemical composition of thegroundwater.

• Detect and quantify the presence andseriousness of any polluting substances in thegroundwater at the very earliest stagepossible.

• Detect the possible release or impendingrelease of contaminants from the wastefacility.

• Provide a rational comparison between thepredicted and actual flow and solute transportrates.

Provide an ongoing and reliable performancerecord for the design and control system(s) foreffectively controlling pollution.

To achieve the above objectives, it may benecessary to employ two separate monitoringsystems in cases where the generation ofhazardous leachate may be a problem. The twomonitoring systems are:

• Early Warming Monitoring Systems• Regional Monitoring

A schematic presentation of these monitoringoptions, in relation to a waste site, is show below.

Legend

G - GAS COLLECTION/SAMPLING N - NEUTRON MOISTURE PENETRATION E - ELECTRICAL CONDUCTIVITY PROBES; MOISTURE SAMPLERS MB - MONITORING BOREHOLES

T - CUT-OFF TRENCH WITH PUMP P - SUMP WITH PUMP GRAVEL LINER LINER AND COVER CONTROL FACILITY

MB

MB

Water table

Idealized section through a waste facility, showing monitoring facilities and pollution control measures

G N G N G

T

P

WASTE

E E



The main difference between these twomonitoring systems is that the Early WarningMonitoring System forms part of the disposaldesign and is independent of the groundwaterregime as well as of any direct geohydrologicalconsiderations.

Regional Monitoring Systems, on the other hand,are entirely dependent on geohydrologicalconsiderations and, in fact, cannot be installedsuccessfully in the absence of such knowledge.

Not all monitoring options need to be applied atevery site. The initial risk assessment will suggestthe monitoring methodology to be applied, as wellas the density of the monitoring network.

Table 6.1 lists minimum monitoring requirementsagainst various waste management activities.Also indicated on this table, is a frequency formonitoring. Table 6.2 provides details onmonitoring networks.

For each of the waste environments in these tablesan attempt has been made, based on South Africanexperience, to select only those monitoringmethodologies that would provide meaningfulresults. This explains the general absence ofmonitoring selections within the unsaturated zone.It has been found that specialized equipment suchas pressure/vacuum lysimeters and electricalconductivity probes soon becomes dysfunctional.Direct measurement of water quality fromleachate collectors is more reliable.

Monitoring of the groundwater system (Table 6.1)seems very extensive at first glance, but this is notthe case. Once a borehole has been drilled, waterlevels, quality, yield and usage can easily beascertained. Yield is usually only measured once.

6.2 Early Warning Systems

Early warning systems comprise measurementsdone on top of a disposal dump, within the dumpitself and directly underneath the dump in theunsaturated zone. Such monitoring usuallyincludes:• Rainfall: Rainfall that infiltrates into awaste dump increases the overall pollutionpotential from that dump. Rainfall for the past 24hours must be recorded at 8h00 every morning.

• Evaporation potential: The amount ofpotential evaporation from free-standing watercan be determined by measuring water lossesfrom a Class A evaporation pan, or calculated byusing a suitable equation such as Penmann. Inview of difficulties that industries have inaccurately monitoring the potential evaporationfor a specific locality, the measurement of panevaporation is only a requirement at hazardousdisposal sites. For all other sites, approximateevaporation potential values can be obtained fromthe Department.

• Run-off: The amount of water flowing offa disposal site, or a larger complex such as a mineor a power station, is an important component inthe calculation of water and salt balances for thesite or complex. Run-off quantities and qualitiesmust be recorded continuously, when specified inthe permit.

• Leachate Collection/Toe Seepage: Analy-sis of leachate from leachate collectors or toeseepage is considered to be the most importantearly warning indicator. Leachate collectors arepart of the design detail for certain wastemanagement facilities. Samples must be collect-ed, preserved and analyzed according tospecifications in this manual.

• Rehabilitation: Rehabilitation on top ofwaste must be done as soon as is reasonablypossible or otherwise specified in the permit. Thiswill limit ingress of water, thus reducing thevolume of leachate to be dealt with.

• Gas monitoring: Gas monitoring must bedone at Landfill and Hazardous sites whereindicated in Table 6.1. Suggestions for gasmonitoring are included in the document onMinimum Requirements for Waste Disposal byLandfill, Section 11.5.5.

6.3 Regional Monitoring Systems

Regional monitoring refers primarily to measure-ments done in the vicinity of the waste facility, upto such distances as may be required by thespecific monitoring system. Monitoring is usuallydone at:

• Boreholes.• Fountains, dams, pans streams and rivers.



Table 6.1. Minimum monitoring requirements at various types of wastemanagement facilities

Rai

nfal

l

Eva

pora

tion

Run

-off

(vol

ume,

qua

lity)

Wat

er in

filtra

tion

on w

aste

Toe

see

page

from

was

te

Soi

l cov

er o

n w

aste

Veg

etat

ion

on w

aste

or s

oil

Bio

assa

ying

Pre

ssur

e va

cuum

lysi

met

ers

Gas

sam

pler

s

Ele

ctric

al c

ondu

ctiv

ity p

robe

s

Leac

hate

col

lect

ors

Tem

pera

ture

with

in w

aste

Spe

cial

det

ecto

rs

Spe

cial

mon

itorin

g ho

les

Oth

er h

oles

Gro

undw

ater

leve

ls

Gro

undw

ater

che

mist

ry

Bor

ehol

e yi

eld

Gro

undw

ater

usa

ge

Foun

tain

see

page

Wat

er b

alan

ce

d d mm m y y m yes yes m 3m y y m m

d m m y y m yes yes m 3m y y m mm m y y yes yes m 3m y y m m

m y y yes yes y y y y y ym m yes yes 3m 3m y y m m

d y wd d no yes y y y y y m

m no yes y y y y y mm no yes y y y y y ym no yes y y y y y y

d d

d d yes yes 3m 3m y y m mm m yes yes 3m 3m y y m m

m yes yes 3m 3m y y m mm y yes yes 3m 3m y y m m

m yes yes 3m 3m y y m md y

d d m y y y m m yes yes 3m 3m y y m md d m y y m yes yes y 3m y y m m

m yes yes y 3m y y mm no yes y 3m y y m

d yes yes y 3m y y md

d d d m m m m y m m m m yes yes m m y y m y

d d m m m m y yes yes m m y y m m

d d yes yes m m y y y

no yes y y y y

no yes y y y y

yes yes m m m m m

d m no yes y y y y

Refer to specif ic waste above, such as general, hazardous, irrigation, impoundment

As specified by the CNS in collaboration w ith the DWA&F

Mines – Reactive environmentSlimes (Slurry)Ore discardsRock Discards (opencast)Rock discards (other)Mine w ater (impoundment)Mine w ater (discharged)

Mines – Inert environmentSlimes (slurry)Rock discardsOre discardsMine w ater (discharged)

Coal fired power stationsCoal stockpilingAsh disposal (slurry)Ash disposal (dry)Dirty w ater systemsWater discharged

General wasteLarge (>500 t/d)Medium (26 – 500 t/d)Small (1 – 25 t/d)Informal (<1 t/d)

SewageUnlined maturation pondsSludge

Hazardous waste

Waste irrigation

Agriculture (feed lots)

Agriculture (diffuse sources)

Septic tanks and pit latrines

Underground storage tanks

Urban development

Industries

Radioactive waste

Explanation of codes: d = daily monitoring; w = weekly monitoring; m = monthly monitoring; 3m = 3-monthly monitoring; y = yearly monitoring

At or near surface monitoring Within waste or unsat. zone Groundwater monitoring



Monitoring boreholes

The main objective in placing a monitoringborehole is to intersect groundwater moving awayfrom a waste management facility.

In porous flow aquifers

In porous flow aquifers monitoring boreholesshould be located on either side of the wastefacility, in the direction of the groundwatergradient. If very little is known about thegroundwater gradient, then at least one monitoringborehole should also be placed at the lowesttopographical point.

In cases where the aquifer consists of weatheredgranite or other igneous rock, geophysicalmethods should be used to determine the size,shape and orientation of the aquifer.

In fracture flow aquifers

Fractures and other lineaments such as doleritedykes may be identified by using aerial photos,satellite images, airborne magnetics; followed byground geophysics such as magnetic, electro-magnetic, resistivity and ground penetrating radar.These are specialized techniques and shouldpreferably be applied by geohydrologist.

Borehole design

The local geology dictates the borehole con-struction. Examples of equipped boreholes areincluded on this and the following page.

Data required from boreholes are:

• Geological log.• Water intersections (depth and quantity).• Construction information (depth of hole and

casing, borehole diameter, method drilled,date drilled).

• Use of water, if not solely for monitoring;frequency of abstraction; abstraction rate andwhether other water sources are readilyavailable.

• Water quality (see chapter on chemicalanalyses).

SHALE

SANDSTONE

ConcreteConcrete

Typical installation required

average depth 40 metres.

WEATHERED

SHALE

SILTSTONE

CASING CAP WITH BOLT

SHORT CASING (5-15m), SLOTTED

BOTTOM

OPEN HOLE

for monitoring boreholes into solid rock,

SOLID ROCK

LOOSE ROCK

ConcreteConcrete

Typical installation for monitoring boreholes into the loose material such as sand,

gravel, discards or rock spoil at the opencast mines

CAP

SLOTTED PVC CASING WITH

PROTECTION

ORIGINAL HOLE, NOW COLLAPSED OR BACK-FILLED


BOTTOM

OR SAND




Borehole type

• Boreholes must be drilled by a drillingtechnique that will not introduce pollutioninto the aquifer.

• Air-percussion drilling, without the additionof chemicals, is recommended. This allowsthe collection of rock chips and measurementof water yield, while drilling.

• In instances of difficult drilling, degradablechemicals may be introduced.

• Upon completion of drilling, the hole and theinside of the casing should be flushed.

Hole diameter

• Monitoring boreholes must be of a diameterthat will allow easy access to the aquifer, forthe purpose of water sampling and forlowering other test instruments.

• The diameter of the smallest submersiblepump available in South Africa is 100 mm.Holes should therefore preferably have

diameters larger that 110 mm. In smallerholes or during specialized sampling,pneumatic samplers or special small diameterpumps may be used. For newly drilledmonitoring holes, a diameter of 110 – 165 mmis suggested.

Hole depth

• A monitoring hole must be such that thesection of the groundwater most likely to bepolluted first is suitably penetrated, to ensurethe most realistic monitoring results.

• This implies that monitoring holes will at leastextend through the weathered zone, theaquifer below and 5 m into the non water-yielding formation deeper down. The latter isintended to act as a sump where material thatfalls down the borehole will accumulate,without affecting the performance of themonitoring system.

• Groundwater depth commonly ranges from 5-10 m below surface in high rainfall areas, tomore than 50 m below surface in dry areas ofNamaqualand. Weathering can be recognizedby brownish discolouration of the rock.Commonly, weathering extends to 5 – 15 mbelow surface. A depth of 40 – 60 m forboreholes, to monitor groundwater quality,should therefore be sufficient, except inspecial instances.

Casing, screens and filters

• The materials used for casing, screens andfilters in contact with water must becompatible with, and resistant to chemicalattack by the water being monitored.

• Casing, screens and filters must allow easyaccess for monitoring purposes and may in noway block the flow of water through theborehole.

• The top of a casing in a monitoring boreholeshould rise between 30 – 40 cm above thegeneral ground surface, to ensure that surfacerun-off does not flow into the borehole duringflood conditions.

SHALE

SANDSTONE

Typical installation of piezometer tubes

SOIL

SANDSTONE


BOTTOM


ConcreteConcrete

Piezometer tip

Gravel or sand fill

Cement plugBentonite plug Cement plug

Piezometer tip

Gravel or sand fill

in a monitoring borehole



• The casing should preferably be of slottedPVC or a polymer suitable for the particularapplication, protected by a short steel casingat surface. Where monitoring holes are to beinstalled in loose material such as sand,gravel, deposited waste or rock spoil, collapseof the holes may have to be prevented bymeans of properly designed borehole screens.

• A security cap must be fitted to preventaccidental or willful interference with amonitoring borehole. Caps fitted with boltsor secured by other mechanical means mayhave an advantage over locks that can bebroken and vandalized.

• The borehole number should be engravedonto the cap and casing or stamped onto asuitable rustproof tag set into the concreteblock.

• The bottom of the casing should extend only acouple of metres into the solid rock. If thegroundwater level is shallow and is likely torise within the casing, then the casing must beslotted to ensure lateral groundwater flowthrough the casing. A minimum slot densityof 1% is required.

• A concrete block around the top of the casing,to protect the casing and borehole, as well asto prevent surface pollution from flowingdown the side of the casing, is essential.Required minimum dimensions for theconcrete block are 750 mm x 750 mm x150 mm.

Borehole protection

• Monitoring boreholes must be adequatelyprotected to prevent accidental damage of theholes.

• Destruction of a monitoring facility results ina break of the data sequence. Securing ofmonitoring boreholes should therefore be ahigh priority. It is recommended thatmonitoring boreholes should be secured byfencing. Sufficient markings should be postedto prevent accidental damage of the holes.

Groundwater levels

• Groundwater levels must be recorded on aregular basis to within an accuracy of 0,1 m,using an electrical contact tape, floatmechanism or pressure transducer, in order todetect any changes or trends.

Piezometer tubes

• Piezometer tubes must allow easy access forwater sampling over the whole depth of theaquifer.

• Piezometer tubes are installed for variousreasons, into monitoring boreholes.Piezometer tubes are access tubes. Thesetubes are usually installed to differenthorizons within a borehole, and sealed offfrom the other horizons by cement andbentonite clay. The minimum recommendeddiameter for water sampling is 63 mm.

• Regional groundwater levels are indicative ofthe direction of groundwater movement. Achange in the natural water-table gradientindicates that external forces are acting uponthe aquifer. Such forces may be groundwaterabstraction through nearby boreholes orrecharge from impoundments.

Water sampling and preservation

• Water must be sampled and preservedaccording to procedures prescribed inAppendices B and C.

Pumping and/or packer tests

• Where considered necessary by thegeohydrologist or design engineer, pumpingand/or packer tests must be carried out onboreholes, to obtain additional data on thegeohydrological conditions at that particularposition.



Fountains, wells, dams, pans, streams andrivers

• Water sources around a waste managementfacility, within a radius as suggested by therisk assessment, must be sampled andpreserved for chemical analysis.

• Flow from fountains and in streams must beestimated. If pollution occurs as a result ofwaste management, then continuousrecording of flow and water quality should bedone.

Water/salt balances

• Water/salt balances: In instances whereexcess water is present and this water mayhave to be discharged into public streams,water and salt balances are required. Atlarger complexes such as mines, powerstations or large industries, this usuallyimplies water and salt balances for each ofthe contributing components, such as for rawwater intake; for materials brought onto,removed from or disposed of on site; and forrainwater contribution and run-off.

6.4 Monitoring Networks

Monitoring networks at waste managementfacilities must allow monitoring of the system on arepresentative basis (see Table 6.2). The key to

successful monitoring is the linking of pointinformation into larger systems. Referred to asmonitoring networks.

Monitoring networks operate on local, regionaland national scales. A local monitoring networkis intended for the single waste managementfacility, whereas regional monitoring relates to acombination of waste management facilities, suchas those usually present at mines, power stations,other large industries and large municipalities.Monitoring on a national scale, could, forinstance, be meaningful in terms of salt loadswithin catchments.

Monitoring on all these levels is necessary.However, for the purpose of this document, i.e.minimum monitoring requirements at wastemanagement facilities, emphasis is only on thelocal monitoring network. Local monitoringnetworks should extend beyond pollution plumesto allow for the delineation of plumes andinvestigations into the pollution migration rate.

In Table 6.2, the same waste environments asthose in Table 6.1 are listed. For each of theseenvironments, borehole-monitoring networks aresuggested. The typical number of boreholes, theirspacing and suggested monitoring frequency isindicated.



Table 6.2 Recommended monitoring distances and frequencies for different types of wasteenvironments.

Environment No. Holes Distance From Waste Monitoring FrequencyMines – Reactive EnvironmentSlimes (Slurry) 1-3 50-25- m downstream Samples from boreholes every 3 months. SampleOre discards 2-5 50-500 m downstream and above monthly from streams above and below mine. IfRock discards (opencast) 1/250 ha into water accumulations pollution from mine occurs, install recorders inRock discards (other) 1-3 50-200 m downstream streams above and below mine measure dailyMine water (impoundment) 2-6 50-1000 m downstream flow, EC and pH. Sample farmers’ boreholesFramers’ boreholes Within 1-5 km from mine workings 1-5 km radius, initially and when problems are

expected.

Mines – Inert EnvironmentSlimes (Slurry) 0-1 Monthly from streams above and below mine. IfOre discards 0-1 pollution from mine occurs, install recorders inRock discards (opencast) 0-1 streams above and below mine measure dailyRock discards (other) 0-1 flow, EC and pH. Sample farmers’ boreholesMine water (impoundment) 0-1 1-2 km radius, initially and when problems areFramers’ boreholes Within 1-2 km from mine workings expected.

Coal Fired Power Stations Samples from boreholes every 3 months. MonthlyCoal stockpiling 2-3 50-500 m downstream from streams above and below power station. IfAsh disposal (wet) 2-3 50-500 m downstream pollution occurs in streams, install recorders inAsh disposal (dry)Dirty water systems

2-32-3

50-500 m downstream50-500 m downstrem

streams above and below power station measuredaily flow, EC and pH. Sample farmers’

Private boreholes 2-3 Within 1-5 km from mine workings boreholes 1-5 km radius, initially and whenproblems arise

General Waste Samples from boreholes every 6 months or asLarge (>500 t/d) 3-6 20-200 m surrounding specified in permit. Sample water-supplyMedium (150 – 500 t/d) 2-3 20-200 m downstream boreholes 1-5 km radius initially and whenSmall (25 – 149 t/d)Communal (<25 t/d)

1-20-1

20-200 m downstream20 m downstream

problems are expected. Sample surface wateras specified in permit. Sample monthly for

Private boreholes 2-3 Within 1-5 km from waste Leachate, if any.

SewageUnlined maturation ponds 1 20-50 m downstream Samples from boreholes every 3 months.Sludge 1 20-50 m downstream Samples monthly from streams above and below

sewage works.

Hazardous waste 5-10 10-200 m surrounding Site-specific constituents at frequenciesrecommended by impact study

Waste Irrigation 3-6 50-500 m downstream and above Samples from boreholes every 3 months.Monthly samples from streams above and below.

Agriculture – feed lots 2-3 50-200 m downstream Samples from boreholes every 3 months.Monthly samples from streams above and below

Agriculture – diffuse sources 0 Samples from existing water-supply boreholeswhen problems are expected.

Septic tanks and pit latrines 0 Samples from existing water-supply boreholeswhen problems are expected.

Urban development 0 Monthly EC in streams above and belowdevelopment

7: ANALYTICAL VARIABLES


Section 7

ANALYTICAL VARIABLES

Water samples must be analysed by a recognizedanalytical laboratory that uses approvedanalytical procedures.

In instances where permits have been issued,permit conditions will specify the frequency ofanalyses and constituents to be tested for.

For sites presently not regulated by permit, thefollowing guidelines may be used:

The range of elements that may be found byanalysis of a waste environment is very extensive.For the purpose of this document, the requiredanalysis are grouped under two headings:

• Comprehensive analysis• Indicator analysis

7.1 Comprehensive analysis

For all new sites and first time monitoring atexisting sites, a comprehensive analysis isrequired.

It is essential that accurate background levels, foras wide a range of constituents as possible, beestablished at the outset. This will usually includea complete macro analysis as well as an analysisfor the trace elements that could reasonably beexpected to be present within the environmenttested.

7.2 Indicator analysis

Indicator analysis may be performed oncecomprehensive analyses have been completed.This process may continue until undesirabletrends are uncovered.

This will keep analytical costs to a minimum, butstill provide enough information upon whichfurther action can be initiated, if necessary.Depending on the type of waste handled, so-called“pollution indicators” for each of these

environments may be identified. Examples arethe:

• General and special variables for discharge ofindustrial effluent into public streams, such aselectrical conductivity (EC), Na, SO4.

• The so-called swage variables, such as COD,NH4, PO4.

• Hazardous waste disposal variable, such asVOC, THM, CR6+

• General waste disposal variables, such asCOD, Cl, NO3, NH4.

• Mine pollution variables, such as pH, EC, Mn,SO4.

• Power station pollution variables, such as Na,SO4.

• Agricultural variables, such as pesticides,herbicides, NO3.

Apart from this distinction according to the typeof waste environment, another dimension can beintroduced by classifying contaminants into fourclasses, namely:

• Physical, such as pH, EC, alkalinity andacidity.

• Aesthetic, such as iron, manganese, odor andtaste.

• Other inorganic, such as high TDS and heavymetals.

• Other organic, such as toxic or carcinogeniccompounds.

Analysis of physical, aesthetic and inorganicvariables is easily performed. Qualitative andquantitative analysis of organic constituents areextremely complex. In view of these complexitiesand the high cost associated with chemicalanalyses, the list of variables to be tested for underthese minimum monitoring requirements, shouldbe kept as short as possible. Once pollution isdetected, more elaborate tests may be performed.The following table suggests minimum monitor-ing requirements for chemical analyses:

PRO-CON

PRO-CON

7: ANALYTICAL VARIABLES


It is up to the discretion of the individual, whichother parameters are to be analyzed for. E. colishould be analyzed for in instances wherebiological contamination is expected. Ammonia,nitrate and nitrite are meaningful parameters toanalyze for in all environments of human and

animal waste. Many modern analyticallaboratories are using multi-element analyticaltechniques such as ion chromatography. In theseinstances, the full chromatographic spectrumshould be considered, on condition that this isavailable at the same price as the requiredindicator constituent.

8: DATA STORAGE, PROCESSING, INTERPRETATION AND REPORTING


Section 8

DATA STORAGE, PROCES-SING, INTERPRETATIONAND REPORTING

8.1 Introduction

Data generated during groundwater qualitymonitoring are of two types, namely:

• Data generated once-off• Data generated during follow-up monitoring.

Typical data that is generated once only are detailson monitoring hole construction, geology,borehole depth and yield from water intersectionsin the hole.

Follow-up monitoring, such as groundwaterlevels, water chemistry, water abstraction fromboreholes, waste composition, tons of wastedisposed of, rainfall, surface run-off andrehabilitation progress constitute by far themajority of the observations to be made.

8.2 Data Storage

The Directorate of Water Quality Management ofthe Department has acquired computerized datastorage facilities, into which all information onwaste disposal facilities may be entered. Thesoftware, Waste Manager, has been developed tomeet South African requirements. This softwareis available from the following WEB site:

ftp://igs-nt.uovs.ac.za/wastemanager

The municipality, industry, power station or minemay also use the Waste Manager software, whichruns on a PC. Information on up to ten wastedisposal facilities, for any one locality, may beentered into the database.

Also available within Waste Manager, arefacilities to table and graph information as well asto report to the Department.

8.3 Processing and Interpretation

Waste Manager also has the capability for dataprocessing and interpretation. This relates mainlyto comparisons of performance between wastedisposal facilities on a regional basis.

The table below provides a breakdown of themain features within the software packages.

For those not using the software package, thefollowing action will be required after eachsampling episode:

• Plot or update line graphs for the followingvariables: tons of waste, population served,water chemistry. Identify trends and anomal-ies. Investigate anomalies.

• Tabulate information according to examplesprovided by the Department in the permit forwaste disposal site.

8.4 Reporting to the Department

Submission of information for incorporation intothe data base at the Department can be done oncomputer diskette by those who have copies ofWaste Manager or by submitting reports,including graphs and tables.

It is essential that the information being reportedto the Department has been checked and evaluatedby the waste disposal company before they submitthe results. Reporting should be six-monthly or atthe frequency prescribed in the waste disposalpermit.

In terms of the above issues, the followingrequirements apply:

Data must be stored in such a way as to be easilyaccessible for to the waste manager and for theDepartment.

Data must be processed and interpreted aftereach sampling exercise.

Reporting frequency to the Department will bespecified in the waste management permitconditions. Otherwise, the reporting frequency issix-monthly.

9: IMPLEMENTATION AND MANAGEMENT


Section 9

IMPLEMENTATION AND MANAGEMENT

9.1 Introduction

A breakdown of the degree of initiative andresponse, which will be required to implement andmanage monitoring facilities in South African are,illustrated below:

Statistics on sites adequately equipped withmonitoring facilities.

Environment Sitesequipped

Routinelymonitored

Mines – Reactive environment 35% 15%Mines – Inert environment 0,5% <0,1%Coal fired power stations 90% 90%General waste 10% 5%Sewage – maturation ponds <0,1% <0,1%Hazardous waste 50% 50%Radioactive waste 100% 100%Underground tanks 1% 1%Waste irrigation 15% 10%Agricultural – feed lots 1% <0,1%Agricultural – diffuse sources 3% <0,1%Septic tanks and pit latrines 1% <0,1%Urban development 1% <0,1%

Note: These are approximate percentages based oninformation available in 1997.

It is encouraging to note that many of theindustries already have, without requirement bylegislation to do so, installed monitoring systemsof their own. Many of them already sample, storeand process information according to standardscompatible with those of the Department.

Implementation and management of monitoringsystems is a formidable task, and can only beaccomplished if all parties concerned co-operate.Four levels of implementation and managementare recognized:

• Public participation• Company level• Local authority level• Governmental level

9.2 Public participation

Public participation has for many years beenignored as input. This has now changed andwithout their participation, success with a ventureof this magnitude cannot be achieved.

9.3 Company level

Monitoring programmes, on a company level, ateach of the waste types described in Chapter 6,should be the first initiative. Individual sites forwaste management within municipal boundaries,with a nominated responsible party, are alsoclassified under this category.

Essential issues are:

• Environmental awareness on companymanagement level.

• Acquisition of qualified people to managewaste facilities and liaise with theDepartment.

• Installation of suitable monitoring systems.• Compliance monitoring, i.e. routine

monitoring by the company, within permitstipulations.

• Remedial action, which is often almostimpossible, is the responsibility of the wastemanagement company.

9.4 Local authority level

Within municipal boundaries, one or more wastemanagement facilities usually exist. These aremunicipal or private dumps, sewage treatmentfacilities and urban water run-off.

The following responsibilities lie with localauthorities:

• Performing an annual survey of all wastemanagement facilities within their boundaries.

9: IMPLEMENTATION AND MANAGEMENT


• Ensuring the waste management companiescomply with waste management permitconditions.

• Co-ordination of waste managementactivities.

• Receiving and evaluation of monitoringreports.

• Planning and co-ordination of future wastedisposal, providing adequate waste disposalfacilities, well in time for the application ofwaste management permits from theDepartment.

9.5 Departmental level

The responsibilities of the Department are:

• To receive and process waste managementpermit applications. To issue waste manage-ment permits.

• To perform routine field checks.• To receive and process monitoring reports.• Possible responses will be: issuing of

acceptance letters; requesting additionalinformation; requesting re-evaluation ofmonitoring systems; requesting contaminantclean-up; requesting a financial bond toguarantee successful clean-up and closure ofthe site.

• To maintain a national computerized database on waste management facilities, whichmay be used for the co-ordination of wastemanagement in South Africa and waterquality management on a local and catchmentlevel.

• To initiate training, guidance, public relationsprogrammes and to provide support for thewaste management community to ensure co-operative and successful management of thewaste stream.

10: SUGGESTED READING MATTER


Section 10

SUGGESTED READING MATTER

The following is a list of reading matter,suggested for individuals or companies wishing tobroaden their knowledge on water qualitymonitoring and the environment. The numbersbelow refer to the different chapters in thisdocument on which the literature has a bearing.

1 Background Information

Council for the Environment, 1989. Integrateenvironmental management is South Africa.ISBN 0-621-12496-6. Council for theEnvironment, Private Bag X447, Pretoria 0001.

Council for Industrial Research (CSIR), 1991.The situation of waste management and pollutioncontrol in South Africa. Report to the Departmentof Environment Affairs by the CSIR programmefor the Environment, Pretoria. Report numberCPE 1/91. CSIR, P O Box 395, Pretoria 0001.

Department of Water Affairs and Forestry, 1997.Policy and strategy for management ofgroundwater quality in the RSA – Water qualitymanagement series. Department of Water Affairsand Forestry, Private Bag X313, Pretoria 0001.

Department of Water Affairs and Forestry, 1998.Minimum requirements for the handling,classification and disposal of hazardous waste.Waste Management Series, Document 1.Department of Water Affairs and Forestry, PrivateBag X313, Pretoria 0001.

Department of Water Affairs and Forestry, 1998.Minimum requirements for waste disposal bylandfill. Waste Management Series, Document 2.Department of Water Affairs and Forestry, PrivateBag X313, Pretoria 0001.

Environmental Protection Agency, 1984.Groundwater protection strategy. EPA, Office ofGroundwater Protection, Washington, DC 20460.

Environmental Conservation Act, No. 73 of 1989.

Minerals Act, No. 50 of 1991.

Water Services Act, No 108 of 1997

National Water Bill, 1998.

2 Mission, policies and strategies forgroundwater quality management

Department of Water Affairs and Forestry,November 1992. Groundwater quality manage-ment policies and strategies for South Africa.Open File Report.

3 South African aquifers

Department of Water Affairs and Forestry –Numerous geohydrological reports are availableupon request, for specific aquifers andmunicipalities using groundwater. Directorate ofGeohydrology, DWA&F, Private Bag X313,Pretoria 0001.

Kok, T.S., 1991. The potential risk ofgroundwater pollution by waste disposal. BiennialGroundwater Convention of the GroundwaterDivision of the Geological Society of SouthAfrica and the Borehole Water Association ofSouthern Africa.

National Groundwater DataBase for South Africa– Point information for more than 100 000boreholes is available from the Directorate ofGeohydrology, DWA & F, Private Bag X313,Pretoria 0001.

Water Research Commission – Manygroundwater research reports, usually of aspecialized nature, are available. WRC, P O Box824, Pretoria 0001.

10: SUGGESTED READING MATTER


4 Risk assessment procedures

Environmental Protection Agency, 1985.DRASTIC - A standardized system for evaluatinggroundwater pollution potential using geohydro-logical settings. EPA-report 600/2-85/018.

Environmental Protection Agency, 1991. WHPA,a modular semi-analytical model for thedelineation of wellhead protection areas, Version2.0. EPA, Office of Groundwater Protection,Washington, DC 20460.

Environmental Protection Agency, 1991.VIRALT, a modular semi-analytical andnumerical model for simulating viral transport ingroundwater. EPA, Office of Drinking Water,Washington, DC 20760.

Parsons, R and Jolly, J., 1994. The developmentof a systematic method for evaluating sitesuitability for waste disposal based ongeohydrological criteria. WRC Report 485/1/94,Water Research Commission, P O Box 824,Pretoria 0001.

4 Facilities for monitoring water quality

Borehole Water Association. Know yourborehole, Borehole Water Association of SouthernAfrica, P O Box 1338, Johannesburg 2000.

Environmental Protection Agency, 1985.Groundwater monitoring strategy. EPA, Office ofGroundwater Protection, Washington, DC 20460

Everett, L.G., 1984. Groundwater monitoring:Guidelines and implementing a groundwaterquality monitoring programme. GeniumPublishing Corporation, N.Y.

Everett, L.G., 1985. Groundwater monitoring:Handbook for coal and oil shale development.Developments in Water Science, No.24, Elsevier,N.Y.

Department of Water Affairs and Forestry.Groundwater – Guideline for Boreholes. DWA &F, Private Bag X313, Pretoria 0001.

Weaver, J.M.C., 1992. Groundwater sampling.Research report to the Water ResearchCommission. ISBN 1 874858 44 6.

6 Indicator variables and chemical analyses

American Public Health Association, APHA,AWWA (1985). Standard methods for theexamination. ISBN 0-87553-131-8.

South African Bureau of Standards (SABS)Methods and specifications for water analyses –Refer to Appendix D of this document. SABS,Private Bag X191, Pretoria 0001.

7 Data storage, processing, interpretationand reporting

Department of Water Affairs and Forestry, 1991.Compliance monitoring manual, Version 2.0.DWA & F, Private Bag X313, Pretoria 0001.

Environmental Protection Agency, 1988. EPAworkshop to recommend a minimum set of dataelements for groundwater. Report number EPA440/6-99-005. EPA, Office of GroundwaterProtection, Washington, DC 20460.

Institute for Groundwater Studies, 1994. WasteManager – A computerized data storage,processing and reporting system. Institute forGroundwater Studies, UOFS, Bloemfontein 9300.

8 Implementation and management

Environmental Protection Agency, 1986.Pesticides in groundwater: BackgroundDocument. Report number EPA 440/6-89-002.EPA, Office of Water, Washington, DC 20460.

Environmental Protection Agency, 1989.Wellhead protection programs: Tools for localgovernments. Report number EPA 440/6-89-002.EPA, Office of Water, Washington, DC 20460.

Environmental Protection Agency, 1990.Progress in groundwater protection andrestoration. Report number EPA 440/6-90-001.EPA, Office of Water, Washington, DC 20460.

APPENDIX A: RISK ASSESSMENT PROCEDURES

_______________________________________________________________________________________Minimum Requirements for Water Monitoring at Waste Management Facilities, Second Edition 1998 AA-1

Appendix A

RISK ASSESSMENT PROCEDURES

The required intensity of monitoring at wastemanagement facilities, in terms of time and space,must be determined before a monitoring system isdesigned. This must be done by performing a riskassessment, determining the risk that the aquiferunderneath and adjacent to a waste managementfacility will be polluted by leachate emanatingfrom the waste. A risk assessment thereforeforms the corner stone of a monitoring systemdesign.

For purpose of standardization, two proceduresare suggested to in this report. These are theWASP and AQUAMOD. Each of theseprocedures is intended for different levels of riskassessment and they follow in succession uponeach other.

WASP (Waste-aquifer separationprocedure)

Parsons and Jolly (1994) have developed theWASP procedure under contract for the WaterResearch Commission (WRC). It is intended tobe used for the calculation of a site-suitabilityindex for waste disposal. The site-suitabilityindex can be viewed in the same sense as the riskof groundwater being polluted from a wastemanagement facility. High site-suitability indicesare associated with high risks of the aquifer beingcontaminated. A computer programme byParsons and Jolly (1994), for the calculation of thesite suitability index, is available from the WRCas part of the report.

The WASP procedure, has developed for theWRC, is intended only for general and hazardouswaste. It should be adapted to include otherwastes also considered in this document. Itconsists of a threefold evaluation. Step onerelates to the waste itself. Following this, thezone or barrier between the waste and theunderlying aquifer is evaluated. This includes anevaluation of the soil. Lastly, the aquifer itself isevaluated. In general terms, this risk assessmentis an evaluation of the risk associated with the

vertical seepage of leachate, from the waste intothe aquifer.

Within each of these components, severalsubcomponents are embedded.

In the case of the waste itself, there aresubcomponents such as the toxicity and tonnageof waste. In terms of waste toxicity, it issufficient to classify waste into broader classes,such as garden and building rubble; domestic;domestic and industrial; domestic and liquid; andhazardous. In specific instances, toxicity tests bymeans of bio-assaying, may be conducted.

In terms of the unsaturated barrier zone betweenthe waste and the aquifer, subcomponents such asthickness, hydraulic conductivity and porosity –all relating to the rate at which leachate canpermeate through the barrier zone to reach theaquifer are considered. While the thickness of theunsaturated zone can be ascertained in the fieldthrough drilling, it is generally more difficult toobtain accurate assessments of the hydraulicconductivity and porosity distribution. TheWASP evaluation makes provision for the level ofaccuracy to which a parameter value is known. Itshould therefore be possible to perform theevaluation on estimated values for a start. Theadvantage of doing this lies in the ease with whichseveral areas can be compared with each other, tomake a semi-educated selection for furtherinvestigation.

The risk within the aquifer is quantified byconsidering issues such as the present use,potential for future use and the availability ofalternative water sources.

All of these components are finally related to eachother by extracting a single numeric value thatrepresents the risk of an aquifer being affected bywaste disposal. The higher the score, the greaterthe risk. As a guideline, the following range ofvalues and the associated risk for to the aquifer issuggested:

APPENDIX A: RISK ASSESSMENT PROCEDURES

_______________________________________________________________________________________Minimum Requirements for Water Monitoring at Waste Management Facilities, Second Edition 1998 AA-2

Score Risk Rating<4,0 Very Low

4,0-5,4 Low5,5-6,8 Medium6,9-8,2 High>8,3 Very High

The above scale should be taken as a firstapproximation of the potential risk to pollute theunderlying groundwater resources. The onusremains on the waste manager to prove that thesystem is adequately monitored.

In terms of monitoring, the intensity to whichmonitoring has to be done is directly related to therisk that a waste site may pollute an aquifer. Thefirst step towards the design of a monitoringsystem is therefore to perform the above riskassessment. Sites with low risks will have toinstall the minimum number of monitoringboreholes, as indicated in Table 6.2. Sites withhigh risks will have to be evaluated extensivelyand all the recommended monitoring devices willhave to be installed.

For more information, it is recommended that thereaders obtain the complete documentation andprogramme on the WASP procedure from theExecutive Director, WRC, P O Box 824, Pretoria0001.

Alternatively, this software can be obtained byaccessing the following WEB site:

ftp://igs-nt.uovs.ac.za/wasp

Numerical modelling

Numerical modelling of pollution transportthrough an aquifer is done on a routine basis bygeohydrologists. Any of a variety of models maybe used. It is a requirement that modellers shoulddemonstrate their competence in the modelling ofgroundwater systems, otherwise the DWA&F willnot accept results from simulations.

AQUAMOD is a mass transport model capable ofsimulating pollution transport through an aquifer.This software is available, free of charge from thefollowing WEB site:

ftp://igs-nt.ouvs.ac.za/aquamod

Extensive field surveys are necessary to generatedata of sufficient quality and magnitude for inputinto models of this kind. These models shouldtherefore only be used in instances of extremecomplexity and high risk.

Outputs from these models are usually in the formof particle tracking vectors or contours that showconcentrations of various elements within theleachate plumes. Since these predictions are timedependent, simulations of the propagation ofpollution plumes, many years in advance, may bedone.

Groundwater contours, flow directions andvelocities due to abstraction of groundwater fromfour boreholes.

Simulated pollution transport and dispersion froma waste facility during abstraction of groundwater.

APPENDIX B: BOREHOLE WATER SAMPLING

_______________________________________________________________________________________Minimum Requirements for Water Monitoring at Waste Management Facilities, Second Edition 1998 AB-1

Appendix B

BOREHOLE WATER SAMPLING

A summary of sampling techniques is presentedbelow. For further information, the reader isreferred to the manual on groundwater samplingby Weaver (1992).

Sampling of water from unequipped boreholes is atedious and difficult task. Two methodologiesmay be considered, namely stratified sampling orcomposite sampling.

Stratified Borehole Water Sampling

Stratified sampling is done by removing a smallvolume of water from specific depths within aborehole. A prerequisite for stratified sampling isnot to disturb the water column unduly whiletaking the sample. The intention of stratifiedsampling is to determine the vertical distributionof water quality within a borehole, thusidentifying horizons where pollution enters into aborehole.

In cases which inorganic pollution is dominant, itmay be possible to determine the need and detailof stratified sampling by first carrying out anelectrical conductivity (EC) profile in theborehole.

Several models of stratified samplers arecommercially available. The pneumatic sampleris recommended for South African conditions. Itconsists of a sampling cylinder with a non-returnvalve at the bottom. The cylinder is connected totwo hydraulic tubes. One of the tubes leads t apressurized gas bottle, while the other tube is usedto obtain the water sample.

Procedures for sampling water are as follows:

1. Rinse the sampler and tubes on surface andmake sure that everything works well.

2. Lower the pneumatic sampler to apredetermined depth in the borehole.

3. Pressurize the sampler and flush out any waterwithin the sampler and tubes.

4. Release pressure on the sampler and wait 30seconds for the sampler to refill with water.

5. Pressurize the sampler and collect the watersample from the exit tube.

6. Preserve sample according to suggestions inAppendix C and submit for analysis to arecognized analytical facility.

7. Repeat procedure from number 2 above firsamples from greater depths.

In more than 90% of instances, pollution in SouthAfrican aquifers usually enters boreholes throughfractures in the rock. Stratified sampling thereforeconstitutes an important component in theunderstanding of the distribution of contributingfractures in the aquifer below waste sites.

Composite Borehole Water Sampling

Composite water sampling is usually done bypumping water from a borehole. Procedures forcomposite sampling are as follows:

1. Activate the pump and remove (purge) atleast three times the volume of watercontained in the hole.

2. Collect a water sample.

3. Preserve sample according to suggestions inAppendix C and submit for analysis to areputable analytical facility.

Various types of pumps may be used. Two typesthat may be considered, because of their ease ofinstallation, are the submersible pump and thebladder pump.

Submersible pumps are available throughoutSouth Africa. Even small submersible pumps arecapable of delivering 1,0 litres per second.

APPENDIX B: BOREHOLE WATER SAMPLING

_______________________________________________________________________________________Minimum Requirements for Water Monitoring at Waste Management Facilities, Second Edition 1998 AB-2

Pumpage for 15-20 minutes, before taking asample, should therefore be sufficient in mostinstances. Submersible pumps are recommendedfor the municipality or industry, doing their ownsampling.

Bladder pumps are smaller and easier to install.Yield from these pumps is small and it usuallytakes more than 60 minutes before arepresentative composite sample may be obtained.Bladder pumps are not freely available is SouthAfrica and need to be specially imported.Consulting companies, doing sampling of manydifferent boreholes on a regular basis, mayconsider acquiring bladder pumps, because oftheir ease of use.

Where low-yielding monitoring boreholes areinevitable, removal of the dead volume bypumping could leave the borehole dry. In such

instances, a sample should be taken of the newlyaccumulated groundwater after recovery or partialrecovery of the water level in the borehole. Inextreme cases, it may be necessary to revisit sucha monitoring position a day or more after havingpurged the hole.

Recommendations

• Municipalities and industries performing theirown sampling on a routine basis, shouldperform composite sampling.

• Groundwater consultants and others interestedin the mechanism through which pollutionmay enter into a borehole should consider theneed for performing stratified sampling.

APPENDIX C: SAMPLE FREQUENCY AND PRESERVATION

_______________________________________________________________________________________Minimum Requirements for Water Monitoring at Waste Management Facilities, Second Edition 1998 AC-1

Appendix C

SAMPLE FREQUENCY AND PRESERVATION

Sample bottles and filters

Bottles of plastic, with a plastic cap and no linerwithin the cap are required for most samplingexercises.

Glass bottles are required if organic constituentsare to be tested for.

Such bottles and instructions for samplepreservation should be obtained from theanalytical laboratory.

Sample Frequency

Where waste management permits are issued, theminimum sampling frequency will be prescribed.

In other instances, the following guidelines maybe adhered to:

Groundwater

Groundwater is a slow-moving medium anddrastic changes in the groundwater compositionare not normally encountered within days. Thefrequency, with which water samples are to betaken from groundwater access points, is thereforea function of the sampling objectives.

At any groundwater sampling facility, whetherpermitted or non-permitted, initial samplingshould be done at a frequency high enough toobtain statistically valid background information.For any long-term monitoring facility, three initialsampling exercises, all within 90 days and not lessthan 14 days apart, are suggested.

Depending on the variation amongst these values,future sampling may be planned. A three-monthlysampling frequency will in most instances besufficient.

Surface water

At the other end of the scale lies surface waterchemistry. Surface water chemistry may changewithin minutes, depending on controlled oruncontrolled discharges. The frequency forsurface water quality monitoring should thereforerange from several times a day to weekly.

Continuous monitoring of the discharged flowvolume and quality (be electrical conductivitymethod), is required in instances where pollutedwater is disposed of into a public stream.

Sample Preservation

Where indicated in the table below, samples mustbe preserved.

Sample preservation techniques for various testsvary significantly. The person responsible shouldcheck with the analytical laboratory to ensure thatthe preservation method meets their analyticalrequirements.

The samples should be sufficiently large tofacilitate duplicate analyses.

It is a minimum requirement that samples bepreserved according to specifications in thisdocument.

APPENDIX C: SAMPLE FREQUENCY AND PRESERVATION

_______________________________________________________________________________________Minimum Requirements for Water Monitoring at Waste Management Facilities, Second Edition 1998 AC-2

Minimum requirements for water sample preservation

VARIABLE ACTION

Carbon dioxideChloride – residualDissolved oxygen

pH

Analyze immediately

Elect. ConductivityAcidity

AlkalinityBOD

ColourChromium (VI)

NitriteSilica

Sulphate

No additives.Refrigerate.

Analyze as soon ascan reasonably be

achieved

BoronBromideChlorideFluoride

PotassiumSodium

Analyzewhen

convenient

HardnessMetals (general)

Filter in field.Add NHO3 to pH<2

CODGrease and oil

Nitrogen – NH4

Nitrogen – NO3

Nitrogen – OrganicPhenols

TOC

Add H2SO4 to pH>2

Cyanide Add NaOH to pH>12

Sulphide Add 4 drops 2Nzinc acetate/100 ml

No preservatives are required if the sample is to be analyzed within 6 h.Samples should always be stored or transported at temperatures around 4 degrees centigrade

APPENDIX D: ANALYTICAL PROCEDURES

_______________________________________________________________________________________Minimum Requirements for Water Monitoring at Waste Management Facilities, Second Edition 1998 AD-1

Appendix D

ANALYTICAL PROCEDURES

This chapter is of a technical nature and the readeris referred to the references in the back of thisdocument for more information on the exactanalytical procedures.

Analytical procedures differ greatly fromlaboratory to laboratory. These range from well-documented so-called wet methods to the moresophisticated automated and computerizedprocedures.

Methods commonly used are:

• Titration against indicators, for pH andchloride.

• Specific ion electrode measurement for pHand fluoride.

• Spectrophotometric determination, for nitrateand COD.

• Turbidity measurement, for sulphate andturbidity.

• Conductivity measurement, for electricalconductivity.

• Ion chromatography (IC), for the anions.• Atomic adsorption (AA) – flame and carbon

furnace, for the cations.• Inductively coupled plasma (ICP), for the

cations.• Gas chromatography (GC), for organic

compounds.• Mass spectrometer (MS), coupled with IC or

ICP, for speciation of organic and inorganicsubstances.

• Other specialized and dedicated procedures,such as dissolved oxygen.

Each of the above analytical procedures representsdifferent levels of sophistication. The following isa brief discussion of the various procedures thatare generally available.

SABS

The SABS has drawn up a list of unsophisticatedanalytical procedures. The variables, which maybe tested for, as well as the numbers for the

analytical procedures, are listed below. Details onthese procedures are available form the SABS,upon request. It is recommended that anyoneinterested in setting up small-scale analyticalfacilities for water should consider, first of all, theuse of these well-proven methodologies.

SABS Method Reference List

1. PHYSICAL

DETERMINAND METHODREFERENCE

Colour SABS 198Conductivity SABS 1057Dissolved solids @ 180°C SABS 213Dissolved solids @ 550°C SM 2540 (E)Suspended solids @ 105°C SABS 1049Total solids @ 105°C SM 2540 (B)Total solids @ 550°C SM 2540 (E)Taste and odour SABS 241 3.3Turbidity SABS 197

2. INORGANIC (NON-METALLIC)


Acidity SM 2310

Alkalinity SM 2320Boron SABS 1053Chloride SABS 202

Chlorine (residual) SABS 1052Cyanide (qualitative) SM 4500 – CN/KCyanide (total-quantitative) SABS 204

Fluoride SABS 205Nitrogen:Ammonia – N SABS 217

Kjeldahl – N SM 4500 – N/BNitrate + nitrite – N SABS 210Nitrite – N SM 4500 – NO2

pHPhosphate:Ortho-phosphate SABS 1055

Total phosphate SM 4500 – P/BSilica SM 4500 – Si/DSulphate SM 4500 – SO4/E



Sulphide SABS 1056

3. INORGANIC (METALLIC)


Aluminium SABS 1169Antimony ASTM D 3697Arsenic SABS 200

Cadmium SABS 201Calcium SABS 216Chromium SABS 1054

Chromium (VI) SABS 206Cobalt SABS 1170Copper SABS 203

Iron SABS 207Lead SABS 208Magnesium SABS 1071

Manganese SABS 209Mercury SABS 1059Nickel SABS 1171

Potassium SM 3500 – K/DSelenium SABS 1058Sodium SABS 1050

Zinc SABS 214

4. ORGANIC


Chemical oxygen demand SABS 1048Oil and grease SABS 1051Oxygen absorbed SABS 220Phenolic compounds SABS 211Surfactants (anionic) – MBAS SABS 199

5. SPECIFICATIONS

TITLE METHODREFERENCE

Water for domestic supplies SABS 241-1984

Prepackaged analytical procedures

Also available commercially and based on prin-ciples similar to those of the SABS, are ready

packed liquids, pellets and paper strips, containingexact amounts of reagent required for ameasurement. These facilities are particularlyuseful for use in the field. The advantage of usingthese prepackaged facilities is that nostandardization or calibration is usually required,thus eliminating human error.

Automated equipment

Many types of automated equipment for wateranalysis exist. Most of this equipment iscomputer controlled and operates efficiently.Typical such systems would include automatedwet techniques, AA, ICP, IC, GC and MS.

All of this equipment is expensive and typicallyprices range from R100000 to R2000000 (1997).

Advantages of using these automated techniquesare:

• High throughput of samples. Typicalanalytical times per determination are: IC (1min); AA (<2 min.); ICP (<20 sec.).

• High repeatability.• Detection limits for many of these automated

techniques are orders lower than are those forwet techniques.

Several such automated laboratories presentlyexist in South Africa.

Disadvantages of using these automatedtechniques are:

• High cost of equipment.• The specialized training required for handling

the equipment.

Practical tips

pH

The pH measurement should preferably be doneas the sample is taken. However, pH probes aresensitive pieces of equipment and high turbidity inwater may soon clog the



probe, thus rendering it useless. Because of thisclogging, average life of a glass pH probe, used onan everyday basis in the field, is of the order of 3months. Daily calibration is also required. Inroutine measurements, it is usually sufficient todistinguish between acid, neutral or alkalinewater. For that purpose, the use of pH paper isrecommended.

Electrical conductivity

Electrical conductivity is measured in milli-Siemens per metre. These measurements are fast,cheap and an easy way of determining theapproximate salt concentration in water. Bymultiplying the electrical conductivity value by afactor of between 6–9, the total salt concentrationmay be estimated. The significant range for themultiplication factor is ascribed to the variousconductance factors for different constituents inthe water. Chloride typically has a highconductance (factor 6), while sulphate has a muchlower conductance (factor 9).

Alkalinity and acidity

Alkalinity and acidity values may change rapidlyafter groundwater samples have been withdrawnfrom confined aquifers. For accuratemeasurements, these variables should therefore bemeasured in the field, immediately after thesample has been taken.

Alkalinity and acidity determinations involvetitration of the water, using sulphuric acid, to pHend points of 8,3 and 4,5 respectively. Adding pHindicators to the water could assist detection ofthese end points. However, handling of strongacids in the field could be cumbersome and it isrecommended that, for general applications, thesedeterminations should rather be done within 6hours, in a laboratory. Samples should be storedat 4 degrees centigrade.

Macro cations

Ca, Mg, Na and K usually occur in significantamounts in groundwater. Although wettechniques are available for their determination,AA or ICP are preferable. Wet determination ofparticularly Ca and Mg is based on the indirect

EDTA method, through which calcium andmagnesium hardness is measured. From this, theconcentration of elemental Ca and Mg is thencalculated. This method is not advisable.

Heavy metals

The term heavy metal refers to the metals andmetalloids in the periodic table, with the exceptionof the macro cations, listed above. Since theseelements usually occur in trace quantities,accurate and sophisticated analytical equipment isrequired. AA (carbon furnace) or ICP proceduresare recommended. Modern carbon furnaceequipment allows pre-concentration of elementsthrough multiple injection, and extremely lowconcentrations can be detected. A sequential ICP,coupled with a hydride generator, can also detectheavy metals at satisfactorily low levels.

Anions

A complete scan of the anions present in water (F,Cl, NO2, Br, NO3, PO4 and SO4) can be obtainedwithin 10 minutes or less, by using IC equipment.Detection limits range from less than 1ug/1 tomore than 1 000 mg/l.

Only two limitations may apply – organiccompounds in the water may interfere with thepeak reading for fluoride and a multipointcalibration is necessary for accurate work over awide range of concentrations.

Organic compounds

Analysis for unknown organic compounds is verydifficult, because of the vast range of constituentsthat may be present. The use of GC equipment forroutine analysis of waste of unknown compositionis therefor not feasible. At best, certain probablecompounds, which may be present within thewaste, can routinely be tested for.

MS enables specification of the compounds andintensive effort usually results in recognition andquantification of the compound involved.

Both GC and MS work are highly specialized andexpensive procedures.



Analytical costs

It is expensive to have water analyzed. Typically,a single determination may range from R 5 toR 10000, depending on the complexity of thedetermination. Below is a listing of variablescommonly measured, and their relative costs(1997):

Electrical conductivity R 5 – R 10pH R 6 – R 12

Macro cations per ion R 10 – R 28Anions per ion R 10 – R 30Oxygen absorbed R 10 – R 20

Fluoride R 15 – R 20Chemical oxygen demand R 15 – R 30Ammonia (N) R 15 – R 25

Heavy metals per ion R 15 – R 40Phenol R 150 – R 200Cyanide (quantitative) R 300 – R 400

GC and MS work R 1000 – R 10000

It is often even more expensive to collect samplesfor the field. The number of samples and thevariables to be tested for, should therefore beselected carefully. The scope of an investigationshould therefore be spelt out, before samplingcommences. This will dictate:

• The samples to be taken• The elements to be analyzed• The sampling frequency.

A well-planned monitoring and samplingprogramme will save money in the long run.

APPENDIX E: DATA INTERPRETATION WITH WASTEMANAGER

_______________________________________________________________________________________Minimum Requirements for Water Monitoring at Waste Management Facilities, Second Edition 1998 AE-1

Appendix E

DATA INTERPRETATION WITH WASTEMANAGER

Detailed account of the usage of statisticalmethods is given in a document on compliancemonitoring published by the Department. Otherfacilities for the interpretation of water qualitydata exist within Waste Manger. These includeline and bar charts, or plots of borehole and waterlevel information. Some of these methodologiesare less well known. These are, for instance, thespecialized chemical diagrams, such as the Piperand Expanded Durov Diagrams.

Piper and

Expanded Durov Diagrams

The Piper and Expanded Durov Diagrams allowfor the plotting of eight chemical variables for asingle water sample. Either surface orgroundwater chemistries may be plotted.

The procedure is as follows:

• Calculate concentrations for Ca, Mg, Na, K,Cl, SO4, NO3, T. Alk. In units of milli-equivalents per litre.

• Calculate relative percentages for the cationsand anions.

• Plot the percentages cations in the bottom lefttriangle.

• Plot the percentages anions in the bottom righttriangle.

• Project the two points to the central block onthe Piper or Durov Diagrams and make amark where the two projections cross.

Interpretation is as follows:

• It is a matter of personal preference whetherthe Piper of Durov Diagrams are used.

• Both diagrams should primarily be used asvisual displays, summarizing the chemistry ofall samples taken at a single site or at manysites.

• Of particular value is the identification ofpollution trends, through the aid of these

diagrams. A comparison between plots ofsuccessive sampling exercises will showwhether or not trends in the chemistry of thewater are developing. Trends to observe are:

1) Sodium enrichment – typical ofprocesses such as waste waterdischarge, chemical extraction ofelements from ore, dewatering ofdeep mines, return flow fromirrigation or natural deterioration ofthe groundwater quality by ionexchange within the aquifer.

2) Sulphate enrichment – typical of mostmining environments.

3) Calcium enrichment – typical of limedosing to neutralize acid water.

4) Chloride enrichment – typical ofleachate from domestic waste anddewatering of deep mines.

A word of caution though: groundwater chemistryis one of the most complex natural systems topredict, because of the many processes/variablesthat could affect it. The following are but a fewexamples of chemical changes that could occurwithin an aquifer:

• Dissolution of soluble elements, such as Na,K, Cl and HCO3.

• Precipitation of oversaturated species.• Ion exchange and adsorption onto clays, such

as Ca-adsorption and Na-release.• Chemical reaction between two waters

mixing.• Natural decay of substances, such as modern

pesticides.• Bacterial oxidation/reduction, such as pyrite

oxidation and sulphate reduction.

The specialized diagrams and other techniques forthe interpretation of the data, included withinWaste Manager, may be used to identify trends.If undesirable pollution trends become obvious, itshould be left to the geohydrologist for detailedinterpretation.



Plot of water containing: 50% Ca, 35%Mg, 15% Na+K 80% T.Alk. 10% Cl and 10% SO4

Ca NaT. Alk.

SO4

Cl

Unpolluted water

Opencast coal mine water

Waste water discharge Irrigation return flow

High extraction underground coal mines

Vanadium extraction Gold mine water

Power stations

Domestic waste dumps Natural saline water

Deep mine water

Lime treatment of acid water

Unpolluted water

Seldom found

Seldom found

Examples of typical plotting positions on the Expanded Durov Diagram, for water from various environments

Ca Na+K T. Alk. Cl+NO3 Ca Na+K T. Alk. Cl+NO3

Mg SO4

.

.

. Mg SO4

Mine pollution

Sodium enrichment

Chloride enrichment

Unpolluted groundwater

Unpolluted groundwater

Calcium/magnesium bicarbonate waters Sodium bicarbonate/ chloride waters Sodium chloride waters Calcium/sodium sulphate waters

Legend

Mg

Plotting procedure on the Piper Diagram Examples of typical plotting positions on the Piper Diagram, for water from

various environments



A word of caution though: groundwater chemistryis one of the most complex natural systems topredict, because of the many processes/variablesthat could affect it. The following are but a fewexamples of chemical changes that could occurwithin an aquifer:

• Dissolution of soluble elements, such as Na,K, Cl and HCO3.

• Precipitation of oversaturated species.

• Ion exchange and adsorption onto clays, suchas Ca-adsorption and Na-release.

• Chemical reaction between two watersmixing.

• Natural decay of substances, such as modernpesticides.

• Bacterial oxidation/reduction, such as pyriteoxidation and sulphate reduction.

The specialized diagrams and other techniques forthe interpretation of the data, included withinWaste Manager, may be used to identify trends.If undesirable pollution trends become obvious, itshould be left to the geohydrologist for detailedinterpretation.

APPENDIX F: SUMMARY OF REQUIREMENTS

_______________________________________________________________________________________Minimum Requirements for Water Monitoring at Waste Management Facilities, Second Edition 1998 AF-1

Appendix F

SUMMARY OF REQUIREMENTS

Minimum requirement

• The lower limit which must be complied with.The right to appeal against compliance withthe prescribed minimum requirements, basedupon sufficient motivation, exists.

Monitoring

• The meaningful measurement of a variable(s)on a once-off basis during initial impactassessments, or on a routine basis.

• Table 6.1 lists requirements against variouswaste management activities. Also indicatedon this table is a frequency for monitoring.Table 6.2 provides details on monitoringnetworks.

Waste Management Facility

• All wastes or products stored on a temporaryor permanent basis, that could impact onsurface or groundwater quality, by leachinginto or coming in contact with water. Seealso Waste Management Documents,“Minimum requirements for waste disposalsites” and “Minimum requirements for thehandling and disposal of hazardous waste”

Expertise required

• The installation of groundwater monitoringsystems requires specialized knowledge, andconsultation with an appropriately qualifiedgeohydrologist is a requirement.

Monitoring Network

• Monitoring networks must extend beyondzones of impact.

Aquifer Classification

• It is a requirement that all future wastefacilities be sited on Poor Aquifer Regions. In

the event that this is not possible, a riskassessment and extensive motivation shouldbe submitted to the Department forconsideration.

Risk Assessment

• A risk assessment, to determine the risk ofwater being polluted, must be performed at allwaste sites before the installation of amonitoring system. This is to ensure that thedesign of the monitoring system is adequate.The prescribed methodology for riskassessment is included in Appendix A.

• It is a requirement that modellers shoulddemonstrate their competence in themodelling of groundwater systems, otherwisethe DWA & F will not accept results fromsimulations.

Rainfall

• Rainfall for the past 24 hours must berecorded at 8h00 every morning.

Evaporation potential

• The measurement of pan evaporation is only arequirement at hazardous disposal sites.

Run-off

• Run-off quantities and qualities must berecorded continuously, when specified in thepermit. Leachate Collection/Toe Seepage.

• Samples must be collected, preserved andanalyzed according to specifications in thismanual.

Rehabilitation

• Rehabilitation on top of waste must be doneas soon as is reasonably possible.



Borehole data

Data required from boreholes are:

• Geological log.• Water intersections (depth and quantity).• Construction information (depth of hole and

casing, borehole diameter, method drilled,date drilled).

• Use of borehole water, if not solely formonitoring; frequency of abstraction;abstraction rate and whether other watersources are readily available.

• Water quality (see chapter on chemicalanalyses).

Borehole type

• Borehole must be drilled by a drillingtechnique that will not introduce pollutioninto the aquifer.

Hole diameter

• Monitoring boreholes must be of a diameterthat will allow easy access to the aquifer, forthe purpose of water sampling and forlowering other test instruments.

Hole depth

• A monitoring hole must be such that thesection of the groundwater most likely to bepolluted first is suitably penetrated, to ensurethe most realistic monitoring results.

Casing, screens and filters

• The materials used for casing, screens andfilters in contact with water must becompatible with, and resistant to chemicalattack by, the water being monitored.

• Casing, screens and filters must allow easyaccess for monitoring purposes and may in noway block the flow of water through theborehole.

• A security cap must be fitted to preventaccidental or willful interference with amonitoring borehole.

• Required minimum dimensions for theconcrete block are 750 mm x 750 mm x 150mm.

Piezometer tubes

• Piezometer tubes must allow easy access forwater sampling over the whole of the aquifer.

Borehole protection

• Monitoring boreholes must be adequatelyprotected to prevent accidental damage of theholes.

Groundwater levels

• Groundwater levels must be recorded withinan accuracy of 10 cm using an electricalcontact tape, float mechanism or pressuretransducer.

Pumping and/or packer tests

• Where considered necessary by thegeohydrologist or design engineer, pumpingand/or tests must be carried out on boreholesto obtain additional data on thegeohydrological conditions at that particularposition.

Fountains, wells, dams, pans, streams andrivers

• Water sources around a waste managementfacility, within a radius as suggested by therisk assessment, must be sampled andpreserved for chemical analysis.

• Flow from fountains and in streams must beestimated. If pollution occurs as a result ofwaste managing, then the Department mayrequest continuous recording of flow andwater quality.

Water/salt balances

• Water/salt balances: In instances whereexcess water is present and this water mayhave to be discharged into public streams,water and salt balances are required. Atlarger complexes such as mines, powerstations or large industries, this usuallyimplies water and salt balances for each ofthe contributing components, such as for rawwater intake; for materials brought onto,



removed from or disposed of on site; and forrainwater contribution and run-off.

Monitoring Networks

• Monitoring networks at waste managementfacilities must allow monitoring of the systemon a representative basis (see Table 6.2).

• Local monitoring networks should extendbeyond pollution plumes to allow for thedelineation of plumes and investigations intothe pollution migration rate.

Water sampling

• Water from monitoring positions must besampled according to proceduresprescribed in Appendices B and C.

Sample bottles and filters

• Bottles of plastic, with a plastic cap and noliner within the cap are required for mostsampling exercises.

• Glass bottles are required if organicconstituents are to be tested for.

Sample Preservation

• It is a minimum requirement that samples bepreserved according to specifications in thisdocument.

Sample Frequency

• Where waste management permits are issued,the minimum sampling frequency will beprescribed.

• At any groundwater sampling facility,whether permitted or non-permitted, initialsampling should be done at a frequency highenough to obtain statistically validbackground information. For any long-termmonitoring facility, three initial samplingexercises, all within 90 days and not less than14 days apart, are suggested. Depending onthe variation amongst these values, futuresampling may be planned. A three-monthlysampling frequency will in most instances besufficient.

Surface water

• Continuous monitoring of the discharged flowvolume and quality (by electrical conductivitymethod) is required in instances wherepolluted water is disposed of into a publicstream.

Analytical variables

• A recognized analytical laboratory that usesapproved analytical procedures must analyzewater samples.

• In instances where permits have been issued,permit conditions will specify the frequency ofanalyses and constituents to be tested for.

• For all new sites and first time monitoring atexisting sites, a comprehensive analysis isrequired.

• Indicator analysis may be performed oncecomprehensive analyses have been completed.This process may continue until undesirabletrends are uncovered.

Reporting to the Department

• Data must be stored in such a way as to beeasily accessible for to the waste managerand to the Department.

• Data must be processed and interpreted aftereach sampling exercise.

• Reporting frequency to the Department willbe specific in the waste management permitconditions. Otherwise, the reportingfrequency is six-monthly.

The following actions arerecommended

Public participation

Public participation has for many years beenignored as input. This has now changed andwithout their participation, success with a ventureof this magnitude cannot be achieved.

Company level

Monitoring programmes, on a company level, ateach of the waste types described in Chapter 5,



should be the first initiative. Individual sites forwaste management within municipal boundaries,with a nominated responsible party, are alsoclassified under this category.

Essential issues are:

• Environmental awareness on companymanagement level.

• Acquisition of qualified people to managewaste facilities and liaise with theDepartment.

• Installation of suitable monitoring systems.• Compliance monitoring, i.e. routine

monitoring by the company, within permitstipulations.

• Remedial action, which is often almostimpossible, is the responsibility of the wasteManagement Company.

Local authority level

Within municipal boundaries, one or more wastemanagement facilities usually exist. These aremunicipal or private dumps, sewage treatmentfacilities and urban water run-off.

The following responsibilities lie with localauthorities:

• Performing an annual survey of all wastemanagement facilities within their boundaries.

• Ensuring that waste management companiescomply with waste management permitconditions.

• Co-ordination of waste managementactivities.

• Receiving and evaluation of monitoringreports.

• Planning and co-ordination of future wastedisposal, providing adequate waste disposalfacilities, well in time for the application ofwaste management permits from theDepartment.

Departmental level

The responsibilities of the Department are:

• To receive and process waste managementpermit applications. To issue wastemanagement permits.

• To perform routine field checks.• To receive and process monitoring reports.

Possible responses will be: issuing ofacceptance letters; requesting additionalinformation; requesting re-evaluation ofmonitoring systems; requesting contaminantclean-up; requesting a financial bond toguarantee successful clean-up and closure ofthe site.

• To maintain a national computerized database on waste management facilities, whichmay be used for the co-ordination of wastemanagement in South Africa and waterquality management on a local and catchmentlevel.

• To initiate training, guidance, public relationsprogrammes and to provide support for thewaste management community to ensure co-operative and successful management of thewaste stream.