Geohydrological and Engineering Geological investigation at the ... · dolerite could be observed in close proximity to the project area and the presence of a prominent non-perennial

Technical Report 2012/06/06/GENV

Geohydrological and Engineering Geological investigation at the existing Harding Landfill Site

Prepared for: USK Consulting

Environmental and

Waste Engineering

Final Report

June 2012

Technical Report: 2012/06/06/GENV

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Prepared by

Technical Report: 2012/06/06/GENV

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Geohydrological and Engineering Geological investigation at the existing Harding Landfill Site

21 June 2012

Prepared For:

USK Consulting Environmental and Waste Engineering 23 Ray Craib Cr. Beacon Bay East London 5241

Compiled By:

WS Blay (BSc Hons, Geohydrology)

Project Team:

J. A Myburgh (BSc Hons, Geology) Pr.Sci.Nat

W. S Blay (BSc Hons, Geohydrology)

O. K Skenjana (BSc. Hons, Environmental Geology)

H. Briel (GIS & Data)

F. N De Jager (BSc Hons, Engineering Geology) Pr.Sci.Nat

EASTERN CAPE PROVINCE: 10 Sansom Road, Vincent East London, Postnet 203, Private Bag X9063, East London,5200 Tel: +27-(0)43-726 2070 Fax: +27 (0)43 726 9232 www.ages-group.com

Offices: Eastern Cape Gauteng Limpopo Province Namibia North-West Province Western Cape Zimbabwe

AGES Board of Directors: SJ Pretorius JA Myburgh JJP Vivier JH Botha THG Ngoepe SM Haasbroek R Crosby

JC Vivier FN de Jager AS Potgieter DP van der Westhuijzen AGES Eastern Cape Directors: JA Myburgh FN de Jager J Clark

USK Consulting – Harding Landfill Site Geohydrological and Engineering Geological Site Investigation

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REPORT DISTRIBUTION LIST

Name Institution

Mr Steve Kalule USK Consulting Environmental and Waste Engineering

DOCUMENT HISTORY

Report no Date Version Status

2012/06/06/GENV 21 June 2012 1.0 Final Report


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Although AGES (Pty) Ltd exercises due care and diligence in rendering services and preparing documents, AGES (Pty) Ltd accepts no liability, and the client, by receiving this document, indemnifies AGES (Pty) Ltd and its directors, managers, agents and employees against all actions, claims, demands, losses, liabilities, costs, damages and expenses arising from or in connection with services rendered, directly or indirectly by AGES (Pty) Ltd and by the use of the information contained in this document.

This document contains confidential and proprietary information of AGES (Pty) Ltd and is protected by copyright in favour of AGES (Pty) Ltd and may not be reproduced, or used without the written consent of AGES (Pty) Ltd, which has been obtained beforehand. This document is prepared exclusively for USK Consulting Environmental and Waste Engineering and is subject to all confidentiality, copyright and trade secrets, rules, intellectual property law and practices of South Africa.


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LIST OF ABBREVIATIONS

Abbreviation Description

DRIT Double Ring Infiltration Test

EC Electrical Conductivity

K Hydraulic Conductivity

MAE Mean Annual Evaporation

MAP Mean Annual Precipitation

MAR Mean Annual Runoff

MBGL Meter Below Ground Level (i.e. depth)

mS/m milliSiemens / meter

SWL Static Water Level

T Transmissivity

WWTW Wastewater Treatment Works


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Table of contents

1 INTRODUCTION .................................................................................................. 1

1.1 TERMS OF REFERENCE ............................................................................................... 1

1.2 SCOPE OF WORK........................................................................................................ 1

1.3 PROJECT AREA AND LOCATION .................................................................................... 1

1.4 AVAILABLE INFORMATION ............................................................................................ 2

2 SITE DESCRIPTION ............................................................................................ 4

2.1 GEOLOGICAL SETTING ................................................................................................ 4

2.2 HYDROGEOLOGICAL SETTING...................................................................................... 5

3 RESULTS ............................................................................................................ 6

3.1 GENERAL .................................................................................................................. 6

3.2 GENERALISED SOIL CONDITIONS ................................................................................ 6

3.3 LABORATORY TESTING ............................................................................................... 7 3.3.1 Hillwash Material ............................................................................................................... 8 3.3.2 Ferruginised Residual Siltstone Material ........................................................................... 8 3.3.3 Siltstone Bedrock Material ................................................................................................. 9

3.4 SOIL PERMEABILITY ................................................................................................. 10

3.5 POSITION IN RESPECT OF DOMESTIC WATER SUPPLY .................................................. 11

3.6 GEOPHYSICAL PROFILING ......................................................................................... 14

3.7 SITE HYDROGEOLOGY .............................................................................................. 16

3.8 AQUIFER TESTING .................................................................................................... 19

3.9 WATER CHEMISTRY .................................................................................................. 19

3.10 SITE DRAINAGE ..................................................................................................... 20

3.11 SITE TOPOGRAPHY ............................................................................................... 21

4 SUMMARY ......................................................................................................... 22

5 RECOMMENDATIONS ...................................................................................... 25

6 REFERENCES ................................................................................................... 26

7 PROJECT MAPS ............................................................................................... 27

List of Figures

Figure 1: Harding Existing Landfill Site Locality map (Topographical background) ............................... 3 Figure 2: Karoo Supergroup Stratigraphy (Tankard et al, 1982) ............................................................ 4 Figure 3: Distribution of test pits excavated over the project area (Google Earth with elevation profile) 9 Figure 4: Geophysical profiles at Harding waste site. ........................................................................... 15 Figure 5: Harding waste site elevation profile. ...................................................................................... 16 Figure 6: Harding waste site conceptual model (not to scale). ............................................................. 18


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List of Tables

Table 1: Double Ring Infiltrometer Test – Permeability Data ................................................................ 10 Table 2: Summarised Hydrocensus Data ............................................................................................. 13 Table 3: Detailed Processed Soil Test Results ..................................................................................... 13

List of Photos

Photo 1: Waste pit with visible vertical joints in the siltstone .................................................................. 5 Photo 2: General soil excavatability conditions – Trial Pit HTP5 ............................................................ 7 Photo 3: Farm borehole used for drinking water purposes. .................................................................. 11 Photo 4: Water tanks with dark brown mineral precipitation. ................................................................ 12

List of Appendixes

Appendix A –Double Ring Infiltrometer Test Data

Appendix B –Test Pit Logs

Appendix C –Geophysical Survey Data

Appendix D –Aquifer Testing Data

Appendix E –Water Chemistry Analyses Data

Appendix F –Soil Test Data


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1 INTRODUCTION

A multi-disciplinary geohydrological and engineering geological investigation was carried out at the existing Harding landfill site for the further use and possible expansion of the waste facility for the town of Harding in the Umuziwabantu Local Municipality of the KwaZulu Natal Province.

1.1 Terms of reference

AGES (PTY) LTD was appointed by USK Consulting after submitting a detailed quotation for the geohydrological and engineering geological inputs required for the geohydrological and engineering geological site characterization of the existing landfill site. The AGES geohydrological and geotechnical units followed a multi-disciplinary approach to meet the said objectives of the investigation.

1.2 Scope of work

The geohydrological and engineering geological site characterization entailed the following actions:

• Conduct a hydrocensus of the region 1 – 3 Km radius from the centre of the proposed site. • Investigate water resources near the site in this radius, level, water quality, yield, structural details etc. • Conduct at a risk assessment of contamination of water resource in the region from the landfill site. • Detailed mapping of the hydrogeological structures and features. • Investigation of general geology of the site • Underlying soil and geological features assessment • Assess the suitability of the site from a contamination barrier point of view and look at availability and

suitability of cover material. • Digging of trial pits, soil mechanisms and laboratory investigation, mapping and literature review.

1.3 Project area and location

The landfill site is located 600m east of Harding Town next to the N2 road in the Umuziwabantu Local Municipality of the KwaZulu Natal Province. The regional locality of the site is indicated in Figure 1 with the centre point of the sites roughly located at the following coordinate (WGS84; Geographic Projection):

Harding landfill site:

• Latitude 30.570571° S

• Longitude 29.911280° E


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1.4 Available information

The following sources of information were used during the investigation:

Geological maps

- 3128 KOKSTAD, 1981; scale 1 : 250 000.

Topographical map

- 3029DB HARDING, Third edition, 1981; scale 1 : 50 000.

Geohydrological map

- 2928 DURBAN, First edition, scale 1 : 500 000.

Satellite Imagery

- Google Earth. AfriGIS (Pty) Ltd 2012.


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Figure 1: Harding Existing Landfill Site Locality map (Topographical background)


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2 SITE DESCRIPTION

2.1 Geological setting

According to the geological map 3028 KOKSTAD the project area is underlain by dark-grey shale, medium-grained buff sandstone, siltstone and mudstone of the Ecca Group that is part of the Karoo Supergroup sequence of rocks. The regional geology is indicated in Map 2. The stratigraphical position of the Ecca Group within the Karoo Supergroup is indicated in Figure 2 below.

Dolerite sills have intruded the horizontally orientated sedimentary rocks of the Ecca Group in the region. The Harding waste site is located on the western edge of a dolerite sill striking north east to south west as indicated by the geological map. It is assumed that the dolerite sill extends westward underneath the project area as dolerite could be observed in close proximity to the project area and the presence of a prominent non-perennial spring to the north of the project area. The site is not located close to any major fault zones or dolerite dyke intrusions according to the available geological maps.

The siltstone has a general dip of 3 degrees to the west with prominent sub-vertical WNW trending joints noted in places where the rock is exposed on site, as can be seen in Photo 1. These joints could be associated with the dolerite sheet intrusion below the site causing fractures and joints in the overlying sedimentary formations. The brown precipitation visible in Photo 1 is an indication of groundwater flow along these joints and fractures. These vertical joints and fractures have the potential to increase groundwater flow velocities as well as influence groundwater flow directions.

Quaternary deposits (Alluvium) occur to the north of the landfill site associated with the Mzimkhulwana river.

The geological map does not indicate the presence of any water-soluble rocks or sediments within the project

Figure 2: Karoo Supergroup Stratigraphy (Tankard et al, 1982)


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area. Soluble rocks include dolomite and limestone and are prone to the formation of sinkholes and subsidence. These conditions are therefore not expected in the project area.

Photo 1: Waste pit with visible vertical joints in the siltstone

2.2 Hydrogeological setting

The hydrogeological map 2928 DURBAN describes the project area as being underlain by predominantly argillaceous rocks (shale, carbonaceous shale, mudstone and siltstone) with groundwater generally located intergranular and in fractured zones with expected borehole yields varying from 0.5 to 2.0 l/s at successful boreholes and water quality characterised by an EC of approximately 0-70 mS/m.


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3 RESULTS

3.1 General

A site reconnaissance survey of the existing site was conducted during the last week of April 2012 during which the general geology, geohydrology and engineering geology of the site was assessed, and further site investigation planned. The detailed investigation carried out from 24 to 25 April 2012 at the existing site comprised of the following general actions:

• Conduct a hydrocensus of the region 1 – 3 Km radius from centre of the proposed site.

• Risk assessment of contamination of water resource in the region from the landfill site.

• Detailed mapping of the hydrogeological structures and features.

• Investigation of general hydrogeology of the site

• Underlying soil and geological features assessment

• Assess the suitability of the site from a contamination barrier point of view

3.2 Generalised Soil Conditions

Due to some existing waste sells being open in the western portion of the site, soils could be inspected in this area. Trial pit positions were identified in areas where additional information on soil conditions was needed, especially where weathering could be expected associated with geological structures that could constitute preferential pathways for contaminant transport.

A total of 5 trial pits, numbered TP1 to TP5, were excavated on the 17th of May 2012 utilising a CAT 416 D-type excavator. It was possible excavate to depth of between 1.3 to 2.50 mbgl (mean 1.98 mbgl), after which excavation refused on Siltstone bedrock or excavation was stopped as the TLB-type excavator neared its maximum reach. Excavation refused on 3 of the trial pits with Siltstone bedrock, generally occurring from a depth between 0.6 to 1.4 mbgl (0.9 mbgl). The localities of the test pits are indicated in Figure 3 for reference.

A portion of the project area is covered by Soil of human origin as encountered in 2 of the trial pits. The material consists of sandy silt to sandy clay with scattered to abundant ferricrete nodules, siltstone cobbles, building rubble and other waste.

The project area is generally covered by a layer of hillwash material that is composed of sandy silt to sandy clay that exhibits a firm consistency and a micro-shattered soil structure. The material extends from surface to a depth between 0.20 to 0.60 mbgl (mean 0.33 mbgl).

The transported hillwash material is underlain by Ferruginised Residual Siltstone material that is composed of sandy clay with scattered to abundant ferricrete nodules and siltstone gravel, with a firm consistency and an intact to micro-shattered structure. The material has a thickness between 0.2 and 0.6 m (mean 0.3 m),

The Ferruginised Residual Siltstone material is underlain by Siltstone bedrock material that was encountered in 3 of the trial pits. The siltstone bedrock material is highly weathered to moderately weathered, fine grained, thickly jointed. Joint surfaces are narrow, stained and slightly rough. The material was encountered at depth of between 0.6 to 1.4 mbgl (mean 0.9 mbgl).


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The sidewalls of trial pits remained stable to moderately stable during profiling with little to no collapse and overbreak occurring.

No groundwater seepage was encountered during the investigation. Ferruginised soil conditions were encountered over the entire project area, indicating that the seasonal occurrence of perched groundwater is likely.

The generalised soil conditions are indicated in the Photo below with logs attached in Appendix A.

Photo 2: General soil excavatability conditions – Trial Pit HTP5

3.3 Laboratory Testing

A total of 5 disturbed soil samples, 2 bulk disturbed samples and 3 undisturbed samples were taken for detailed laboratory analysis as part of the investigation. The samples were submitted to an accredited materials laboratory in East London for detailed analysis on the 28th of May 2012.

Processed results are discussed in the paragraphs below and summarized in Table 3. Laboratory instructions and analysis certificates are attached in Appendix F for reference.


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3.3.1 Hillwash Material

The hillwash is generally composed of 32.8% sand, 52.2 % silt, 11% clay, with little or no gravel.

The material classifies as CL: Sandy Lean Clay according to the A.S.T.M. standard on the United Soil Classification system.

The material exhibits is low plasticity, with a liquid limit of 22 %, a plasticity index of 8, a weighted plasticity index of 6.6, and a linear shrinkage of up to 4.5 %.

Mechanical behaviour

• The material is not deemed to be potentially expansive.

• The material is potentially moderately collapsible / compressible with a calculated differential settlement of up to 18 mm.

• The material was not tested for dispersivity, but is considered to be potentially moderately to highly dispersive.

• The material has an A-4 subgrade rating according to AASHTO, classifying as fair for use as subgrade.

The material has a maximum dry density of 2003 kg/m3 and an optimum moisture content of 9.6%. The CBR of the material increases slightly with compaction from 9 at 90% MOD AASHTO to 13 at 95% MOD AASHTO and 19 at 100% MOD AASHTO. The swell of the material is up to 0.6 %. The material classifies as G9 according to TRH14 guidelines

3.3.2 Ferruginised Residual Siltstone Material

The Ferruginised Residual Siltstone material is generally composed of 40.3-51% sand, 28.7-41.9 % silt, 7-20% clay, and up to 9% gravel.

The material classifies as SC: Clayey sand according to the A.S.T.M. standard on the United Soil Classification system.

The fines fraction of the material is medium plastic, with a liquid limit of 29-49 %, a plasticity index of 11-23, a weighted plasticity index of 6.6-12.2, and a linear shrinkage of up to 11.5 %.


• The material is deemed to be potentially slightly expansive with a calculated heave of up to 28mm.

• The material is potentially moderately collapsible / compressible with a calculated differential settlement of up to 47.5 mm.


• The material has a A-7-5 subgrade rating according to AASHTO, classifying as poor for use as subgrade.

The material has a maximum dry density of 1887 kg/m3 and an optimum moisture content of 14.8%. The CBR of the material increases slightly with compaction from 7 at 90% MOD AASHTO to 12 at 95% MOD AASHTO and 19 at 100% MOD AASHTO. The swell of the material is up to 0.3 %. The material classifies as G9 according to TRH14 guidelines.


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3.3.3 Siltstone Bedrock Material

The Siltstone Bedrock material is generally composed of 21.3-59% sand, 20.9-39.7 % silt, 11-17% clay, and up to 22% gravel.

The material classifies as SC: Clayey sand and CL: Gravelly Lean Clay with sand according to the A.S.T.M. standard on the United Soil Classification system.

The fines fraction of the material is medium plastic, with a liquid limit of 33-34%, a plasticity index of 16, a weighted plasticity index of 5.8-9.6, and a linear shrinkage of up to 7.5 %.


• The material is not deemed to be potentially expansive.

• The material is potentially moderately collapsible / compressible with a calculated differential settlement of up to 27.5 mm.


• The material has a A-2-5 subgrade rating according to AASHTO, classifying as good for use as subgrade.

Figure 3: Distribution of test pits excavated over the project area (Google Earth with elevation

profile)


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3.4 Soil Permeability

A total of 3 Double Ring Infiltrometer permeability tests were conducted within the Ferruginised Residual Siltstone (2 tests) and hillwash (1 tests). Permeability test results are summarised in Table 1 below with permeability data and graphs attached in Appendix A for reference.

Table 1: Double Ring Infiltrometer Test – Permeability Data

The measured soil permeabilities of both the transported and Weathered Siltstone materials are generally slightly permeable. The transported and residual soil material of the Harding waste site at DRIT TP1 and TP3 has the most favourable soil permeability for landfill site purposes resulting in the lowest calculated daily flow rate of all three sites.

Assuming a SWL of 5 mbgl follows the topography, the following scenarios were calculated to determine the number of days for surface water to reach the SWL if there is no confining layers, no evaporation, a homogeneous soil profile up to the SWL and no surface runoff. The formula used is as follows: 5.0 m / Calculated Daily Flow Rate = Days for seepage water to reach the SWL.

DRIT TP1 – Ferruginised Residual Siltstone = 52.63 days

DRIT TP2 - Ferruginised Residual Siltstone = 30.49 days

DRIT TP3 - Hillwash = 52.63 days

The assumption is made that it will take any seepage water between 30 and 53 days to reach the SWL.

Conclusion:

Soil permeabilities at the Harding waste site render it suitable for usage as cover material. Shallow soil depths could be a limiting factor should large volumes need to be sourced on site. Perched groundwater conditions do occur over the project area especially during the rainy season when groundwater recharge is at a maximum. Lining of the trenches is recommended to prevent groundwater contamination where perched groundwater occurs and jointing is prominent. Zones where perched groundwater conditions can be expected are delineated in Map 4 as part of this report.

Number Depth (mbgl) Material

DRIT TP 1 0.2 Ferr Res Siltstone 1.10E-04 0.095 Slightly Permeable

DRIT TP 2 0.8 Ferr Res Siltstone 1.90E-04 0.164 Slightly Permeable

DRIT TP 3 0.1 Hillwash 1.10E-04 0.095 Slightly Permeable

DRIT Test InformationMEASURED

PERMEABILITY

(cm/sec)

CALCULATED

DAILY FLOW

RATE (m) COMMENTS


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3.5 Position in respect of domestic water supply

A hydrocensus of the existing site and its surroundings was conducted during site investigations. From information collected at Harding municipality, the town used to be serviced by septic tanks. A number of privately owned boreholes are located in the town. Two geosites were identified in close proximity to the project area as indicated in Table 2.

A borehole (Neil Camp 1) is located approximately 550m downstream and north of the landfill boundary and another borehole (MM 1) identified 1170 m south of the landfill boundary within the town itself. Both were identified for sampling. The borehole (Neil Camp 1) is equipped and is used by a commercial farmer for drinking and domestic water purposes as it is the only available water. The water level of this borehole was measured to be 2.55 mbgl. Dark brown precipitation was noted on the water tanks to which the borehole pumps to storage tanks as indicated in Photo 3.

The borehole (MM 1) located in the town was the only borehole sampled south of the project area. The SWL of borehole MM 1 could not be measured during the investigation due to pump obstruction not allowing access for measuring equipment. Although it is reported that numerous other privately owned boreholes occur within the town at private plots, this borehole was selected for monitoring due to it being the closest borehole upstream of the waste site.

Photo 3: Farm borehole used for drinking water purposes.

Several non-perennial seepage zones were identified to the north and east of the landfill site as indicated in Map 1. At the time of site investigation, the seeps did not have water emanating from it although dampness was noted at some. It is assumed that seeps are associated with seasonal perched groundwater in the area which might be controlled by the top and bottom contacts of the dolerite sheet where it outcrops below the site.


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Hydrocensus data is summarised in Table 2 for reference and local geosite localities are indicated in Map 1 to 3. A water sample (Neil Camp 1) was taken from the borehole indicated in Photo 2 located directly north of the landfill site. This sample was taken to get an indication of the general downstream groundwater quality.

In order to determine the water quality upstream of the landfill site and to identify other sources of pollution a water sample was taken from the borehole MM1 located in the town of Harding.

Photo 4: Water tanks with dark brown mineral precipitation.


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Table 2: Summarised Hydrocensus Data

Table 3: Detailed Processed Soil Test Results

Site type Description Latitude Longitude Altitude (mamsl)

Distance from

Landfill (m)

Static Water

Level (mbgl)

Sample

Taken

Borehole Neil Camp 1 -30.5621 29.91467 819 550 2.55 Yes

Borehole MM 1 -30.5723 29.89448 847 1170 - Yes

Stream Stream Sample -30.5612 29.91028 808 720 - Yes

HARDING HYDROCENSUS AND SAMPLING TABLE

GRAD ING ANALYSES ATTERBERG LIM ITS LS POTENT IALLY ADV ERSE GEOTECHN ICAL CHARACTERIST ICS

Number Dept h Orig in Gravel Sand Silt C lay LL PI PI ' % A .S.T .M . TRH 14 Expansiveness Dispersivit y

(m - m) % % % % %

pH

Conduct iv

it y

(mS/ m)

% Wat er

Sat urat ion

HTP 1/1 0.80 - 1.30 Siltstone Bedrock 22 21.3 39.7 17 34 16 9.6 7.0 - - -CL: Gravelly Lean Clay with

Sand- Low Risk Medium Risk - Medium to High Risk

HTP 3/1 0.10 - 0.50 Hillwash 4 32.8 52.2 11 22 8 6.6 4.5 - - - CL: Sandy Lean Clay G9 Low Risk High Risk - Medium to High Risk

HTP 3/2 0.70 - 2.30 Ferruginised Residual Siltstone 11 40.3 28.7 20 49 23 12.2 11.5 - - - SC: Clayey Sand G9 Medium Risk Medium Risk - Medium to High Risk

HTP 5/1 0.30 - 0.50 Slight ly Ferruginised Residual Siltstone 0 51.1 41.9 7 29 11 6.6 5.5 - - - SC: Clayey Sand - Low Risk Medium Risk - Medium to High Risk

HTP 5/2 0.70 - 1.20 Siltstone Bedrock 9 59.1 20.9 11 33 16 5.8 7.5 - - - SC: Clayey Sand - Low Risk Medium Risk - Medium to High Risk

DETAILED PROCESSED SOIL TEST RESULTS - GENV HARDING LANDFILL SITE INVESTIGATION

SOIl CHEM ISTRYCorrosivenes

s

( Conduct ivit

y)

M ATERIALS CLASSIF ICAT IONSAM PLE INFORM ATION

Co llapse /

Compressib il i t y


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3.6 Geophysical profiling

From geological maps and site mapping, a prominent dolerite sheet was found to outcrop approximately 500m south-east of the eastern boundary of the waste site. Remote sensing and geophysical geo-magnetic profiling has confirmed the presence of this dolerite sheet which is expected to extend towards the west below the waste facility. This dolerite sheet is expected to occur approximately 40m below the waste site and localised seeps were noted, possibly associated with the upper contact of the sheet. Occurrences of these seeps are indicated in Map 1 and 3.

• Geophysical profile H1 was conducted in a north to south direction on the southern boundary of the landfill site. The data of profile H1 is indicative of a dolerite sill from start to end of the profile with a total length of 300m

• Profile H2 was conducted in a west to east direction for a total of 860m along the local airport runway to determine if there are any dolerite dykes or faults striking through the landfill site in a north south direction. The profile did not indicate the presence of any dolerite dykes, only the presence of a dolerite sill throughout the profile.

• Profile H3 was conducted on the north western boundary of the landfill site with a length of 340m to determine the possibility of a structure striking through the drainage visible from 135m to 215m on the profile. The data does indicate an anomaly between 135m and 215m which could be interpreted as a dolerite dyke or fault. This structure is the most probable cause of the drainage having developed at this locality and should be taken into account for future monitoring purposes.

• The last profile H4 was conducted north of the landfill site with a length of 250m. The data from this profile indicated the presence of a dolerite sill throughout the profile.

It is imperative that monitoring boreholes be drilled upstream and downstream of the proposed waste site directly into the dolerite sheet. Positions of proposed monitoring boreholes are indicated in Map 3.

The observation is that non-perennial seeps occur associated with the dolerite sheet and that groundwater movement takes place along this sheet.

Results from the geophysical surveys are attached in Appendix C for reference.

Conclusion:

Groundwater flow velocities will be enhanced along joints and seams related to the underlying dolerite sill and its top and bottom contact with the siltstone, resulting in possible faster transport of contaminants or pollutants along these joints and seams in a westerly and northerly direction.. Flow velocities will also increase in areas where there are possible fault zones in the dolerite sheet. It is highly recommended that monitoring boreholes be drilled in the positions specified in Map 3 of the waste site in order to determine the presence of pollutants.


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Figure 4: Geophysical profiles at Harding waste site.


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3.7 Site Hydrogeology

The Harding landfill site is located at an elevation of approximately 860 mamsl on the northern slope of a ridge. The whole site is underlain by Ecca shale/mudstone/siltstone which dips approximately 3 degrees to the west with a dolerite sheet underlying these formations with approximately the same orientation. Dendritic precipitation is visible in the well jointed Ecca formation. Site hydrogeology is therefore dictated by the horizontally orientated sedimentary layers with very low vertical hydraulic conductivities expected in the range of 0.095 m/d to 0.164 m/d. The site overlays a dolerite sheet and it is expected for this dolerite sheet’s top contact to occur at approximately 30m-40m below the waste site itself.

Groundwater movement is expected to mimic the topography due to no groundwater abstraction taking place in the direct vicinity of the site. Groundwater movement is further influenced by prominent WNW trending joints that occur in siltstones noted on the site itself. Groundwater at the waste site is therefore expected to flow in a general north-westerly direction. A conceptual model was constructed as indicated in Figure 6 to illustrate the expected depth to static water level below the waste site as well as it’s relation to the nearby rivers, the downstream borehole and the dolerite sheet.

The waste site is located approximately 700 m north of the Mzimkhulwana river and 630 m south of the Mzimkhulwana river.

Figure 5: Harding waste site elevation profile.

Conclusion:

Groundwater at the Harding waste site is expected to flow in a north-westerly direction. Flow will be influenced by the dip angle of sedimentary rocks and the dolerite sheet that occurs approximately 32 m below the site as well as WNW trending joints and fractures noted in the siltstone on site Joints and fractures could possibly increase groundwater flow velocities. The static groundwater level is expected to be approximately 9 m below surface at the waste site facility with seasonal perched water expected during the rainy season. Excavation beyond 4m depths on site will bring contaminants within 5m of the expected static water level which is unacceptable. Waste sells will need to be sealed should this be the case. A monitoring borehole will have to be drilled as a matter of urgency to confirm the exact depth to groundwater on site.


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Should any dolerite material be intersected during excavation on site, it will be an indication that the underlying sheet is irregular in form or possibly have secondary dykes associated with it that could not be identified through site mapping or geophysical surveys. Precaution with then have to be taken by sealing such waste sells as the dolerite contacts are deemed to be a preferential flow path which could link pollutants to downstream groundwater users.


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Figure 6: Harding waste site conceptual model (not to scale).


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3.8 Aquifer Testing

Aquifer testing was conducted on the existing borehole (Neil Camp 1) during the second site visit. The existing pump in the borehole was used for the test while the water level response was monitored within the borehole. The borehole was measured to be 55m deep and the SWL was 2.55 mbgl before the pump was switched on.

A constant discharge test was conducted at 0.40 l/s which resulted in a total drawdown of 10.1 m over a period of 360 minutes after which the pump was switched off to allow recovery. The borehole recovered 96.42% over a period of 90 minutes.

The drawdown and recovery curves of the test data indicated an average transmissivity of 1.0 m2/d.

Conclusion:

The low T value can be ascribed to small fractures in the formation where low flow velocities occur. The hydraulic conductivity (K) is also very low due to the correlation between T and K where:

K (m/d) = T (m2/d) / Aquifer thickness (m).

In the case of the downstream borehole Neil Camp 1 it can be assumed that the aquifer is approximately 52.45 m thick which will result in a K value of 0.02 m/d. This indicated that contaminants will travel at 0.02 m/d through the aquifer where it is homogeneous. More prominent fractures in the geological formation as those noted on site can increase the T and K values. Should pollutants therefore reach the aquifer, it will take more than 70 years to reach the nearest groundwater user. This period will however decrease significantly should fractures or dolerite contacts be intersected by waste cell construction. It is concluded that expected groundwater flow velocities through the siltstone that occurs on site is sufficiently low to warrant the operation of a well-managed waste facility, given the precautions stated in this report are adhered to.

Aquifer testing results are attached in Appendix D for reference.

3.9 Water chemistry

Water samples were taken from an existing downstream borehole (Neil Camp 1), a stream (Stream Sample) leading to the downstream dam north of the project area and a borehole (MM1) located in the town of Harding to determine the general groundwater quality of the area.

The water from the borehole (Neil Camp 1) classifies as DWAF Drinking Water Class 4 (Completely Unacceptable water quality) due to a Total and Faecal Coliforms count of 1000 and 1200 respectively and the water from this borehole also classifies as DWAF Drinking Water Class 3 (Poor water quality) due to a Manganese concentration of 1.4 mg/l.

The water sample taken from the stream (Stream Sample) classifies as DWAF Drinking Water Class 3 (Poor water quality) due to a Total Coliforms count of 400 and 21.8 Turbidity units. The Total Coliforms could be the result of occasional waste water spillage or overflows into the stream from the waste water treatment works that occurs 2.8 km west of the dam and sampling point.


20

Water from the borehole (MM 1) located in the town of Harding classifies as DWAF Drinking Water Class 1 (Good water quality) with elevated concentrations of Chloride, Iron, Magnesium and Electrical Conductivity.

Chemical water analyses results are attached in Appendix E for reference.

Conclusion:

The occurrence of elevated Manganese concentrations (1.4 mg/l) in the water from the Neil Camp 1 borehole is expected to originate from manganese rich dendrites in the form of the mineral pyrolusite, which is occasionally found in Ecca formations. Such precipitates were noted in rock exposures on site and is most probably the cause of brown to black staining noted on water tanks into which this borehole discharges. The water from this borehole has been classified as DWAF Class 4 due to Total and Faecal Coliforms counts, 1000 and 1200 respectively, resulting in the water having unacceptable quality. Elevated faecal concentrations are most likely due to a nearby septic tank or the cattle kraals and activity in direct vicinity of the borehole. It is likely that this borehole is also not constructed with sufficient sanitary seals to protect it from pollutants originating from surface.

3.10 Site drainage

The existing landfill site is located in the Quaternary Catchment T52K within the MVOTI to UMZIMKULU water management area. The waste site drains by means of surface flow primarily in a northern and western direction to the Mzimkhulwana River which drains in a regional southern direction to the Indian Ocean. Slope angles are moderate to low as the site is located on a hillcrest to side slope as can be seen in the conceptual model – Figure 6.

The existing waste water treatment works is located 2.15 km north west of the landfill site as indicated in Map 1 and 3. If spillage occurs at the WWTW, it can reach the Mzimkhulwana river which will result in the dam north and downstream of the landfill site to be contaminated with Faecal and Total Coliforms.

Harding town used to be serviced by septic tank systems which could have caused localised groundwater contamination in the town. The results of the borehole MM1 sampled in town did however not have any Coliform contamination which predicts that there is a positive response in the aquifer due to the septic tank-eradication programme that the municipality is busy with.

Conclusion:

The landfill site is well drained and the site drainage conditions are suitable to be used as landfill site as the low slope angles are preferred for the construction of landfill sites depending on the type of landfill to be used. It is recommended that an efficient surface run-off control system be implemented to prevent excessive run-off of water by creating soil berms. Seasonal shallow groundwater conditions can be expected towards the central parts of the site due to seasonal groundwater seepage occurring in the area as indicated in Map 4.


21

3.11 Site topography

The general calculated slope of the landfill site is derived from the 20m contours of the topographical map and Google Earth Pro. The landfill site is located on the northern sideslope of the hill on which the local airport runway is located as seen in Map 1.

The landfill site has an average slope angle of 3.48°, dipping to the north and west as indicated in Figure 6.

Conclusion:

The landfill site has a low general slope of 3.48°. The site topography is suitable for the use of a landfill site due to the low slope angle and topographical setting.


22

4 SUMMARY

Based on the results and the conclusions of the geohydrological and engineering geological investigation, the following summary and recommendations are made for the existing landfill site at Harding Town:

• A multi-disciplinary geohydrological and engineering geological investigation was carried out at the existing Harding landfill site for the further use and possible expansion of the waste facility for the town of Harding in the Umuziwabantu Local Municipality of the KwaZulu Natal Province.

• Harding existing waste site is located 600m east of Harding Town next to the N2 road in the Umuziwabantu Local Municipality of the KwaZulu Natal Province. The regional locality of the site is indicated in Figure 1.

• According to the geological map 3028 KOKSTAD the project area is underlain by dark-grey shale, medium-grained buff sandstone, siltstone and mudstone of the Ecca Group that is part of the Karoo Supergroup sequence of rocks. The regional geology is indicated in Map 2.

• The siltstone has a general dip of 3 degrees to the west with prominent sub-vertical WNW trending joints noted in places where the rock is exposed on site, as can be seen in Photo 1. These joints could be associated with the dolerite sheet intrusion below the site causing fractures and joints in the overlying sedimentary formations. The brown precipitation visible in Photo 1 is an indication of groundwater flow along these joints and fractures. These vertical joints and fractures have the potential to increase groundwater flow velocities as well as influence groundwater flow directions. Quaternary deposits (Alluvium) occur to the north of the landfill site associated with the Mzimkhulwana river.

• The geological map does not indicate the presence of any water-soluble rocks or sediments within the project area. Soluble rocks include dolomite and limestone and are prone to the formation of sinkholes and subsidence. These conditions are therefore not expected in the project area

• The hydrogeological map 2928 DURBAN describes the project area as being underlain by predominantly argillaceous rocks (shale, carbonaceous shale, mudstone and siltstone) with groundwater generally located intergranular and in fractured zones with expected borehole yields varying from 0.5 to 2.0 l/s at successful boreholes and water quality characterised by an EC of approximately 0-70 mS/m.

• A site reconnaissance survey of the existing site was conducted from 24 to 25 April 2012 during which the general geology, geohydrology and engineering geology of the site was assessed, and further site investigation planned.

• A total of 5 disturbed soil samples, 2 bulk disturbed samples and 3 undisturbed samples were taken for detailed laboratory analysis as part of the investigation. The samples were submitted to an accredited materials laboratory in East London for detailed analysis on the 28th of May 2012.

• The project area is generally covered by a layer of hillwash material that is composed of sandy silt to sandy clay that exhibits a firm consistency and a micro-shattered soil structure. The material extends from surface to a depth between 0.20 to 0.60 mbgl (mean 0.33 mbgl).

• A total of 3 Double Ring Infiltrometer permeability tests were conducted within the Ferruginised Residual Siltstone (2 tests) and hillwash (1 tests). Permeability test results are summarised in Table 1

• The measured soil permeabilities of both the transported and Weathered Siltstone materials are generally slightly permeable. The transported and residual soil material of the Harding waste site at DRIT TP1 and TP3 has the most favourable soil permeability for landfill site purposes resulting in the lowest calculated daily flow rate of all three sites.

• A hydrocensus of the existing site and its surroundings was conducted during site investigations. From


23

information collected at Harding municipality, the town used to be serviced by septic tanks. A number of boreholes are located in the town. Two geosites were identified in close proximity to the project area as indicated in Table 2. A borehole (Neil Camp 1) is located approximately 550m downstream and north of the landfill boundary and another borehole (MM 1) identified 1170 m south of the landfill boundary within the town itself. Both were identified for sampling. The borehole (Neil Camp 1) is equipped and is used by a commercial farmer for drinking and domestic water purposes as it is the only available water. The water level of this borehole was measured to be 2.55 mbgl. Dark brown precipitation was noted on the water tanks to which the borehole pumps to storage tanks as indicated in Photo 3.

The borehole (MM 1) located in the town was the only borehole sampled south of the project area. The SWL of borehole MM 1 could not be measured during the investigation due to pump obstruction not allowing access for measuring equipment. Although it is reported that numerous other privately owned boreholes occur within the town at private plots, this borehole was selected for monitoring due to it being the closest borehole upstream of the waste site.

• From geological maps and site mapping, a prominent dolerite sheet was found to outcrop approximately 500m south-east of the eastern boundary of the waste site. Remote sensing and geophysical geo-magnetic profiling has confirmed the presence of this dolerite sheet which is expected to extend towards the west below the waste facility. This dolerite sheet is expected to occur approximately 40m below the waste site and localised seeps were noted, possibly associated with the upper contact of the sheet. Occurrences of these seeps are indicated in Map 1 and 3. Geophysical profile H1 was conducted in a north to south direction on the southern boundary of the landfill site. The data of profile H1 is indicative of a dolerite sill from start to end of the profile with a total length of 300m. Profile H2 was conducted in a west to east direction for a total of 860m along the local airport runway to determine if there are any dolerite dykes or faults striking through the landfill site in a north south direction. The profile did not indicate the presence of any dolerite dykes, only the presence of a dolerite sill throughout the profile. Profile H3 was conducted on the north western boundary of the landfill site with a length of 340m to determine the possibility of a structure striking through the drainage visible from 135m to 215m on the profile. The data does indicate an anomaly between 135m and 215m which could be interpreted as a dolerite dyke or fault. This structure is the most probable cause of the drainage having developed at this locality and should be taken into account for future monitoring purposes. The last profile H4 was conducted north of the landfill site with a length of 250m. The data from this profile indicated the presence of a dolerite sill throughout the profile.

• The Harding landfill site is located at an elevation of approximately 860 mamsl on the northern slope of a ridge. The whole site is underlain by Ecca shale/mudstone/siltstone which dips approximately 3 degrees to the west with a dolerite sheet underlying these formations with approximately the same orientation. Dendritic precipitation is visible in the well jointed Ecca formation. Site hydrogeology is therefore dictated by the horizontally orientated sedimentary layers with very low vertical hydraulic conductivities expected in the range of 0.095 m/d to 0.164 m/d. The site overlays a dolerite sheet and it is expected for this dolerite sheet’s top contact to occur at approximately 30m-40m below the waste site itself. Groundwater movement is expected to mimic the topography due to no groundwater abstraction taking place in the direct vicinity of the site. Groundwater movement is further influenced by prominent WNW trending joints that occur in siltstones noted on the site itself. Groundwater at the waste site is therefore expected to flow in a general north-westerly direction. A conceptual model was constructed as indicated in Figure 6 to illustrate the expected depth to static water level below the waste site as well as it’s relation to the nearby rivers, the downstream borehole and the dolerite sheet. The waste site is located approximately 700 m north of the Mzimkhulwana river and 630 m south of the Mzimkhulwana river.

• Aquifer testing was conducted on the existing borehole (Neil Camp 1) during the second site visit. The existing pump in the borehole was used for the test while the water level response was monitored within the borehole. The borehole was measured to be 55m deep and the SWL was 2.55 mbgl before the


24

pump was switched on. A constant discharge test was conducted at 0.40 l/s which resulted in a total drawdown of 10.1 m over a period of 360 minutes after which the pump was switched off to allow recovery. The borehole recovered 96.42% over a period of 90 minutes. The drawdown and recovery curves of the test data indicated an average transmissivity of 1.0 m2/d.

• In the case of the downstream borehole Neil Camp 1 it can be assumed that the aquifer is approximately 52.45 m thick which will result in a K value of 0.02 m/d. This indicated that contaminants will travel at 0.02 m/d through the aquifer where it is homogeneous. More prominent fractures in the geological formation as those noted on site can increase the T and K values. Should pollutants therefore reach the aquifer, it will take more than 70 years to reach the nearest groundwater user. This period will however decrease significantly should fractures or dolerite contacts be intersected by waste cell construction. It is concluded that expected groundwater flow velocities through the siltstone that occurs on site is sufficiently low to warrant the operation of a well-managed waste facility, given the precautions stated in this report are adhered to.

• The occurrence of elevated Manganese concentrations (1.4 mg/l) in the water from the Neil Camp 1 borehole is expected to originate from manganese rich dendrites in the form of the mineral pyrolusite, which is occasionally found in Ecca formations. Such precipitates were noted in rock exposures on site and is most probably the cause of brown to black staining noted on water tanks into which this borehole discharges. The water from this borehole has been classified as DWAF Class 4 due to Total and Faecal Coliforms counts, 1000 and 1200 respectively, resulting in the water having unacceptable quality. Elevated faecal concentrations are most likely due to a nearby septic tank or the cattle kraals and activity in direct vicinity of the borehole. It is likely that this borehole is also not constructed with sufficient sanitary seals to protect it from pollutants originating from surface.

• The existing landfill site is located in the Quaternary Catchment T52K within the MVOTI to UMZIMKULU water management area. The waste site drains by means of surface flow primarily in a northern and western direction to the Mzimkhulwana River which drains in a regional southern direction to the Indian Ocean. Slope angles are moderate to low as the site is located on a hillcrest to side slope as can be seen in the conceptual model – Figure 6. The existing waste water treatment works is located 2.15 km north west of the landfill site as indicated in Map 1 and 3. If spillage occurs at the WWTW, it can reach the Mzimkhulwana river which will result in the dam north and downstream of the landfill site to be contaminated with Faecal and Total Coliforms. Harding town used to be serviced by septic tank systems which could have caused localised groundwater contamination in the town. The results of the borehole MM1 sampled in town did however not have any Coliform contamination which predicts that there is a positive response in the aquifer due to the septic tank-eradication programme that the municipality is busy with.

• The landfill site has a low general slope of 3.48°. The site topography is suitable for the use of a landfill site due to the low slope angle and topographical setting.

• Based on available information it is expected that mechanical excavation will be possible to depths of 3m in weathered siltstone.

• The siltstone bedrock classifies as G9 material according to the TRH14 guidelines and is suitable for use during construction. Shallow soil depths could be a limiting factor should large volumes need to be sourced on site.


25

5 RECOMMENDATIONS

• Based on hydrogeological findings, the further usage of the Harding Waste Facility can only be considered if the following recommendations are strictly adhered to:

• A site characterisation borehole should be drilled associated with the structure that was noted from geophysical surveys along the north-western boundary of the site as a matter of urgency. This borehole will serve to confirm the depth to static water level as well as possible increased flow velocities associated with the structure which occurs here. This borehole should be tested as well.

• At least 2 additional up- and downstream monitoring boreholes should be drilled as part of the implementation of the future monitoring programme.

• Waste cells constructed in the delineated increased perched groundwater zone (MAP 4) should be sealed if perched groundwater is noted during excavation.

• Excavation beyond 4m depths on site will bring contaminants within 5m of the expected static water level which is unacceptable. Waste sells will need to be sealed should this be the case. This will only be possible to quantify once the recommended immediate borehole is drilled.

• Should any dolerite material be intersected during excavation on site, it will be an indication that the underlying sheet is irregular in form or possibly have secondary dykes associated with it that could not be identified through site mapping or geophysical surveys. Precaution with then have to be taken by sealing such waste sells as the dolerite contacts are deemed to be a preferential flow path which could link pollutants to downstream groundwater users and surface water bodies.

• Non-perennial seeps occurring east and north of the site should be included in the monitoring protocol – specifically in the rainy season when perched groundwater conditions and seepage is expected. These seeps should be fenced off to prevent any use of the water during the rainy season.

• Surface water sampling downstream of the waste facility should be included in the monitoring protocol.

• Historically used full waste cells should all be re-visited to ensure that efficient storm water control measures are in place to prevent the ingress of any surface water.

• It is highly recommended that a community awareness programme be conducted to inform the local community about the health and pollution risks associated with landfill sites.

• Elevated faecal concentrations noted at the privately owned borehole downstream of the waste facility is most likely due to a nearby septic tank or the cattle kraals and activity in direct vicinity of the borehole. It should be recommended to the farmer not to use this borehole unless water is treated or reconstructed to protect it from pollutants originating from surface around the borehole.

• Any un-monitored increased abstraction of groundwater by the possible future drilling of boreholes within a 1km radius of the waste site can increase flow gradients and velocities and will have to be discouraged should it be considered by the municipality or land users.


26

6 REFERENCES

• Second edition of the South African Water Quality Guidelines (DWAF, 1996) and Health Guidelines: Drinking Water Quality (Department of Health, 1995)

• Engineering Geology of Southern Africa, Vol. 3. Building Publications, Pretoria. BRINK, A B A, 1979.

• Soil Mechanics, Sixth Edition. Department of Civil Engineering, University of Dundee UK. CRAIG RF, 1997.


27

7 PROJECT MAPS

MAP 1: Topographical Map


28

MAP 2: Geological Map


29

MAP 3: Ortho Map


30

MAP 4: Expected Perched Groundwater Map


31

APPENDIX A

Double ring infiltrometer test data


32

PROJECT:

Inner Ring Dia.: 30 cm

Ring Height: 20 cm

Test No.:

Test Depth:

Material:

Date:

Time (sec) Cum. Infilt

0 0.0

15 -0.1

30 -0.5

45 -0.6

60 -0.6 1 min

90 -0.7

120 -0.7 2 min

150 -0.8

180 -1.0 3 min

210 -1.0

240 -1.2 4 min

270 -1.3

300 -1.3 5 min

360 -1.4 6 min

420 -1.5 7 min

480 -1.6 8 min

540 -1.8 9 min

600 -2.0 10 min

900 -2.2 15 min

1200 -2.9 2 0 min

1500 -3.0 2 5 min

1800 -3.1 3 0 min

2700 -3.3 4 5 min

3600 -3.6 1 HOUR

4500 -4.0 1 hr 15 min

5400 -4.1 1 hr 3 0 min

6300 -4.2 1 hr 4 5 min

7200 -4.3 2 HOURS

8100 2 hr 15 min

9000 2 hr 3 0 min

9900 2 hr 4 5 min

10800 3 HOURS

h1 = 4.0 init ial height ( cm)

h2 = 4.3 f inal height ( cm)

�� t = 2700 t ime d if f erence ( sec)

km = 1.1E-04 cm.s-1

Ferr Res Siltstone

DOUBLE-RING INFILTROMETER TEST

TP 1

0.2 mbgl

HARDING LANDFILL SITE INVESTIGATION

2012/05/17

-5.0

-4.0

-3.0

-2.0

-1.0

0.0

0 60

0

12

00

18

00

24

00

30

00

36

00

42

00

48

00

54

00

60

00

66

00

72

00

78

00

84

00

90

00

96

00

10

20

0

10

80

0

CU

MU

LA

TIV

E IN

FIL

TR

AT

ION

(c

m)

TIME (seconds)


33

PROJECT:


Ring Height: 20 cm

Test No.:

Test Depth:

Material:

Date:


0 0.0

15 0.0

30 0.0

45 0.0

60 0.0 1 min

90 0.0

120 -0.1 2 min

150 -0.1

180 -0.1 3 min

210 -0.1

240 -0.2 4 min

270 -0.2

300 -0.2 5 min

360 -0.2 6 min

420 -0.2 7 min

480 -0.2 8 min

540 -0.2 9 min

600 -0.3 10 min

900 -0.3 15 min

1200 -0.5 2 0 min

1500 -0.6 2 5 min

1800 -0.6 3 0 min

2700 -0.6 4 5 min

3600 -0.7 1 HOUR

4500 -0.8 1 hr 15 min

5400 -1.0 1 hr 3 0 min

6300 -1.1 1 hr 4 5 min

7200 -1.3 2 HOURS

8100 2 hr 15 min

9000 2 hr 3 0 min

9900 2 hr 4 5 min

10800 3 HOURS




km = 1.9E-04 cm.s-1

DOUBLE-RING INFILTROMETER TESTHARDING LANDFILL SITE INVESTIGATION

TP 2

0.8 mbgl

Ferr Res Siltstone

2012/05/17

-2.0

-1.0

0.0

0 60

0

12

00

18

00

24

00

30

00

36

00

42

00

48

00

54

00

60

00

66

00

72

00

78

00

84

00

90

00

96

00

CU

MU

LA

TIV

E IN

FIL

TR

AT

ION

(c

m)

TIME (seconds)


34

PROJECT:


Ring Height: 20 cm

Test No.:

Test Depth:

Material:

Date:


0 0.0

15 0.0

30 -0.1

45 -0.1

60 -0.1 1 min

90 -0.2

120 -0.2 2 min

150 -0.2

180 -0.2 3 min

210 -0.2

240 -0.2 4 min

270 -0.2

300 -0.2 5 min

360 -0.3 6 min

420 -0.4 7 min

480 -0.4 8 min

540 -0.4 9 min

600 -0.4 10 min

900 -0.5 15 min

1200 -0.5 2 0 min

1500 -0.5 2 5 min

1800 -0.6 3 0 min

2700 -0.9 4 5 min

3600 -1.1 1 HOUR

4500 -1.2 1 hr 15 min

5400 -1.4 1 hr 3 0 min

6300 -1.5 1 hr 4 5 min

7200 -1.6 2 HOURS

8100 2 hr 15 min

9000 2 hr 3 0 min

9900 2 hr 4 5 min

10800 3 HOURS




km = 1.1E-04 cm.s-1

DOUBLE-RING INFILTROMETER TESTHARDING LANDFILL SITE INVESTIGATION

TP 3

0.1 mbgl

Hillwash

2012/05/17

-2.0

-1.0

0.0

0 60

0

12

00

18

00

24

00

30

00

36

00

42

00

48

00

54

00

60

00

66

00

72

00

78

00

84

00

90

00

96

00

CU

MU

LA

TIV

E IN

FIL

TR

AT

ION

(c

m)

TIME (seconds)


35

APPENDIX B

Test Pit Logs


36


37


38


39


40


41

APPENDIX C

Geophysical survey data


42

115

140

165

190

215

27820

27840

27860

27880

27900

27920

27940

27960

27980

0

20

40

60

80

100

120

140

160

180

200

220

240

260

280

300

Resistivity (Ohm/m)

Magnetic (nanotesla)

Station number (m)

HARDING LANDFILL SITE INVESTIGATIONProfile H 1

Magnetic & Resistivity Profiling (Wenner Configuration)

MAGNETIC RESISTIVITY

115

140

165

190

215

27750

27800

27850

27900

27950

28000

28050

28100

0

20

40

70

110

150

190

230

270

310

350

390

430

470

510

550

590

630

670

710

750

790

830

Resistivity (Ohm/m)


Station number (m)




115

140

165

190

215

27750

27800

27850

27900

27950

28000

28050

28100

28150

28200

0

20

40

60

80

100

120

140

160

180

200

220

240

260

280

300

320

340

Resistivity (Ohm/m)


Station number (m)





43

115

140

165

190

215

27850

27900

27950

28000

28050

28100

28150

28200

0

40

80

120

160

200

240

Resistivity (Ohm/m)


Station number (m)





44

APPENDIX D

Aquifer Testing Data


45

CONSTANT DISCHARGE TEST AND RECOVERY

BOREHOLE NO. : 0 PROJECT: Harding CLIENT: 0

ALTERNATIVE NO. : 0 SITE NAME: Harding

DEPTH OF PUMP (mbdl): 45.00 PUMP TYPE USED: Electric Submersible OPERATOR: Martin / Gert

INLET DIAMETER (mm): 32 EXISTING EQUIPMENT: 0 CONTRACTOR: Intaba Construction

TEST DATE: 2012/05/03 TEST DATE: 2012/05/03 TOTAL TIME - PUMPED (min): 360 TOTAL TEST TIME (min): 450

STARTED TIME: 7:30 AM COMPLETED TIME: 3:00 PM TOTAL TIME-RECOVERY(min): 90 AVERAGE YIELD (l/s): 0.41

DISCHARGE BOREHOLE OBSERVATION BOREHOLE 1 OBSERVATION BOREHOLE 2 OBSERVATION BOREHOLE 3

CASING HEIGHT (magl): 0.00 No. : No. : No. :

CASING DEPTH (mbdl): 0.00 DATUM LEVEL (magl): DATUM LEVEL (magl): DATUM LEVEL (magl):

CASING ID (mm): 165.00 CASING DEPTH (mbgl): CASING DEPTH (mbgl): CASING DEPTH (mbgl):

BOREHOLE DEPTH (mbgl): 0.00 BOREHOLE DEPTH : BOREHOLE DEPTH : BOREHOLE DEPTH :

WATER LEVEL (mbgl): 2.55 WATER LEVEL: WATER LEVEL: WATER LEVEL:

DATUM LEVEL (magl): 0.00 DISTANCE (m): DISTANCE (m): DISTANCE (m):

Time Drawdown Yield Recovery Time Drawdown Recovery Time Drawdown Recovery Time Drawdown Recovery

(min) (m) (l/s) (m) (min) (m) (m) (min) (m) (m) (min) (m) (m)

1 0.89 0.46 8.80 1 1 1

2 1.40 0.46 8.40 2 2 2

3 1.65 0.46 7.40 3 3 3

5 1.92 0.46 5.79 5 5 5

7 2.15 0.46 4.67 7 7 7

10 2.43 0.46 4.40 10 10 10

15 2.96 0.45 4.20 15 15 15

20 3.45 0.45 3.44 20 20 20

30 4.13 0.44 2.10 30 30 30

40 4.65 0.40 1.15 40 40 40

60 5.65 0.38 0.82 60 60 60

90 6.56 0.37 0.37 90 90 90

120 7.40 0.38 120 120 120

150 8.00 0.35 150 150 150

180 8.53 0.35 180 180 180

210 9.00 0.35 210 210 210

240 10.33 0.35 240 240 240

300 10.00 0.35 300 300 300

360 10.10 0.35 360 360 360

420 420 420 420

480 480 480 480

540 540 540 540

600 600 600 600

720 720 720 720

840 840 840 840

960 960 960 960

1080 1080 1080 1080

1200 1200 1200 1200

1320 1320 1320 1320

1440 1440 1440 1440

1560 1800 1800 1800

1680 2280 2280 2280

1800 2880 2880 2880


46

BOREHOLE NUMBER: 0

CALIBRATION TEST AND RECOVERY

Discharge 1: 0.00 Discharge 2: Discharge 3: Discharge 4: Discharge 5: Discharge 6:

Drawdown 1: 0.00

Drawdown 2: 0.00

Drawdown 3: 0.00

Drawdown 4: 0.00

Drawdown 5: 0.00

Drawdown 6: 0.00

Duration 1: 0

Duration 2: 0

Duration 3: 0

Duration 4: 0

Duration 5: 0

Duration 6: 0

Recovery (m): 0.00

Recovery (min): 0

STEPPED DISCHARGE TEST AND RECOVERY

Discharge 1: Discharge 2: Discharge 3: Discharge 4: Discharge 5: Discharge 6:

Drawdown 1: 0.00

Drawdown 2: 0.00

Drawdown 3: 0.00

Drawdown 4: 0.00

Drawdown 5: 0.00

Drawdown 6:

Duration 1: 0

Duration 2: 0

Duration 3: 0

Duration 4: 0

Duration 5: 0

Duration 6: 0

Recovery (m): 0.00

Recovery (min): 0

CONSTANT DISCHARGE TEST AND RECOVERY

TEST INFORMATION

Date tested 03-May-12 Water level (mbgl) 2.55 Depth of pump (mbgl) 45

CD duration 360 CD discharge rate 0.41 CD drawdown 10.33

Available drawdown (m) 42.45 % Recovery after CD 96 % after 90 min

-12

-10

-8

-6

-4

-2

0

1 10 100 1000

TIME (t) IN MINUTES

DRAWDOWN (s) IN M

ETRES

Constant discharge rate

Recovery

0.00

0.20

0.40

0.60

0.80

1.00

1 100 10000

TIME (t) IN MINUTES

DRAWDOWN (s) IN

METRES

Discharge rate 1

Discharge rate 2

Discharge rate 3

Recovery

Step 2

Step 3

0.00

0.20

0.40

0.60

0.80

1.00

1 10 100

TIME (t) IN MINUTES

DRAWDOWN (s) IN

METRES Discharge Rate 1

Discharge Rate 2

Recovery

Discharge Rate 3


47

APPENDIX E

Water Chemistry data


48

Harding Landfill Site

Borehole Id Neil Camp 1

Date Sampled 04-May-12

Drinking water class 4

Sample Number 7401

Class

Viable organisms 0

Faecal coliforms 1000.00 4

Total coliforms 1200.00 4

Electrical Conductivity EC mS / m 84.00 1

Total Dissolved Salts TDS mg / l 438.00 0

pH Value pH 6.90 0

Turbidity NTU 0

Arsenic As mg / l 0.00 0

Cadmium Cd mg / l 0.01 2

Calcium Ca mg / l 58.00 0

Chloride Cl mg / l 131.00 1

Copper Cu mg / l 0

Fluoride F mg / l 0.36 0

Iron Fe mg / l 0.01 1

Total Hardness CaCO 3 mg / l 0

Magnesium Mg mg / l 19.00 0

Manganese Mn mg / l 1.40 3

Nitrate N mg / l 0.01 0

Nitrate NO 3 mg / l 0

Potassium K mg / l 1.50 0

Sodium Na mg / l 25.40 0

Sulphate SO 4 mg / l 156.00 0

Zinc Zn mg / l 0.06 0

Ammonia NH 4 mg / l 0.13

P - Alkalinity CaCO 3 mg / l

M - Alkalinity CaCO3 mg / l

Calcium Hardness CaCO3 mg / l

Magnesium Hardness CaCO3 mg / l

Carbonate CaCO3 mg / l

Bicarbonate HCO 3 mg / l

Silica Si mg / l

Phosphor P0 4 as P mg / l

Micro-

biological

properties

Physical

Properties

Chemical properties

Chemical properties

(not required for the clasification of

domestic drinking w

ater supply)


49


Borehole Id MM 1



Sample Number 7402

Class

Viable organisms 0





pH Value pH 7.60 0

Turbidity NTU 0

Arsenic As mg / l 0.00 0

Cadmium Cd mg / l 0.01 2



Copper Cu mg / l 0



Total Hardness CaCO 3 mg / l 0


Manganese Mn mg / l 0.02 0






Zinc Zn mg / l 0.02 0


P - Alkalinity CaCO 3 mg / l

M - Alkalinity CaCO3 mg / l

Calcium Hardness CaCO3 mg / l

Magnesium Hardness CaCO3 mg / l



Silica Si mg / l


Micro-

biological

properties

Physical

Properties

Chemical properties

Chemical properties


domestic drinking w

ater supply)


50


Borehole Id Stream Sample



Sample Number 7400

Class

Viable organisms 0





pH Value pH 7.10 0

Turbidity NTU 21.80 3

Arsenic As mg / l 0

Cadmium Cd mg / l 0



Copper Cu mg / l 0



Total Hardness CaCO 3 mg / l 51.00 0


Manganese Mn mg / l 0






Zinc Zn mg / l 0


P - Alkalinity CaCO 3 mg / l 10.00

M - Alkalinity CaCO3 mg / l 65.00

Calcium Hardness CaCO3 mg / l 23.00

Magnesium Hardness CaCO3 mg / l 28.00



Silica Si mg / l


Micro-

biological

properties

Physical

Properties

Chemical properties

Chemical properties


domestic drinking w

ater supply)


51


52


53


54

APPENDIX F

Soil Test data


55

Sample Number Depth Origin Swell TRH14 Class

MDD Kg/m3 OMC % 100 98 95 93 90

HTP 3/1 0.10 - 0.50 Hillwash 2003 9.6 19 17 13 12 9 0.6 G9

HTP 3/2 0.70 - 2.30 Ferruginised Residual Siltstone 1887 14.8 19 16 12 10 7 0.3 G9

MOD. AASHTO CBR at % MOD.AASHTO

0

10

20

30

40

50

60

70

80

90

100

88 90 92 94 96 98 100 102

% CBR

MOD AASHTO (%)

CBR vs Relative Density

HTP 3/1

HTP 3/2


56


57

Documents

Geohydrological and Engineering Geological investigation at the ... · dolerite could be observed in close proximity to the project area and the presence of a prominent non-perennial