AN ENGINEERING GEOLOGICAL INVESTIGATION · Geological and Environmental Services ... The remaining...

AN ENGINEERING GEOLOGICAL INVESTIGATION

FOR A

PROPOSED NEW CEMETERY AT STORMS RIVER

PREPARED BY:

PREPARED FOR:

SETPLAN SETTLEMENT PLANNING SERVICES

CONSULTING TOWN PLANNERS

P.O. BOX 2446

NORTH END

6056

JANUARY 2008

Tel: 041 373 8871 • Fax: 041373 6549 • Cell: 082 499 3140 • PO Box 27996 GREENACRES 6057

Table of Contents

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

1.1 BACKGROUND................................................................................................................................1

1.2 LOCATION ......................................................................................................................................2

2 SITE DESCRIPTION.....................................................................................................................3

2.1 TOPOGRAPHY, DRAINAGE AND GEOMORPHOLOGY ........................................................................3

2.2 CLIMATE ........................................................................................................................................4

2.3 VEGETATION ..................................................................................................................................5

3 INVESTIGATION PROCEDURE................................................................................................6

3.1 DESK STUDY INVESTIGATION ........................................................................................................6

3.2 FIELD INVESTIGATION....................................................................................................................6

3.3 LABORATORY AND SOIL TESTING ..................................................................................................6

Soil Testing Laboratory Data ...........................................................................................................7

4 GEOLOGICAL ENVIRONMENT...............................................................................................9

4.1 GEOLOGICAL FORMATION..........................................................................................................9

Kouga Formation..............................................................................................................................9

Baviaanskloof Formation..................................................................................................................9

4.2 GROUNDWATER ...........................................................................................................................10

5 ENGINEERING GEOLOGICAL EVALUATION...................................................................11

5.1 EXPANSIVE SOIL ..........................................................................................................................11

5.2 DISPERSIVE SOIL..........................................................................................................................11

5.3 POTENTIALLY COLLAPSIBLE SOIL................................................................................................12

5.4 COMPRESSIBLE HORIZONS ...........................................................................................................12

6 CEMETERY SITE SELECTION PROCEDURES ..................................................................13

6.1 BACKGROUND..............................................................................................................................13

6.2 SITE SELECTION CRITERIA ...........................................................................................................13

7 EVALUATION OF THE STUDY AREA USING THE SELECTION CRITERIA ..............15

7.1 SOIL EXCAVATABILITY ................................................................................................................15

7.2 SOIL PERMEABILITY.....................................................................................................................15

7.3 POSITION IN RESPECT OF DOMESTIC WATER SOURCES ...............................................................16

7.4 POSITION IN RESPECT OF DRAINAGE FEATURES ..........................................................................16

7.5 SITE DRAINAGE............................................................................................................................17

7.6 SITE TOPOGRAPHY .......................................................................................................................17

7.7 BASAL BUFFER ZONE...................................................................................................................17

7.8 GRAVE STABILITY........................................................................................................................18

8.9 SOIL WORKABILITY .....................................................................................................................18

7.10 CEMETERY SIZE .......................................................................................................................18

8 PROJECT OVERVIEW ..............................................................................................................19

9 REPORT PROVISIONS ..............................................................................................................20

10 REFERENCES..............................................................................................................................21

Storms River Cemetery: Engineering Geological Investigation

Geological and Environmental Services • PO Box 27996 GREENACRES 6057 • Tel: 041 373 8871 • Cell: 082 499 3140

ii

Appendices

Appendix 1: Figures

Appendix 2: Trial Pit Profiles

Appendix 3: Laboratory Soil Results



1

1 Introduction

1.1 Background

A new cemetery site is required for the Storms River community in the south-western part of the Eastern

Cape Province. The existing cemeteries in the area are unsuitable for cemetery purposes due to shallow

bedrock conditions and perched water tables / flooding after wet periods. The remaining functional

cemetery sites are also too small, located long distances away from the town and rapidly reaching full

capacity.

Six proposed cemetery candidate sites were selected by Setplan Settlement Planning Services in

conjunction with the local Storms River community. Open pieces of land that appeared suitable from both

an accessibility and vegetation area point of view were selected as potentially suitable sites and subjected

to a more detailed engineering geological investigation. These candidate sites were also ranked by the

Storms River community according to certain social criteria.

The ranking of the candidate sites during this initial social and town planning site selection process is as

follows:

Candidate Site 1: Rugby Field (most preferred)

Candidate Site 2: Adjacent Rugby Field

Candidate Site 3: Keurboom Forest

Candidate Site 4: National Road Site

Candidate Site 5: Plantation Site

Candidate site 6: Existing Goena cemetery (least preferred)

The engineering geological investigation was commissioned to determine which of the above candidate

sites is the most suitable for cemetery site establishment based on the prevailing geological conditions.

Cognisance was also taken of the recommended cemetery site selection criteria, public pedestrian and

vehicular accessibility, and various Department of Water Affairs and Forestry (DWAF) constraints

(perched water table activity and proximity to drainage channels.



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The findings of the engineering geological investigation form the basis of the environmental investigation,

which has been completed. Environmental authorisation is required from the Department of Economic

Affairs Environment and Tourism (DEAET) in terms of current environmental legislation to rezone the

candidate site for cemetery usage.

Verbal instruction to undertake the engineering geological investigation was received from Mr Brendan

Hindes of Setplan on Tuesday 1 November 2005. The field investigation was carried out on Wednesday

16 November 2005.

1.2 Location

The Storms River village is located about 5 km west of the Paul Sauer Bridge (Storms River Bridge /

Tsitsikamma Total village tourist stop). The existing small cemetery at Goena (candidate site 6) visited

during the field investigation is located adjacent to an electricity sub-station about 10 km south of the

Storms River village.

The remaining five candidate sites investigated during the field work are located in close proximity to the

village town centre, with the two rugby field sites (candidate sites 1 and 2) located on the eastern outskirts,

the Keurboom forest site on the north-eastern outskirts (between the town infrastructure and the N2

highway), the national road site to the north of the N2 highway and the plantation site to the west of

Storms River, west of the perennial Witteklip River (Appendix 1, Figure 1).

Each of the five candidate sites represents greenfield properties that have been deemed large enough from

a town planning perspective. The candidate sites under investigation were selected by the planners and

local authorities with input from the local community. The local community have ranked the candidate

sites based on social criteria as outlined previously.



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2 Site Description

2.1 Topography, Drainage and Geomorphology

The study area is situated on a regional, flattened marine terrace which slopes very gently towards the

south (seawards). Fluvial incision into the terrace (due to an ancient drop in sea-level), has resulted in a

series of steep-sided river valleys in this area. The Witteklip River to the west of the Storms River village

is located in one of these steep-sided gorges. A less prominent ephemeral drainage channel also occurs to

the west of the preferred cemetery site and flows southwards through the central parts of the Storms River

village. None of the candidate sites assessed during this investigation occur within drainage channel or

obvious wetland environments.

Candidate Site 1 (rugby field)

This candidate site is located to the east of the Storms River village on flat ground with no significant fall.

Surface run-off at this site would be problematic and drainage infrastructure would be required to prevent

pounding of surface water in depressions after wet periods. This site occurs at a height of about 240

metres above mean sea-level.

Candidate Site 2 (adjacent rugby field)

This candidate site is located to the east of the Storms River village on flat ground with a very gentle

southerly-sloping gradient. An ephemeral drainage channel flows towards the south-east about 150

metres south of the area investigated. This site occurs at a height of about 220 metres above mean sea-

level.

Candidate Site 3 (keurboom forest)

This is the preferred candidate site according to the local community and is located to the north-east of the

Storms River village on flat ground with a very gentle southerly-sloping gradient. An ephemeral drainage

channel flows towards the south about 100 metres west of the area investigated. This site occurs at a

height of about 250 metres above mean sea-level.



4

Candidate Site 4 (national road)

This candidate site is located to the north-west of the Storms River village, north of the N2 highway. It is

situated on gentle to moderately sloping ground with gradients to the north and north-west. The site is

bound by the N2 highway to the south and the R102 roadway to the north. An ephemeral, northerly

sloping drainage channel occurs to the north and north-west of this candidate site. This site occurs at a

height of about 250 metres above mean sea-level.

Candidate Site 5 (plantation)

This candidate site is located to the west of the Storms River village on gently sloping ground with a

north-easterly-sloping gradient. An ephemeral drainage channel flows towards the south-east about 100

metres east of the area investigated. This site occurs at a height of about 215 metres above mean sea-

level.

Candidate Site 6 (existing Goena cemetery)

This candidate site is located to south of the Storms River village on gently sloping ground with a

southerly-sloping gradient. An ephemeral drainage channel flows towards the east about 50 metres south

of the area investigated. This site occurs at a height of about 245 metres above mean sea-level.

2.2 Climate

According to the South African Weather Bureau (WB40, 1988) moderate coastal climatic conditions

prevail in the Storms River area. Rainfall varies between 950 mm and 1200 mm per annum falling

throughout the year. Summer (January) temperatures vary from an average maximum of about 24 °C to an

average minimum of about 15 °C, whilst winter (July) maximums and minimums are about 18 °C and 8

°C respectively.

Winter months are generally dominated by south-westerly and westerly winds associated with passing low

pressure (cold front) systems. During the summer months, high pressure systems result in easterly and

south-easterly dominated wind storms. These high pressure systems also frequently bring mid-afternoon

thunderstorms to the interior region.



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Weinert’s climatic N number is approximately 1 implying that chemical weathering dominates over

mechanical weathering. This has an influence on weathering rates down to competent bedrock in the

Tsitsikamma region.

2.3 Vegetation

The candidate sites under investigation all occur on land where some sort of transformation has taken

place and where pristine natural vegetation conditions no longer occur. The candidate sites near the rugby

field complex are underlain by short grass, whilst the preferred site is dominated by mature Keurboom

trees where an original pine plantation used to occur. Candidate site 4 is blanketed by tall Fynbos and

thicket species (including alien vegetation infestation) and the plantation site occurs in cleared plantation

lands. The existing candidate site occurs in a clearing adjacent to an existing plantation.



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3 Investigation Procedure

3.1 Desk Study Investigation

The investigation commenced with a desk study of all available information sources, including previous

engineering geological investigations conducted in the Storms River area. This study gave an indication

of the general environmental conditions, geology and soil profile to be expected. Potential engineering

geological problems and cemetery constraints could also be identified.

3.2 Field Investigation

Field work took place on Wednesday 16 November 2005 when fifteen (15) trial pits were excavated

within some of the proposed candidate sites. Four (4) trial pits were opened at candidate site 1 (rugby

field), three (3) at candidate site 2 (adjacent rugby field), four (4) at the preferred site, candidate site 3

(Keurboom forest) and four (4) trial pits at the national road site (candidate site 4). All of the trial pits

were opened using a JCB 3CX backactor made available by SANParks.

Trial pits were not opened at candidate site 5 (plantation) and candidate site 6 (existing cemetery) as these

sites were deemed unsuitable for the establishment of a new cemetery by the local community, based on

planning and social reasons.

The trial pit profiles are included in Appendix 2 of this engineering geological report, whilst the trial pit

positions at the various candidate sites are indicated on the plans included in Appendix 1.

3.3 Laboratory and Soil Testing

Three (3) disturbed soil samples were taken from the trial pits for laboratory testing and subjected to

Foundation Indicator testing as per TMH1 test methods A1 to A5. One sample was collected from

candidate site 1 (rugby field), one from the preferred candidate site 3 (Keurboom forest) and one from the

fourth candidate site (national road). Only sites that appeared to be potentially suitable for cemetery

establishment were tested during field work, hence no disturbed samples were taken from trial pits opened

in candidate site 2 (adjacent rugby field) during the field investigation.



7

The disturbed samples are considered representative of the soil horizons occurring within the candidate

sites under investigation. The laboratory soil testing was conducted by Ultralab Civil Engineering

Services CC of Port Elizabeth.

Soil sample depths are indicated in Table 1 and on the trial pit profiles in Appendix 2 of this report, whilst

the laboratory soil test results are included in Appendix 3.

Soil Testing Laboratory Data

The disturbed samples tested during this investigation are considered representative of the natural soil

horizons occurring within the candidate sites assessed. The laboratory soil testing was conducted by

Ultralab Civil Engineering Services CC of Port Elizabeth. Details regarding the sampling position (trial

pit number), sampling depth and laboratory testing procedures are indicated in Table 1 below.

Table 1: Disturbed soil sample testing details.

Trial Pit No Sample No Sampling Depth (below

surface)

Laboratory Testing

RF3 RF3A 0,3 to 0,8 metres Foundation Indicator

KF4 KF4A 0,5 to 1,0 metres Foundation Indicator

NR1 NR1A 1,0 to 1,5 metres Foundation Indicator

The following abbreviations apply to Table 1:

RF: Rugby Field candidate site (site 1)

KF: Keurboom Forest candidate site (site 3)

NR: National Road candidate site (site 4)

Foundation Indicator laboratory results are summarised in Table 2 overleaf. These laboratory results were

used to substantiate conditions described in Chapter 5 of this report.



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Table 2: Summarised Foundation Indicator laboratory results.

Sample

No.

Clay Content

(%)

Liquid

Limit (%)

Plasticity

Index (fines)

Linear

Shrinkage (%) Heave

Permeability

(cm/s) Horizon

NR1A 12 34 17 8.0 Medium (8 mm) 9,0 x 10-6 Sandy Clay Colluvium

KF4A 4 21 7 3.0 low 1,6 x 10-5 Weathered bedrock

RF3A 6 22 6 2.5 low < 1 x 10-6 Weathered bedrock

The following abbreviations and definitions apply to Table 2:

LL: Liquid Limit.

PI: Plasticity Index (fines less than 0.002 mm)

LS: Linear Shrinkage.

Heave: According to Van der Merwe’s method.

Permeability: Using Hazen’s formula (k = 100D102).

Horizon: As per Chapter 4.2 of this report.



9

4 Geological Environment

According to the 1:250 000 Geological Map (3322 OUDTSHOORN) published by the Geological Survey

of South Africa, the study area may be underlain by either the Kouga Formation or the Baviaanskloof

Formation (or both - Kouga Formation to the north and Baviaanskloof Formation to the south). Both of

these formations represent quartzitic sandstone bedrock and are both overturned in the Storms River area.

4.1 Geological Formation

Kouga Formation

The Kouga Formation is an Eastern Cape equivalent of the Skurweberg Formation in the Western Cape.

The Kouga Formation also forms part of the Nardouw Subgroup, Table Mountain Group of the Cape

Supergroup. This formation generally comprises thickly-bedded, medium to coarse grained, white-

weathering quartzitic sandstone, which is usually about 200 to 400 metres thick.

Data collected during the field investigation suggests that quartzitic sandstone occurs at shallow to

moderate depth throughout all of the candidate sites assessed.

Baviaanskloof Formation

The Baviaanskloof Formation (also of the Nardouw Subgroup, Table Mountain Group of the Cape

Supergroup) generally comprises fine-grained structureless sandstone and sub-ordinate black shale. This

formation attains thicknesses of between about 180 and 200 metres and conformably overlays the above-

mentioned Kouga Formation.

Data collected during the field investigation suggests that quartzitic sandstone occurs at shallow to

moderate depth throughout all of the candidate sites assessed.



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4.2 Groundwater

Perched water tables were encountered in trial pits opened at candidate site 1 (rugby field), candidate site

2 (adjacent rugby field) and candidate site 4 (national road) during the field investigation. Considering the

geological conditions (weathered clay over shallow bedrock) in the Storms River area, the gentle

topography and very high rainfall the presence of perched water tables is virtually guaranteed throughout

the region and would probably occur in all six candidate sites assessed during this investigation.

From a hydrological perspective, therefore, the candidate site that is best placed would be the preferred

site as perfect hydrological conditions for cemetery establishment in the Storms River area is unlikely to

occur. Hydrological constraints to be aware of when planning a cemetery in the region include distances

from surface drainage channels and adequate depths down to competent bedrock (associated perched

water tables).



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4 Engineering Geological Evaluation

The engineering geological evaluation is based on the results of the desk study, observations and

interpretations made on site, the laboratory results (see Appendix 3) and previous investigations conducted

in the region. A broad overview of the geotechnical constraints that are predicted to occur within the

study area based on the findings during this investigation are as follows:

5.1 Expansive Soil

The clayey colluviums encountered at candidate site 4 (sample NR1A) proved medium expansive with a

heave value of about 8 mm. The laboratory results suggest that expansive clay may be a factor in the area.

No evidence of expansive clayey conditions were noted in the preferred candidate site 3 (keurboom forest)

but the occurrence of such expansive clayey material cannot be ignored. Field evidence such as thick

clayey material, slickensiding and dessication cracks frequently suggest expansive conditions. If such

heave indicators are noted during site clearing and construction then cemetery infrastructure should be

designed with expansive clay in mind.

5.2 Dispersive Soil

Clay is an assemblage of microscopic platelets, which are held together by various forces. A high

percentage of sodium cations in the clay cause the platelets to be loosely bound. Should water with a low

concentration of dissolved salts (such as rainwater) find an initial micro-channel in such a soil mass, the

loosely held platelets will disperse and be carried away resulting in soil erosion and piping.

No significant erosion problems are predicted at the preferred cemetery site, however, as the prevailing

grades are too low to encourage significant surface water flow or seepage, required to facilitate erosion

scour. Disturbed footprints should, nevertheless, be covered with natural vegetation as soon as possible to

limit exposure of the sub-soil environment to the atmosphere.



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5.3 Potentially Collapsible Soil

A soil with a collapsible fabric is defined as a soil that can withstand relatively large imposed stresses with

small settlements at low in situ soil moisture content, but which will exhibit a decrease in volume and

associated settlement with no increase in the applied stress if wetting up occurs. The change in volume is

associated with a change in the soil fabric (collapse of grain structure) and is applied to an additional

settlement, which occurs due to the wetting up of partially saturated subsoil, which has a collapsible

fabric.

According to the laboratory results none of the samples tested proved collapsible. This was confirmed by

comparing the sample grading curves with Knight (1961) and Errera’s (1977) grading envelopes for

collapse potential. This is not, therefore, considered a significant constraint and precautions to counter

heave will reduce any effect of collapse potential across the site.

5.4 Compressible Horizons

In a dry state the topsoil is slightly compressible, whereas the colluvium and weathered bedrock would

become compressible under saturated conditions. Soil saturation and compressibility would also be

exacerbated by the flat grades across the site.



13

6 Cemetery Site Selection Procedures

6.1 Background

Cemeteries have a fairly severe pollution potential, especially if sited incorrectly. Leachate produced in a

cemetery is of a pathogenic nature and can pollute surface water features and ground water if located too

close. The bacteriological, virological and parasitic organisms in this leachate have been shown to travel

far greater distances within the soil and ground water than previously thought and that the lifespan of

some organisms (especially viruses) within the ground water is sufficiently long to pose contamination

problems hundreds of metres away under certain conditions. Ground water is a vital resource in the

Eastern Cape Province and adequate measures should, therefore, be taken to prevent such additional

pollution.

To counter the pollution potential of a cemetery site, which is of at least equal magnitude as that posed by

a conventional waste disposal site a set of ten criteria has been applied to this site to establish its

suitability for cemetery purposes. These criteria, if adhered to should ensure the correct siting of any

cemetery. The selected site at Storms River should also comply with the recommended criteria as set out

below. Performance of this site in relation to the criteria is discussed in Chapter 7 of this engineering

geological report.

6.2 Site Selection Criteria

The cemetery site selection criteria are not only designed to counter pollution problems but also take

cognisance of other constraints such as slope, shallow bedrock and soil stability. The ten criteria are

mentioned below with a brief description of each.

Χ Soil Excavatibility: A minimum excavatable depth of 1,8 metres is preferred for cemetery

purposes, although depths exceeding 2 metres would be more desirable.

Χ Soil Permeability: Soil permeabilities should preferably fall between the following limits: 1 X 10-

7 cm per second and 1 X 10

-4 cm per second. Too high permeabilities would allow rapid leachate spread

and too low permeabilities would inhibit the decomposition process.



14

Χ Position in Respect of Domestic Water Sources: Minimum safe distances between a cemetery

and domestic water source such as a borehole or storage dam would be between 100 and 450 metres in the

Storms River area depending on the prevailing soil permeabilities.

Χ Position in Respect of Drainage Features: Minimum safe distances between a cemetery and

drainage feature, would be between 50 and 150 metres, once again depending on the prevailing soil

permeabilities.

Χ Site Drainage: Good site drainage is required to firstly prevent soil erosion and secondly to

prevent ponding, marshy conditions, unnecessary water ingress and cemetery degradation.

Χ Site Topography: A gradient of between 2° and 6° is considered ideal for cemetery purposes.

This slope range will ensure adequate drainage, minimise erosion and promote human and mechanical

mobility on site.

Χ Basal Buffer Zone: A basal buffer zone refers to the soil succession between the base of the

deepest grave and the water table. The buffer zone is essentially a barrier between the source of pollution

and the valuable water resource. A buffer zone of at least 2,5 metres is preferred.

Χ Grave Stability: Competence of the grave verge is important for a number of reasons, the most

prominent being that a few days usually elapses between excavation and use, hence the need for a few

days of “stand up” time.

Χ Soil Workability: This refers to the ease at which the soil can be manipulated in and out of the

graves.

Χ Cemetery Size: A minimum sized cemetery to justify the costs of investigation and

implementation is recommended. The 2,9 hectare site should be suitable for the Storms River community

for at least 15 years (assume burial rates of about 10 burials per month).



15

7 Evaluation Of The Study Area Using The Selection Criteria

Evaluation of the study area in terms of the ten cemetery site selection criteria reveals that candidate site 3

(keurboom forest) to the north/ north-east of the Storms River village is generally the most suitable for

cemetery purposes. A few minor constraints do, however, occur at this site that is common to the region.

7.1 Soil Excavatability

Trial pit depths revealed during the field investigation proved highly variable in all candidate sites

subjected to trial pit excavation. Trial pit depths ranged from 1,1 to 1,5 at candidate site 1 (rugby field),

0,7 to 0,8 metres at candidate site 2 (adjacent rugby field), 0,8 and 1,8 metres at candidate site 3

(keurboom forest) and 0,9 and 2,2 metres below surface at candidate site 4 (national road). Minimum

excavatable depths of 1,8 metres are preferred for cemetery purposes, which was only attained at

candidate site 3 (preferred site) and candidate site 4. The other sites are deemed unsuitable for cemetery

site establishment based on soil excavatability requirements.

7.2 Soil Permeability

Soil permeabilities are marginal with regards the recommended limits. The permeability tests revealed

permeability rates (determined using Hazen’s formula) of between < 1,0 X 10-6

(impervious) and 1,6 X

10-5 (semi-pervious to impervious) cm per second (see Table 2).

On site permeabilities generally appear to fall outside the upper permeability limit (10-4

cm per second)

and the site is, therefore, considered marginally acceptable in terms of the recommended soil permeability

range. The preferred site reveals permeability values closest to the preferred values of the candidate sites

assessed during this investigation.



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7.3 Position In Respect Of Domestic Water Sources

The minimum safe distance between this cemetery and a domestic water source would be about 100 to

150 metres (based on a number of factors, including soil permeability, climate and soil moisture

conditions). As far as could be ascertained the nearest domestic water source is well outside this distance.

The underlying quartzitic sandstone is a good aquifer, but is isolated from the surface by impervious

clayey material (colluviums and completely weathered bedrock).

A row of indigenous trees should, nevertheless, be planted around the cemetery. Apart from the aesthetic

qualities, trees also tend to absorb large quantities of polluted water from the soil. Exotic tree species

should be avoided as far as possible in this regard.

7.4 Position In Respect Of Drainage Features

The minimum safe distance between the cemetery boundary (preferred candidate site) and the surrounding

drainage feature to the west, should be about 50 metres. This safe distance is derived from available

literature and based on the prevailing conditions in the area.

This minimum safe distance implies that the entire study area may not be suitable for cemetery purposes.

The cemeteries western boundary would have to move to ensure a minimum distance of 50 metres from

the neighbouring drainage channel is attained. This area may, however, be suitable for alternative land

uses such as parking facilities or other cemetery related infrastructure that does not involve burial.



17

7.5 Site Drainage

Site drainage appears to be moderately problematic for the establishment of a cemetery at the site.

This is one of the inevitable flaws with cemetery sites in Storms River area as the region is

characterised by flat and gentle grades in response to the marine terrace origins of the land surface.

An effective on site drainage system should, therefore, be constructed across the study area. This

system could include a soil berm around the upper northern and north-eastern section of the preferred

cemetery site, which would prevent excess sheet-wash from entering the site. In addition, artificially

sloping drainage ditches should be located along access roads and paths, thus collecting run-off from

the high-lying areas and rapidly channelling it away from the site towards the south and south-west.

Grass cover and trees would also improve site drainage.

7.6 Site Topography

Site topography ties in with site drainage. Gentle slopes with a southerly to south-westerly sloping

gradient of less than 1° occur across the preferred site. These gradients not are regarded as ideal for

the establishment of cemetery sites, but there are very few alternative sites in the Storms River area.

The marginal slopes in the study area are regarded as an acceptable trade-off for the establishment of a

cemetery site, as this criteria is not considered a fatal flaw. Surface drainage conditions can also be

improved by using certain engineering options.

As far as possible, burial should always commence in the lower lying areas and proceed towards the

higher lying land. This is done so that grave diggers are not exposed to polluted soil and seepage from

higher lying graves. Graves should also be orientated parallel to the contours as far as possible. T his

will reduce leachate seepage velocities. The issue of grave orientation is, however, not always flexible

as certain communities insist on a specific grave orientation from a religious and cultural point of

view.

7.7 Basal Buffer Zone

A marginal adequate basal buffer zone occurs in parts of the study area. The basal buffer zone

generally consists of sandy clay colluviums and weathered bedrock. Ground water is generally not

associated with this transported horizon, which forms an impervious buffer between the grave site and

the residual mudstone and sandstone aquifer at depth.

The impervious nature of these clayey material renders a thinner basal buffer zone acceptable for a

cemetery site in this region. Basal buffer zones are also not considered a fatal flaw and should

adequate burial depth be achieved at a cemetery site the depth to competent bedrock is not an overly

significant constraint.



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7.8 Grave Stability

Soil consistencies are generally in the soft to firm and occasionally stiff range for the colluvium and

weathered bedrock. This facilitates ideal grave stability conditions, although hand excavation may

prove slightly difficult during dry periods.

8.9 Soil Workability

Soil workability is generally satisfactory although the more clayey material may be less workable after

prolonged dry periods. This is, however, only a minor constraint and should not detract from overall

site suitability for cemetery purposes.

7.10 Cemetery Size

The preferred cemetery site covers a surface area of about 2,92 ha (29 200 m2). It has been assumed

that a 20 metre buffer will be established along the western boundary due to the proximity of the

ephemeral drainage channel and a further 25% of the property is lost to accommodate vegetation

clumps in the layout plan. This suggests that about 18 000 m2 will be available for burial purposes at

the cemetery once established.

Planning records suggest that the Storms River community buries about 4 to 5 persons per month (data

obtained from SA Police Services records). For planning purposes it has been assumed that a

maximum of 10 burials will take place at Storms River per month.

This implies about 1 200 graves over a 10-year period, which will cover a surface area of about 9 290

m2

under a conventional cemetery layout. Increased burials of between about 1 500 and 2 000 graves

over a 15 year period will occupy a footprint of about 15 400 m2.

The preferred site, therefore, has sufficient surface area to conservatively meet the requirements of the

Storms River community for 15 years, which is deemed adequate for planning purposes.



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8 Project Overview

The Storms River village does not have access to a suitable cemetery that meets the standard cemetery

selection criteria and the existing cemetery at Goena is deemed unacceptable by the community for

social reasons. Numerous candidate cemetery sites were selected by the local authorities, planners and

the local community for assessment as potentially suitable cemetery sites. These candidate sites have

been subjected to an environmental investigation and engineering geological assessment to confirm

suitability for cemetery purposes.

The engineering geological investigation showed that the regional marine terrace in the Tsitsikamma

region is characterised by flat grades, shallow bedrock, a surficial weathered clayey horizon and

perched water tables. These ground conditions are problematic for the establishment of a cemetery,

which implies that not all of the cemetery selection criteria can be strictly applied to sites under

investigation in this region.

Cemetery site selction constraints common to the region include shallow depth of soil to bedrock,

impervious soil permeabilities, proximity to drainage channels, site drainage and basal buffer zones.

constraints identified at this site include dispersive soil, collapse potential, compressible soil with

These constraints are surmountable but may result in additional costs to manage the constraints such as

poor surface drainage and create buffer zoned from drainage features.

Based on the findings of this engineering geological report, the candidate site that proved to be the

most suitable as it complied with more of the cemetery site selection criteria then any of the other sites

assessed. This site also proved ot be the preferred site by the local community. Candidate sites 5

(plantation) and 6 (existing cemetery) were not assessed during the geological investigation as they

were eliminated from the process by the local community based on social constraints (distance from

Storms River, cemetery size and suitability for burials).



20

9 Report Provisions

This investigation is aimed at providing the project engineers with an indication of the suitability of the

candidate site for cemetery establishment purposes. The preferred candidate site should also be

assessed based on the compliance with the preferred cemetery site selection criteria.

Fortunately the engineering geological investigation found that the site that is preferred by the local

community also proves to be the most suitable in terms of the standard cemetery site selection criteria.

This preferred cemetery site is also deemed acceptable by the local authorities, including the

SANParks and DWAF (landowners).

It is, therefore, recommended that should a cemetery be established in the Storms River area that

candidate site 3 (Keurboom forest) be used and that the other candidate sites assessed during this

investigation be ignored.



21

10 References

• Brink A. B. A. (1981). Engineering Geology of Southern Africa, Vol. 2. Building Publications,

Pretoria.


Pretoria.


Pretoria.

• Brink A. B. A., Partridge T. C. & Williams A. A. B. (1980). Soil Survey for Engineering,

Caledon Press - Oxford.

• Frankipile South Africa (Pty) Ltd. (1995). A guide to practical Geotechnical Engineering in

South Africa.

• Jennings J. E., Brink A. B. A., Williams A. A. B. (1973). Revised Guide to Soil Profiling for

Civil Engineering Purposes in South Africa. Trans. SAICE. Vol. 15, No.1, Jan. 1973.

• Johnson, M. R. and le Roux, F. G. 1994. The Geology of the Grahamstown Area.

Explanation booklet for Council for Geoscience sheet 3326 (1:250 000 scale). Government

Printer, Pretoria.

• Knight, K. (1961). The collapse structure of sand sub-soils on wetting. PhD thesis, Department

of Civil Engineering, University of the Witwatersrand, South Africa.

• Lewis, C. A. 1996. The Geomorphology of the Eastern Cape. Grocott & Sherry Publishers.

• Rahn, P. H. (1996). Engineering Geology, an Environmental Approach. Prentice Hall P T R, pp

657.

• Van Der Merwe, D. H. (1964). The prediction of heave from the plasticity index and

percentage clay fraction of soils. Transactions of the South African Institute of Civil Engineers,

Volume 6, No 6, pp103 to 107.

• Weather Bureau (1998). Climate of South Africa - Climate statistics: 1961 to 1990 (WB42).

Government Printer, Pretoria.

• Weinert H. H. (1980). The Natural Road Construction Materials of Southern Africa.

Academica, Cape Town.

APPENDIX 1

STORMS RIVER CEMETERY

GEOTECH INVESTIGATION

Figures

STORMS RIVERVILLAGE

Locality 1:150,000

LIMITS OF LIABILITY and DISCLAIMER of WARRANTYSetplan PE makes no warranty of any kind, expressed or implied, with regard to the data andshall not be held liable in any event for any incidental or consequential damages in connectionwith or arising out of the use of this data. The data remains the sole property of the CLIENTand may only be used with the prior written approval of the CLIENT.

Date: Plan No:February 2006 KK/Storms/01a

Client:KouKamma Municipality

FIGURE 1Locality plan of candidate cemetery sites

STORMS RIVER CEMETERYGeotechnical Investigation

Scale:

Notes and Amendments:

1:15,000

PLAATBOSNATURE

RESERVE

AkkerlaanForestryHousing

ForestryStation

!H!H

!H

!H

!H

!H

Site 5:Plantation

Site 1:Rugby Field

Site 4:National Road

Site 3:Keurboom Forest

Site 6:Existing Cemetery

Site 2:Adjacent Rugby Field

±

Legend

!H CANDIDATE SITE

ROAD

N2 National Route

Other

STORMS RIVERVILLAGE

Locality 1:150,000


Date: Plan No:February 2006 KK/Storms/01b


FIGURES 2 & 3trail pit locations at Sites 1 and 2

as alternative cemetery sites


Scale:


!H

!H

!H

!H

!H

!H

!H

!H

!H

PLAATBOSNATURE

RESERVE

AkkerlaanForestryHousing

ForestryStation

395

395

578RF3 (23.892°E -33.97562°S)

RF2 (23.8915°E -33.97548°S)

RF4 (23.89008°E -33.97402°S)

RF1 (23.89152°E -33.97525°S)

ARF3 (23.89235°E -33.97663°S)

ARF2 (23.89168°E -33.97638°S)

ARF1 (23.89052°E -33.97585°S)

Site 1:Rugby Field

Site 2:Adjacent Rugby Field

1:1,500

±

!H CANDIDATE SITE

!H TRAIL PIT LOCATION

ROAD

N2 National Route

Other Access

CONTOUR (20m)

PROPERTY BOUNDARY

Legend

STORMS RIVERVILLAGE

Locality 1:150,000


Date: Plan No:February 2006 KK/Storms/01c


FIGURE 4trail pit locations at Site 3



Scale:


!H!H

!H

!H

!H

395

578

118

KF4 (23.89068°E -33.96875°S)

KF3 (23.89072°E -33.96853°S)

KF2 (23.89098°E -33.96808°S)

KF1 (23.89078°E -33.96802°S)Site 3:Keurboom Forest

1:1,500

±

!H CANDIDATE SITE


ROAD

N2 National Route

Other Access

CONTOUR (20m)

PROPERTY BOUNDARY

Legend

STORMS RIVERVILLAGE

Locality 1:150,000


Date: Plan No:February 2006 KK/Storms/01d


FIGURE 5trail pit locations at Site 4



Scale:


!H!H

!H

!H

!H

STORMSRIVIERWEST

118

122

216

271

179

251

310

589

297

289309

302

172 173

301

622

288

269176

177

311

178 270

306 305

298221

174

299293

280283

307223

222

224

220282

290

219

295292

343

285

300

272

291294

287284

281

275

268

274273276

267

277 278 580

175

579 581 582

312

584583587586585

588

279218

286

296

308

266264 265262 263261260259

250

212

185

181

183182

213

184

214

256

215

255

252

254

180

253

NR3 (23.87825°E -33.9655°S)

NR2 (23.87683°E -33.9652°S)

NR4 (23.87517°E -33.96492°S)

NR1 (23.87623°E -33.96512°S)

Site 4:National Road

1:1,500

±

!H CANDIDATE SITE


ROAD

N2 National Route

Other Access

CONTOUR (20m)

PROPERTY BOUNDARY

Legend

APPENDIX 2

STORMS RIVER CEMETERY

GEOTECH INVESTIGATION

Trial Pit Profiles

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