waste impact report, january 2014, sec · dea&dp reference number 10/2/2/1/in10 of 2012 sec...

Waste Impact Report, January 2014, SEC

Ross Excavations (Pty) Ltd

FINAL WASTE IMPACT REPORT Infilling and Removal of Infill on a Portion of Wetland Situated on

Erf 1, Mfuleni.

June 2014

DEA&DP Reference Number 10/2/2/1/IN10 OF 2012 SEC Reference Number: 013041

PO Box 30134, Tokai, 7966 Telephone: 021 712 5060, Fax: 021 712 5061

Email: [email protected]

FINAL WASTE IMPACT REPORT

UNLAWFUL INFILLING AND REMOVAL OF INFILL IN A WETLAND SITUATED

ON A PORTION OF PORTION 2 OF REMAINDER OF ERF 1, MFULENI

TABLE OF CONTENTS ITEM PAGE

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

2 TERMS OF REFERENCE AND DETAILS OF ENVIRONMENTAL ASSESSMENT PRACTITIONER....................................................................................................................................... 2

3 RECEIVING ENVIRONMENT .................................................................................................................. 3

3.1 BIOPHYSICAL CHARACTERISTICS OF THE SITE....................................................................................................4

3.1.1 Geology ........................................................................................................................................... 4

3.1.2 Hydrology and Vegetation .............................................................................................................. 4

4 ACTIVITY DESCRIPTION ....................................................................................................................... 5

5 IDENTIFIED WASTE ............................................................................................................................... 6

5.1 LEGAL FRAMEWORK FOR CLASSIFICATION OF THE INFILL MATERIAL ..............................................................6

6 DESCRIPTION OF POTENTIAL IMPACTS ............................................................................................ 8

6.1 PHYSICAL PROPERTIES OF THE WASTE AND ASSOCIATED POTENTIAL IMPACTS ................................................8

6.2 TRANSPORTATION, DUMPING, REMOVAL AND LAWFUL DISPOSAL OF THE “CLEAN” RUBBLE: POTENTIAL

IMPACTS ........................................................................................................................................................................9

7 IMPACT ASSESSMENT ........................................................................................................................ 10

7.1 IMPACT ON THE ECOLOGICAL CONDITION AND FUNCTIONING OF THE MFULENI WETLAND .............................. 10

7.2 IMPACT ON HEALTH AND SAFETY OF SURROUNDING COMMUNITY ................................................................. 12

7.3 AESTHETIC IMPACTS ....................................................................................................................................... 12

7.4 IMPACT OF DISPOSAL OF FILL MATERIAL ON LANDFILL AIRSPACE ................................................................. 13

7.5 SUMMARY OF KEY FINDINGS OF THE IMPACT ASSESSMENT ............................................................................ 14

7.5.1 Uncertainties, Assumptions and Gaps in Knowledge ................................................................... 15

List of Figures

Figure 1 Site Location ............................................................................................................................. 3

SEC Reference 013041: Final Waste Impact Report: Erf 1, Mfuleni.

List of Appendices

Appendices

Appendix A Drawings

1) Site Location Maps 2) Site Photographs

Appendix B Terms of Reference Documents

1) Court Order, September 2012 2) Letter of Instruction from DEA&DP, September 2013

Appendix C Rehabilitation Plan

Appendix D Environmental Management Plan

Appendix E

Specialist Input 1) A Wetland Determination in the Mfuleni Area, June 2011: Dr Donovan

Kotze 2) Assessment of Wetland Infilling: Portion 2, Remainder of Erf 1, Mfuleni,

August 2013, Freshwater Consulting Group

Appendix F

1) Excerpt from a USEPA report, Characterization of Building-Related Construction and Demolition Debris in the United States, 1998, showing the typical constituents of construction and demolition debris.

2) Material Safety Data Sheet for Asbestos 3) City of Cape Town Letter on Waste Disposal Tariffs, June 2013


Glossary and Abbreviations

Glossary

Hazardous waste

Any waste that contains organic or inorganic elements or compounds that may, owing to the inherent physical, chemical or toxicological characteristics of that waste, have a detrimental impact on health and the environment.

General waste Waste that does not pose an immediate hazard or threat to health or to the environment.

Inert waste

Waste that: a. does not undergo any significant physical, chemical or biological

transformation after disposal; b. does not burn, react physically or chemically biodegrade or

otherwise adversely affect any other matter or environment with which it may come into contact; and

c. does not impact negatively on the environment, because of its pollutant content and because the toxicity of its leachate is insignificant.

Construction waste / building waste and Demolition waste

Waste, excluding hazardous waste, produced during the construction, alteration, repair or demolition of any structure, and includes rubble, earth, rock and wood displaced during that construction, alteration, repair or demolition.

Builder’s rubble

Builder’s rubble is generally accepted as comprising the following materials: concrete, bricks, tiles, ceramics, and gypsum based materials; wood; glass; plastic; asphalt, bitumen and bitumen products; metals; soil and dredged spoil; insulation materials; and mixed construction and demolition waste

Clean builder’s rubble

Concrete, bricks, tiles, ceramics, soil and possibly some asphalt.

Asbestos

Asbestos is an indigenous fibrous mineral that has been mined in a number of sites in Southern Africa and, because of its excellent resistance to heat, has been used for the manufacture of various products since the 1900’s.

Abbreviations

NEMA National Environmental management Act, Act No. 107 of 1998, as amended

NEMWA National Environmental Management: Waste Act, Act No. 59 of 2008

OHS Act Operational Health and Safety Act, Act No. 85 of 1993

DEA&DP Western Cape Department of Environmental Affairs and Development Planning

DWA Department of Water Affairs

Ross The applicant, Ross Excavations (Pty) Ltd

SEC Sillito Environmental Consulting

FCG Freshwater Consulting Group

MSDS Material Safety Data Sheet

EMP Environmental Management Programme

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FINAL WASTE IMPACT REPORT

UNLAWFUL INFILLING AND REMOVAL OF INFILL IN A WETLAND SITUATED ON A PORTION OF PORTION 2 OF REMAINDER OF ERF 1, MFULENI

1 INTRODUCTION

Remainder of Erf 1, Mfuleni, is a portion of land situated in the predominantly low income and

informally developed area of Mfuleni, Cape Town. The property is zoned for Limited Use in terms of

the City of Cape Town’s zoning scheme, and according to the City’s wetland layer, most of the site

constitutes wetland. The remaining portions, as well as some wetland areas on the site have been

transformed or developed in an informal capacity for livestock farming.

During 2009, an approximately 5400m2 area of wetland on Remainder Erf 1 was filled using

construction rubble. The infilling was undertaken by the applicant, Ross Excavations (Pty) Ltd

(“Ross”), on behalf of Luluma Lorraine Matyolo/Dube and others. The infilling was undertaken in

contravention of various national environmental legislation and regulations and so compliance

enforcement action was taken against Ross, Ms Matyolo/Dube and others by the Western Cape

Department of Environmental Affairs and Development Planning (DEA&DP). The enforcement action

culminated in a Court Order issued on behalf of the landowner and local authority, City of Cape Town,

stating that Ross was to remove the fill material in accordance with an approved rehabilitation plan.

However, during July 2013, it was established that the fill material had already been removed by

excavator and not in accordance with any approved rehabilitation plan. As such, the removal of the

infill constituted a contravention of the Court Order, with the added concern that the removal, not

being in accordance with an approved Rehabilitation Plan, exacerbated any negative impacts already

occurring in association with the original wetland infilling.

In September 2013, the DEA&DP issued a letter of instruction for Ross to proceed in a manner which

is, as far as possible, compliant with the intention of the Court Order. As such, SEC was appointed by

Ross to compile this Waste Impact Report, as well as an Environmental Management Plan to govern

any rehabilitation activities which need to take place on the wetland site. The EMP has been attached

as Appendix D.

Also in accordance with the DEA&DP’s letter of instruction, the Freshwater Consulting Group has

compiled a Rehabilitation Plan for the site. The Rehabilitation Plan provides a methodology for

rehabilitating the wetland area, and is attached as Appendix C.

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2 TERMS OF REFERENCE AND DETAILS OF ENVIRONMENTAL ASSESSMENT PRACTITIONER

Sillito Environmental Consulting (SEC) has been appointed as the independent Environmental

Assessment Practitioner (EAP) to fulfil the requirements of the letter of instruction issued by the

DEA&DP to Ross Excavations (Pty) Ltd on 03/09/2013. The letter requires that an independent EAP

is appointed to compile a Waste Impact Report and EMP to address the unlawful infilling and removal

of the infill on a portion of wetland on Portion of Portion 2 of the Remainder of Erf 1, Mfuleni. These

reports need to evaluate the impacts of the activity and provide recommendations for rehabilitating the

property in an environmentally sound manner.

The Terms of Reference for the Waste Impact Report are as follows. The report must include:

1) The volume of waste which was previously unlawfully removed from the wetland and safe

disposal certificates for the waste.

2) An assessment of the waste which was previously unlawfully removed, including an

assessment of the impact of the waste removal on the receiving environment and in

particular, the wetland water and soil.

3) An assessment of the impact of the disposal of the removed waste on the receiving

environment.

4) The volume and type of waste that remains on the property

5) The methods for the removal and disposal of the remaining waste and the estimated

timeframe for removal of all remaining waste.

6) The impact of the disposal of the remaining waste on the receiving environment.

7) An Environmental Management Plan must be compiled, which will include the duties of the

Environmental Control Officer; the routes which the trucks will follow when removing the

waste; and details on dust and noise management, ablution facilities, etc. in relation to

rehabilitation activities on the site. The EMP has been attached in Appendix D.

Please refer to the letter attached in Appendix B.

This Waste Impact Report was prepared by Colleen McCreadie of SEC, and reviewed by Adrian

Sillito. Adrian Sillito is a certified environmental assessment practitioner (CEAPSA), Professional

Natural Scientist (Pr.Sci.Nat.) and a member of the International Association for Impact Assessment

(IAIA). Adrian has seventeen years’ experience in the field of environmental management and impact

assessment. Colleen has an Economics Honours degree from UCT and has six years’ experience in

environmental management and impact assessment. She is a member of IAIA.

SEC has extensive experience in impact assessment processes and in environmental management.

SEC has completed many thousands of applications in terms of national environmental legislation in

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most provinces of South Africa since 1998. SEC does not have and will not have any financial interest

in the undertaking of the activity, other than remuneration for work performed in terms of the letter of

instruction issued by the DEA&DP. SEC has no vested interest in the outcome of legal proceedings

between the DEA&DP and Ross Excavations (Pty) Ltd.

3 RECEIVING ENVIRONMENT

The unlawful infilling of a wetland with construction waste, and the unlawful removal of the infill

material without the implementation of an approved Rehabilitation Plan, took place on a Portion of

Portion 2 of Remainder of Erf 1, Mfuleni. The area where the infilling and removal took place, or “the

site”, is an approximately 5400 m2 portion of the property, and is situated within a wetland which

covers a large percentage of the property.

Figure 1 Site Location

Image courtesy of the Freshwater Consulting Group

Wetland immediately surrounds the site. Just beyond that is situated small-scale market-garden type

agriculture. There are lots where vegetables are being grown and lots where livestock farming is

taking place: mostly goats and pigs. Just beyond the agricultural land use are informal residential

dwellings, with a more formalised, low income residential area, including a school, situated just

beyond.

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Much of the Remainder of Erf 1 is wetland, with some of the areas on the property which are being

used for small-scale agricultural use and informal residential use, encroaching on the wetlands. The

original unlawful infilling of the wetland on the site took place to increase the area available for pig

farming.

3.1 Biophysical characteristics of the site

3.1.1 Geology

According to the available 1:50 000 scale geological map for the area (3418 BA Mitchells Plain), the

site is underlain by Transported sediments of Quaternary Age comprising of white sand with finely

crushed shell; pebbles and shells in places along the beach. This is underlain at depth by

Malmesbury group bedrock comprising of phyllite; greywacke and quartzitic sandstone; interbedded

lava and tuff.

3.1.2 Hydrology and Vegetation

The 1:500 000 scale hydrogeological map series (3317 Cape Town) and the 1:3 000 000 scale

Aquifer Classification Map of South Africa compiled by the Department of Water Affairs indicates that

the site is underlain predominantly by intrusive granite and undifferentiated coastal deposits

(unconsolidated to semi-consolidated sediments including sand, calcrete, calcarenite, aeolianite,

marine gravel, clay, silcrete and limestone). This results in the formation of an intergranular and

fractured major aquifer with a vulnerability rating of “most vulnerable” and a “high” susceptibility

rating1.

The aquifer is further classified as having median borehole flow rates of >5.0 litres per second. Water

quality in terms of its electrical conductivity ranged between 70 and 300 mS/m which is considered

moderate.

According to the Freshwater Consulting Group’s wetland report undertaken during August 2013, the

site forms part of a broader wetland, a mosaic of depressions and wetland flats occurring on a plain.

The depressions drain inwards and there are no channelled inflows to the wetland, i.e. groundwater is

the major source of water input into the wetland, besides rainfall and localised runoff. The FCG also

found that there appears to be no surface connection between the broader wetland and the nearby

Kuils River, which lies about 500m east of the site.

According to the FCG report, the broader wetland within which the site lies has been categorised as

an Aquatic Critical Biodiversity Area 1 (CBA1), and is thus considered to be of particularly high

1Vulnerability: likelihood of contaminants reaching a specific position in the groundwater system after introduction at some location above the uppermost aquifer. Susceptibility: a qualitative measure of the relative ease with which a groundwater body can be potentially contaminated by anthropogenic activities and includes both aquifer vulnerability and the relative importance of the aquifer in terms of its classification.

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importance from a wetland biodiversity conservation perspective. The broader wetland also falls within

a corridor which is identified in the City of Cape Town’s Biodiversity Network as a Terrestrial CBA1,

i.e. the terrestrial vegetation is considered to be irreplaceable (Cape Flats Dune Strandveld, which is

categorised as Endangered in the national list of threatened ecosystems).

The FCG’s investigation also found, however, that the vegetation of the broader wetland has been

“significantly altered from its presumed natural state” and found to be largely modified due to

encroachment by human settlements. The water quality was found to be moderately modified due to

the development surrounding the area, with factors such as sewage inflows, livestock activities and

contaminated stormwater inflows affecting the water quality. The infill material is also considered to

have had a localised effect on water quality in the wetland due to leaching of cement residues and

other construction related materials.

Taking these factors into consideration, as well as determining the extent to which the wetland is likely

to be providing most of the potential ecosystem services it could provide (such as phosphate trapping

and flood attenuation), the FCG rated the broader wetland to be of moderate to high conservation

importance. Please refer to the FCG’s August 2013 report, which is contained in Appendix E, for more

information.

4 ACTIVITY DESCRIPTION

The unlawful activities which were undertaken are twofold: the original infilling of the wetland with

some 400 – 500m3 of clean builder’s rubble (according to the applicant), which has been determined

to have taken place between December 2009 and May 2010; and the unlawful removal of the fill

material without the implementation of an approved rehabilitation plan, which took place around June

2013.

According to a 2005 study undertaken by Ingerop on behalf of the City of Cape Town (Investigation

for the Management of Builders Rubble in the Metro), builder’s rubble is generally accepted as

comprising the following materials: concrete, bricks, tiles, ceramics, and gypsum based materials;

wood; glass; plastic; asphalt, bitumen and bitumen products; metals; soil and dredged spoil; insulation

materials; and mixed construction and demolition waste.

For a detailed breakdown of typical constituents of building waste, please refer to Appendix F, which

contains an extract from a report on the “Characterization of Building- Related Construction and

Demolition Debris in the United States” published by the USEPA in 1998.

“Clean” builder’s rubble, which is crushed to provide “clean” fill material for infilling purposes,

comprises concrete, bricks, tiles, ceramics, soil and possibly some asphalt (Pers. Comm, John Ross,

2013). From SEC’s second site visit in December 2013, the composition of the remaining fill material

suggests that mainly “clean” fill material was used as infill, with about <5% plastics, wood, etc.

included.

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The original wetland infill would have comprised transportation of the fill material to the site by heavy

vehicle, and tipping onto the site.

The removal of the rubble was undertaken by excavator after which it was removed from the location

by heavy vehicle. This is confirmed by photographs of the site during July 2013, supported by the

professional opinion of the Freshwater Consulting Group, who visited the site just after it had been

cleared. The FCG states in their August 2013 report that much of the site had been excavated to a

level lower than the existing ground level, resulting in the loss of topsoil over most of the site.

SEC’s second site visit of December 2013 confirmed that there is still some rubble remaining on the

site. The volume is estimated to be some 90m3, i.e. three truckloads.

5 IDENTIFIED WASTE

5.1 Legal Framework for Classification of the Infill Material

The infilling of the wetland was undertaken using “clean” building rubble: concrete, bricks, tiles,

ceramics, soil and some asphalt. All of these materials were noted at SEC’s site visit of December

2013. Please refer to Appendix A for a detailed photographic record. A significant quantity of waste

tyres also remain at the site; and a minor quantity of asbestos was also noted during the December

site visit. The origin of the waste tyres is unknown. The origin of the asbestos is also unknown, but

due to the minimal quantity and remnant nature, it can be assumed that it was included in the clean fill

material tipped by the applicant.

According to the 2013 National Waste Classification and Management Regulations (Regulation 4 (1)

read together with Annexure 1), building waste, asbestos waste and waste tyres do not require

classification: their properties are well known and the management of these waste types is already

governed by relevant legislation, including the National Environmental Management: Waste Act, Act

No. 59 of 2008 (NEMWA) and the 2001 Asbestos Regulations published in terms of the Operational

Health and Safety Act, Act No. 85 of 1993 (OHS Act).

“Clean” Building Rubble

According to the NEMWA, “building and demolition waste” is defined as “waste, excluding hazardous

waste, produced during the construction, alteration, repair or demolition of any structure, and includes

rubble, earth, rock and wood displaced during that construction, alteration, repair or demolition”.

According to the City of Cape Town’s Integrated Waste Management By-Law, 2008, "’building waste”

means waste produced through the construction, alteration, repair or demolition of any structure both

manmade and natural, and includes rubble, earth, wood and rock that is displaced during any

construction, alteration, repair or demolition, but excludes garden waste”.

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The fill material used for the infilling of the site is thus clearly legally defined as “building and

demolition waste” or as “building waste”. The NEMWA classifies building waste as “general waste”,

which is defined in the NEMWA as “waste that does not pose an immediate hazard or threat to health

or to the environment”.

Waste Tyres

Waste tyres are considered to be an inert waste, i.e. according to the NEMWA, “inert waste” is waste

that:

a) “does not undergo any significant physical, chemical or biological transformation after

disposal;

b) does not burn, react physically or chemically biodegrade or otherwise adversely affect any

other matter or environment with which it may come into contact; and

c) does not impact negatively on the environment, because of its pollutant content and because

the toxicity of its leachate is insignificant”

Being an inert waste, waste tyres are defined by the NEMWA as “general waste”.

Asbestos Waste

Asbestos waste is classified as a hazardous waste, which the NEMWA defines as “any waste that

contains organic or inorganic elements or compounds that may, owing to the inherent physical,

chemical or toxicological characteristics of that waste, have a detrimental impact on health and the

environment”.

Asbestos is considered to be hazardous due to the detrimental health impacts of respirable asbestos

fibres. These fibres are present in “raw” asbestos, crumbled asbestos products, on disposal

equipment and clothing which has been contaminated with asbestos, etc. Even the management of

asbestos in a non-friable form, such as asbestos sheets and pipes, is regulated due to the potential

for release of harmful fibres.

The management of asbestos waste is governed by the Asbestos Regulations published in 2001 in

terms of the OHS Act. This is primarily from the perspective of occupational human health. As a

hazardous waste, the management of asbestos waste is also governed by the NEMWA and all

relevant regulations such as the National Norms and Standards for Disposal of Waste to Landfill,

2013.

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6 DESCRIPTION OF POTENTIAL IMPACTS

6.1 Physical Properties of the Waste and Associated Potential Impacts

“Clean” Building Rubble

Being classified as general waste and comprising predominantly inert waste, the building rubble is

problematic mainly from the perspective of the physical impact on the wetland (alteration to hydrology

and geomorphology), unsightly dumping, and a safety hazard for people using the area: possible

sharp objects, etc. There is also the possibility of the leaching of cement residues from the rubble

which could possibly alter the pH and the salinity of the water within the wetland.

According to Ross, only “clean” builders rubble was used as fill material at the site. Observations at

SEC’s site visits support this assertion. The potential for more problematic leachate which could be

associated with construction waste (such as gases or leachate from sheet rock or plasterboard during

decomposition) is therefore considered to be negligible.

Waste Tyres

Waste tyres comprise relatively inert materials, with the only real risk associated with their disposal

being fire risk, which can negatively impact the surrounding community. The tyres are, however,

unsightly, and have been unlawfully dumped in contravention of various pieces of environmental

legislation (regulating activities near or within a wetland; regulating management and disposal of

waste; etc.).

Asbestos Waste

Asbestos waste is considered to be hazardous waste, since occupational exposure to respirable

asbestos fibres has detrimental health impacts: asbestosis can occur, which can result in secondary

lung infections, lung cancer, respiratory and cardiac failure, etc. Asbestos fibres can also be harmful if

swallowed on an acute basis. Please refer to the attached Material Safety Data Sheet for more detail

on the health impacts of the three commonly found forms of asbestos, which is contained in Appendix

F.

The isolated fragments of asbestos observed at the site therefore pose some risk to people using the

area around the wetland and should be removed in accordance with applicable regulations for

handling and disposal.

In terms of impact on the wetland soil and water, there have been studies undertaken which show

some impact by asbestos on wetland vegetation: oxidative stress and phytotoxicity2. The fragments of

asbestos observed during SEC’s site visit of December 2013 were very isolated, however. This

suggests that the potential impacts on freshwater ecology are likely to be limited.

2 http://www.ncbi.nlm.nih.gov/pubmed/15386121

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6.2 Transportation, Dumping, Removal and Lawful Disposal of the “Clean” Rubble: Potential

Impacts

Besides the potential impacts associated with the actual waste as described in Section 6.1, there are

other aspects of the unlawful infilling of the wetland, the unlawful removal of the fill material and the

eventual lawful disposal of the remaining fill material which have the potential for associated impacts.

Impact of Trucks and Excavators

Impacts include transforming the vegetation, hydrology and geomorphology of the edges of the

wetland just surrounding the site, where the trucks accessed the site to tip the rubble, and later where

the trucks and excavators accessed the site to unlawfully remove the rubble. The repeated trips could

have compacted the access points to some extent, as well as damaged vegetation.

Similarly, when the remaining rubble is lawfully removed in accordance with an approved

Rehabilitation Plan in due course, this impact can potentially occur.

Impact of Removal of Infill by Excavation

The unlawful removal of the rubble from the wetland, without the implementation of an approved

Rehabilitation Plan, entailed removal of the fill material by excavator only. The original Court Order of

11/09/2012 anticipated the potential for an even greater negative impact on the wetland than the

original infilling, by the removal of the topsoil and seed bank during infill removal activities. The Court

Order stipulated that the Rehabilitation Plan for the removal of the material must include the

requirement that the final layer of material is removed by hand in order to avoid the removal of topsoil.

The removal by excavator of the fill material, according to the Freshwater Consulting Group, caused a

complete loss of wetland plants in the cleared area; as well as a loss of topsoil. The topsoil would

have contained seeds and remnant plant material that may have resulted in the natural regeneration

of some of the vegetation. Therefore, the excavation reduced the rehabilitation potential of the site

significantly.

The removal of the fill material was also undertaken to a level below the existing ground level of the

area. According to the Freshwater Consulting Group, the hydrological functioning of the wetland may

be impacted by more extensive and/or deeper inundation than would have occurred before the

wetland was altered; and the geomorphology of the wetland was altered due to topographical

changes.

Impact of Disposal of Rubble

The fill material which was unlawfully removed, as well as the removal in due course of the remaining

rubble at the site, will impact on available landfill airspace. The applicant has advised that the rubble

which was already removed was disposed of at Coastal Park landfill site. According to the applicant,

no disposal certificates were obtained at the time. Information obtained from the City of Cape Town’s

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solid waste department suggests that no such certificates would have been issued at the time: from

June 2013 onwards, the City has not charged a tariff for the disposal to landfill of clean builder’s

rubble. Please refer to the City’s June 2013 letter of explanation on waste disposal tariffs, which is

contained in Appendix F.

Once the remaining rubble has been removed, the applicant has advised that it will similarly be

disposed of at the Coastal Park landfill site.

7 IMPACT ASSESSMENT

7.1 Impact on the ecological condition and functioning of the Mfuleni wetland

A wetland assessment of the site and the surrounding wetland on the Remainder of Portion 2 of Erf 1,

Mfuleni, was undertaken by the Freshwater Consulting Group in August 2013. The study assessed

the impacts of the wetland infilling and the subsequent removal of the fill material from the site. The

following methodology was used:

a) The present ecological condition of the affected wetland and the likely historical condition of

the wetland prior to the start of the infilling activities was established3

b) A qualitative evaluation of the most important ecosystem services (ecological functions) likely

to be provided by the affected wetland was made4; and

c) The conservation importance of the affected wetland was established5.

Based on these investigations, an assessment was made of the probable impacts of the infilling and

infilling-removal activities on the affected wetland area.

The FCG found the following:

“At a localised scale, the infilling and subsequent infilling-removal activities within the wetland

area on Erf 1, Mfuleni, have clearly had a major detrimental impact on a portion of the wetland...

In this disturbed area, there has been a complete loss of wetland plants, a large amount (if not

all) of the topsoil has been removed (which would have contained seeds and remnant plant

material that may have resulted in the natural regeneration of some of the vegetation), the local

topography has been altered, and there is likely to have been a localised alteration of the

hydrology (with more clay material relatively close to the surface than there was previously,

3 Ecological condition is determined by assessing hydrology, geomorphology, vegetation and water quality. 4 Ecological functions or ecosystem services include flood attenuation, nitrate removal, carbon storage, erosion control, etc. 5 Conservation importance is determined by factors such as the condition and characteristics of the greater wetland which the site forms part of, the nature of the land-use activities in the areas surrounding the wetland, whether the broader wetland forms part of an intact ecological corridor, etc.

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leading to ‘perched’ conditions, and the excavation below the existing ground level likely to result

in deeper inundation than before)…

The overall findings of this investigation were that the localised impacts of the infilling and

infill-removal activities on the ecological condition and functioning of the wetland on Erf 1,

Mfuleni, were of high intensity but that these activities only affected a small proportion of the

greater wetland area within which they occurred. The negative impacts on the Aquatic CBA

Wetland that was affected, which was not in pristine ecological condition when the activities

commenced, were rated to be of medium to high significance, taking into account the context

and scale of the impacts”

Please refer to the FCG’s August 2013 Wetland Report contained in Appendix E for more information,

including full details on the assessment methodology, detailed background information on the

condition of the wetland, etc.

Unless the removal of the remaining fill material takes place in accordance with the methodology

recommended in the Rehabilitation Plan contained in Appendix C, it can be expected that continued

removal activities will simply exacerbate the impacts which have been found to occur. The impacts

would worsen to a relatively minor degree considering the severity of the impacts already incurred,

and the small scale of the remaining fill material.

The trucks which were used to tip the building rubble and then the excavators and trucks used to

remove the rubble would have had some impact on the condition of the edges of the site: compacting

the ground; destruction of vegetation; etc. The Freshwater Consulting Group does not raise this as an

issue in their July 2013 assessment of the condition of the wetland, however. In addition, SEC’s site

visits of March and December 2013 found that the edges of the site are very heavily impacted: the

edges are being encroached on by the small scale farming activities taking place around the site; and

evidence of more widespread illegal dumping around the site is clear.

It is therefore considered likely that the vehicles which accessed and which will access the site

associated with the infilling and removal of the infill, did and will have negligible impacts. As a best

practice measure, the FCG has recommended that the vehicles that will be accessing the site for the

removal of the remaining rubble on the site should do so by the established pathways / informal

roadways to the site. These are illustrated in the Rehabilitation Plan contained in Appendix C.

Mitigation

The Rehabilitation Plan contained in Appendix C, once approved by the relevant authorities6, must be

implemented during the removal of the remaining fill material and the rehabilitation of the site.

6 The Western Cape Department of Environmental Affairs and Development Planning (DEA&DP); the Western Cape region of the Department of Water Affairs (DWA); and the City of Cape Town’s Environmental Resource Management and Catchment Management departments.

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7.2 Impact on Health and Safety of Surrounding Community

The waste tyres pose a fire risk at the site; the remnants of asbestos items such as roof sheets and

pipes represent a health risk to the community and especially to workers who will be removing the fill

material; and the building rubble represents some negative impact on the safety of the surrounding

community, e.g. children playing he in the area could be hurt by sharp concrete or tile fragments.

The removal of the remaining fill material and the removal of the waste tyres in an uncontrolled

manner could represent some risk to the community if standard health and safety measures are not

implemented, e.g. contractors driving under the influence of alcohol. The removal of the asbestos

remnants in an uncontrolled manner – i.e. not in accordance with statutory requirements – poses a

risk primarily to the contractors who will undertake the removal of the fill material and any persons

who may be in close proximity to the material.

Mitigation

Removal of the remaining fill material in accordance with the EMP attached in Appendix D will ensure

that any health and safety risks are minimised. The EMP contains standard best-practice measures

pertaining to handling of materials, contractor conduct on site, etc.

A registered asbestos contractor should be present during the removal of the remaining fill material at

all times. The asbestos contractor will identify asbestos remnants and ensure that they are handled

and disposed of in accordance with statutory requirements, such as the Asbestos Regulations, 2001;

the Department of Water Affairs and Forestry’s National Policy on the Handling and Disposal of

Asbestos in terms of the Environment Conservation Act; and the provisions of the NEMWA with

respect to hazardous waste handling and disposal (the National Norms and Standards for the Storage

of Waste, November 2013; the National Norms and Standards for Disposal of Waste to Landfill,

August 2013).

7.3 Aesthetic Impacts

The unlawful infilling of the wetland area on the site with building rubble represented an aesthetic

disturbance to the area. Similarly, the remaining rubble is unsightly. The area where the site is

situated is predominantly used for small scale agricultural activities and the sense of place is quite

rural with some informal residential development as well.

However, the site and surrounds is quite clearly a target area for illegal dumping. The eastern edge of

the site is inundated with waste tyres of unknown origin; and the informal access way to the site from

the north (depicted in Figure 3 of the Rehabilitation Plan) was edged by dumping (mostly construction

waste) in several places along the route when SEC conducted site visits during March and December

2013.

13


Mitigation

Whilst it is hoped that the removal of the remaining fill material and the site rehabilitation will restore

the site to a more rural sense of place, this is considered to be unlikely: the area is quite clearly a

known area for illegal dumping, there is no fencing or similar access control, and so the site is likely to

continue to be dumped on, with a detrimental impact on the aesthetic value of the area.

7.4 Impact of Disposal of Fill Material on Landfill Airspace

According to the applicant, the fill material already removed was disposed of at the Coastal Park

Landfill site. The remaining material is planned to be similarly disposed of at the Coastal Park site.

There are thus associated impacts in terms of use of scarce landfill airspace.

The applicant, Ross Excavations (Pty) Ltd is a demolition contractor and so is responsible for the

management of waste generated by other parties, i.e. there is no direct link between the activities

which Ross undertakes and the generation of waste.

However, Ross does have a choice in the manner in which the rubble is disposed of. The waste which

was and will be disposed of to landfill could easily be recycled. The crushing of clean building rubble

is a long-established practice with readily available equipment and proven processes. The crushed

aggregate is accepted for various construction specifications, such as bulk services engineering

(pavements, curbstones), roads and low-income housing.

The cost of recycling the rubble is however higher than the free disposal of clean rubble to the City’s

landfill sites (Ross are in the process of applying for a waste licence to establish their own crushing

facility, but the process has been delayed significantly due to an illegal land invasion, and the

subsequent unlawful commencement of crushing on a site where there is significant opposition from

neighbouring parties7).

The impact can therefore be viewed in one of two ways: as a direct impact associated with Ross

operations (demolition and transportation of construction waste); or as an impact associated with the

construction industry in South Africa, where the proponent of any particular construction or demolition

project is not held liable in terms of the “polluter pays principle” for the end disposal of their waste. In

such an environment, the waste generator is free to choose the waste management contractor which

is the least expensive. With the disposal of clean rubble being free at the City’s landfill sites; and there

being very few licensed rubble crushing facilities operational in the greater Cape Town metropole

(SEC is aware of only one, but there may be more as of 2014), recycling of rubble is not sufficiently

encouraged on an institutional level.

7 Section 24G Rectification Application for a rubble crushing facility at the Ross Maitland head office, Erf 117870, Maitland; DEA&DP Reference Number: 14/2/1/A7/13/Erf 117870, Maitland

14


Due to the quantities of rubble associated with the wetland infilling (according to the applicant, some

400 – 500m3), the impact can be considered to be minimal.

Mitigation

The only mitigation available is for the remaining rubble (estimated by SEC to be some 90m3) to be

crushed at a licensed rubble crushing facility.

7.5 Summary of Key Findings of the Impact Assessment

The impact assessment has found the following:

1) The impact on the ecological condition and functioning of the wetland were of high intensity

but localised, affecting only a small portion of the wetland situated on Erf1, Mfuleni. Due to the

scale of the impacts and the estimated ecological condition of the Aquatic CBA wetland area

before the infilling occurred, the impacts were found to be of medium to high significance.

2) The impact on the health and safety of the surrounding community due to the illegal dumping

of building rubble, minor remnants of waste asbestos and a significant quantity of waste tyres

was found to be quite low. This takes into account the scale of the activity and the

predominantly non-hazardous nature of the waste which was used as fill material.

3) The aesthetic impacts of the unlawful infilling of the wetland and subsequent removal of the fill

material are considered to be of medium significance: the surrounding area is quite rural in

nature, but there is high evidence of other ongoing illegal dumping activities, which detract

from the rural sense of place of the immediate area.

4) The impact of the disposal of the building rubble on scarce landfill airspace is considered to

be minimal, due to the quantities of rubble involved (some 400 – 500m3 of material has

already been disposed of, and some 90m3 of remaining material still needs to be disposed of).

Mitigation to be implemented should be as follows:

1) Once approved by the relevant authorities, the Rehabilitation Plan and Environmental

Management Programme contained in Appendices C and D respectively must be

implemented during the removal of the remaining rubble and the rehabilitation of the site.

2) The EMP must include construction industry best practice measures to govern aspects such

as materials management, employee conduct on site, and dust and noise management; detail

on ablution facilities; mechanisms for monitoring compliance with the EMP and the

Rehabilitation Plan; the responsibilities of the various parties for implementation of the EMP

and Rehabilitation Plan; and the environmental awareness training that will take place for the

contractors involved in the removal of the remaining rubble and the rehabilitation of the site.

15


7.5.1 Uncertainties, Assumptions and Gaps in Knowledge

The following uncertainties, assumptions and gaps in knowledge pertain to this impact assessment:

• It has been assumed that specialist findings are accurate and impartial; that mapping data

from sources such as Google Earth is accurate; and that information on the rubble quantities

provided by the applicant, is accurate.

• The origin of the waste tyres is unknown. The origin of the asbestos is also unknown, but due

to the minimal quantity and remnant nature, it can be assumed that it was included in the

clean fill material dumped by the applicant.

• Besides the above, there are no assumptions, uncertainties or gaps in knowledge which are

material to this application.

Report written by : Report reviewed by:

Colleen McCreadie Adrian Sillito

CEAPSA, Pr. Sci. Nat. I:\Jobs\SEC Jobs\013041\Outputs\Final Reports\013041 Final Waste Impact Report June 2014.docx

A Wetland Determination in the Mfuleni Area, June 2011, Dr Donovan Kotze

1

Mfuleni

A wetland determination in the Mfuleni area, Cape Town

DRAFT

Dr Donovan C Kotze Mondi Wetlands Programme

14 June 2010

Introduction

On 6 June 2011 the Department of Water Affairs requested urgent assistance from the Mondi Wetlands

Programme with a wetland determination in the Mfuleni area of Cape Town (Figure 1). This was in response

to illegal dumping of landfill material which had recently occurred on a suspected wetland. As an associate

of the Mondi Wetlands Programme, the request was forwarded to me, and I undertook a wetland assessment

on 9 June accompanied by Department of Water Affairs Staff.

The primary purpose of the assessment was to determine if the area on which illegal dumping of landfill had

occurred was a wetland or not. The DWAF (2006) guidelines and Kotze et al. (1996) were used as the basis

for carrying out the assessment, and recommendations were also given in terms of rehabilitating the site.

The visit also provided an opportunity to contribute to building the capacity of individuals within the

Department of Water Affairs.

Figure 1: Location of the site ( ), with wetland areas from the City of Cape Town’s wetland layer

represented in light green (source: Dr E Day).

In order to place the site in a broader context, it can be seen that it is located in low-lying land adjacent to

the Kuilsrivier which is very rich in wetlands (Figure 1). According to the wetland map for Cape Town, the

illegal dumping site is located well within wetland JES0593 (Figure 1). In the 2009 image (Figure 2) the

dark green tone of wetland vegetation on the site prior to dumping is clearly visible and in the 2010 image

2

(Figure 2a) the area covered by the dumped material can be seen contained within the dark green area

(Figure 2).

Figure 2: The site in 2/12/2009 prior to dumping (a) and 12/05/2011 subsequent to commencement of

dumping (b).

b

a

3

Methods

The National Water Act defines wetlands as “Land which is transitional between terrestrial and aquatic

systems where the water table is usually at or near the surface, or the land is periodically covered with

shallow water, and which in normal circumstances supports or would support vegetation typically adapted to

life in saturated soils.”

In the absence of long term data on the water table and flooding, soil morphology has been widely

demonstrated to be a very reliable indicator of the presence of the water table at or near the surface (Tiner

1993), and the natural vegetation growing at a site is also a reliable indicator, but may in some cases have

been removed, e.g. if replaced with a crop (Tiner 1993).

In determining whether the Mfuleni area is a wetland or not, the two primary sources of evidence examined

were the morphology of the soil and the vegetation occurring on the site, and supplementary sources of

information used were the presence and depth of saturated soil conditions and the landform setting (DWAF,

2006). These sources of evidence were examined at four sample points around the landfill, located

immediately adjacent to the edge of the fill itself. The GPS locations were recorded for each sample point

with a Garmin GPS 60, and photographs were taken of each sample point.

In describing the soil, particular note was taken of the chroma of the soil matrix, the presence of mottling

and other morphological conditions indicating prolonged saturated conditions. Soil was extracted with a

dutch screw soil auger, and a Munsell colour chart was used for describing the colour changes down the soil

profile. In describing the vegetation, note was taken of the dominant/sub-dominant plant species growing at

the sample site, in order to determine if the site supports hydric (wetland) species. The depth at which

saturated soil conditions were encountered directly was also measured and the landform setting of the site

noted.

Results and conclusions

At all four locations around the landfill both sources of primary evidence (soil and vegetation) indicated

very clearly that the area was a wetland (Box 1). All soil profiles had chromas of 2 or less and some

organic streaking or oxidised rhizospheres in the upper 50 cm of the profile. At all of the four sites the

vegetation was strongly dominated by wetland species (i.e. species adapted to saturated conditions) as listed

by Glen (2010) (Box 1).

In addition, free water indicating close to saturated conditions was encountered close to the soil surface at all

of the sample points despite the fact that the assessment was conducted early in the wet season and

following a relatively dry summer. Furthermore, all of the sampling sites and the overall site are located

within a depressional landform setting, which is conducive to the retention of water and promoting wetland

conditions.

Box 1: Sample point descriptions

Sample point 1 (34 00 36.3S and 18 40 41.0E) Photo 1 and 2

Soil description

0-5cm: 10YR 4/1.5 loam

5-20 cm: 10YR 6/1 with 6/1.5 blotches, sandy loam

20-45 cm: 10YR 7/1 with 7/2, sandy loam

4

45-50 cm: as above but with free water

50-60 cm: 10YR 7/2 with 10YR 7/1 blotches, loamy sand with free water

Based on the above the soil is concluded to be hydric (i.e. a wetland soil) and seasonally saturated

Vegetation

Wetland species: Elegia tectorum, Juncus kraussii, cf. Centella sp., Stenotaphrum secundatum

Sample point 2 (34 00 35.6S and 18 40 42.6E)Photo 3 and 4

Soil description

0-5cm: 10YR 4/1 loam

5-20 cm: 10YR 5/1 with 6/2 blotches, sandy loam

20-35 cm: 10YR 7/2 with few 3/1 streaks, loamy sand

35-55 cm: 2.5 Y 7/1.5 loamy sand with free water

Based on the above the soil is concluded to be hydric and seasonally saturated

Vegetation

Wetland species: Elegia tectorum, Juncus kraussii, cf. Centella sp.. Facultative species: Cynodon dactylon

Sample point 3 (34 00 34.8S and 18 40 47.4E)Photo5 and 6

Soil description

0-10cm: 2.5Y 2/1 with 5/1 blotches, sandy loam

10-20 cm: 2.5Y 7/2 with 5/1 blotches, sandy loam

20-35 cm: 2.5Y 7/2 with few orange oxidised rhizospheres, sandy loam

35-45 cm: 2.5Y 7/2 with 2.5 Y 5/1 streaks/blotches

45-55 cm: 2.5Y 7/2 loamy sand with free water


Vegetation

Wetland species: Elegia tectorum, cf. Centella sp. ,

Facultative species: Willdenowia teres, Stenotaphrum secundatum,

Sample point 4 (34 00 34.6S and 18 40 41.8E) Photo7

Soil description

0-10cm: 7.5YR5/4, loam (soil washed in from the landfill)

10-20cm: 10YR 6/2 with 5/1 blotches

20-25 cm: 10YR/5/1 with 10YR6/2 blotches, sandy loam

25-40cm: 10YR 6/1 with 6/2 blotches and few oxidised rhisospheres

40-50 cm: 10YR7/2 sandy loam with few oxidised rhizospheres

50-60 cm: 2.5Y7/2 sandy loam

60-70 cm: 2.5Y7/2 sandy loam with free water


Vegetation

Very disturbed; Wetland species: Elegia tectorum , cf. Centella sp.

Facultative species: Willdenowia teres

The infilling has raised the ground surface over a metre above the natural ground level, the wetland

character of the area beneath the dumped material has been lost and its functionality critically compromised.

The local impact on natural habitat and biodiversity is also high given that the vegetation on which the

5

dumping occurred was still in reasonably good condition. This is based on the fact that most of the

vegetation immediately adjacent to the dumping is still in reasonably good condition and that in the Google

image in the year before the dumping (Figure 2b) the colour and texture of the image in the dump site and

immediately adjacent to the site are much the same. Thus, prior to the dumping the vegetation beneath the

dump site can be assumed to have been in a similar condition to that which now remains immediately

adjacent to the dumping. Overall therefore, the local impacts are considered to be very high, which is of

further significance given the very high cumulative loss of lowland wetlands in the greater Cape Town area.

Thus, rehabilitation of the area is recommended.

Rehabilitation recommendations

Much of the impacts could be reversed if all of the fill material was carefully removed. Although many of

the plants are likely to have been killed beneath the fill material, it is likely that many propagules would

have survived. These propagules could then promote regeneration of the vegetation once the fill was

removed. Regeneration would also be promoted from adjacent wetland areas, particularly the immediately

adjacent areas. Encouraging regeneration of the vegetation was observed at Moddervlei, a similar wetland

type in the Cape Town area which was infilled and then rehabilitated through the removal of the fill (Day et

al., 2005). However, it is very important to emphasize that the removal needs to be very carefully executed.

Firstly, the adjacent area of intact wetland should not be disturbed, e.g. by being driven on by vehicles.

Secondly, complete removal is required, but no more than that, i.e. leaving the original topsoil in an intact

state. This will require that the final layer of fill material be removed by hand. It may also be that the area

beneath the fill will have become compacted, in which case, measures will also be required to mitigate this.

References

DAY E, BIRD M, DAY J, 2005. Biodiversity and ecological significance of the Moddervlei – a partially

restored seasonal wetland on the Cape Flats, Western Cape. Report to the Table Mountain Fund, Cape

Town. TMF project number ZA571.

DWAF, 2006. A practical field procedure for identification and delineation of wetlands and riparian areas.

Department of Water Affairs and Forestry, Pretoria.

GLEN, R. 2010 Annotated checklist of the wetland flora of southern Africa. National Botanical Institute,

Pretoria.

KOTZE D C, HUGHES J C, KLUG J R, and BREEN C M, 1996. Improved criteria for classifying hydric

soils in South Africa. S. Afr. J. Plant Soil 13: 67-73.

TINER R W, 1993. The primary indicators method – a practical approach to wetland recognition and

delineation in the United States. Wetlands 13: 50-64.

Assessment of Wetland Infilling: Portion 2, Remainder of Erf 1, Mfuleni, August 2013,

Freshwater Consulting Group

9 Orca Close Kommetjie 7975

Cell: 072 377 7006 Email: [email protected]

PORTION 2 OF REMAINDER OF ERF 1, MFULENI:

ASSESSMENT OF IMPACTS OF WETLAND INFILLING AND

PROVISION OF REHABILITATION RECOMMENDATIONS

--- DRAFT REPORT FOR COMMENT ---

Prepared for:

Sillito Environmental Consulting

Suite 105, Block B2, Tokai Village Centre

Vans Road, Tokai 7966

Prepared by: Dean Justin Ollis Pr. Sci. Nat.

July 2013

The Freshwater

Consulting Group

Assessment of wetland infilling: Portion 2, Remainder of Erf 1, Mfuleni

Table of Contents

Acknowledgements

1. Introduction ....................................................................................................................................... 1

1.1. Background .................................................................................................................................. 1

1.2. Terms of reference ....................................................................................................................... 1

2. Approach to and limitations of the investigation ................................................................................ 2

2.1. Approach ...................................................................................................................................... 2

2.2. Limitations ................................................................................................................................... 4

3. Description of the affected wetland and surrounding areas ............................................................... 4

3.1. Current situation (May 2013) ........................................................................................................ 4

3.2. Historical analysis ........................................................................................................................12

4. Assessment of the impact of the infilling and infilling-removal activities ...........................................15

5. Conclusions .......................................................................................................................................17

6. Recommendations ............................................................................................................................18

6.1. On-site measures for the rectification of impacts ........................................................................18

6.2. Rehabilitation of off-site wetlands ...............................................................................................18

7. References ........................................................................................................................................21

Appendix 1: Historical aerial photos and Google Earth images of the study area


Acknowledgements

The following people are gratefully acknowledged for their assistance with this project:

Matthew Bird for assistance with the fieldwork and the provision of historical data and photographs.

Nancy Job for useful discussions and input regarding the recommendations.

City Maps (CCT GIS Department), in particular Niyaaz Ramjam, for the provision of georeferenced, high-

resolution colour aerial photographs of the study area.

Colleen McCreadie (SEC) for provision of background information.


1

1. Introduction

1.1. Background

In September 2012, a Court Order was issued to Ross Demolition, in response to an application against the

company by the City of Cape Town for the illegal infilling of a wetland on Portion 2 of a remainder of Erf 1,

Mfuleni with building rubble. The Order instructed Ross Demolition to engage the services of a suitably

qualified and experienced Environmental Assessment Practitioner (EAP), at their own cost, to prepare a

Waste Impact Report, which must include an Environmental Management Programme (EMP) and a

Rehabilitation Plan for the removal of infill from the affected wetland. The Court Order stated, further, that

the EMP and Rehabilitation Plan must be submitted to the City of Cape Town and the Western Cape

Department of Environmental Affairs & Development Planning (DE&DP) for approval prior to the

commencement of any implementation of in respect thereof, and that such approval may only be given

after consultation with the Department of Water Affairs (DWA). Within 30 days of approval of the EMP and

Rehabilitation Plan, Ross Demolition were to commence with the implementation of rehabilitation of the

affected environment, under the supervision of a suitably qualified and experienced Environmental Control

Officer (ECO). Upon completion of the rehabilitation measures, a Post-rehabilitation Report was to be

submitted to DEA&DP, DWA and the City of Cape Town, which should include verification from the ECO

that the rehabilitation was completed in accordance with the approved plans, followed by an inspection of

the affected environment by DEA&DP, DWA and the City of Cape Town so as to ensure that all the

rehabilitation objectives contained in approved plans have been achieved.

Sillito Environmental Consulting (SEC) was appointed by Ross Demolition as the EAP to prepare the Waste

Impact Report and accompanying documents. Dean Ollis of the Freshwater Consulting Group (FCG) was

subsequently sub-contracted by SEC to conduct an assessment of the affected wetland and compile the

required Rehabilitation Plan, and to conduct a follow-up assessment to evaluate the implementation of the

Rehabilitation Plan.

Upon conducting an initial site visit on 7 May 2013, it was discovered by FCG that the majority of the infill

within the wetland area on Erf 1, Mfuleni, had already been removed. As such, the original scope of work

had to be adjusted.

1.2. Terms of reference

The modified terms of reference for FCG’s input into this investigation (as agreed upon between SEC, FCG

and the City of Cape Town) were as follows:

Assess and report on the current baseline conditions of the wetland area.

Establish the probable impact which the infilling of the wetland had on the ecological value and

functioning of the wetland, for inclusion in the Waste Impact Report to be compiled by SEC.

Compile a draft Rehabilitation Plan that provides recommendations for restoring the ecological viability

and functioning of the affected wetland.

Finalise the Rehabilitation Plan after input on the draft report has been obtained (via SEC) from the City

of Cape Town, DEA&DP and DWA.

Undertake a follow-up site visit once the Rehabilitation Plan has been implemented.

Compile a short report on the ecological effectiveness of the implementation of the Rehabilitation Plan,

for inclusion in the post-rehabilitation audit report to be compiled by SEC for submission to the

relevant authorities.


2

2. Approach to and limitations of the investigation

2.1. Approach

The approach taken by FCG to providing the required freshwater ecological input into this investigation was

as follows:

All available information and documentation pertaining to the infilling of the wetland on the subject

property was reviewed.

A GIS version of the most recent (2012) edition of the City of Cape Town’s Wetlands Map was examined

to ascertain whether any wetlands or other freshwater ecosystems of have been identified on or in

close proximity to the subject property, and to note what the conservation status is of any mapped

wetlands in the area.

Relevant maps, aerial photographs and Google Earth imagery of the study area were examined,

including historical imagery, to gain an understanding of the contextual setting for the required

Rehabilitation Plan.

A site visit to the infilled wetland area was undertaken on 7 May 2013, during which the approximate

extent of the wetland that has been affected by the infilling (and infilling-removal) activities was

delineated, the characteristics of the affected wetland (and surrounding areas) were noted, and

observations of the nature and extent of the impacts were made.

Maps showing the location and approximate extent of the affected wetland area in relation to the

surrounding areas were compiled, from a few years before the start of the infilling activities to the

most recent time period for which imagery is available.

Historical photographs and data (for water quality, vegetation, aquatic macroinvertebrates, and habitat

integrity) that were collected from the affected wetland area in 20071 were collated and analysed, to

gain a better understanding of the ecological condition of the wetland before the infilling activities.

The present ecological condition of the affected wetland and the likely historical condition of the

wetland prior to the start of the infilling activities were categorised (on a rating scale of A to F, as per

Table 1), using the WET-Health “Level 2” assessment technique (after Macfarlane et al. 2009), which

entails a relatively detailed and comprehensive assessment (versus a rapid and largely desktop-based

assessment at “Level 1”).

A qualitative evaluation of the most important ecosystem services (ecological functions) likely to be

provided by the affected wetland was made, using the WET-EcoServices assessment method (after

Kotze et al. 2009).

The conservation importance of the affected wetland was categorised (as high, medium or low) using

an approach developed by FCG for rating the conservation importance of wetlands on the basis of a

number of ecological criteria (see Table 2). The results of the WET-EcoServices assessment (see above)

were used to inform the evaluation of wetland importance.

Based on the information obtained through completion of the above-mentioned investigations, an

assessment was made of the probable impacts of the infilling (and infilling-removal) activities on the

ecological condition and functioning of the affected wetland area.

Rectification and rehabilitation measures were formulated, which are considered to be most

appropriate for the current situation on the subject property.

A draft report was compiled (the current report), which provides a discussion of the assessment of the

probable impacts of the infilling (and infilling-removal) activities on the affected wetland area that was

1 The affected wetland was one of the sampling sites for the Wetlands Health and Importance (WHI) Research Programme conducted under the auspices of the Water Research Commission (see Day & Malan 2010).


3

undertaken, and recommendations for the rectification of the impacts and what are considered to be

the most appropriate wetland rehabilitation measures.

Table 1: Ecological condition categories (from DWAF 1999, after Kleynhans 1996)

CATEGORY DESCRIPTION SCORE (% OF TOTAL)

A Unmodified, natural. 90-100

B Largely natural with few modifications. A small change in natural habitats and biota may have taken place but the ecosystem functions are essentially unchanged.

80-90

C Moderately modified. A loss and change of natural habitat and biota have occurred but the basic ecosystem functions are still predominantly unchanged.

60-79

D Largely modified. A large loss of natural habitat, biota and basic ecosystem functions has occurred.

40-59

E The loss of natural habitat, biota and basic ecosystem functions is extensive.

20-39

F Modifications have reached a critical level and the ecosystem has been modified completely with an almost complete loss of natural habitat and biota. In the worst instances the basic ecosystem functions have been destroyed and the changes are irreversible.

0-19

Table 2: Criteria used to assign low, moderate or high conservation importance to the affected wetland (note that the highest category applicable to any wetland, based on any one criteria, is the one accorded the wetland as a whole) [from Ewart-Smith & Ractliffe (2002)]

Low conservation importance:

does not provide ecologically or functionally significant wetland habitat, because of extremely small size or degree of degradation; and/or

of extremely limited importance as a corridor between systems that are themselves of low conservation importance.

Moderate conservation importance:

provides ecologically significant wetland habitat (e.g. locally important wetland habitat types); and/or

fulfils some wetland functional roles within the catchment; and/or

acts as a corridor for fauna and/or flora between other wetlands or ecologically important habitat types; and/or

supports (or is likely to support) fauna or flora that are characteristic of the region and/or provides habitat to indigenous flora and fauna; and/or

is a degraded but threatened habitat type (e.g. seasonal wetlands); and/or

is degraded but has a high potential for rehabilitation; and/or

functions as a buffer area between terrestrial systems and more ecologically important wetland systems; and/or

is upstream of systems that are of high conservation importance.

High conservation importance:

supports a high diversity of indigenous wetland species; and/or

supports, or is likely to support, red data species; supports relatively undisturbed wetland communities; and/or

forms an integral part of the habitat mosaic within a landscape; and/or

is representative of a regionally threatened / restricted habitat type; and/or

has a high functional importance (e.g. nutrient filtration; flood attenuation) in the catchment; and/or

is of a significant size (and therefore provides significant wetland habitat, albeit degraded or of low diversity).

It is anticipated that the current report will be circulated to the relevant officials at the City of Cape Town,

DEA&DP and DWA, and to Ross Demolition, for their comment and input. Once comments have been


4

received from the various parties and taken into account, the report will be finalised for consideration by

the City of Cape Town and DEA&DP as the required Rehabilitation Plan.

2.2. Limitations

The following limitations apply to the investigation undertaken by FCG for this project:

The total extent of the broader wetland area within which the infilling and infill-removal activities were

undertaken was not accurately delineated, but the approximate extent of this wetland was obtained

from the City of Cape Town’s Wetlands Map.

No site visit to the affected area was undertaken by FCG when the infill material was still present.

There were relatively large time-gaps (up to one year) in the availability of historical aerial imagery

(colour aerial photographs and Google Earth imagery) for the study area.

Very little background information was available for the affected wetland area, with the only historical

data that could be obtained having been collected 2 to 3 years before the infilling activities started.

3. Description of the affected wetland and surrounding areas

In the sub-sections below, a description of the affected wetland on Erf 1, Mfuleni, at the time of the site

visit by FCG (in May 2013) and of the surrounding areas is given, followed by a description of the wetland

and surrounding areas in the preceding years dating back to before the start of the infilling activities. This

provides a baseline for the assessment of the infilling (and infilling-removal) activities presented in Section

4 of the current report.

3.1. Current situation (May 2013)

At the time of the site visit by FCG (7 May 2013), the infill material that had previously been dumped in the

wetland on Portion 2 of the remainder of Erf 1, Mfuleni, had been mostly removed (see photo in Figure 1)

but car tyres that had apparently been used to build structures for livestock on top of the infilled area were

still present (see photo in Figure 2) and it was evident that not all of the rubble had been removed (e.g. see

photo in Figure 3).

Figure 1: Photo showing a portion of the cleared area within a broader wetland area (note the wetland vegetation along the edges of the cleared area, in the foreground and on the left)


5

The rubble had clearly been removed by earth-moving machinery and, over a large portion of the cleared

area, material had been excavated to a level lower than the existing ground level (e.g. see photo in Figure

4). The infill-removal activities, therefore, appear to have resulted in the loss of topsoil over most of the

previously infilled area. In addition, over the whole of the cleared area, there were still pieces of rubble

(mostly bricks) left behind by the earth-moving operations. The soils within the cleared area consisted of a

mixture of sand and clay, and they were saturated to the surface, with free water (indicating the level of

the localised water table) present within 30 cm of the ground surface towards the centre of the cleared

area.

Figure 2: Tyres left behind after the clearing of the infill

Figure 3: Rubble left behind after the clearing of the infill


6

At the time of FCG’s site visit, there was a herd of pigs foraging in and around the cleared area (see photo in

Figure 5) and, surrounding the cleared area, there were a number of informal houses and livestock pens

(e.g. see photo in Figure 6).

Figure 4: A portion of the cleared area where material was excavated to a level below the existing ground level (also note loose bricks and other rubble still present in the cleared area)

Figure 5: Pigs foraging in and around the cleared area at the time of the site visit (excavation of material to below existing ground level also apparent in this photo)


7

Immediately adjacent to the north-eastern edge of the cleared area, there was a relatively intact and

relatively extensive patch of indigenous wetland vegetation (see photo in Figure 7). Wetland plant species

observed here included the rush Juncus kraussii, the sedge Ficininia nodosa, the restio Elegia tectorum and,

unexpectedly along the edges, the low-growing salt-marsh plant Sarcorcornia sp. The soils in this area

consisted of mostly of lightly saturated greyish sand, with scattered fragments of rubble material present

(possibly indicative of some historical infilling in the area).

Based on the site visit (e.g. see Figures 1 and 7) and an analysis high-resolution colour aerial photographs

obtained from the City of Cape Town (see Figure 8 and Appendix 1), it could be seen that the cleared area

that had previous been filled in forms part of a broader wetland area. This broader wetland area has been

captured on the City of Cape Town’s Wetlands Map (February 2012 version) and is shown as a green

outline on the maps in Appendix 1 and in Figure 8. The broader wetland was classified by FCG as a mosaic

of depressions and wetland flats occurring on a plain, with the depressions being endorheic (inward-

Figure 6: A livestock enclosure adjacent to the cleared area, with chickens and geese (there are a number of similar livestock enclosures in the surrounding area)

Figure 7: A relatively intact portion of the broader wetland adjacent to the cleared area (immediately to the north-east), with indigenous wetland vegetation present


8

draining) with no channelled inflows (following the classification system of Ollis et al. 2013). Although the

Kuils River is relatively close to the wetland (approximately 500 m to the east), there does not appear to be

any present-day surface connection between the river and the wetland. The area that was filled in

represents approximately 7% of the total extent of the broader wetland, which is approximately 8 ha in

size.

Figure 8: Location of the disturbed (previously infilled) area on Erf 1, Mfuleni, in relation to the broader wetland (as delineated on the City of Cape Town’s Wetlands Map), overlaid on a high-resolution colour aerial photograph from December 2012 (obtained from the City’s GIS Department) when the infill material was still present (note presence of what are apparently livestock structures on top of infill)

According to a wetland prioritisation exercise undertaken by Snaddon & Day (2009) for the City of Cape

Town, the broader wetland within which the infilling activities were undertaken on Erf 1, Mfuleni, was

categorised as an Aquatic Critical Biodiversity Area, Category 1 (Aquatic CBA1) – these represent the

highest ranking natural or semi-natural wetlands within each type (top quarter of total scores) and are thus

considered to be of particularly high importance from a wetland biodiversity conservation perspective. The

wetland occurs within a corridor of the City of Cape Town’s Biodiversity Network that has been categorised

as a CBA1b site, representative of sites that are considered to be irreplaceable and of high or medium

condition from a terrestrial flora perspective. The dominant terrestrial vegetation type in the area is Cape

Flats Dune Strandveld (after Mucina & Rutherford 2006 and according to the more detailed vegetation map

of the City of Cape Town), which has been categorised as an Endangered terrestrial ecosystem type

according to the national list of ecosystems that are threatened and in need of protection published in

terms of the National Environmental Management: Biodiversity Act (Act No. 10 of 2004) (in Government

Notice No. 1002 of December 2011).


9

Wetland assessment results (May 2013)

The overall results of the assessment of the present ecological condition of the affected wetland, taking the

entire wetland area as captured on the City’s Wetlands Map into consideration, are summarised in Table 3,

below.

Table 3: Results of assessment of present ecological condition of affected wetland immediately after the clearing of the infill (compare with Table 4)

Present ecological condition: May 2013 (soon after clearing of infill)

Component Ecological Category (A-F)a Anticipated trajectory of changeb

Hydrologyc B ↓

Geomorphologyd B/C ↓

Vegetationc D ↓↓

Water qualitye C ↓ a See Table 1 for description of categories. b ↓ = condition is likely to slowly deteriorate over the next 5 years; ↓↓ = rapid deterioration is expected. c Assessed using the appropriate WET-Health Level 2 module. d Assessed on the basis of professional opinion, using the WET-Health Level 2 assessment framework as a guide (the geomorphology module of WET-Health is not directly applicable to depressions and wetland flats). e Assessed using an Excel model for the tentative categorisation of the Present Ecological Status (PES) of water quality within a wetland, which is based primarily on the estimation of the extent of different land-uses in the catchment of a wetland, as presented in the Manual for the Rapid Ecological Reserve Determination of Inland Wetlands (Rountree et al. 2013).

The present hydrological functioning of the broader wetland within which the infilling and infilling-removal

activities were undertaken was rated to be largely natural with few modifications (Ecological Category B),

based on the assumption that the hydrology of the wetland is dominated by the rise and fall of the regional

water table associated with the underlying (unconfined) Cape Flats Aquifer, with the possibility of a

‘perched water table’ in areas where there is an underlying clay subsoil layer relatively close to the ground

surface. The anticipated trajectory of change is a slow deterioration over the next five years due to the

likely encroachment of urban and peri-urban development into the wetland as the pressure to move into

marginal land in the Mfuleni area increases. Despite the high degree of urban development in the areas

surrounding the wetland (and within certain portions of the wetland itself), the rising water table in winter

still appears to result in the seasonal saturation of soils within the wetland and shallow inundation of

depressions within the wetland area. The hydrological functioning of the portion of the wetland that was

filled in with rubble and other material would have been significantly affected while the infill material was

still in place because the ground level would presumably have been raised above the level where there

would be seasonal inundation and saturation of the soils. Subsequent to the removal of the infill, the

affected area is now below the surrounding ground level (as described above) and may experience more

extensive and/or deeper inundation than it would have before the infilling – this area only represents 5 to

10% of the broader wetland area, however, so the overall effect of this on the hydrological functioning of

the entire wetland is not considered to be of particularly high significance.

The main impact on the geomorphology of the affected wetland has been topographic alterations and

associated infilling/deposition within the wetland. Besides the disturbed area of the wetland under

investigation, where rubble was deposited into a seasonally inundated portion of the wetland (apparently

to allow for the establishment of livestock enclosures in the area), there appears to have been localised

infilling elsewhere within the broader wetland where houses and/or roads have been established. The

overall present-day geomorphological condition of the broader wetland area was rated to be largely

natural to moderately modified (Ecological Category B/C), and the anticipated trajectory of change is a slow


10

deterioration over the next five years (assuming that urban and peri-urban development will encroach

more and more into the wetland area over time). The geomorphological modification of the disturbed area

that was infilled and then cleared has, obviously, been substantial (especially when the infill material was

still present) but this area only represents approximately 7% of the overall wetland area.

The vegetation within the broader wetland area has been significantly altered from its presumed natural

state, with only a few patches of relatively intact indigenous vegetation remaining and even these areas

only contain hardy indigenous plant species (it is presumed the natural assemblage of plants that occurred

within the wetland would have been more diverse than that which remains today). Land-uses that have

already encroached into the wetland include housing development (including some gardens), roads and

other infrastructure, livestock-related agricultural development and grazing, and infilling. Overall, the

degree of alteration of the vegetation within the broader wetland was rated to be largely modified

(Ecological Category D), with rapid deterioration anticipated in the next few years as development pressure

on the land increases resulting in more encroachment by a variety of land-uses into the wetland.

The water quality within the wetland was rated to be moderately modified (Ecological Category C), with the

major sources of pollution likely to be diffuse inputs from the increasingly urbanised areas surrounding the

wetland (such as sewage inflows from areas that are not connected to a waterborne sewage treatment

network, and contaminated stormwater runoff from roads and industrial areas), and inputs from the

livestock-related activities within and in close proximity to the wetland. It is presumed that the water

quality of the wetland is affected by activities that impact on the quality of the underlying groundwater,

which can be located relatively far away from the wetland but above the same aquifer, as this is considered

to be the major source of water input into the wetland (besides direct precipitation and localised runoff).

The rubble that was dumped in the wetland would most likely have had a localised effect on the water

quality of that portion of the wetland, when the rubble was still present, through the leaching of cement

residues and other substances from the foreign material (which would possibly alter the pH and the salinity

of the water within the wetland).

The results of the WET-Services assessment for the wetland on Erf 1, Mfuleni (as summarised in Figure 9)

revealed that the extent to which the wetland is likely to be providing most of the potential ecosystem

services is only at a moderately low to intermediate level, with the exception of three ecosystem services

(phosphate trapping, nitrate removal, and biodiversity maintenance) that are possibly being provided to a

moderately high extent (with overall scores >2). The regulating services of flood attenuation, streamflow

regulation and erosion control are not being provided by the wetland because it is not directly connected

to a stream drainage network. The relatively high scores obtained for phosphate trapping and nitrate

removal are largely due to the low gradient of the wetland (being located on a plain), the presence of

depressions, and the vegetated nature of relatively large portions of the wetland. The relatively small size

of the wetland (<10 ha) and the general lack of water flow through the system (most of the water

movement within the wetland is predicted to be in the form of vertical fluctuations, as opposed to

horizontal flows) would, however, limit the degree to which the wetland would actually be assimilating

nutrients. A relatively high score was obtained for the maintenance of biodiversity because the wetland is

considered to be a wetland type (i.e. Strandveld depression / wetland flat in the City of Cape Town)

subjected to a high level of cumulative loss (located within a nationally threatened vegetation type, namely

Cape Flats Dune Strandveld), and the level of cumulative loss of wetlands in the overall catchment has been

relatively high. If Red Data species (or viable habitat for Red Data species) were confirmed to be present in


11

the wetland, such as certain endemic frog species that could occur in the region, the extent to which the

wetland would be maintaining biodiversity would be greater.

Figure 9: Summary of the WET-EcoServices results for the broad wetland area on Erf 1, Mfuleni, displayed as a ‘spider diagram’ (according to the scoring guidelines, the likely extent to which each of the potential ecosystem services is being supplied by a particular wetland would be ‘low’ to ‘moderately low’ for scores ≤ 1.2, ‘intermediate’ for scores of 1.3-2.0, ‘moderately high’ for scores of 2.1-2.8, and ‘high’ for scores >2.8)

Overall, the broader wetland area that was impacted by the infilling and infilling-removal activities on Erf 1,

Mfuleni, was rated to be of moderate to high conservation importance. The reasons for this are that the

wetland is likely to be providing locally important wetland habitat types, fulfilling some wetland functional

roles (i.e. providing ecosystem services) within the catchment but to a limited degree, provides habitat for

indigenous flora and fauna in a largely transformed area where indigenous habitat is becoming increasingly

scarce, and it is a degraded but threatened wetland type (these are all factors indicative of moderate

conservation importance, as per Table 2), while at the same time the wetland is representative of a

regionally threatened / restricted habitat type (i.e. depressions / wetland flats within Cape Flats Dune

Strandveld, which is classified as an Endangered vegetation type) and is, therefore, of potentially high

conservation importance according to the criteria listed in Table 2. If the wetland was confirmed to be

supporting Red Data species, then it would possibly be appropriate to categorise it as being of high

conservation importance.

The degraded and ever-deteriorating present ecological condition of the wetland (as described above)

means that it would have to be substantially rehabilitated, particularly with respect to the vegetation

within the wetland, for it to attain the potentially high conservation value that it may have. The

rehabilitation potential of this wetland is, however, considered to be very limited. This is because it is

surrounded by relatively expansive (formal and informal) urban areas and, although it is located within an

area forming part of the City of Cape Town’s Biodiversity Network, the wetland is not connected to any

sufficiently large parcels of undeveloped land that are ecologically intact (or restorable) so that it can

become part of a viable ecological corridor. Furthermore, the opportunity to rehabilitate the wetland is

significantly limited by the human settlement and associated livestock-farming activities that have been

allowed to expand right up to the edge of, and into, the wetland. Ecologically effective rehabilitation would

require the removal of human settlement and livestock from the wetland, or at least portions of the

wetland, and some sort of mechanism to prevent future encroachment back into the rehabilitated areas.

0.0

1.0

2.0

3.0

4.0Flood attenuation

Streamflow regulation

Sediment trapping

Phosphate trapping

Nitrate removal

Toxicant removal

Erosion control

Carbon storageMaintenance of biodiversity

Water supply for human use

Natural resources

Cultivated foods

Cultural significance

Tourism and recreation

Education and research

WET-EcoServices: Mfuleni wetland (May 2013)


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3.2. Historical analysis

The wetland area on Erf 1, Mfuleni, that was filled in was one of the study sites for the Wetlands Health and

Importance (WHI) Research Programme, as confirmed by checking the GPS coordinates of the relevant

study site that were captured by the WHI research team. Water quality, vegetation, aquatic invertebrate

and habitat integrity data collected from this study site in early October 2007 were obtained from one of

the research team members (M. Bird from UCT), together with photographs of the site, to gain a better

understanding of the characteristics of the disturbed portion of the wetland prior to the start of the infilling

activities. At the time of sampling (September/October 2007), the area was a shallowly inundated

(maximum depth 0.5-1.0 m), partially vegetated wetland with limited human settlement around the edges

(see photos in Figure 10).

Figure 10: Photographs of a portion of the wetland that was filled in on Erf 1, Mfuleni, taken in early October 2007 before commencement of the infilling activities (photos taken by M. Bird)


13

The following water quality data were collected from an inundated portion of the wetland during the site

visit for the WHI Programme in October 2007:

pH = 8.2

Electrical conductivity = 144 mS/m

Dissolved oxygen percentage saturation = 78-93%

Water temperature = 21-23oC

Turbidity = 2 NTU

Nitrate (NO3) = 0.03 ug/l

Nitrite (NO2) = 0.02 ug/l

Ammonium (NH4) = 10.64 ug/l

Total Inorganic Nitrogen (NO3 + NO2 + NH4) = 10.7 ug/l = 0.01 mg/l

Orthophosphate (PO4) = below detection limit

The once-off water quality data (above) indicate that, at the time of sampling, the water in the wetland was

alkaline (pH > 8), with a slightly elevated conductivity but not brackish (conductivity >100 mS/m but

<500 mS/m), a low concentration of suspended solids (turbidity < 5 NTU), and a low concentration of

nitrogen- and phosphorus-related nutrients. It is difficult to draw too many conclusions from once-off

water quality like these, but most of the variables were indicative of relatively unimpacted conditions (at

the time of sampling), with the possible exception of the relatively high pH value that could be indicative of

a loss of fynbos vegetation (strandveld) in the catchment of the wetland because freshwater ecosystems in

fynbos-dominated areas away from the coast tend to have naturally acidic (low pH) water.

The plant species collected from the portion of the wetland that was sampled in October 2007 were as

follows (grouped according to plant family, with alien species indicated by an asterisk):

Juncaceae (rushes): Juncus capensis, Juncus kraussii

Lobeliaceae: Monopsis lutea

Poaceae (grasses): Cynodon dactylon (kweek), Helictotrichon longum, Imperata cylindrica (cotton

grass), Stenotaphrum secundatum* (Bufallo grass)

Resedaceae: Reseda lutea*

Restionaceae (restios): Elegia tectorum

If the alien species are excluded, a total of 7 indigenous plant species from 5 families were recorded from

the portion of the wetland that was sampled. This does not represent a particularly high diversity of plants.

Other plants that were recorded in the area, but not from the sampling points, at the time of sampling

included the sedge Ficinia nodosa, the shrub Senecio halimifolius, and the salt-marsh plant Sarcocornia sp.

None of the identified plant species within the wetland were Red Data species.

Aquatic macroinvertebrates were collected from two habitats within the portion of the wetland that was

sampled in October 2007, namely submerged vegetation and emergent vegetation. Most of the aquatic

macroinvertebrates collected from the wetland were insects (Class Insecta) with a few species of snails

(Class Gastropoda) recorded. A total of 11 families of macroinvertebrates were collected from both

sampling habitats within the wetland, with 14 genera identified within these families and 11 taxa identified

to species level. This represents a moderate level of diversity. None of the identified aquatic

macroinvertebrate species were Red Data species.


14

The habitat integrity assessment of the wetland undertaken for the WHI study, which was based primarily

on an estimation of the proportional extent of different land uses within 500 m of the wetland, generated a

so-called Human Disturbance Score (HDS) of 69%, which was translated into an overall condition rating of

Ecological Category D (i.e. largely modified). The hydrology, geomorphology, vegetation and water quality

components were not, however, separately analysed. This makes it impossible to compare this previous

assessment with the more detailed assessment of wetland condition undertaken in May 2013 for the

current investigation. Nevertheless, the result does show that the wetland was, by no means, in a pristine

state in October 2007, prior to the start of the infilling activities. A retrospective, more detailed assessment

of the predicted environmental condition in 2009-2010, shortly before the commencement of the infilling

activities, has been undertaken for the current investigation (see subsection below) on the basis of the

historical data from 2007 and an historical analysis of high-resolution aerial photographs and Google Earth

imagery.

The analysis of aerial photographs and Google Earth imagery of the study area (see Appendix 1) revealed

that since June 2007, a relatively short time before the WHI sampling in October of that year, there has

been a steady increase in the degree of encroachment into the wetland and in the intensification of the

urban development around the wetland. There were significantly more roads and houses (and other

structures such as livestock enclosures) within the wetland, and in the buffer area around the wetland, by

December 2012 than there were in 2007. The analysis of historical aerial imagery also showed that the

infilling activities under investigation commenced sometime between November 2009 and November 2010

(more than likely during 2010), with a number of structures having been built on top of the infill material by

April 2011. It appears as though the infilling activities ceased sometime between April and December 2011,

as there was no further increase in the extent of the infill footprint after this. The most recent imagery

available was from April and December 2012, before the commencement of the infilling removal activities

that are presumed to have been undertaken shortly before the site visit by FCG in May 2013.

Wetland assessment results (2009-2010)

The information and data collected from the wetland area in October 2007, and the analysis of aerial

imagery were used as a basis for an assessment of the presumed ecological condition of the broader

wetland on Erf 1, Mfuleni, in 2009-2010 before the commencement of the infilling activities. As in the case

of the May 2013 assessment, the WET-Health assessment framework (after Macfarlane et al. 2009) was

used so that the results could be compared. A summary of the results for 2009-2010 is presented in Table

4, below, which should be compared with the results for May 2013 presented in Table 3.

Table 4: Results of assessment of presumed ecological condition of affected wetland before the commencement of the infilling activities sometime between Nov 2009 and Nov/Dec 2010 (compare with Table 3)

Presumed ecological condition before infilling (2009-2010)

Component Ecological Category (A-F)a Anticipated trajectory of changeb

Hydrologyc A/B ↓

Geomorphologyd B ↓

Vegetationc C ↓↓

Water qualitye B/C ↓ a, b, c, d See notes below Table 3.

The hydrology, geomorphology and water quality of the wetland were all assessed to be half an Ecological

Category better, in terms of condition, in 2009-2010 compared to the present state in May 2013. All of

these components of wetland condition were likely to be deteriorating slowly at that time, as was the


15

prediction for the present-day assessment. The condition of the vegetation within the wetland, on the

other hand, was assessed to be one full Ecological Category better in 2009-2010 compared to May 2013

(Category C vs. Category D), with the anticipated trajectory of change evaluated to be a rapidly

deterioration for both time periods. Most of the negative changes in the condition of the broader wetland

between 2009/2010 and May 2013 are thought to be largely the result of increasing encroachment into the

wetland by humans and livestock, and the infrastructure associated with housing and livestock rearing

(including access roads), especially with regard to hydrology and water quality. The infilling and subsequent

infilling-removal activities within the wetland that have taken place during this time period have obviously

impacted negatively on the condition of the wetland, especially in terms of the geomorphology and (more

so) vegetation, but it is important to bear in mind that the disturbed area only represents less than 10% of

the overall extent of the broader wetland.

The results of the WET-EcoServices assessment were that the degree to which the wetland on Erf 1,

Mfuleni, is likely to be providing each of the ecosystem services considered in the assessment was generally

very similar in 2009-2010 to the situation in May 2013 (as presented previously in Figure 9). The only

differences were that the degree to which the wetland would have been providing nitrate removal, erosion

control and carbon storage services was likely to have been slightly higher in 2009-2010 compared to the

present-day situation. These predicted differences, which were quite marginal, were largely due to the

wetland having better vegetation cover in 2009-2010 compared to May 2013.

The broader wetland area was still considered to be of moderate to high conservation importance in 2009-

2010, based on the same reasoning used to arrive at this conservation importance rating for the situation in

May 2013. In June 2007 or earlier, when the degree of encroachment into the wetland and its surrounding

buffer area appears to have been significantly less than the situation in the months and years following this

(see Appendix 1), the rehabilitation potential of the wetland is likely to have been a lot greater and it would

have probably been appropriate to rate the conservation importance of the wetland as being high at that

stage.

4. Assessment of the impact of the infilling and infilling-removal activities

At a localised scale, the infilling and subsequent infilling-removal activities within the wetland area on Erf 1,

Mfuleni, have clearly had a major detrimental impact on a portion of the wetland (as illustrated, for

example, by the comparative photographs in Figure 11). In this disturbed area, there has been a complete

loss of wetland plants, a large amount (if not all) of the topsoil has been removed (which would have

contained seeds and remnant plant material that may have resulted in the natural regeneration of some of

the vegetation), the local topography has been altered, and there is likely to have been a localised

alteration of the hydrology (with more clay material relatively close to the surface than there was

previously, leading to ‘perched’ conditions, and the excavation below the existing ground level likely to

result in deeper inundation than before).


16

Figure 11: Photographs of the affected wetland taken from a similar position in May 2013 (top) and in September 2007 (bottom)

From an ecological perspective, it is important that there should be some rectification of the impacts on the

wetland that has been impacted by the infilling-related activities, especially due to the affected wetland

having been identified as an Aquatic CBA within the City. At the same time, however, it is important to

May 2013

September 2007


17

evaluate the impacts at a broader scale, taking into account the condition and characteristics of the greater

wetland, and the nature of the land-use activities in the areas surrounding the wetland.

From the assessment presented in this report, it is apparent that the wetland that was impacted was not in

pristine condition when the infilling activities commenced (probably sometime in 2010) and the future

state of the wetland is under severe threat from increasing urban development around and within the

wetland. The condition and ecological functioning of the greater wetland that the disturbed area forms a

small portion of was not directly impacted to a highly significant degree by the infilling and infilling-removal

activities, if the entire wetland unit (as shown on the City’s Wetlands Map) is considered as a whole. This is

due to the steady deterioration in the condition of the various components of the wetland that have been

taking place in addition to the infilling and because of the relatively small proportion of the overall wetland

extent represented by the filled-in area (<10% of the total area). Notwithstanding this assertion, it does

appear that the infilling of a portion of the wetland on Erf 1, Mfuleni, did indirectly impact the greater

wetland to a relatively significant degree by providing an impetus for increased encroachment into the

wetland, particularly by livestock-related activities.

Overall, the negative impacts of the infilling and infill-removal activities on the ecological condition and

functioning of the affected wetland (taken as the broader CBA wetland unit shown on the City’s Wetlands

Map) were rated to be of medium to high significance, with a moderate to high degree of confidence. This

is based on the extent being taken to be local (bearing in mind that only a small portion of the regionally

important wetland was impacted), the intensity as high (considering the area within which the impact

occurred on its own), and the duration as medium to long term (as the impacts are predicted to be

relatively long-lasting but not permanent).

5. Conclusions

The overall findings of this investigation were that the localised impacts of the infilling and infill-removal

activities on the ecological condition and functioning of the wetland on Erf 1, Mfuleni, were of high

intensity but that these activities only affected a small proportion of the greater wetland area within which

they occurred. The negative impacts on the Aquatic CBA Wetland that was affected, which was not in

pristine ecological condition when the activities commenced, were rated to be of medium to high

significance, taking into account the context and scale of the impacts. While it is important that some on-

site rectification measures are implemented, the potential for proper rehabilitation of the affected wetland

is considered to be very low. This is because urban and peri-urban land-use activities have already

encroached into the wetland and into the buffer area around the wetland, which would threaten the

ecological integrity of the rehabilitated wetland, and because the broader wetland does not form part of an

intact ecological corridor. Instead of fully rehabilitating the affected wetland, which would require some

sort of active management from the City for such rehabilitation to be effective (including the removal of

people and livestock from the wetland area, or at least the prevention of further encroachment into the

wetland), it is thus recommended that Ross Demolition should contribute to the rehabilitation of similar

off-site wetlands in an area where there would be a greater chance of rehabilitation success. This off-site

rehabilitation should be carried out in collaboration with the City of Cape Town (see detailed

recommendations in following section), as they are the ultimate custodians of the wetlands within the City

that have been designated as Aquatic CBAs.


18

6. Recommendations

As indicated above, it is recommended that on-site measures should be implemented by Ross Demolition

to rectify some of the existing impacts to the affected wetland and, instead of attempting to fully

rehabilitate the impacted wetland, Ross Demolition should contribute to the rehabilitation of appropriate

off-site wetlands where there would be a greater chance of achieving ecologically successful and

sustainable rehabilitation.

6.1. On-site measures for the rectification of impacts

Immediate implementation of the following on-site rectification measures by Ross Demolition are

recommended:

The loose bricks and other rubble that were not removed from the previously infilled area by the earth-

moving machinery that was used for the initial clearing operations should be manually removed (by

hand) and disposed of at a permitted waste disposal site.

The tyres that were left behind after the initial clearing of the infill should also be manually removed

and disposed of at a permitted waste disposal site, even if these were not originally dumped in the

wetland by Ross Demolition.

If alien invasive plants (especially Acacia spp.) have started sprouting within the disturbed area where

the infill was previously, these should be removed by hand and disposed of at an permitted garden

refuse disposal facility.

These recommended rectification measures should be implemented under the guidance of an ECO and,

once they have been completed, verification of this should be provided by the ECO and a site inspection

should be conducted by officials from the City of Cape Town, DEA&DP and DWA. The officials should decide

whether they are satisfied with the implementation of the on-site rectification measures and whether a

follow-up site visit by a freshwater ecologist is required.

It is predicted that the cleared area will be inundated during the wet season for periods of a few weeks to a

few months at a time, thus hydrologically functioning in a similar way to the wetland that occurred there

before the commencement of the infilling activities. Due to the flat landscape setting of the area (on a

plain) and the nature of the dominant water movement (i.e. vertical fluctuations of subsurface water),

there is unlikely to be a high erosion risk associated with leaving the ground bare. Furthermore, it is

predicted that, over time, the affected area will spontaneously be re-colonised by vegetation. Follow-up

removal of alien invasive plant species that will inevitably sprout in the disturbed area will be vital to ensure

that it does not become overgrown with alien vegetation. It is recommended that Ross Demolition should

pay for the services of a landscaping contractor to conduct follow-up alien vegetation clearing in the

disturbed area on a bi-monthly basis (i.e. every two months) for a period of one year and, after six months

and again after one year, the City of Cape Town should conduct a site inspection to check that the follow-

up alien vegetation clearing is being done to their satisfaction. Thereafter, the maintenance of the area will

become the responsibility of the landowners and the City of Cape Town.

6.2. Rehabilitation of off-site wetlands

With all the vegetation and much of the topsoil having been removed from the area that was cleared of

infill, it would be very difficult, time-consuming and expensive to successfully rehabilitate this affected

portion of the wetland on Erf 1, Mfuleni. For example, topsoil would have to be brought in, which would

have to be free of alien invasive plant material (especially seeds), and appropriate indigenous wetland plant


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species (that may need to be propagated or harvested from nearby areas) would have to be planted in the

imported topsoil, with regular irrigation possibly required in the first few weeks after planting and the

implementation of a maintenance programme for a few months thereafter (including the follow-up

removal of alien invasive plants that sprout in the rehabilitated wetland area). Many of these measures

would probably not have been required to achieve a relative measure of rehabilitation success if the infill

material had been more carefully removed, in which case on-site rehabilitation may have been more

appropriate.

In addition to the above-mentioned constraints, as highlighted previously in this report, the long-term

sustainability of properly rehabilitating the disturbed wetland area is questionable because of the high level

of threat to the future ecological integrity of the broader wetland that the disturbed area forms part of. It

is, however, important to take cognisance of the fact that the affected area was a relatively ecologically

intact portion of a CBA wetland within a threatened vegetation type. As such, if the disturbed wetland area

is not fully rehabilitated, there would have to be some sort of compensatory mitigation for the wetland

degradation that has occurred as a result of the infilling and infill-removal activities on Erf 1, Mfuleni. Based

on the overall findings of the ecological investigation presented in the current report, undertaking or

contributing to the rehabilitation of similar wetlands that are located in a context that is more conducive to

the creation of an ecologically viable wetland conservation area is considered to be a more appropriate

option to explore. The map below shows where similar wetlands (i.e. Dune Strandveld depressions and

wetland flats – in yellow) have been mapped relatively close to the affected site, according to the City of

Cape Town’s Wetlands Map, and where these wetlands are situated in relation to the Biodiversity Network.

Figure 12: Map showing similar wetlands (Dune Strandveld depressions and wetland flats) relatively close to the affected wetland on Erf 1, Mfuleni, as captured on the City of Cape Town (CCT) Wetlands Map, in relation to the CCT Biodiversity Network


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The recommendations for the rehabilitation of off-site wetlands as compensation for the wetland

degradation on Erf 1, Mfuleni, that resulted from the infilling and infill-removal activities undertaken by

Ross Demolition are as follows:

Officials from the City of Cape Town, DEA&DP and DWA should identify possible sites for off-site

wetland rehabilitation, with input from a freshwater ecologist (to be paid for by Ross Demolition).

Ideally, the sites that are considered should be of a similar wetland type (depressions or wetland flats

within Cape Flats Dune Strandveld vegetation), should be CBA wetlands, should be within the

Biodiversity Network, and should occur in a context where sustainable rehabilitation efforts are likely

to result in sustainable wetland improvement and conservation (the map in Figure 12 could be used as

a starting point for this exercise).

The City of Cape Town, DEA&DP and DWA should decide whether Ross Demolition should be instructed

to pay for specific rehabilitation interventions at the target site that is selected, and for the detailed

Rehabilitation Plan that would be required for the target site, or whether the company should rather

be handed a fine of a fixed amount to be used (by the City) for the compensatory rehabilitation of off-

site wetlands.

Once a calculation has been made of the amount of money that Ross Demolition should be made to

pay towards the rehabilitation of off-site wetlands, administrative measures should be put in place to

ensure that this money is actually used for the designated purpose.

These recommended off-site rehabilitation measures do not negate the need for the on-site

rectification measures recommended above.

Finally, it is strongly recommended that the City of Cape Town should undertake an inventory and

assessment of the wetlands on the City’s Wetlands Map that have been categorised as CBA wetlands, to

determine which of these should be given the greatest prioritisation in terms of rehabilitation and

conservation efforts. This assessment should include the ground-truthing of the present ecological

condition of the CBA wetlands, and of the contextual setting of each wetland and the level of threat to their

future state. Such a study would provide a good basis for the identification of critically important wetlands

that should be earmarked by the City for improved protection status, which would hopefully prevent the

sort of situation that has been allowed to happen with the degradation of the CBA wetland on Erf 1,

Mfuleni.


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7. References

Day E and Malan H (2010). Tools and metrics for assessment of wetland environmental condition and socioeconomic

importance: handbook to the WHI research programme. WRC Report No. TT433/09. Water Research

Commission, Pretoria.

Department of Water Affairs & Forestry [DWAF] (1999). Appendix R4: Intermediate Habitat Integrity Assessment (for

use in the rapid and intermediate habitat assessments), in: Resource Directed Measures for Protection of

Water Resources. Volume 3: River Ecosystems Version 1.0. Department of Water Affairs and Forestry, Pretoria,

pp. R4/1–R4/11.

Ewart-Smith JL and Ratcliffe SG (2002). Assessment of the Potential Impacts of the Proposed N1/N2 Winelands Toll

Highway Project on Aquatic Ecosystems. Specialist EIA Report to Crowther Campbell & Associates, on behalf of

the National Roads Agency.

Kleynhans C (1996). A qualitative procedure for the assessment of the habitat integrity status of the Luvuvhu River.

Journal of Aquatic Ecosystem Health 5: 41–54.

Kotze D, Marneweck G, Batchelor A, Lindley D and Collins N (2009). WET-EcoServices: A technique for rapidly

assessing ecosystem services supplied by wetlands. WRC Report No. TT 339/09. Water Research Commission,

Pretoria.

Macfarlane D, Kotze D, Ellery W, Walters D, Koopman V, Goodman P and Goge C (2009). WET-Health: A technique for

rapidly assessing wetland health. WRC Report No. TT 340/08. Water Research Commission, Pretoria.

Mucina L and Rutherford MC (eds) (2006). The Vegetation of South Africa, Lesotho and Swaziland. Strelitzia 19. South

African National Biodiversity Institute, Pretoria.

Rountree M, Malan H and Weston B (2013). Manual for the Rapid Ecological Reserve Determination of Inland

Wetlands (Version 2.0). Joint Department of Water Affairs and Water Research Commission report. Water

Research Commission, Pretoria.

Snaddon K and Day E (2009). Prioritisation of City Wetlands. Report prepared by the Freshwater Consulting Group for

the Department of Environmental Resource Management, City of Cape Town.

Historical aerial photographs and Google Earth imagery: June 2007 – December 2012

June 2007

February 2009

November 2010

December 2010

February 2011

April 2011

April 2012