ASSESSMENT OF POLLUTION AND VULNERABILITY OF WATER SUPPLY AQUIFERS OF AFRICA CITIES
A case for
JOHN LAING, MASS MEDIA AND MISISI AREAS
in
Lusaka, Zambia
GRZ
Map of Zambia showing the location of Lusaka
Map of the City of Lusaka
Perspective views of parts of the city of Lusaka
This project was made possible by the generous support of United Nations Educational Scientific and Cultural Organisation (UNESCO), United Nations Environment Programme (UNEP) and United Nations Human Settlements Programme (UN-HABITAT) with support of the Government of the Republic of Zambia (GRZ) through the Ministry of Energy and Water Development (MEWD).
Table of Contents
Acknowledgements i
abbreviations and Acronyms iii
1 INTRODUCTION 1
1.1 location and geomorphology 1
1.2 climate 2
2 geology 3
2.1 Important Geological Structures 3
2.2 Evidence for major geologic structures 4
3 Rainfall 6
3.1 Drainage 7
Fig. 9: Map showing the city boundary, topography and drainage of the Lusaka plateau. 7
3.2 Potential Evapotranspiration, ETpot 7
3.3 Actual evapotranspiration, AET 9
3.4 Groundwater Recharge, GWR 9
hydrogeology 12
issues and problems in the city of lusaka 15
3.5 General 15
3.6 Current land use practices in the city 15
3.7 water supply and groundwater abstraction 17
3.8 waste disposal practices 19
3.8.1 Disposal of sewage and wastewater 19
3.8.2 Disposal of Solid Waste 20
23
4 existing data on the project areas 24
5 some Initiatives undertaken 26
5.1 The WHO – funded Project 26
5.2 the unesco – unep sponsered project 26
5.3 project Objectives 26
5.4 Expected outputs 27
5.5 execution Methodology 27
5.6 Selection of Project areas 27
6 Water quality assessment in the project areas 29
6.1 General 29
6.2 Geologic setting of the misisi and john laing areas 29
6.3 Solid Waste Disposal 30
6.4 Excreta Disposal 30
6.4.1 Septic tanks 30
6.4.2 Pit Latrines 31
7 groundwater quality assessment 34
7.1 General 34
7.2 water quality 34
7.2.1 Sampling Campaigns 34
7.2.2 Analytical Results 35
7.3 Safety of water for domestic use 39
7.4 Sensitisation, educational and awareness programmes 39
8 REFERENCES AND BIBLIOGRAPHIES 40
AET Actual Evapotranspiration
CBoH Central Board of Health
ECZ Environmental Council of Zambia
ETpot Potential Evapotranspiration
GRZ Government of the Republic of Zambia
GWR Groundwater Recharge
ITCZ Inter-Tropical Convergence Zone
LCC Lusaka City Council
LWSC Lusaka Water and Sewerage Company
SRO Surface Runoff
UN-HABITAT United Nations Human Settlement Programme (formerly UNCHS (Habitat))
UNEP United Nations Environment Programme
UNESCO United Nations Educational, Scientific and Cultural Organisation
UNZA University of Zambia
WHO World Health Organisation
ZAB Zaire Air Boundary
At a water point in Misisi Compound
1INTRODUCTION
From its earliest days of settlement in the early 1900s, the suitability of Lusaka’s location has been a source of great controversy, the major one having been hitherto the nature of the bedrock and the hydrogeologic regime underlying the city. Even during the city’s founding, it usually experienced periodic rises of the water table close to the ground surface, causing occasional flooding.
Consequently, the city has experienced rapid population growth resulting in unplanned settlement patterns. This population has grown from only about 195,700 at independence in 1964, rising to about 536,000 in 1980, and about 769,000 in 1990. In the year 2000, the city population was estimated at two million (Fig. 1).
1.1location and geomorphology
The city of Lusaka (Fig. 2) was established as a rail siding in 1905 and because if its central location, it was inaugurated the new capital city of Zambia (then Northern Rhodesia) on 31 May 1935. The topography of Lusaka is characterised by a plateau to the south and west standing at an elevation of 1,200 metres, while flat-topped hills to the north and east of the city stand at an elevation of about 1,300 metres above sea level. The city’s topography and morphology have been greatly influenced by the underlying geology.
Fig. 2: Location of the city of Lusaka
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