Zamsif Utilization of Nutrient Rich Water Report 02092004 Edited Everything

EFFECTS OF USING WASTEWATER ON VEGETABLE GROWING AND THE ASSOCIATED SOCIO-ECONOMIC IMPACTS ON FARMERS IN THE KAFUE LAGOON AREAS AND ALONG

NGWERERE RIVER

By

Charles Bwalya Chisanga Oscar Musweu Silembo

Report PMA 14 September 2004

Ministry of Finance and National Planning Zambia Social Investment Fund

Zambia Social Investment Fund (Zamsif)

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Acronyms BOD Biochemical Oxygen Demand Cd Cadmium COD Chemical oxygen Demand Cu Copper DFID Department for International Development DO Dissolved Oxygen DWA Department of Water Affairs ECZ Environmental Council of Zambia EU European Union FDC Flow Duration Curve Hg Mercury LCC Lusaka City Council MFNP Ministry of Finance and National Planning NCZ Nitrogen Chemicals of Zambia NSR National Scientific Research Pb Lead PMA Poverty monitoring Analysis PRSP Poverty Reduction Strategy Paper WHO World Health Organization WSP Waste Stabilization Ponds ZESCO Zambian Electricity Supply Corporation Zn Zinc ZNS Zambia National Service


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DISCLAIMER This document is an output from a small study funded under the Poverty Monitoring Analysis (PMA) of Zambia Social Investment Fund (Zamsif) under the Ministry of Finance and National Planning carried out by Oscar M. Silembo and Charles Bwalya Chisanga all members of the Water and Sanitation Association of Zambia (WASAZA). The views expressed in this report are not necessarily those of Zamsif and so do not represent the views of Zamsif. The researchers named on this report bear the responsibility of any complaint that may arise as a result of this report. Zamsif shall not be liable to any legal suits should any arise due to the content of this report.


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ACKNOWLEDGEMENT We would like to thank the Zambia Investment Social Fund (Zamsif) for financial support to undertake the study under the Poverty Monitoring Analysis (PMA). We also thank the Environmental Engineering Laboratory of the School of Engineering and the Food Science Laboratory in the Science of Agriculture of the University of Zambia for carrying out the water quality testing and the quality testing of crops for heavy metals respectively. Their large contribution to the study is gratefully acknowledged. We also like to extend our thanks to the research assistants Chalo Cosmas and Chisanga Siwale (employees of Department of Water Affairs) Mainess K. Manninga (member of Water and Sanitation Association of Zambia), and Constancy Zulu (student of University of Zambia in the Science of Natural Sciences) who assisted in administering the questionnaires, entering the data in excel and data analysis in Ngwerere Catchment. We also appreciate the part played by the Water and Sanitation association of Zambia (WASAZA) for making it possible for us to use their printer in the production of this report.


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TABLE OF CONTENTS iv Contents Acronyms ii Disclaimer iii Acknowledgement iv Executive summary x

CHAPTER 1

INTRODUCTION 1.1 BACKGROUND 3 1.2 GENERAL OBJECTIVE 4 1.2 SPECIFIC OBJECTIVES 4 1.3 JUSTIFICATION 5 1.4 Significance of the Parameters 5

1.4.1 Temperature 5 1.4.3 Conductivity 5 1.4.2 pH: 6 1.4.4 Total Suspended Solids 6 1.4.5 Biochemical Oxygen Demand (BOD) 6 1.4.6 Chemical Oxygen Demand (COD) 6 1.4.7 Dissolved Oxygen 6 1.4.8 Ammonia/Nitrates 7 1.4.9 Phosphates 7 1.4.9 Phosphates 7 1.4.10 Faecal Coliforms 7 1.4.11 Cadmium (Cd) 8 1.4.12 Copper (Cu) 8 1.4.13 Sulphate (SO4) 9 1.4.14 Iron (Fe) 9 1.4.15 Lead (Pb) 9 1.4.16 Mercury (Hg) 9

1.5 LIMITATION 10

CHAPTER 2 LITERATURE REVIEWING

2.0 INTRODUCTION 11 2.1 QUANTITY OF WASTEWATER PRODUCED 13 2.2 TOXICOLOGICAL ASPECTS 13 2.3 COSTS AND BENEFITS 14 2.4 AGRONOMIC ASPECTS 15


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2.5 ENVIRONMENTAL EVALUATION OF WASTEWATER 16 2.6 PUBLIC HEALTH ASPECTS 16 2.7 ENVIRONEMENTAL ASPECTS 17 2.8 SOCIOCULTURE AND SOCIO ASPECTS 18 2.8 EFFLUENTS FROM NITROGEN CHEMICALS OF ZAMBIA, SHIKOSWE STREAM AND LEE YEAST 20 2.9 IRRIGATION METHODS AND POLICY ASPECTS 20

CHAPTER 3 DESCRIPTION OF STUDY AREA

3.0 NGWERERE CATCHMENT 21 3.1 KAFUE LAGOON 21

CHAPTER 4 METHODOLOGY

4.1 INTRODUCTION 25 4.2 DOCUMENT REVIEW 25 4.3 FIELD INVENTORIES AND DATA COLLECTION 25

4.3.1 FIELD INTERVIEWS 25 4.3.2 SAMPLING OF WATER, SEDIMENT AND PLANTS 26 4.3.2.1 NGWERERE 26 4.3.2.2 KAFUE LAGOON AREA 27 4.3.2.3 MEASUREMENTS OF PARAMETERS 28

4.3.2.3.1 LABORATORY TESTS 28 4.3.2.4 QUANTITY OF WASTEWATER 28

CHAPTER 5 ANALYSIS AND RESULTS

5.0 FINDINGS FROM FIELD INTERVIEWS 30 5.1 DEMOGRAPHIC INFORMATION ON HOUSEHOLDS

USING THE WASTEWATER 30 5.1.1 General Information of respondents 30 5.1.2 Kafue Lagoon Area 30 5.1.3 Ngwerere River area 30

5.2 AGRICULTURAL PRACTICE 31 5.2.1 PLOT SIZE AND CROP CHOICE 31

5.3 WATER MANAGEMENT AND WATER SOURCES 32 5.3.2 CONVEYANCE OF WATER AND FIELD APPLICATION 33

5.4 CROP MARKETING BY FARMERS IN NGWERERE AND KAFUE LAGOON AREAS 34 5.4.1 CROP MARKETING BY FARMERS IN NGWERERE AREA 35 5.4.2 CROP MARKETING BY FARMERS IN KAFUE LAGOON 35

5.5 CROP YIELD AND EARNING 36 5.5.1 Earnings from sales of crops in Kafue Lagoon Areas 36 5.5.2 Earnings from sales of crops in Ngwerere River Area 38


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5.6 PUBLIC HEALTH ISSUES 39 5.7 CONSTRAINTS FACED BY FARMERS IN KAFUE

LAGOON AND NGWERERE RIVER AREA 40 5.8 QUANTITY OF WASTEWATER 41 5.9 FINDINGS FROM WATER, SEDIMENT AND

PLANT SAMPLE ANALYSIS 45 5.9.1 PLANT SAMPLE ANALYSIS 45 5.9.2 WATER QUALITY 46

5.9.2.1 Ngwerere River and Kafue Lagoon Areas 46 5.9.2.2 Microbiological Results 47

5.9.2.3 PHYSICOCHEMICAL PARAMETERS 50 5.9.2.3.1 Ngwerere River 50 5.9.2.3.2 Kafue Lagoon Area 52

5.9.2.4 SEDIMENT ANALYSIS FROM NGWERERE RIVER AND KAFUE LAGOON AREAS 56

CHAPTER 6

DISCUSSION OF RESULTS AND FINDINGS 57 6.1 Water Quality 57 6.2 Plants 57 6.3 Sediments 57 6.4 Physicochemical Parameters 58

CHAPTER 7 CONCLUSION AND RECOMMENDATIONS

CONCLUSION 60 RECOMMENDATIONS 61 LIST OF TABLES Table 2.1: Recommended Revised Microbiological Quality

Guidelines for Wastewater Use in Agriculture 14 Table 2.2: Recommended Revised Microbiological Quality Guidelines for Wastewater Use in Agriculture 19

Table 4.1: Methods of analyzing quality parameters 28 Table 5.1: Gender and age of respondent 30 Table 5.2: Summary of General Observation on the Study Sites 31 Table 5.3: Crop Selection 32 Table 5.4: Methods of marketing adopted in Ngwerere

and Kafue Lagoon 34 Table 5.5: Crops grown in Kafue Lagoon Area, yields, unit and price per unit 37 Table 5.6: Farmers‘ total income in Kafue Lagoon and Ngwerere River Areas 37 Table 5.7: Crops grown in Ngwerere River Area, yields, unit and price per unit 38 Table 5.8: Clinical data from Kasisi Rural Health Centre 39 Tables 5.9: Constraints faced by farmers 40


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Table 5.10: FLOW DURATION TABLE 42 Table 5.11: Exploratory Analysis of Heavy Metals in Crops at Ngwerere River and Kafue

lagoon Areas 45 Table 5.12: Number of organisms per 100ml 47 Table 5.13: Number of organisms per 100ml 48 Table 5.14: Ranges of Contamination and Recommendations (after Westcot, 1997) 48 Table 5.15: Results of analysis of effluents from Ngwerere River Areas 50 Table 5.16: Results of analysis of effluents from Ngwerere River Areas 51 Table 5.17: Results of analysis of effluents from Ngwerere River Areas 52 Table 5.18: Results of analysis of effluents from Nitrogen Chemicals of Zambia 53 Table 5.19: Results of analysis of effluents from Shikoswe Stream 54 Table 5.20: Results of analysis of effluents from Lee Yeast 55 Table 5.21: Analyzed sediments from Ngwerere area from Ngwerere Sampling Points 56 Table 5.22: ANALYSED SEDIMENTS FROM KAFUE LAGOON 56 LIST OF FIGURES Figure 3.1: Map of Ngwerere Area 23 Figure 3.2: Map of Kafue Lagoon 24 Figure 5.1: Water sources used for irrigating crops in Kafue Lagoon 33 Figure 5.2: Conveyance of water for irrigation in Kafue Lagoon Area 33 Figure 5.3: Conveyance of water for irrigation in Ngwerere River area 34 Figure 5.4: Market channels for crops grown in the Ngwerere River Area 35 Figure 5.5: Mechanism in Marketing of Produce by Farmers in

Kafue Lagoon 36 Figure 5.6: Ngwerere River mean monthly flows 41 Figure 5.7: Flow Duration Curve for Ngwerere River 43 Figure 5.8: Total, Base-flow and Surface Runoff 43 Figure 5.9: Total hydrograph and Base-flow from October 2002 to August 2003 44 Figure 5.10: Logarithmic plot of microorganisms at 3 sites along Ngwerere River 49 Figure 5.11: Logarithmic plot of number of microorganisms at 2 sites at Kafue Lagoon 49 LIST OF PLATS Plat 5.1: A plot of Rape in Ngwerere River Area near Ngwerere Estate Weir 34 Plat 5.2: Plots of Rape in Chamba Valley near the Ngwerere River 35 Plat 5.3: Rape and tomatoes in Chamber Valley 37 Plat 5.4: Crop fields being watered 40 Plat 5.5: Crop in Kafue Lagoon Area near effluent channel from Lee Yeast 45 Plat 6: Below Spill way at Kasisi Dam (third sampling point) 47 REFERENCES 62


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APPENDICES 66 Annex I: Questionnaires for the project on the use of nutrient enriched water

for growing food crops in the Ngwerere river catchment and at the Kafue Lagoon 67

Annex II Table A.1: Wastewater treatment and quality criteria for irrigation

(State of California 1978) 73 Annex III Irrigation Water Quality Guidelines

Table B. 1: Guidelines for Interpreting Water Quality for Irrigation 74 Annex IV Table 2B: Recommended Maximum Concentrations of Trace Elements in

Irrigation Water 75 Annex V Table C. 3: Constituents of concern in wastewater treatment and irrigation

using reclaimed municipal wastewater 76 Annex VI Questionnaire results 77 Annex VII ANALYSED WATER QUALITY DATA from Ngwerere Sampling Points 85 Annex VIII ANALYSED WATER QUALITY DATA from Kafue Lagoon Areas 87 Annex IX ANALYSED SEDIMENTS FROM NGWERERE AREA from Ngwerere

Sampling Points 88 Annex X ANALYSED SEDIMENTS FROM KAFUE LAGOON 89 Annex XI BASEFLOW INDEX CALCULATION for Ngwerere Estate Weir 90 Annex XII CURRENT NATIONAL WATER QUALITY STANDARDS

IN USE IN ZAMBIA 91

Annex XIII Results of Effluents from Nitrogen Chemicals of Zambia (NCZ) 92 Annex XIV Chemical analysis of Effluents from Lee Yeast Factory 93


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EXECUTIVE SUMMARY

The sources of wastewater are made up of domestic wastewater, industrial wastewater, storm-water and groundwater seepage entering municipal sewage network. Domestic wastewater is made up of effluent discharge from household, institutions, and commercial buildings. Industrial wastewater is the effluent discharged by manufacturing plants. Wastewater is composed of organic matter, nutrients, inorganic matter, toxic chemicals and pathogens. In many place the wastewater is discharged into water bodies or the environment treated or pre-treated or as raw sewage.

In urban and peri-urban areas in developing countries, poor farmers commonly use wastewater to irrigate high-value crops. In many places the pre-treated or untreated wastewater is their only source of irrigation water—so their livelihoods depend on it. But, as well as bringing benefits, the unregulated use of wastewater or nutrient enriched water also poses risks to human health and the environment. Wastewater irrigation can also significantly contribute to household and urban food security and nutrition. Recent studies conducted in several Asian and African cities have revealed that wastewater agriculture has accounted for over 50% of urban vegetable supply. Wastewater is used as a source of irrigation water as well as a source of plant nutrients and trace elements allowing farmers to reduce or even eliminate the purchase of chemical. One tenth or more of the world‘s population currently eats food produced on wastewater (but not always in a safe way). The study was carried out in two phases within a period of two months in the field and preparation of the report. A literature review on wastewater reuse Quality sampling of water, plants and river bed sediments and testing supplemented with a

review of water quality data obtained in the past studies carried out in Ngwerere River and Kafue Lagoon Areas. The sediment and plant testing for heavy metals was only for exploratory purposes. The methods used for analysis were Electrometric, Gravimeteri, Titrimetric, Nessler, Vanamolybdic, Dichromate and Phenanthroline Sepectrophostometric, Turbidimetric, membrane filtration, Atomic absorption and Kjeldahl destruction.

Questionnaire formulation and administering in Ngwerere River and Kafue Lagoon Areas. Questionnaires were analysed using excel, graphs and figures.

Literature review Westcot (1997) makes a distinction between direct and in-direct reuse. Direct reuse is the planned use of raw or treated wastewater, where control exits over the conveyance of wastewater from the point of collection or discharge from a treatment plant to a controlled area where it is used for irrigation. This is the situation in many developed nations. Indirect reuse is the situation found in many developing national like Zambia where municipal and industrial wastewater is discharged without treatment or monitoring into the watercourses draining an urban area. There is no control over the use of water for irrigation. Microbiological contamination: The WHO guidelines provide a limit for permissible levels of microbiological contamination in water. Westcot (1997) addresses the question how the WHO guidelines can be applied where farmers are irrigating using water from rivers downstream of large urban centres. He suggests that in the absence of better information it is prudent to use the WHO standard for faecal coliforms as the quality standard. He also suggests establishing a routine water quality-monitoring programme, based on faecal coliforms number to support


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certification programme for high risk or restricted crops. This requires education of consumers and encouraging market forces whereby consumers chose to buy certified produce. It is argued that this approach is more realistic than attempting to impose crop restrictions which also almost impossible to enforce. The wastewater can be used for unrestricted irrigation of crops such as lettuce, salads and cucumbers grown for direct human consumption and eaten raw and for restricted irrigation of crops not intended for direct human consumption such as cotton, sisal, wheat and sunflower. The criteria for unrestricted irrigation contain the same helminthes

criteria for restricted irrigation, in addition to a restriction of 1000 faecal coliforms per 100ml treated effluents. Restricted irrigation refers to the irrigation of crops not intended for direct

human consumption and there should be 1 human intestinal nematode egg per liter implying a greater than 99% treatment level. Reuse of (pre) treated wastewater, especially in agriculture, could considerably contribute to water resources conservation, recycling of nutrients and prevention of surface water pollution. Water quality guidelines are necessary for wastewater irrigation, but they are rather strict and developing countries cannot afford the expensive treatment. Trace elements and heavy metals: It is widely accepted that levels of trace elements and heavy metals in irrigation water are likely to be toxic to plants in concentration below that which may pose a profound risk to human health and provides a degree of natural protection to irrigators. This study focused on heavy metal in the water, plant tissue and sediments. The findings indicate that the heavy metals in water were not detection. Some of the heavy metals were found in the plants such as lead, zinc and cadmium. Copper and mercury were not detected in both the water column and plant tissues. Compared with the thresholds for plants the heavy metals in plants below the limits, which is not harm to human health. Questionnaire administering: The majority of the peasant farmers in Kafue Lagoon are women and in Ngwerere are men. Plant Analysis, Water quality, Sediments and Questionnaire administering Plant analysis: heavy metals were not detected in mercury and copper. Lead, zinc and cadmium were detected. Compared with the threshold values the value for lead, zinc and cadmium do not pose any risk to human health. Physicochemical parameters: For Ngwerere river area the physicochemical results were within the limits of the ECZ, WHO, DWA and EU guidelines for water quality. However, the pH was higher than the recommended upper limit of 9 in some cases. Ammonia levels at N1 and N2 (that is urban and peri-urban areas) was higher than the WHO drinking water guideline value of 0.5mg/l. On average sodium was higher than the guideline value of 200mg/l which can lead to the problem of specific ion toxicity and salinity problems. Total suspended solids (TSS) at N1 and N3 were also higher than the ECZ guideline value of 100mg/l. The conductivity, phosphorus and calcium levels at Lee Yeast sampling point were higher than the recommended standard by ECZ. High calcium and conductivity levels were also reported by Sinkala et al (1996). The source of the calcium is mainly the geology of the area. The high conductivity corresponds to high sodium content of the effluent. The Shikoswe effluent had relatively high levels of ammonia and phosphate, the reason being that it carries mainly sewage effluents.


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All the other parameters measured were lower than the recommended maximum concentration in irrigation water, according to Pescod (1997). The concentration of heavy metals and boron in the water at all the sampling points were below the detection limit of the method of analysis which is also far below the recommended maximum concentrations Sediments: Two samples were collected on different days at both sites. After about a week, there was a high increase in the concentration of Zn, Fe, Pb and Cu at the first two sites (N1 and N2) on the Ngwerere River. At Kafue lagoon, there was also an increase in the heavy metal content after 12 days at the Shikoswe stream site, also indicating a relatively high rate of deposition. The results from the sediments samples during the study period were compared with the standards in the Netherlands. Microbiological: For Ngwerere River only the last point (N3 about 23 km from source) qualifies

for unrestricted irrigation according to the WHO guideline value of 1000 faecal coliform/100ml.

Under unrestricted irrigation vegetables and salad crops can be grown using water with 1000 faecal coliform/100ml. Therefore, the growing of vegetables at the other sites (N1 and N2) poses a health risk to workers (or producers) and the consumers due to high levels of faecal coliforms. Kafue Lagoon Areas, the Shikoswe and Lee Yeast effluent streams the values for faecal

coliforms were above the WHO guideline of 1000 faecal coliforms/100ml Summary of the conclusions. The WHO guidelines for microbiological quality of wastewater use/or reuse for irrigation are

intended as a guide for the design of treatment plants There is no evidence of pollution with heavy metals that may pose a threat to irrigated

crops Water salinity may pose a threat to crop production in both areas There is also need to embark on an education programme for farmers and the public Using the WHO guidelines only restricted irrigation can be practiced


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CHAPTER 1

INTRODUCTION 1.1 BACKGROUND In urban and peri-urban zones in developing countries, poor farmers commonly use nutrient-rich sewage and wastewater to irrigate high-value crops. In many places, this untreated wastewater is their only source of irrigation water—so their livelihoods depend on it. But, as well as bringing benefits, the unregulated use of wastewater also poses risks to human health and the environment. Wastewater irrigation can also significantly contribute to urban food security and nutrition. Recent studies in several Asian and African cities have revealed that wastewater agriculture has accounted for over 50% of urban vegetable supply (IWMI, 2003). Wastewater is used as a source of irrigation water as well as a source of plant nutrients (such as nitrogen, phosphorus and potassium) and trace elements (K, Na, etc) allowing farmers to reduce or even eliminate the purchase of chemical fertilizer and organic matter that serves as a soil conditioner and humus replenisher (IWMI-RUAF, 2002). IWMI-RUAF (2002) indicated that Lunven (1992) estimated that one tenth or more of the world‘s population currently eats food produced on wastewater (but not always in a safe way). Wastewater reuse in agriculture is economically feasible, environmentally sound use of municipal wastewater for irrigation and aquaculture. Reclaiming municipal wastewater for agricultural reuse is becoming increasingly recognized as an essential management strategy in areas of the world where water is in short supply (Khouri et al., 1994). Wastewater reuse has two main objectives, that of improving the environment in that it reduces the amount of waste (treated or untreated) discharge into watercourses, and it conserves water resources by lowering the demand for freshwater abstraction. In the process, reuse has the potential to reduce the cost of both wastewater disposal and the provision of irrigation water, mainly by practicing urban and peri-urban agriculture. Wastewater is defined as waste matter entering water (Huang, 1994). The sources of wastewater as indicated by Hussain et al., (2002) are made up of domestic wastewater, industrial wastewater, storm-water and groundwater seepage entering municipal sewage network. Domestic wastewater is made up of effluent discharge from household, institutions, and commercial buildings. Industrial wastewater is the effluent discharged by manufacturing plants. Wastewater is composed of organic matter, nutrients, inorganic matter, toxic chemicals and pathogens. The final composition of raw wastewater depends on the sources and its characteristics. Its disposal involves the collection, treatment, and sanitary disposal. A large volume of wastewater is discharged untreated into water bodies or is used for irrigation. Wastewater is used widely in both the industrialized and developing countries (Idelovitch and Ringskog, 1997) and is increasingly seen as a resource, and it is often reused legally and clandestinely (Hussain et al., 2002; Idelovitch and Ringskog, 1997). Wastewater as a resource can be applied to productive uses since it contains nutrients that have the potential for use in agriculture, aquaculture, and other activities (Hussain et al., 2002). However, the same raw or pre-treated wastewater could pose health hazard to handlers and consumers of the crops grown using it (Westcot, 1997). Despite the health hazards associated with crops grown in the Kafue Lagoon due to the use of NCZ wastewater for irrigation, findings by Enviro-line (1998) revealed that trucks loaded with a variety of vegetables and sugar cane come from Kafue about 50 kilometer south-west of Lusaka to Kamwala and Soweto markets to sell these products. Most of this merchandise


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bought in bulk by marketers is sold to unsuspecting Lusaka consumers. Many Kafue residents earn their living by selling these crops grown in the lagoon using effluents from punctured pipes and from canals carrying industrial wastewater, to water their crops. Similarly the Ngwerere River has its share of urban and peri-urban agricultural activities despite the river being chemically and biologically polluted (NSR, 1983). Later studies also proved that Ngwerere River was polluted (Tembo et al., 1997; Silembo, 1998). The report by Tembo et al (1997) and Silembo (1998) revealed, through laboratory investigation, that the water in Ngwerere River was not suitable for drinking and but could be used for irrigation and fishing purposes. The water would pose a health risk to the water users and consumers of crops. It was further demonstrated that the river exhibits significant self-purification capacity along its stretch from Garden Compound to the confluence with the Chongwe River. For instance in 1996, faecal coliform spatially reduced from 18, 000, 000 colonies per 100 ml in the upper reaches to less than 1000 colonies per 100 ml in the lower reaches near the Chongwe-Ngwerere confluence. In the lower reach water could also be safely used for fishing and washing. At such low levels of coliform (1000/100 ml) and other parameters being acceptable, the water could be used for irrigation according to the WHO guidelines value of

1000 per 100 ml for unrestricted irrigation and 100, 000 per 100 ml for restricted irrigation. This reduction in pollution could have occurred mainly because of sedimentation and dilution processes along the river. Tembo et al (1997) recommended that future research on the river should incorporate total nitrogen, biological oxygen demand and chemical oxygen demand tests in order to understand the pollution of the river in greater detail. The current study has incorporated BOD, COD, total nitrogen and flow measurements as recommended by the previous studies in order to compare the situation about 8 years later. The research also links water analysis to the users of water, a link that was left out in previous studies. Therefore socio-economic factors have been considered in the study. 1.2 GENERAL OBJECTIVE The study focused on assessing the Effects of using wastewater on vegetable growing and the associated socio-economic impacts on farmers in the Kafue Lagoon Areas and along Ngwerere River. 1.2 SPECIFIC OBJECTIVES The following were the specific objectives: 1.2.1 To determine the effects of crops grown and sold on the socio-economic status of the

local peasant farmers in the Kafue Lagoon and Ngwerere; 1.2.2 To analyze relevant wastewater quality parameters in nutrient enriched water and

compare them with the WHO guidelines and the Environmental Council of Zambia (ECZ) standards and document the quality of treated wastewater;

1.2.3 To suggest measures for reducing health hazards to growers and vegetable consumers;

1.2.4 To determine environmental valuation of wastewater by the community and its contribution to poverty reduction.


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1.3 JUSTIFICATION Though sewage wastewater is thought to be a health hazard, it is possible to make it good for several beneficial uses. There was need therefore, to undertake this study and gain more insight into the situations at Ngwerere river and Kafue Lagoon areas where wastewater was increasingly used for irrigating crops and vegetables, which were mainly sold in Kafue town and Lusaka City. The study would enable the analysis of the costs and benefits of using such water for agriculture. Scientific data is thus required to establish the relationship between the quality of water and crop yield. Greater yield indicates that there is more income for peasant farmers and this has a direct relation with poverty alleviation. 1.4 Significance of the Parameters The choice of parameters to be tested was based on the type of pollution expected from the domestic and industrial wastewater since a considerable portion of the stream‘s inflow is from these two sectors. However, other parameters (such as dissolved oxygen, hydrocarbons, PCBs and cyanide) though relevant to the research were not investigated (see section 1.4). The parameters tested were pH, temperature, conductivity, total suspended solids, BOD, COD, nitrates, ammonia, total phosphates, total nitrogen and E. coli, faecal streptococci, faecal coliform, magnesium, calcium, boron, sodium, iron lead, copper, cadmium and mercury. The parameters are listed below with an indication of their relevance: 1.4.1 Temperature: When the temperature of a waterway is raised, pollution occurs even though no nutrients have been added or removed from the water. There are two principle effects to this phenomenon. Firstly, solubility of oxygen decreases with increasing temperatures. Secondly, the metabolic reaction of the micro-organisms increases with temperature. An increase of temperature thus produces simultaneously, a decrease in the availability of dissolved oxygen and an increase in the rate at which it is being consumed. This reduces a streams self-purification capacity and thus usually results in pollution. According to ECZ the temperature of effluents at the point of entry to receiving water body should not exceed 40oC. 1.4.2 pH: pH is a measure of the concentration of hydrogen ions. pH values for natural waters range from 5 to 9. Like temperature pH also affects the chemical reactions of compounds and elements in a solution. For example the conversion of ammonium ions to free ammonia increases with an increase in pH as shown below; NH4

+ = NH3+ H+

Ammonia (NH3) is toxic to fish and other aquatic organisms. The pH can be used as a parameter for early warning of pollution in a water body. 1.4.3 Conductivity: The conductivity of a solution is a measure of its ability to conduct an electrical current and approximates the number or concentration of ions on that solution. Since the nature of the electrolyte has minor influence on the conductivity, conductivity can therefore be used to estimate the total ionic concentration of a water sample, which in most cases approximates the


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total dissolved solids. Total dissolved solids even when non-toxic and non-nutrient in nature will reduce oxygen solubility and therefore indirectly contribute to pollution. 1.4.4 Total Suspended Solids: Suspended solids may cause pollution in a lot of ways. The presence of suspended solids hinders light from reaching photosynthetic organisms, so reducing oxygen production; If present in large quantities, suspended solids will increase the effective viscosity of the water and impair flow in a waterway thereby reducing the oxygen dissolution; When these solids settle they form a layer on the waterway bed through which oxygen penetration is very difficult, thus producing an anaerobic sediment layer. They also present an aesthetically unpleasant appearance; Finally, suspended solids consist of organic materials, which decompose slowly, releases soluble nutrients into the water, thus exerting delayed oxygen demand. 1.4.5 Biochemical Oxygen Demand (BOD): The Biochemical Oxygen Demand (BOD) is the amount of dissolved oxygen required for the complete decomposition of the biodegradable matter in a sample. The BOD test is used to determine the pollution strength of domestic and industrial wastes in terms of oxygen that they will require if discharged into natural watercourses in which aerobic conditions exist. In other words this test assesses the oxygen used up in the actual biological breakdown of a waste sample, and is an effective laboratory simulation of the microbial self-purification process. The standard BOD test demands the incubation of a sample at 2oC for a period of 5 days and is abbreviated as BOD. In this period the BOD registered is virtually due to the breakdown of the major proportions of carbonaceous matter. The biological degradation of biodegradable carbonaceous matter is complete after 20 days at 2oC. BOD20

20 = 1.46 * BOD20 The breakdown of nitrogen compounds starts after approximately 10 days and takes a long time. In the absence of dissolved oxygen tests the BOD would give an indication of organic pollution in the water. 1.4.6 Chemical Oxygen Demand (COD): The Chemical Oxygen Demand (COD) is the amount of oxygen taken up by a waste sample from potassium dichromate after two hours of refluxing with concentrated sulphuric acid. The COD test, like the BOD test, is also used as a means of measuring the pollution strength of domestic and industrial wastes. In this test nearly all-organic matter is virtually completely oxidized. It thus gives an indication of the total oxygen demand of a waste sample. The ratio of the BOD to the COD is therefore a guide to the proportion of organic materials present in a waste sample, which are biodegradable. 1.4.7 Dissolved Oxygen: Free dissolved oxygen is the essential reagent for aerobic processes. When aerobic organisms utilize organic nutrients, they consume dissolved oxygen at the same time. If the dissolved oxygen is not replenished to such an extent that total depletion occurs, aerobic


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processes stop giving way to the slow and malodorous anaerobic process. This implies that aquatic life, be it macro or micro-organisms cannot survive. The availability of free dissolved oxygen is thus the key factor limiting the self-purification capacity of a watercourse. When nutrient solutes (e.g. waste, sewage, etc.) enter a relatively unpolluted water course it accelerates the rate of oxygen depletion as most oxygen is then used in the breaking down of these nutrients by the aerobic bacteria resulting in the low concentrations of dissolved oxygen. This therefore means a low concentration of dissolved oxygen is an indicator of pollution. 1.4.8 Ammonia/Nitrates: Ammonia as ammonium ions or as free ammonia is the most common occurring nitrogenous pollutant. It usually stems from decaying organic matter, fertilizers and sometimes from geological formations. Because of its smell it is undesirable to water. It is also toxic to aquatic life in small concentrations. Its presence in a watercourse, if stemming from organic matter, represents fresh pollution. The other problem of ammonia as a pollutant is that it exerts a very high oxygen demand for its complete oxidation as shown below. NH4 +2O = NO3 +2H + H2O From the above equation it is evident that the presence of nitrates is an indication that nitrogen pollution either from organic nitrogen compounds or inorganic compounds like fertilizers had taken place in a watercourse. Therefore in a watercourse one would expect the concentration of nitrates to increase as ammonia gets oxidized. Nitrates usually cause eutrophication, which is pollution of a watercourse by heavy organic growth (usually algae). This will produce an unsightly green slime-layer over the surface of the watercourse. Apart from this, eutrophication will cause the following problems: As photosynthesis involves the creation of organic matter from inorganic materials and so resulting in the production of large quantities of organic substances where very little or nothing existed before. When these photosynthetic organisms die off, their components become organic nutrients exerting an oxygen demand on a watercourse. In the absence of light, many types of algae consume oxygen and this may lead to serious deoxygenation at night with serious repercussions to aquatic life. Sometimes, when a thick algal blanket is produced, light may not penetrate the lower layers of the blanket, so that even in the presence of light, algae in the lower levels are using up oxygen. 1.4.9 Phosphates: Phosphates usually stem from detergents, sewage, and sometimes-geological formation. Higher concentration of phosphates, usually if present together with ammonia and nitrate, is an indication of pollution. Phosphates as pollutants are usually significant because they promote eutrophication (see also Nitrates) 1.4.10 Faecal Coliforms: Faecal coliforms are not pathogenic themselves but their presence in water indicates the possible presence of pathogens, usually of faecal origin. The absence of faecal coliforms


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indicates that faecal pollution is absent in a watercourse. Faecal coliforms are very suitable indicators because of the following reasons: Their presence is detected by relatively simple analytical procedures The analysis is not time consuming Since the number of coliforms is usually much greater than that of possible pathogens, there is a greater margin of safety provided. 1.4.11 Cadmium (Cd) Cadmium, Cd, is a silvery-white soft metallic element that is highly toxic to marine and fresh water aquatic life. Many of its organic and inorganic salts are highly soluble. The presence of cadmium in the aquatic environment is of concern because it bio-accumulates. Cadmium has a low solubility under conditions of neutral or alkaline pH and highly soluble under acidic conditions, where toxic concentrations can easily arise from the dissolution of cadmium from cadmium-plated materials. Cadmium is known to inhibit bone repair mechanisms, and is teratogenic, mutagenic and carcinogenic. 1.4.12 Copper (Cu) Copper is an essential trace element for organisms but becomes toxic at higher concentrations. In general only the dissolved form is considered when the toxicity is evaluated. The toxicity of copper is regulated by hardness (calcium and magnesium), organic substances, other metal ions and pH. These substances either directly bind copper in less toxic forms or are indicators of such binding compounds. Algae, especially blue-green, nitrogen fixing algae, are very susceptible to Cu. Copper is bioaccumulated in many organisms, but not to a high extent in fish flesh. Long-term exposure colours the fish dark and they become lethargic. Also haematological effects appear. Copper is essential for plants. When the concentration in soil increases, for example due to elevated concentrations in irrigation water, to 150-400 mg/kg toxicity will appear. Copper is generally non-toxic to livestock. 1.4.13 Sulphate (SO4) Sulphates are discharged from acid mine waste and many other industrial processes such as tanneries, textile mills and processes using sulphuric acid, sulphates or sulphides. Atmospheric sulphur dioxide discharges on combustion of fossil fuels and roasting of sulphide ores can give rise to sulphuric acid in rainwater (acid-rain) and as such, this results in the return of sulphate to surface waters in the environment. The interactions of sulphate are governed by the associated cations, usually magnesium and sodium. For example, magnesium will induce diarrhea whereas, sodium will not. Sulphate has an adverse effect on the palatability of water below the concentration that causes acute toxic effects. Sulphate can cause diarrhea and poor productivity in young animals and animals without prior exposure. The degree of sulphur tolerance depends on species, age, adaptation period and the principal cations associated with the sulphate ion. Adverse effects are more likely associated with high concentrations of magnesium and sodium sulphate than calcium sulphate.


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1.4.14 Iron (Fe) Typically, the concentrations of dissolved iron in unpolluted surface water is 0.001 - 0.5 mg/l. The chemical behaviour of iron in the aquatic environment is determined by oxidation-reduction reactions, pH and the presence of co-existing inorganic and organic complexing agents. Using chemical thermodynamic data it has been predicted that iron (II) will predominate at low pH in the absence of oxygen; some Fe (II) hydroxyl complexes will be present at alkaline pH. At low pH (<3) in oxygenated water, the Fe(III) iron predominates; however, at neutral and alkaline pH, hydroxide complexes are formed. In the presence of oxygen Fe (II) iron is oxidized and as a result, iron is usually found in the a-quatic environment as colloidal suspension of Fe(III) hydroxide particles. Iron is an essential constituent of animal diets, but can be harmful in large amounts even though it has a low order of toxicity. Iron may cause clogging of lines to stock watering equipment. Concentrations of up to 10 mg/l have not affected palatability of water to cattle. Plants require iron for growth. Iron deficiency can occur in alkaline soils. Dissolved iron in irrigation water precipitates upon aeration; hence it is unavailable to the roots of plants. The precipitate can cause damage to plants by coating the leaves, and may clog irrigation equip-ment. Precipitated iron in soils binds the essential elements phosphorous and molybdenum, making them unavailable to plants. Overhead sprinkling may result in unsightly deposits on plants, equipment and buildings. 1.4.15 Lead (Pb) Lead is used in the production of lead acid storage batteries, tetraethyl lead, pigments and chemicals, solder, other alloys and cables. In tap water lead is dissolved from plumbing fittings containing lead in pipes, solder or service connections to homes. Other sources of lead in the aquatic environment include soil and atmospheric fallout. Lead is a bio-accumulative general poison. A maximum of 0.5 mg/l is said to be safe for animals but cases of livestock poisoning have been reported at lower concentrations. Decomposition of organic matter by bacteria is inhibited by more than 0.1mg/l. Lead causes a film of mucous to form on gills and then over the fish‘s body, thus suffocating the fish. The toxicity of lead is reduced by water hardness. Lower aquatic life appears more tolerant than fish to lead. 1.4.16 Mercury (Hg) Mercury (Hg) is among the most toxic of the heavy metals. In inorganic form the acute toxicity is about 0.005 to 0. 1 mg/1. In nature inorganic mercury ions are easily transformed by microbial activity into organic mercurial compounds, as methyl mercury and di-methyl mercury. Since these forms are lipophilic they are even more toxic to biota. The norm used in this guideline is based on toxicological effects on human consumption of fish. Mercury affects the central nervous system. In pregnant women methyl mercury is also transferred to the foetus and may affect the brain, which is sensitive at this stage. The concentration of mercury in fish should be less than 0.5 mg/kg fresh weight.


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1.5 LIMITATION Data Gap - There is no consistent baseline data on river water quality Finances - All necessary water quality parameters could not be undertaken due to financial constraints. Transport - Given the required frequency of water quality sampling and laboratory testing the total distance to be covered exceeded the budgeted for total distance. The time Factor – The time given to submit the progress report and later on the final draft report dictated the rate of implementation of planned activities. It did not coincide with the time required for data analysis e.g. the laboratory analysis took longer than expected. Hence the sampling interval was intense (3 samples per week in Ngwerere and 1 sample per week in Kafue Lagoon) and thus affected the carrying out of other activities such as questionnaire administering and report compilation within the study period. Time was also needed to link with other institutions and organizations within the frame of the study for interviews. The period of sampling was short hence the seasonal trends could not be captured. Sampling – The population was sampled using the grid method. Randomization was not possible in the framework of this study because of time, accessibility of farms/gardens and distance constraints. The period of the sample from the field to be test and the results being made available to the research team took a lot of time for further analysis. This affect the compilation and interpretation of the data took some time.


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CHAPTER 2

LITERATURE REVIEWING 2.0 INTRODUCTION Domestic human waste is defined as human excreta, urine, and the associated sludge collectively known as black-water, as well as, kitchen wastewater and wastewater generally through bathing (collectively known as grey-water) (Rose, 1999). Wastewater is defined as waste matter entering water and its disposal involves the collection, treatment, and sanitary disposal (Huang, 1994). According to Huang (1994) issue of sewage disposal assumed increasing importance in the early 1970s. Hussain et al. (2002) noted that sources of wastewater are domestic wastewater, industrial wastewater, storm water and by groundwater seepage entering municipal sewage network. Domestic wastewater is made up of effluent discharge from households, institutions and commercial buildings. Industrial wastewater is the effluent discharged by industries. Wastewater is composed of organic matter, nutrients, inorganic matter, toxic chemicals and pathogens. The final composition of raw wastewater depends on the sources and its characteristics. Khouri et al (1994) reported that reclaiming municipal wastewater for agricultural reuse is increasingly recognized as an essential management strategy in areas of the world where water is in short supply. Wastewater reuse in agriculture requires consideration of the health impact, agricultural productivity, economic feasibility and sociocultural aspects. According to Nicholas O'Dwyer and Partners Consulting Engineers, (1978) and WWI (1989) the most common analysis of wastewater includes the measurements of solids, biochemical oxygen demand (BOD), total coliform, chemical oxygen demand (COD), chloride, sodium, phosphate, total nitrogen, calcium, temperature and pH. The solids include both the dissolved and suspended solids. Sewage treatment proceeds in three stages in other countries – primary, secondary and tertiary stages. In the primary treatment stage, solid wastes are removed through mechanical process and organic matter is removed by biological process in the secondary treatment stage. The third stage is the tertiary treatment stage, which is the polishing stage. Normally, it involves the removal of for instance phosphorus and nitrogen. According to Proprasset et al (2000) any type of wastewater treatment system is based on natural processes, be it chemical, physical or biological, and its design is aimed at creating the optimum conditions for enhancement of the rate of these natural processes. Natural systems for wastewater management include a host of treatment techniques apart from the use of stabilization ponds, which is common in Zambia.

Anaerobic treatment of wastewater is carried out in low-rate systems (septic tank or lined pit) or in high-rate systems (anaerobic filter, upflow anaerobic sludge blanket reactor, anaerobic contact process). All anaerobic systems are based on the degradation of organic material by a consortium of anaerobic bacteria. The process results in the production of biogas, which contains up to 80% of methane that can be re-used for electricity generation.

Wetlands are plots of land where the water is at (or above) the ground surface long enough each year to maintain saturated soil conditions and the growth of related vegetation. Constructed wetlands are plots of land specifically designed to act as wetlands for purification of wastewater. The two types of constructed wetlands are free water surface and subsurface flow constructed wetlands.


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Macrophyte ponds are modified waste stabilization ponds. A cover of floating plants floats on the water surface. Plants such as water hyacinth (Eichhornia crassipes) and duckweed (Lemnacaea) are used to take up nutrients from the wastewater and to provide a pond environment that is not disturbed by wind action so that sedimentation is optimal.

Water based fish-aquaculture transforms the nutrients that are present in wastewater into proteins. The fish feed on algae or macrophytes that grow using the nutrients.

Terrestrial methods can be divided into slow rate (or irrigation) processes (SR), rapid infiltration processes (RI) and overland flow processes (OF)

In Zambia stabilization ponds are used for treating wastewater. These are comprised of the anaerobic, facultative and maturation ponds. Anaerobic ponds receive effluents of high organic loading and have retention time of one to five days and depth of 2-4 meters. Facultative ponds are used to treat the wastewater and have generally a depth of 1-1.5 meters. The retention time for the wastewater is five to thirty days. Maturation ponds on the other hand, remove faecal bacteria and the retention period of the effluent is 5-10 days and their depth are 1-1.5 meters (GKW Consult, 2001). In principle, natural pond can be aerobic, facultative, or anaerobic. Aerated ponds are a manmade development and these reduce the amount of land required by adding artificial aeration. Stabilization or oxidation ponds are used extensively in developing countries. A relatively new system of natural stabilization ponds used extensively in Israel, and also in Spain, California, and Santiago, Chile, is the deep reservoir treatment, which consists of deep stabilization ponds (8-12 meters deep) (Idelovitch and Ringskog, 1997). These are used for both seasonal storage and effluent purification. The system can reduce bacteria level in the effluent by as much as 99.999 percent depending on retention time (DFID, 2000). In Northeast Brazil Waste Stabilization Ponds (WSP) comprise one or more series of anaerobic, facultative and maturation ponds (Mara, 1997). The anaerobic ponds receive a high organic loading that they are devoid of oxygen and BOD removals are very high over 70 percent retention time of only one day at 25oC. Facultative ponds (biological treatment) with a retention time of only 3-5 days at 25oC can reduce filtered BOD to well below the 25 mg/l EU requirement for WSP effluents and the oxygen needed by the heterotrophic bacteria are supplied through photosynthesis of the pond algae (DFID, 1997). The wastewater treated in this way can be used for restricted irrigation. Aerobic bacteria convert the organic matter to stable forms such as carbon dioxide, water, nitrates, and phosphates as well as other organic materials (Huang, 1994). Nicholas O'Dwyer and Partners Consulting Engineers (1978) indicated that present treatment has very little effects on reducing the BOD of raw sewage, solid content, chlorides, sulfate, ammonia, and organic nitrogen and trace metals. Maturation ponds are primarily used to ensure the removal of faecal bacteria and viruses to safe levels so that the effluents can be used without risk to public health for crop irrigation and/or fish culture (Mara, 1997). Price (2003) indicated that the treatment and use of wastewater is both a challenge and an opportunity for municipalities. It is a challenge because the use of non-treated wastewater is often the only option available for peri-urban farmers. This poses potential serious health problems of the presence of bacteria, viruses and parasites. It is an opportunity because wastewater is a valuable resource, not only from an economic viewpoint but also from an environment perspective (conservation of water resources, nutrient recycling etc).


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2.1 QUANTITY OF WASTEWATER PRODUCED According to Huang (1994) domestic sewage results from people‘s day-to-day activities, such as bathing, body elimination, food preparation, and recreation, averages about 227 litres (about 60 gal) per person daily. Raw sewage includes waterborne waste from toilets, sinks and industrial processes. The average monthly water consumption for an average household size of 7.5 inhabitants living in high/medium cost areas and 6.0 inhabitants living in low cost area (as found valid in various urban centers in Zambia) are 50, 690 cubic meters per month and 43, 446 cubic meters per month respectively (GKW Consult, 2001). 17 percent of the households in Zambia use flush toilets. The quantity of industrial wastewater varies depending on the industry and management of its water usage, and the degree of treatment before it is discharge. Domestic wastewater consists of about 99.9 percent water and 0.1 percent solids. With increasing global population, the gap between the supply and demand for water is widening and is reaching such alarming levels that in some parts of the world it is posing a threat to human existence (Hussain et al., 2002). Society on the other hand, is subjected to continuous expansion with increased food requirements and food insecurity. Lusaka Water and Sewerage Company, which is owned by the Lusaka City Council, is responsible for management of sewerage and sludge (ECZ and LCC, 1997). According to ECZ and LCC (1997) there are basically four plants in Lusaka that handles the sewerage sludge produced in Lusaka; the Chelston and Kaunda Square maturation ponds and the Chunga and Manchinchi conventional plants. Lusaka Province has 21 percent of households with flush toilets and 3 percent (communal/shared flush toilets), 35 percent (own pit latrine), 37 percent (communal/shared pit latrine), 1 percent (other toilet facilities) and 3 per cent have no toilet facilities (CSO, 1998). Literature from CSO revealed that the total household in Lusaka is 275, 000. 2.2 TOXICOLOGICAL ASPECTS Documents reviewed indicated that the amount of most chemicals in wastewater (raw or treated) is generally below the toxic level for humans. Industrial wastewater can add toxic levels of certain compounds such as heavy metals and organic pollutants. The contamination can endanger human health if uncontrolled irrigation is being practiced or affect the irrigation system design with significant amounts of hazardous compounds. In order to lessen the impact of compounds such as heavy metals and organic pollutants, these should be treated at the sources. Hide et al (2001) reported that it is widely accepted that levels of trace elements and heavy metals in irrigation water are likely to be toxic to plants at concentration below that which they pose a significant risk to human health (ANNEX III). According to Hussain et al (2002) heavy metals in wastewater pose a health risk if they are ingested in sufficient concentrations, and can be dangerous. In principle, uptake of heavy metals by crops and the risk posed to consumers may not be an issue as plants cannot resist high concentrations of these pollutants and die off before they become a threat to humans (see Table 2.1 and ANNEX III and IV). This provides a degree of natural protection of irrigators and consumers as plants fail to thrive and farmers abandon the source well before levels present a risk to human health. Literature indicated that they are currently no guidelines for permissible levels of trace elements and heavy metals in wastewater used for irrigation, which relate to the potential risk to human health as a consequence of crop uptake and bio-accumulation. According to Hide et al (2001)


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most authors cite the table of phytotoxic threshold prepared by the National Academy of Science and National Academy of engineering (1972) and Pratt (1972), or refer to the Who drinking water guidelines (WHO, 1993). The data is indicated in Table 2.1. Table 2.1: WHO and EU Drinking Water Quality Guidelines for Heavy Metals and

Threshold Values Leading to Crop Damage (mg/l) Element WHO drinking water

guidelinesa EU drinking water guidelinesb

Recommended maximum concentration for cropc

Arsenic 0.01 0.05 0.1 Cadmium 0.003 0.005 0.01 Chromium 0.05 0.05 0.1 Copper 2 0.2 Iron 0.3 0.1-3.0 5.0 Mercury 0.001 0.2 - Manganese 0.5 0.001 0.2 Nickel 0.02 0.05 0.2 Lead 0.01 0.05 5.0 Zinc 3 0.1-5.0 2.0

Sources: a WHO (1993) b Cited by Chapman (1996) c Cited by Pescod (1992)

Scott et al (2000) noted that environmental accumulation of heavy metals resulting from wastewater irrigation and sludge is a contentious issue. Khouri et al (1994) indicated that cadmium (Cd), for example could be present in municipal wastewater at levels that are not toxic to plants but could build up inside the plant tissue to levels harmful to humans or animals. Similar build up can occur in animal such that heavy metals contained in forage have been shown to accumulate in cow‘s milk, which could lead to hazardous build up in the consumer‘s body. Ensink et al (2002) indicated in a study undertaken in Pakistan that accumulation of heavy metals proved to be almost negligible, with only increased levels of lead, copper and manganese, even in the fields that had received wastewater for over 30 years. All the current heavy metal concentration levels are unlikely to seriously affect crop production as they were within the ranges of normal soil concentrations. Apart from containing heavy metals and trace elements wastewater also contains high concentrations of dissolved salts (Hussain et al., 2002). Salinity-related impacts of wastewater irrigation on soil resources can be expressed in economic terms such as (1) potential yield and income loss; (2) loss of soil productivity; (3) depreciation in market value of land; and (4) cost of soil reclamation measures. 2.3 COSTS AND BENEFITS Irrigation with wastewater could be an attractive way of disposing wastewater from an environmental point of view (Khouri et al., 1994). The combined benefits of reduced treatment and disposal cost and increased agricultural production may justify investment in an irrigation system. Before one can endorse wastewater irrigation as a means of increasing water supply for agriculture (Hussain et al., 2002), a thorough analysis must be undertaken from an economic perspective as well. The economic effects of wastewater irrigation need to be evaluated not only from the social, economic, and ecological standpoint, but also from the sustainable development perspective.


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2.4 AGRONOMIC ASPECTS

Wastewater has phosphates and nitrates, which are channeled into land as fertilizers (Karpagma, 1999). DFID (1998) discovered that Community based approaches (in Latin America in particular) separate ‗grey‘ wastewater (non-faecally contaminated wastewater) from ‗black‘ wastewater (that is faecally contaminated) so that they can be reused as irrigation water and the black water/waste treated and reused as fertilizer. The wastewater can be used for unrestricted irrigation of crops such as lettuce, salads and cucumbers grown for direct human consumption and eaten raw and for restricted irrigation of crops not intended for direct human consumption such as cotton, sisal, wheat and sunflower (WHO, 1989). Idelovitch and Ringskog (1997) observed that the most attractive and widespread reuse of effluents is to irrigate agricultural crops, pasture, or natural vegetation. Other important uses of wastewater include recharge of groundwater, as cooling water, recreational water, industry construction and dust control, wildlife habitat improvement, aquaculture and municipal non-portable uses such as landscape and golf course irrigation (Hussain et al., 2002; Idelovitch and Ringskog 1997). Reuse of (pre) treated wastewater, especially in agriculture, could considerably contribute to water resources conservation, recycling of nutrients and prevention of surface water pollution. Water quality guidelines are necessary for wastewater irrigation, but they are rather strict and developing countries cannot afford the expensive treatment (Steenvoorden et al., 2004). Wastewater is used widely in many parts of the world, both in industrialized and developing countries (Idelovitch and Ringskog, 1997). Increasing sewage or wastewater is seen as a resource, and it is often reused legally and clandestinely (Hussain et al., 2002; Idelovitch and Ringskog, 1997). Hussain et al., (2002) observed that wastewater in developed countries is treated prior to its use in irrigation and environmental standards are applied. The wastewater is used for irrigation of fodder, fiber and other seed crops and, to a limited extent for the irrigation of orchards, vineyards, and other crops. DFID (1998) revealed that the water and nutrient content in particular can be very useful for agriculture purposes - for example through irrigation. Khouri et al (1994) indicated that wastewater contains nutrients and trace elements necessary for plant growth. Five Mm3 of wastewater contain about 250, 000kg of phosphorous, and 150, 000kg of potassium. Whether additional fertilizer is required depends on the crop being irrigated. Soil deficiency can be corrected by the trace elements in wastewater and clearly speaking the nutrients in wastewater are beneficial. While wastewater is a resource for productive uses it can be dangerous to use in an untreated form. The dangerous practice of direct and indirect use of untreated wastewater is common practice in regions like Lima, Mexico City, and Santiago (DFID, 1998; Idelovitch and Ringskog, 1997). The practice can be made safe by treating the waste, restricting its use to only on industrial or fodder crops or applying the waste in specific ways or at certain times (DFID, 1998). Moreover, the report by Hussain et al. (2002) revealed that in developing countries, though standards are set, these are not strictly adhered to and wastewater, in its untreated form, is widely used for agriculture and aquaculture. Idelovitch and Ringskog (1997) have observed in their report that the most attractive and widespread reuse of effluents is to irrigate agricultural crops, pasture, or natural vegetation. Other important uses of wastewater include, recharge of groundwater, industry construction and dust control and wildlife habitat improvement (Hussain et al., 2002; Idelovitch and Ringskog, 1997).


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Dubbeling and Santanddreu (2003), explains that urban agriculture (UA) is practiced inside (intra urban) or on the outskirts (peri-urban) of a town or a city. It focuses on raising food and animal crops. It includes recycling household waste and wastewater for agricultural purposes, the process and distribution of different food and non-food products using human and material resources, products and services that are found in the surrounding areas. An increasing number of local and national governments are promoting UA in response to serious problems of poverty, food insecurity, and environmental degradation. 2.5 ENVIRONMENTAL EVALUATION OF WASTEWATER Generally speaking, environmental valuation is used to determine the willingness of people to attach a value of an environmental good such as use of nutrient enriched water in agriculture. There are two types of techniques used in environmental valuation: those relying on revealed preferences or what humans actually do in the markets; and those relying on stated preferences or what humans say they would do in a hypothetical market context. Thus both of these approaches attempt to evaluate human behavior in economic terms but they differ in the sense that the former is based on actual or observed behavior while the latter is based on potential or likely behavior (Hussain et al., 2002). 2.6 PUBLIC HEALTH ASPECTS The use of untreated wastewater for irrigation poses a high risk to human health in all age groups. However, the degree of risk may vary among the various age groups. Untreated wastewater irrigation leads to relatively higher prevalence of hookworm (Feenstra et al., 2000), and Ascariasis infections among children (Cifuentes et al., 2000; and Habbari et al., 2000). The DFID-sponsored research in North-east Brazil has shown that bacterial pathogens such as Vibrio cholera, Salmonella species and Campylobacter species are present in wastewater (DFID, 1998). With many guidelines dealing with water quality for irrigation purposes, the microbiological aspects have always predominated perhaps, because of their immediate human health consequences. Chang et al (1996), notes that, few of the irrigation water quality criteria were developed specifically for wastewater irrigation. The public health risks associated with wastewater reuse include increased exposure to infectious diseases, trace organic compounds (Cooper, 1991), and heavy metals. Wastewater contains the full spectrum of enteric pathogens endemic within a community (Scott et al., 2000). Many of these can survive for weeks when discharged on the land, notwithstanding the presence of infective organisms, however, epidemiological studies have shown that the mere presence of pathogen does not necessarily increase human diseases. Of particular interest from a public health perspective are the helminthes (Ascaris and Trichuris), which have both a relatively long persistence and a small infective dose. The risks of intestinal nematodes in untreated wastewater are recognized as important, both for consumers and irrigators (Shuval, 1991). According to Rose (1999), the most recent guidelines directing the reuse of wastewater to a level considered safe to protect human health are those outlined in the Engelberg Standards, later adopted as the WHO of 1989 ‗‗Health Guidelines for the Use of Wastewater in Agriculture and Aquaculture‘‘. According to Mara and Cairncross (1989) the WHO guidelines outline acceptable microbial pathogen levels for treated wastewater for reuse in unrestricted and restricted irrigation. In practice, most developing countries use untreated wastewater for agriculture for a variety of reasons. These include the cost of treatment and the loss of precious nutrients. However, treatment of wastewater prior to agricultural use is believed to be essential:


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first from the public health protection point of view and to respect local social and religious beliefs (Mara, 2000). According to Hussain et al (2002) in view of these requirements, water scarcity, dry land farming, hot climatic conditions and the high economic value of fresh water resources, a great deal of research and development effort has been undertaken particularly in Israel, for the reuse of wastewater. Furthermore, in the absence of too high a concentration of waste from industrial sources, an efficient treatment option for conventional wastewater treatment is to use primary sedimentation followed by secondary biological treatment using high-rate biological processes. Unrestricted irrigation refers to all crops grown for direct human consumption and eaten raw (e.g., lettuce, salads, cucumber etc.,) and also the irrigation of sports fields, public parks, hotel lawns, and tourist areas. The criteria for unrestricted irrigation, contain the same helminthes criteria for restricted irrigation, in addition to a restriction of no more than a geometric mean concentration of less than or equal to 1000 faecal coliforms per 100ml treated effluents. These guideline as noted by Mara and Cairncross (1989) have been introduced to protect the health of consumers who may eat uncooked crops such as vegetables and salads (Table 2.2). In order to achieve the microbiological quality, a series of stabilization ponds need to be designed (WHO, 1989). These are series of ponds, which are used in treating the wastewater before it is discharged into the environment. Restricted irrigation refers to the irrigation of crops not intended for direct human consumption and there should be no more than one viable human intestinal nematode egg per liter implying a greater than 99% treatment level (Table 2.2). This guideline has been introduced to protect the health of field workers and to indirectly protect consumers and grazing cattle (Mara and Cairncross, 1989). Restricted irrigation can be applied to industrial crops (e.g., cotton, sisal, and sunflower, wheat, barley, oats); and fruit trees, fodder crops and pastures (WHO, 1989). The wastewater retention in stabilization ponds should be 8-10 days or equivalent helminthes and faecal coliform removal (Cornish, 1999). The human intestinal nematodes include, roundworm (Ascaris lumbricoides); hookworm (Ancylostoma duodenale and Necator americanus); and whipworm (Trichuris trichiura) Mara (2000). Nitrates and trace organic chemicals leaching to the groundwater are considered to pose a potential health risk. However, there is very limited documented evidence that these chemicals have been the cause of human disease (Cooper 1991). The leaching of salts, nitrates and microorganisms would be of little concern anyway in areas where groundwater cannot be utilized because of high fluoride, iron, arsenic or salt levels. In these cases the groundwater has no valuable use attached to it (Hussain et al. 2002). 2.7 ENVIRONEMENTAL ASPECTS Mara (1977) and USEPA (1992) indicated that one of the negative environmental impacts associated with wastewater use is groundwater contamination through high concentrations of nitrates, salts and micro-organisms. Faruqui et al. (2002) indicated that environmental issues associated with untreated wastewater reuse are contamination and clogging of soil particles. Egziabher et al., (1994) noted that environmental contamination could be mitigated by treatment of domestic wastewater for unrestricted use. WHO (1989) and Cornish et al. (1999) emphasized that unrestricted irrigation should have no more than one thousand fecal coliform bacteria per hundred milliliter. Eutrophication of water bodies would be the ecological impacts related from nutrient rich drainage water, in the vicinity of wastewater agricultural areas and those related to buildup of


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heavy metals and toxic contamination of ecosystem components. Eutrophication affects fish species and fish populations and thereby commercial fishing at such places is affected (income loss). Another consequence of eutrophication is the disappearance of popular fish species important for recreational fishing (welfare loss to general public) (Hussain et al., 2002). 2.8 SOCIOCULTURE AND SOCIO ASPECTS Peri-urban and urban agriculture is understood to be the agriculture activities undertaken within the area immediately surrounding the city, where the presence of the city has an impact on land use, property rights and where proximity to the urban market and urban demand drive change in agricultural production (Hide et al., 2001). Furthermore, urban agriculture is one of the several strategies used by the urban and peri-urban dwellers to cope with poverty. It is mainly carried out by, but not restricted to, the urban and peri-urban poor in their efforts to meet the food needs of their households. The sale of the produce is an integral part of the food production. And acts as a source of cash without cutting the household‘s food supply. Revenue accruing from sale of the produce is used for various purposes, such as purchase of household requirements, education of children and health expenses. Khouri et al (1994) indicated that a physical, natural resources-oriented survey complemented by a socio-economic study of the community affected by the reuse project would reveal the need for reuse. The acceptance of wastewater reuse and the adoption of practices for its safe implementation will be influenced by the sociocultural makeup of the people involved (that is the values, beliefs, and customs that are concerned with water supply, sanitation, hygiene and other activities related to water use). Literature consulted revealed that there are few reconnaissance-type studies that describe sociocultural aspects of reuse (Khouri et al., 1994). Hussain et al (2002) indicated that the social concerns about the potential risk of wastewater irrigation originate from concerns regarding impacts on environmental quality, public health and safety. These concerns may be addressed with appropriate educational and public awareness programs. The cost of public education, awareness and demonstration programmes can be used as a choice for the valuation of social impacts of wastewater irrigation programmes, using awareness and sensitization educational models.


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Table 2.2: Recommended Revised Microbiological Quality Guidelines for

Wastewater Use in Agriculturea

Category Reuse Condition Group exposed Irrigation technique

Intestinal nematodesb

(arithmetic mean no. of eggs per literc

Faecal coliform (geometric mean no. per 100 mld

Wastewater treatment expected to achieve required microbiological quality

A Unrestricted irrigation A1 For vegetables and salad crops eaten uncooked; sports field, public parkse

Workers, consumers, public

Any 1f 103 Well-designed series of waste stabilization ponds (WSP), sequential batch-fed wastewater storage and treatment reservoirs (WSTR) or equivalent treatment (e.g. conventional secondary treatment supplemented by either polishing ponds or filtration and disinfections)

B Restricted Irrigation Cereal crops, industrial and fodder crops; and pasture and treesg

B1 Worker (but no children <15 years), nearby communities B2 as B1 B3 Workers including children <15 years, nearby communities

Spray or sprinkler Flood/furrow Any

1

1

0.1

105

103

103

Retention in WSP series including one maturation pond or in sequential WSTR or equivalent treatment (e.g. conventional secondary treatment supplemented by either polishing ponds or filtration) As for category A As for category A

C Localized irrigation category B crops if workers and public exposure does not occur

None Trickle, drip or bubbler

N/A N/A Pretreatment as required by irrigation technology, but not less than primary sedimentation

Source: WHO (1989) cited by Pescod (1992) Note: In specific cases, local epidemiological, sociocultural, and environmental factors should be taken into account, and the guidelines modified accordingly.

a. In specific cases, local epidemiological, sociocultural and environmental factors should be taken into account and the guidelines modified accordingly

b. Ascaris and Trichuris species, and hookworm; the guideline limit is also intended to protect against risks from parasitic protozoa

c. During the irrigation period/season (if the wastewater is treated in WSP or WSTR which have been designed to achieve these egg numbers, then routine effluent quality monitoring is not required)

d. During the irrigation period/season (faecal coliform counts should preferably be done weekly, but at least monthly)

e. A more stringent guideline limit (<200 faecal coliform/100ml) is appropriate for public lawns, such as hotel lawns, with which the public may come into direct contact

f. This guideline limit can be increased to <1 egg/l if (I) conditions are hot and dry and surface irrigation is not used or (II) if wastewater treatment is supplemented with antihelmintic chemotherapy campaigns in areas of wastewater reuse.

g. In the case of fruit trees, irrigation should cease two weeks before fruit is picked, and no fruit should be picked off the ground. Sprinkler irrigation should not be used.


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2.8 EFFLUENTS FROM NITROGEN CHEMICALS OF ZAMBIA, SHIKOSWE STREAM AND LEE YEAST According to Sinkala et al (1996), the storm washing are collected in storm water drains and joins the Shikoswe stream which passes through the NCZ plant and finally into the Kafue river. The washing from the ammonium plant contain ammonia and nitrates. These are not allowed to go in the storm water drains but go to the balance tank where the effluent is neutralized by addition of lime before pumping to the ponds located 2 kilometers out the plant. Some of the results from the study which was conducted in 1996 to 1997 by Sinkala et al noted that the concentration of nitrates from NCZ were higher than the ECZ limit of nitrate levels found in the effluents (Annex XIII). The effluent from Lee Yeast is used by the community between the factory and the Kafue River, for vegetable growing. The effluent is known to contain low nutrient level except for high Chemical Oxygen Demand (COD) and Biological Oxygen Demand (BOD). Sinkala et al (1996) indicated that the effluents from Lee Yeast contain very high total coliforms count per 100ml compared to ECZ limit. The Total Dissolved Solids (TDS) and Total Solids (TS) were also higher than the ECZ limit for effluents and wastewater (Annex XIV). 2.9 IRRIGATION METHODS AND POLICY ASPECTS Irrigation methods can be organized into both means of distributing the raw wastewater to the plants to minimize contamination of the plants, and precautions that the farmers can take to protect their own health. The main irrigation method currently practiced is the use of watering cans that accentuate the risk of contamination of the plants and farmers. Egziabher et al., (1994) showed that lettuce irrigated with watering cans has higher levels of contamination by faecal coliforms and streptococcus than lettuce irrigated by hosing water into the furrow. Another way of mitigation would be to practice restricted irrigation as recommended by the WHO. Thus the latter method would be more preferred. In the Zambian context this may be challenging in that crops such as lettuce and tomatoes are some of the most profitable crops for peri-urban and urban agriculture. An education programme for farmers, the public, and municipal officials would be essential to effectively deal with this issue of peri-urban and urban agriculture. The National Water Policy of 1994 specifies that water for irrigation should be fit for human consumption and not cause soil degradation but enhance high crop yield. Within the broad objective for agriculture the MFNP (2002) indicates that since the poor rely often on the environment for their livelihood, attacking poverty in rural areas is necessarily improving people‘s ability to derive livelihood from natural resources. On the other hand, the Health Policy fosters that in order to have a well-nourished and health population that can contribute to the national economic development there is need to achieve sustainable food and nutrition security.


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CHAPTER 3

DESCRIPTION OF STUDY AREA 3.0 NGWERERE CATCHMENT The Ngwerere is a small river whose origin is in the city of Lusaka and it stretches over a distance of approximately 30 kilometers as shown in Figure 3.1. The Goma Lakes of the University of Zambia Campus, which runs on the eastern side, feed the stream. The other streams have their sources near the main police station at Church road and in Roma near the Great East road. According to Tembo et al (1997), the stream near ZESCO (Zambian Electricity Supply Corporation) on the northern side of the Great East Road looks heavily polluted and digestion is seen to be taking place. In the reach between this point and the confluence in Roma sedimentation takes place and aeration is enhanced by the turbulent nature of flow at some points. The stream passes through a swampy area with several streamlets of relatively clear groundwater, which causes dilution. Wastewater is also discharged into the Ngwerere River from the Manchinchi Wastewater Treatment Plant. The colour of this water was green due to the presence of the algae during the study period. The most upstream point which is accessible in the rural area through which the Ngwerere River runs is at the road bridge near the school just out of Ngwerere compound. A pump drawing water for irrigation makes the water turbid during periods of pumping. Just before the confluence of the Chongwe and the Ngwerere Rivers at Tembo farm some 20 km northeast of UNZA campus. In this rural area, a lot of farming activities are taking place and thus a lot of water is drawn from the Ngwerere River for irrigation. The Ngwerere River discharges into the Chongwe River, which is a tributary of the Zambezi River. Wastewater (nutrient enriched water) in the Ngwerere River is utilized for irrigating a variety of crops/or vegetables within the catchment. Crops are watered in the dry and to some extent in portion of the catchment in the wet season using the pre-treated wastewater. The crops grown include cabbages, pumpkins leaves, sweet potato leaves, Chinese cabbage, lettuce, rape, onion, spinach, tomatoes, maize and sugar cane. The vegetables and sugar canes are sold to individual consumers and vegetable traders at the public markets (Soweto Market and others) in Lusaka. 3.2 KAFUE LAGOON A map of the Kafue Lagoon study area is shown in Figure 3.2. The Kafue Lagoon contains effluents with toxic chemicals from NCZ (Enviro-line, 1998). The Kafue lagoon receives effluents from Lee Yeast and Nitrogen Chemicals of Zambia. According to ECZ (1994) the Nitrogen Chemicals of Zambia (NCZ) opened a sulphuric acid plant in 1983. It produces sulphuric acid, which is used in the manufacturing of fertilizers. This process results in the production of sulphur dioxide and effluents containing hazardous chemicals. These are discharged into the drain and it mixes with the sewerage effluents. Lee Yeast Company also discharges the effluents into the lagoon from its manufacturing processes. According to Sinkala et al (1996), the storm washing are collected in storm water drains and joins the Shikoswe stream which passes through the NCZ plant and finally into the Kafue river. Lee Yeast is situated in Kafue town and has three factories within its premises, namely the Yeast factory, Methylated Spirit Factory and a Bakery. The raw materials for the Yeast factory


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are the molasses (carbon sources), urea, Di-ammonium phosphates and Magnesium sulphate, Zinc Sulphate, Chlorine and Ammonium Sulphate. The raw materials are mixed in various proportions in three vessels. The yeast pulp is separated from the liquid and this forms the effluents discharged by the Yeast factory. However, the Kafue residents and peasant farmers earn their living by selling vegetables grown within the Lagoon. Individual consumers and traders purchase the crops from Kafue Estate and Kafue town respectively. A few individual consumers go into the Lagoons to purchase the crops and these include: sugar canes, cabbages, rape, onions, guavas, cassava, tomatoes and Chinese cabbage.


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CHAPTER 4

METHODOLOGY 4.1 INTRODUCTION The methods used during the study were both qualitative and quantitative in the generation of information as well as documenting the findings. 4.2 DOCUMENT REVIEW Documents and reports were reviewed on the work done on utilization of wastewater or nutrient enriched water in Zambia and other parts of the world. Various legislative articles from institutions such as the Environmental Council of Zambia and Ministry of Health were also reviewed. Other documents such as the WHO guidelines and ECZ wastewater Standards on the safe use of water for irrigation were also considered. 4.3 FIELD INVENTORIES AND DATA COLLECTION 4.3.1 FIELD INTERVIEWS Information was gathered by using a combination of observations, field surveys and structured interviews with selected growers. Surveys were carried out to ascertain the types of crops grown within the Ngwerere catchment and at Kafue Lagoons. Questionnaires were formulated and tested in the field. After being improved upon the questionnaires were administered in the field to gather information on how the communities or peasant farmers‘ value enriched wastewater in irrigation. The individual farmer interview covered personal and household information, household socio-economic status, and crop marketing, healthy aspects, cropping pattern, plot characteristics, water management and farmer‘s conception of constraint. At the peasant farmer‘s level information was collected on the history of irrigated vegetable farming, the level of interest shown by the farming individuals, gender, irrigated vegetables grown, common methods of conveying water and sources of water. The questionnaire is reproduced in Annex I and the location of the survey sites are shown in Figures 3.1 and 3.2. The individual farmer interview covered personal and household information, household socio-economic consideration, plot characteristics, water management, cropping pattern, plot input-output data and farmers conception of constraints. The sample size was determined whilst in the field by knowing the population of farmers within the two study areas. A case study was used in collecting data aimed at achieving the specific objectives. According to Young, a case study is a method of exploring and analysing the life of a social unit, be it a person, a family, an institution, cultural group or even an entire community (Ghoshi, 1992). The sampling technique used before administering the questionnaires was a random sampling by the Grid System technique used in coming up with the population. The Grid System method involves putting a screen with squares on a study map and the areas falling within selected


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squares are selected samples. This method is generally used for selecting a sample of an area (Ghoshi, 1992). 4.3.2 SAMPLING OF WATER, SEDIMENT AND PLANTS 4.3.2.1 NGWERERE The full stretch of the Ngwerere River (about 30 km, see figure 3.1) was surveyed to select three points for sampling (water, sediment, plants) and testing over a period of 2 months. The three sites were chosen according to the following criteria: Accessibility Representativeness of the site with respect to project objectives Ease of sampling and on-site tests Sites that would enable transportation of samples to the laboratory within seven (7) hours The site should be at or near a point where reliable flow measurement could be measured

or estimated Site 1 (Near Garden Site 3 ponds, N1) This site is located between Garden compound and Roma Township (Latitude 15o22‘09.1‖, Longitude 028o18‘07.6‖). It is a few meters downstream of the confluence of the two main arms of the Ngwerere River one originating from the town area (visible opposite ZESCO Ltd) and another from the Northmead/Olympia residential area. An effluent stream from Garden Site 3 maturation ponds and another from N‘gombe/Kalundu residential area join the latter before the confluence of the two arms (near Mazyopa Compound). This captures the total pollution leaving the City of Lusaka. Furthermore this site was also used by the study of Tembo et al in 1997 hence it would give a reasonable comparison, about eight years later. Site 2 (At Ngwerere Estate Weir, N2) This station is just upstream of the Ngwerere Estate Weir (about 500m, Latitude 15o19‘, Longitude 028o19‘). At this point, the river has passed through several gardening communities but the water quality is expected to improve more than at Site 1 which is 5 km away. The main advantage of Site 2 was the proximity to the permanent gauging station belonging to the Department of Water Affairs, which would enable the estimation of river flow at this point. Site 3 (Below Kasisi dam, N3) This site was located after the Kasisi Mission dam about 15km from Site 2. This represents the river before the confluence with the Chongwe River. By this time the river had undergone substantial self-purification and it was expected that the vegetables grown in this area would have less contamination than those grown in the upper reaches. Sampling Being a narrow channeled stream, the Ngwerere was assumed to be completely mixed over its depth and width. This was further confirmed by taking conductivity measurements along the cross-section and at various depths. The conductivity did not vary significantly for the purposes of this study. (However, this was only done for conductivity and so there may still be need to confirm with another parameter). A grab water sample collected at about 5cm depth in the middle of the river channel was considered representative enough. The water samples were obtained by wading into the river, immersing a sample bottle about 5cm below the water surface and collecting the water. Because the water was clear in most instances, the bottle could be held against the flow without catching any floating debris. For


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chemical analysis a polythene bottle (1000ml) was used while for heavy metals a 500ml bottle with 2ml nitric acid inside was used. A sterilized glass bottle was used for microbiological sampling. The bottles were then kept in a cool box packed with ice blocks. Another 1000ml-polythene bottle was used to store bottom sediment, which was scooped from the riverbed where it had accumulated. This was stored separate from the water samples. Care was taken to avoid cross-contamination by correctly labeling all the bottles and recording in a field record book, and starting sampling with the least polluted site (start with Site3, then Site2 and finally Site1). Site1, Site2 and Site3 are later designated as N1, N2 and N3, respectively for convenient identification. In-situ water tests were carried out using the Horiba Water Checker U-10 model. It was used to measure water temperature, pH, conductivity and salinity. These parameters are reliably measured in-situ due to their tendency to change with slight changes in surrounding temperature and ionic activity 4.3.2.2 KAFUE LAGOON AREA The Kafue lagoon area is located about 45km south of the City of Lusaka (figure 3.2). The area spans a total of approximately over 10 hectares of land under mostly sugar cane cultivation. The land was surveyed to select two points for sampling (water, sediment, and plants) and testing over a period of 2 months. The sites were chosen according to the following criteria: Accessibility Representativeness of the site with respect to project objectives Ease of sampling and on-site tests Sites that would enable transportation of samples to the laboratory within seven (7) hours Site 1 (Shikoswe Stream) The site is located (latitude 15o45‘23.5‖, longitude 028o09‘40.2‖) on the effluent canal passing through the Nitrogen Chemicals of Zambia before it enters the fields, where the water is diverted for irrigation through a series of smaller earth canals. The effluent from NCZ mixes with domestic sewage. Site 2 (Near Lee Yeast, LY) This site is located (latitude 15o45‘21.2‖, longitude 028o09‘36.6‖) before the fields and on the effluent canal coming from Lee Yeast factory, which produces yeast. Because of the deep brown colour of the water, it is usually mixed with the water coming from the Nitrogen Chemicals of Zambia before applying it to the fields. In-situ water tests were carried out using the Horiba Water Checker U-10 model. It was used to measure water temperature, pH, conductivity and salinity. Site 3 (Nitrogen Chemicals of Zambia, NCZ) This site is located (latitude 15o45‘28.0‖, longitude 028o09‘52.5‖) on the eastern part of the Shikoswe stream below the footbridge. The NCZ effluents are discharged into this canal, which passes through the vegetable and sugar cane fields. This is the site where ECZ also conduct their quality testing of the effluents being discharged by NCZ from the Plant.


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4.3.2.3 MEASUREMENTS OF PARAMETERS. 4.3.2.3.1 LABORATORY TESTS Samples were tested at the Environmental Engineering laboratory of School of Engineering at the University of Zambia. The choices of the parameters to be tested are explained in chapter one. Time was a major constraint with regard to sampling and testing. The requirement that some of the test be done immediately after sampling made it imperative that sampling points were reasonably spaced and time spent at each site minimized so as to enable delivery of samples at the laboratory in good time. This was necessary for quality control/assurance of samples collected. The methods used to test the various selected parameters are listed in the table below are listed below.

Table 4.1: Methods of analyzing quality parameters

Parameter Method

Physical

pH Electrometric

Conductivity Electrometric

Salinity Electrometric

Total Suspended Solids (TSS) Gravimetric

Chemical

Bi-Carbonates Titrimetric

Ammonia Nessler Spectrophotometric

Sulphates Turbidimetric

Nitrates Electrometric

Total Phosphates Vanamolybdic Spectrophotometric

Chemical Oxygen Demand Dichromate Spectrophotometric

Nitrogen Kjeldahl Destruction

Metals

Cadmium Atomic absorption

Copper Atomic absorption

Cobalt Atomic absorption

Zinc Atomic absorption

Iron Phenanthroline Spectrophotometric

Sodium Flame Photometric

Calcium Titrimetric

Magnesium Titrimetric

Microbiological

Biological Oxygen Demand Modified Winkler

Faecal Coliforms Membrane Filtration

Faecal Streptococci Membrane Filtration

E. Coli Membrane Filtration

4.3.2.4 QUANTITY OF WASTEWATER The quantity of wastewater in the Ngwerere stream was computed by analyzing the hydrological data from the Ngwerere Hydrological Station of the Department of Water Affairs. Hydata and Arida software were used to compute the total surface run-off and then separating the base-flow from the total surface runoff in cubic meters. This was undertaken to know the amount of wastewater in the Ngwerere river and the contribution of the groundwater to the


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surface run-off passing through the hydrological station for the Department of Water Affairs (DWA).


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CHAPTER 5

ANALYSIS AND RESULTS 5.0 FINDINGS FROM FIELD INTERVIEWS The questionnaire formulated had sections each focusing on a major topic. The following were the sections in the questionnaire: Demographic information on households using the wastewater, Agricultural Practice, Water Management, Crop marketing, Public health issues, Attitudes toward organizations responsible for delivery of water related services and Perceived problems and possible solutions. 5.1 DEMOGRAPHIC INFORMATION ON HOUSEHOLDS USING THE WASTEWATER 5.1.1 General Information of respondents A summary of general information of respondents is given in Tables 5.1 Table 5.1: Gender and age of respondent

Gender Age

Males % Females % Mean Minimum Maximum

Ngwerere Area 34 81 8 19 30 15 45

Kafue Lagoon 12 40 18 60

35 26 45

All 46 26

Farmers producing irrigated vegetables in Kafue Lagoon study area are mostly women (60%) and 40% are men. In Ngwerere area it is the opposite of the scenario in the Lagoons, the majority of farmers producing irrigated crops being men (81%) and 19% are women (more information in annex I). 5.1.2 Kafue Lagoon Area The education levels of the respondents varied - 26% had no formal education and 74% having formal education (17% had secondary level education, while 57% had gone up to primary level). The main occupation of peasant farmers in the Lagoon is gardening whilst the second occupation include various activities such as selling of charcoal, farming, piece work and keeping of livestock (more information in Annex I). The main sources of income for the peasant farmers in Kafue Lagoon Areas are selling of vegetables and sugar canes and gardening. The alternative sources of income are the same as the main sources. 5.1.3 Ngwerere River Area The education levels of the respondents varied - 14% had no formal education and 86% having formal education (31% had secondary level education, 53% had gone up to primary level and


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2% had gone up to tertiary level). Approximately 19% of the farmers interviewed were women and 81% are men in the Ngwerere area. The main occupation of peasant farmers in the Ngwerere River area are gardening, producing and selling of vegetables, maize growing and farming. The main sources of income for the peasant farmers in Ngwerere River area are selling of vegetables, and gardening. The alternative sources of income are retirement package (pension money), rental from houses, business and piece of work, selling of pesticides, selling of vegetables and gardening (more information in Annex I). 5.2 AGRICULTURAL PRACTICE The study was carried out in two sites: Ngwerere River and Kafue Lagoon Areas. An overview of the two-study site is presented in table 5.2 below. Kafue Lagoon farmers abstract their irrigation water from the Lee Yeast effluent canal, Shikoswe stream and Nitrogen Chemicals of Zambia effluent canal. Ngwerere river Area farmers extract their water irrigation from the Ngwerere River. Table 5.2: Summary of General Observation on the Study Sites

Observation Items Study Site

Ngwerere River Area Kafue Lagoon Area

1. Land tenure status -Farmers own land -Zambia National Service -Communal land -Leasehold

-Freehold

2. General land layout and land use

-House erected on upper portion for owners use -land is rented -Land belongs to ZNS

-Freehold -Discharge of effluent Lagoon

3. Sources of irrigation water -Permanent stream running within the catchment -Stream pools -Shallow wells

-Effluent canals from Lee Yeast, NCZ effluent canal and Shikoswe stream

4. Methods of irrigation -Manually using buckets and tins -Use engine pump and hose pipes

-Manually using buckets and tins -Furrows and canals

5. Cropping pattern -Vegetables and maize -Vegetables, maize and sugar cane

5.2.1 PLOT SIZE AND CROP CHOICE The average plot size for the surveyed farms (small-scale peasant farmers) in Ngwerere area is 0.25 ha and ranges from 0.1 ha to 0.5 ha whilst in Kafue Lagoon is 1.2 ha and ranges from 0.25 ha to 2 ha respectively. Actual plot measurements were not taken due to time factor and the study team did not have the equipment such as measuring tape or surveyors band. Farmers were asked to estimate their plot areas during the interviews although the interviewer


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could also estimate sometimes by counting steps. The number of crops grown on each farm varied from farmer to farmer and from season to season. Table 5.3 below identifies the crops grown by farmers in Ngwerere and Kafue Lagoon areas. Each farmer grows an average of 5 crops. However, most farmers seem to concentrate on one or two crops. In the study areas, the peasant farmers irrigate high-value crops, which are also shown in the table below. Table 5.3: Crop Selection

Crop Ngwerere River Area Kafue Lagoon Areas

Cabbage xxx

Tomato xxx xx

Sweet potato leaves xxx

Chinese cabbage xxx xxx

Lettuce xxx

Onion xxx

Rape xxx xxx

Carrot xxx

Green pepper xx

Nchembele xxx

Potatoes xxx

Pumpkin leaves xxx

Okra x

Chikolowa x

Cassava x x

Bananas x

Guava x

Beans x x

Egg plant xxx

Sugar cane xxx

Maize x x

White logo xx

Mupilu xxx xxx

Spinach xxx

Legend x Least frequently grown xx Moderately grown xxx Most frequently grown

5.3 WATER MANAGEMENT AND WATER SOURCES Figure 5.1 shows the different water sources used for irrigation in the Kafue Lagoon. 32% of the respondents rely on shallow dug out. 14% of the respondents use the canal, which carries wastewater from Lee Yeast whilst 29% of the respondents use effluents coming from the Nitrogen Chemicals of Zambia (NCZ). The sample size used was 30 respondents. The major water source for irrigation is the Ngwerere River. The most common method of applying water was to collect it from the stream or river, and to apply it to the crops using water cans or buckets (10 to 20 litre containers). Even though this is labour intensive method, some farmers were able to apply nearly to the entire crop water requirement.


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Figure 5.1: Water sources used for irrigating crops in Kafue Lagoon

Water Sources Used for Irrigation

Shallow dug

out

32%

Gutter

10%

NCZ Canal &

Shikoswe

Stream 10%

Guter+NCZ &

Lee Yeast 5%

NCZ Canal

29%

Canal from Lee

Yeast 14%

5.3.2 CONVEYANCE OF WATER AND FIELD APPLICATION Figure 5.2 show that 88% of the respondents convey water to irrigate the crops manually using buckets. The distance that farmers convey water from the sources to the field varies greatly between individual farms. The water is conveyed manually using a bucket of 20 litre or 10 litre containers to irrigate the crops. The frequency of irrigation various according to the crops, its stage of development and the weather but is also influenced by groundwater seepage from the furrows. Figure 5.2: Conveyance of water for irrigation in Kafue Lagoon Area

Conveyance of Water for Irrigation in Kafue Lagoon Areas

Manually using a

bucket & small

canals

4%

Flood Irrigation

4%

Underground

water

4%

Manually using a

bucket

88%


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Figure 5.3: Conveyance of water for irrigation in Ngwerere River

Conveyance of Water for irrigation in

Ngwrere River AreaPump

using

engine

7%

Manually

using

bucket/tin

93%

The respondents interviewed in Ngwerere River area (figure 5.3) irrigate their crops manually using bucket/watering can (93%) and engine/pump and 7% of the respondents use pumps (treadle pumps and engine pumps) and hose pipes to convey the water from the river channel on to their fields of crops. 5.4 CROP MARKETING BY FARMERS IN NGWERERE AND KAFUE LAGOON AREAS Information on the mechanisms used by farmers to market their crops was obtained from the interviews with farmers. Comparative data collected from the farmers survey are summarized in the table below.

Plat 5.1: A plot of Rape in Ngwerere River Area near Ngwerere Estate Weir

Table 5.4: Methods of marketing adopted in Ngwerere and Kafue Lagoon

Mechanism % of farmer

Ngwerere Area (50 farmers) Kafue Lagoon (30 farmers)

Take produce to market 74 67%

Consumers buy from field 12 17%

Traders buy from field 14 13%

Others 5% 3%

100% 100%


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5.4.1 CROP MARKETING BY FARMERS IN NGWERERE AREA The single most common means of marketing the produce is for growers to market and sale their produce individually at markets: Soweto, Town Centre, Kabanana, Chipata Compund, Ngombe, Katabalala, Chaisa, Garden, and Kaunda Square markets which is at 69%. 5% of the farmers sell their produce to Fresh Mark in Lusaka town. Traders (14%) from nearby compound buy the crops which they later sale in different parts of Lusaka. Individual consumers also buy crops from the Ngwerere river areas. The crops are marketed individually (83%) or as a formal group (12%) or traders (3%) buy the produce from the farmers which they later sell. The results are shown graphically in figure 5.4.

Figure 5.4: Market channels for crops grown in the Ngwerere River Area

Traders buy from

field 14%

Consumers buy from

field 12%

Take produce to

market 69% Others (Fresh Mark)

5%

Plat 5.2: Plots of Rape in Chamba Valley near the Ngwerere River

5.4.2 CROP MARKETING BY FARMERS IN KAFUE LAGOON The single most common means of marketing the produce is for growers to sale their produce as individuals and this is at 100%. Individual farmers market the produce of the Kafue Lagoon by taking them to the markets. There are sold in different parts of Kafue and Lusaka including Chirundu. The following are the areas were the produce is sold: Kalukungu market, Kafue Estates market, Zambia Compound Market and Solloboni Market, Lusaka urban and Lusaka rural and Chirundu. Some traders from Lusaka, Chilanga and Chirundu purchase the produce


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from the growers and later resale in Lusaka or Chirundu. Some individual farmers market their own crop at the markets in Kafue Town and individual traders buy the produce from the growers at their field. Selling directly to traders who visit the field is practiced at 13%. Selling of some produce from the field to local consumers is reported at 17%. The selling of produce to market by farmer is at 67%. Figure 5.5: Mechanism in Marketing of Produce by Farmers in Kafue Lagoon

Take produce to

market

67%

Consumers buy

from field

17%Traders buy

from field

13%

Others

3%

5.5 CROP YIELD AND EARNINGS The yield of vegetables varied from one respondent to the other and the figures are based on the data obtained from the farmers through interviews. Secondary data to cross check the findings from the field was not obtained from the Ministry of Agriculture and Cooperatives and other sources. As such the incomes of the farmers are indicative figures. A further analysis of income and expenditure pattern at household level could be a subject another research. 5.5.1 Earnings from sales of crops in Kafue Lagoon Areas The income realized from the sale of different crop varies depending on the type of crop, number of customers and season (with respect to price). For example rape is harvested seven times before another crop is planted and this on average means that rape can be planted twice in a year. At each pick or harvest a 50 Kg sack of vegetables (not 50kg of vegetables) is sold between K 4, 000 and K 10, 000. Taking an average selling price of K7000 per bag of rape the total income realized is K140, 000.00 per year. However, more bags per pick can be sold (e.g. three 50 kg sacks of rape per day sold between K8, 000 to K10, 000 each) and furthermore, the same farmer could sell a handful of rape at K500.00 per bunch. The farmer can have more than one crop e.g. rape and tomato. One box of tomatoes costs between K18, 000 to K20, 000 each. The average income that can be estimated is only indicative for a specific crop. Further information on yields and prices are indicated in table 5.5 and 5.6.


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Table 5.5: Crops grown in Kafue Lagoon Area, yields, unit and price per unit

Months

Crop S O N D J F M A M J J A Area (acres) Yield Unit Price per unit (kwacha)

Cabbage 50kg sack 20000-30000

Tomato 0.25-1.5 acre 2-10 boxes 1 box 5000-25000

Mupilu 1 acre - 0.25 ha 2 - 8 bags 50 kg sack 15000-40000

Chinese cabbage 0.25 acres - 0.5 acre 5-9 bags 50 kg sack 7000

Onion 1 acre 1 bag 50 kg 15000

Rape 0.25 acre - 0.25 ha 1-2 bags 25-50kg sack 5000-35000

Pumpkin leaves 0.25 acre 6 bags 50 kg sack 5000-10000

Chikolowa 50 kg sack 18000

Cassava

Bananas Per bunch 2000

Guava

Beans Per bundle 500

Sugar cane 1 acre 50 bundles Portion 8000 per portion

Maize 1 acre 200-500 per cob

300 per cob

Table 5.6: Farmers’ total income in Kafue Lagoon and Ngwerere River Areas

Amounts in Zambian Kwacha

Per plot Per day Per week Per year

Kafue Lagoon Areas 100, 000 8 000 - 60 000 8 000 – 500 000 800 000-1, 000, 000

Ngwerere river Area K30 000 – 40 000 K5, 000-K80, 000 K15 000 – K500 000 200 000 – 2 400 000

Plat 5.3: Rape and tomatoes in Chamber Valley


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Table 5.7: Crops grown in Ngwerere River Area, yields, unit and price per unit

Crop Months

S O N D J F M A M J J A Area (acres) Yield Unit Price per unit (Kwacha)


per head 1000

Tomato 1 acre 2-6 boxes 1 box 10000-70000

Spinach 0.25 ha 3 bags 50-75kg 40000-60000


Nchembele 1 acre - 0.25 ha 4-6 bags 50 kg sack 15000-30000

Chinese cabbage 0.25 acres - 0.5 acre 5-9 bags 50 kg sack 30000

Lettuce 0.25 acres 10 bags 50 kg sack 20000

Lettuce per head 500

Onion 0.5 ha 10kg porch 35000


Rape 0.25 acre - 0.25 ha 6-12 bags 50kg sack 15000-60000

Carrot 0.25 -0.5 acre 5-9 bags 300 kg 2000-2500/kg

Green pepper per kg 1500

Potatoes 4 bags 50 kg 48000

Pumpkin leaves 15meters*20meters 8*50kg bags 50 kg sack 15000-35000

Okra 1 acre 1 bag 50 kg sack 7000

Maize 1 acre 10 cobs @ 3000-K3500

5.5.2 Earnings from sales of crops in Ngwerere River Area Similar analysis for Ngwerere River Areas as for Kafue Lagoon Areas (Section 5.1). The income realized by a farmer is higher than the one in the Lagoons. The average income realize per month from selling of vegetables by farmers is K200, 000 because they have a wider market coverage and relatively shorter distances to markets and higher demand for the crops. For instance Kafue Lagoons, sugar cane must be transported to far away markets such as Lusaka and Chirundu. Further information on yields and prices are indicated in table 5.6 and 5.7.


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5.6 PUBLIC HEALTH ISSUES The diseases, which are prevalent in the two study areas, are malaria, bilharzias and diarrhoeaFor the Ngwerere area, secondary data obtained at Kasisi Rural Health Centre helped to confirm the findings. This is contained in Table 5.7 below. The table indicates the figures of reported cases of water-borne diseases associated with the river water including all age groups from the year 2000 up to June 2004. Malaria tops the list as the most prevalent, followed by diarrhoea, bilharzias and dysentery. Considering the total population of the Kasisi sub-catchment (11,450), the disease burden is relatively high, especially for the current year, which by June 2004 (half way) had malarial cases already higher than the total cases of each of the previous years. For diarrhoea, the cases were higher than half of the average cases for previous years. The same applies to this year‘s (2004) bilharzias and dysentery cases when compared to cases for last year (2003). But it is mainly malaria and bilharzias, which may be directly related to the Ngwerere river water. The two diseases are closely associated with damming of watercourses. Up to Kasisi Mission and before its confluence with the Chongwe River the Ngwerere River has several dams, which reduce the velocity of the river, resulting in sedimentation of suspended materials including bilharzias snails and creation of a conducive environment for mosquito breeding. Table 5.8: Clinical data from Kasisi Rural Health Centre

Kasisi Catchment Area (clinical data)

Population 11,450

Disease Year June

2000 2001 2002 2003 2004

Malaria 3242 3459 2902 3575 4014

Diarrhoea N/B 279 275 277 361 187

Bilharzias 77 57 36 56 33

Dysentery 30 41 65 122 66

Other parts of the river catchment near stabilization ponds and near overgrown parts of the river are likely to be affected by these diseases. The levels of microorganisms as determined by laboratory analysis (see Figures 5.10 and 5.11) clearly bring out the evidence of existing health risks associated with the river water. Moreover the river water quality does not improve to the extent where it can be used for domestic use, especially drinking after receiving mainly municipal wastewater including wastewater from the residential and trade areas, and the Lusaka Water and Sewerage Company treatment plants near the source and along the river. Fifty four percent (54%) of the respondents in Ngwerere catchment said the river water was not fit for drinking but was good for irrigation. However, fifty percent (50%) of them said none of the members of their household had suffered from any disease associated with the river water in the past one year. The answer to the question on disease infection could have been affected by bias because some of the respondents expressed fear that they would be banned from using the water as some organizations had hinted in the past. Nevertheless, other factors could explain why the disease infection was lower than expected in the light of the perceived threat of using the river water for irrigation, namely:

Most respondent‘s homes are far away (>3 km) from the river.

The fact that they are aware of the risk involved they take some precautions, e.g., some bring clean drinking water to the fields from safer sources.

Most of the frequently grown vegetables require cooking before eating


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The case at Kafue Lagoon is quite similar to the Ngwerere situation. Fifty three percent (53%) of the respondents said the water used for irrigation posed a threat to human health while fifty percent (50%) said none of the members of their household had suffered any illness as a result of the water they used for irrigation. However, at Kafue Lagoon the distance between the waste streams and residential areas was shorter (about 1 km). In addition the water from Lee Yeast and Shikoswe stream was visibly dark brown and laden with faecal matter, respectively, so much that one would not obviously drink it.

Plat 5.4: Crop fields being watered 5.7 CONSTRAINTS FACED BY FARMERS IN KAFUE LAGOON AND NGWERERE

RIVER AREA Tables 5.9: Constraints faced by farmers

Type of constraint Study sites

Ngwerere River Area Kafue Lagoon Areas

Inadequate irrigation water x

High input costs xx

Inadequate technical support xxx xx

Conveyance of water xxx xxx

Storage of the crops is a big problem xxx

The crops became spoiled xxx xx

Price variation xxx xxx

Transport expenses xxx xxx

Lack of credit for capital development xxx

Theft of crops xxx xxx

Marketing of produce xxx xxx Legend x – a minor problem xx – a moderate problem xxx – a major problem


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5.8 QUANTITY OF WASTEWATER The total surface runoff and base-flow was computed by using the Hydata, spreadsheet and ARIDA software at the Department of Water Affairs Water Resources Unit were used. The surface runoff was estimated by using Flow Duration Curves (FDC). A FDC is a cumulative frequency curve that shows the percentage of time during which specified discharges were equaled or exceeded during the period of a record. It represents a non-sequential series of stream flow events and it combines in one curve the flow characteristics of a stream throughout the range of discharge without regard to the sequence of occurrence (UNESCO, 1984). Figure 5.6: Ngwerere River mean monthly flows

Ngwerere River at Estate Weir - Mean monthly flows

Monthly flow Mean flow

Flo

w (

cu

me

cs)

0.01

0.1

1

10

1999 2000 2001 2002 2003 2004

Ngwerere River at Estate Weir - Mean monthly flows

Monthly flow Mean flow

Flo

w (

cu

me

cs)

0.01

0.1

1

10

Figure 5.6 above shows the mean monthly flows for the Ngwerere River at Estate Weir station of the Department of Water Affairs. It shows the mean monthly flow for a period ranging from 1999 to 2004. The figure shows the behaviours of the monthly and mean monthly flows at Ngwerere Estate Weir in Chamba Valley area. Tables 5.10 and Figure 5.7 shows the flow duration data for Ngwerere River at Estate weir. The flow duration curve is used for analyzing hydrological data. According to Smakhtin (2000) and UNESCO (1984) a Flow Duration Curve (FDC) is a relationship between any given discharge value and the percentage of time that this discharge is equaled or exceeded. FDC is frequently used in water quality calculations, design of run-of-river abstraction schemes, and estimation of required environmental flows. In this study the FDC was used to separate the surface runoff and base-flow from the total surface runoff. The results are shown in figure 5.8 and ANNEX VIII. As can be seen in figures 5.7, 5.8, 5.9 and Annex VIII the Ngwerere catchment contributes enough base-flow from the groundwater storage. In hydrologic studies, flow duration values of 90, 95 and 99% (see Table 5.10 and Figure 5.7) are used as measures of a stream‗s low flow potential. The 90% value is used as a measure of groundwater contribution to stream flow (Cross, 1949). This same value has been used as a


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measure of run-of –the-river hydro-power potential (Searcy, 1959). Other potential uses of the low flow portion of a duration curve include analysis relating to irrigation and urban water supplies. The low flow portion of the curve (Figure 5.6) is an index of the amount of groundwater being contributed to stream flow from natural catchment storage. If the slope of the curve in the low flow portion is flat, groundwater contributions are significant. On the other hand a steep curve indicates poor base-flows and probable cease-to- flow conditions. Thus a duration curve is a valuable tool that can be used for comparing drainage basin characteristics, particularly the effect of geology on low flows. The analysis shown in figures 5.6 and 5.7 are for one hydrometric station on the Ngwerere River at Ngwerere estate Weir. The hydrological data analyzed is from the 1970s to August 2004. There is significant contribution of groundwater to the total surface runoff as can be seen in figure 5.6 and Annex IX. Table 5.10: FLOW DURATION TABLE

FLOW DURATION TABLE

Station Number: 5016

Name: Ngwerere River at Estate Weir

Time-Series: Mean Daily Flow

Period of analysis from: 1-Oct-1980 to 30-Sep-2004

Seasonal flow duration analysis from Jan to Dec

Time interval (days) = 10 Intervals in period = 8757

Station 5016

Intervals with data 8534

Intervals missing or out of season 223

Mean daily flow 0.486

95 percentile (Q95) 1.093







Percentiles in litres/second/sq km

Mean daily flows from 1-Oct-1980 to 30-Sep-2004


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Figure 5.7: Flow Duration Curve for Ngwerere River

1 Day Flow Duration Jan to Dec

Ngwerere River at Estate Weir Mean Daily Flow

litre

s/s

eco

nd

/sq

km

0.0

20.0

40.0

60.0

80.0

0.01 0.10 1.00 10.00 50.00 90.00 99.00 99.90 99.99

1-Oct-1970 to 30-Sep-2004dwa Figure 5.8: Total, Base-flow and Surface Runoff


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Figure 5.9: Total hydrograph and Base-flow from October 2002 to August 2003

Base Flow Index - Ngwerere River at Estate Weir

Total Hydrograph Baseflow

Flo

w (

cu

me

cs)

0.0

0.3333333

0.6666667

1.0

1.3333333

1.6666667

2.0

O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S2002 2003 2004

1-Oct-2001 to 30-Sep-2004dwa


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5.9 FINDINGS FROM WATER, SEDIMENT AND PLANT SAMPLE ANALYSIS 5.9.1 PLANT SAMPLE ANALYSIS In the Ngwerere River Area, the crop samples were collected in Chamba Valley near Ngwerere Estate Weir. Only the leaves of rape were collected and taken to Food Science Laboratory at the University of Zambia in the School of Agriculture. In the Kafue Lagoon Areas three samples of crops were collected and taken for analysis of heavy metal concentration at the University of Zambia. The leaves of rape (medium and large) sampled were collected near the Lee Yeast effluent canal as shown in Plat 5.5. One sample of the sugar cane stock was collected because large quantities of sugar canes sold in Lusaka, Chirundu and other areas come from the Kafue lagoon Areas in Kafue.

Plat 5.5: Crop in Kafue Lagoon Area near effluent channel from Lee Yeast The analysis for heavy metals in crops/or vegetables was only for exploratory purposes. Table 5.11: Exploratory Analysis of Heavy Metals in Crops at Ngwerere River and Kafue lagoon Areas Test Ngwerere River

Area Kafue Lagoon Areas Threshold

values (Anonymous)

Leaves of rape Plot A (same crop of rape) Plot B

Rape Medium leaves of rape

Large leaves of rape

Sugar cane

Lead (Pb) mg/kg 0.07 0.07 0.012 0.02 5

Copper (Cu) mg/kg Not detected Not detected Not detected Not detected 50

Zinc (Zn) mg/kg 0.095 0.082 0.123 0.005 50

Cadmium (Cd) mg/kg 0.049 0.049 0.028 0.036

Mercury (Hg) mg/kg Not detected Not detected Not detected Not detected


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Although heavy metals were not detected in the water samples (water used for irrigation), some of them were found in the plant and sediment samples. Mercury and copper were not detected in both water and plant samples. 5.9.2 WATER QUALITY A total of eight (8) sampling campaigns at each site in Ngwerere and four (4) at each site in Kafue were carried out between 6th July 2004 and 20thAugust 2004. In total two (2) campaigns in Ngwerere involved one (1) duplicate sample for each site and in Kafue two (2) campaigns included one (1) duplicate sample at three (3) sites

5.9.2.1 Ngwerere River and Kafue Lagoon Areas

The results obtained so far (see Annex VII) show that most of the parameters including conductivity, salinity, calcium, sulphate, total nitrogen, total phosphate, BOD, total suspended solids and iron tended to reduce in concentration from the upstream reaches in the urban area to the downstream reaches in the rural area of the river catchment. This indicated that the pollution was heavier in the former than in the latter stretches of the river. This can be explained by the fact that near its source, Ngwerere River received effluents from industries (needs to be investigated further), markets and residences near Lusaka town area, and from the Lusaka Water and Sewerage Company wastewater treatment plant (Manchinchi) in Garden Compound. Previous water quality surveys in 1996 and 1998 also found a similar trend (Tembo et al 1997; Silembo 1998). Though most of the physical and chemical parameters were within the recommended limits for irrigation and other uses, microbiological parameters showed that the river was heavily polluted. Throughout the river stretch, the water was not suitable for drinking, and at some points even for irrigation according to WHO and FAO guidelines Unexpectedly, there were no heavy metals detected in the water. It is probable that metals like copper and lead easily precipitated out of solution given the high pH values (8-10) found in the river. For quality control/assurance purposes duplicate samples were obtained during selected sampling campaigns and some samples taken to an independent laboratory for cross-checking. Nevertheless, the independent laboratory (Manchinchi Laboratory for Lusaka Water and Sewerage Company) did not carry out the analysis in good time for reporting. Effluents from Lee Yeast and Shikoswe were heavily contaminated with respect to faecal coliforms. The water was not safe for use without treating it. Like the Ngwerere case, there were no heavy metals detected in the irrigation water that was sampled from the canals.


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Plat 5.6: Below Spill way at Kasisi Dam (third sampling point) 5.9.2.2 Microbiological Results

The microbiological results, their mean values and standard deviations of the entire sampling period (7th July – 19th August 2004) are presented in Table 5.12 and 5.13 below. For Ngwerere River, N1 to N3 represented sampling stations on the river from the upstream reaches (about 3km from the source) to the down stream reaches (about 23 km from the source). Refer to Figure 3.1 for the map of the Ngwerere area and also Figure 3.2 for the map of the Kafue Lagoon area with sampling points highlighted. The sampling points were picked on the effluent streams: Nitrogen Chemicals of Zambia carrying effluent from the factory, Shikoswe stream carrying effluents mainly domestic wastewater and the Lee Yeast carrying effluent from the factory but somewhat mixed with sewage.

Table 5.12: Number of organisms per 100ml

Ngwerere River

Sampling Date 07.07.04 08.07.04 12.07.04 13.07.04 16.07.04 04.08.04 05.08.04 19.08.04 Mean SD

Faecal coliform

N1 12,000 9,000 9,300 4,000 3,100 18000 17500 9000 10,000 5000

N2 4,000 5,000 1,700 8,500 2,000 12350 15000 8700 7,000 5000

N3 340 380 1,200 1,400 1,200 7850 9000 1000 3000 4000

E.coli

N1 120 96 6,200 2,200 2,200 500 520 7000 2,000 3000

N2 100 100 1,000 4,000 1,200 453 470 6100 2000 2000

N3 90 90 400 500 1,000 313 175 700 400 300

Faecal Streptococci

N1 900 70 500 1,000 220 8000 8500 290 2,000 4000

N2 400 388 100 1,500 210 5500 7500 320 2000 3000

N3 70 10 400 300 190 1385 1805 420 600 700

SD=standard deviation


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Table 5.13: Number of organisms per 100ml

Kafue Lagoon

Sampling Date 08.07.04 20.07.04 11.08.04 18.08.04 Mean SD

Faecal coliform

Lee Yeast 8,000 4,000 2000 5000 3000

Shikoswe Stream 8,000 3,300 8900 2500 6000 3000

E.coli

Lee Yeast 5,000 2,000 1800 3000 2000

Shikoswe Stream 76 1,200 3750 2000 2000 2000

Faecal Streptococci

Lee Yeast 120 800 180 400 400

Shikoswe Stream 96 1,000 2150 210 900 900

SD=standard deviation

Westcot (1997) argued that the WHO or Engelberg standards for faecal coliforms were design guidelines and suggested that in the absence of better information, it is ―prudent‖ to use them as the quality standard to aim for in waters that are known to currently fall short of that quality. Therefore, in this study, the water quality was interpreted with respect to the WHO guidelines and recommendations by Westcot considering the fact that adequate epidemiological and water quality information was not available at the time of the current study. The following table (Table 5.12) shows the ranges of contamination and recommendations by Westcot (1997) based on a minimum of 5 (five) samples taken over the irrigation season.

Table 5.14: Ranges of Contamination and Recommendations (after Westcot, 1997)

Mean number of faecal coliforms/100ml Recommendation

<1000 (<103) Appropriate for the irrigation of vegetables

1000, - 10,000 (103 – 104) Potentially safe if the source of contamination (presumed to be localized) can be eliminated

10,000 – 100,000 (104 – 105) Heavy contamination requiring treatment before the water can be used for unrestricted cropping

>100,000 (>105) Extensive heavy contamination-highly unsuited for irrigation

Compared to Table 5.14 above, the water at both Ngwerere and Kafue Lagoon area was potentially safe as long as the pollution sources were eliminated. But elimination of the sources of pollution is not feasible in both situations because the contaminated water is also the water used for irrigation by the peasant farmers in these areas and is their main source of income and food. Other options such as improving the efficiency of wastewater treatment plants (especially desludging) upstream or expanding the treatment plants may be considered. There are large variations in the faecal coliform numbers at each point on the Ngwerere River over the study period, hence high standard deviations. This was probably due to variation in wastewater discharges and composition, flow pattern of the river and its tributaries and abstraction for irrigation. Such variations in coliform counts were also reported in a study in Ghana carried out by Cornish et al (1990). Between points N2 and N3, there were massive abstractions of water from the river and a few dams by large-scale farmers. However it was not verified whether there was significant return flow from the farms.


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In terms of the spatial distribution of the microorganisms on the Ngwerere River, the log plot (Figure 5.9) shows that more organisms (hence more pollution) were found upstream in the urban/peri-urban area of Lusaka City (N1 and N2) than downstream in the rural area.

Figure 5.10: Logarithmic plot of microorganisms at 3 sites along Ngwerere River

Mean spatial distribution of microorganisms

1

10

100

1,000

10,000

N1 N2 N3

Sampling site

log

(n

um

be

r p

er

10

0m

l)

Faecal coliform

E.coli

Faecal Streptococci

Figure 5.11: Logarithmic plot of number of microorganisms at 2 sites at Kafue Lagoon

Mean number of microorganisms at Kafue

Lagoon

1

10

100

1,000

10,000

Lee Yeast Shikosw e Stream

sampling sites

log

(n

um

ber

per

100m

l)

Faecal coliform

E.coli

Faecal

Streptococci


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5.9.2.3 PHYSICOCHEMICAL PARAMETERS

5.9.2.3.1 Ngwerere River General the physical-chemical parameters are within the limits of the ECZ, WHO, DWA and EU guidelines for water quality as shown in table 5.15, 5.16 and 5.17. Table 5.15: Results of analysis of effluents from Ngwerere River Areas

Parameters N1 SD N2 SD N3 SD

ZNBS/DWA drinking water guidelines (permissible)

WHO drinking water guidelines

EU drinking water guidelines

pH 10 0.7 8 0.5 8 0.7 6.5 - 9.0 7.0 - 8.5

Conductivity 590 13 569 8 417 13 1500

Water Temperature 18 0.4 16 0.4 18 1

Salinity (%) 0.02 0.00 0.02 0.00 0.01 0.00

Magnesium (mg/l) 36 10 36 9 43 15 150

Calcium (mg/l) 81 6 84 11 53 12 200

Sulphate (mg/l) 33 4 29 4 23 5 400

Total Nitrogen (as N mg/l) 3 7 5 6 1 0

Total Phosphates (as PO4-P mg/l) 3 1 3 1 0.5 1

Ammonia (as NH4-N mg/l) 4 0.1 4 0.1 0 0.1 0.5

Biochemical Oxygen Demand (O2 mg/l) 20 5 19 9 8 6

Chemical Oxygen Demand (O2 mg/l) 72 24 39 23 38 21

Total Suspended Solids (mg/l) 117 4 94 6 102 3 0

Bicarbonates (as CaCO3 mg/l) 330 14 333 33 263 18

Nitrates (as NO3-N mg/l) 3 5 3 5 2 5 10 30 mgNO3/l

Iron (mg/l) 1 1 0.3 0.6 1 1 1 0.3 0.1 - 3.0

Sodium (mg/l) 232 11 219 9 219 9 200?

Lead (mg/l) 0 0 0 0 0 0 0.5 0.01 0.05

Copper (mg/l) 0 0 0 0 0 0 1.5 2 -

Cadmium (mg/l) 0 2 0 2 0 2 0.01 0.003 0.005

Mercury (mg/l) 0 3 0 3 0 3 0.001 0.001 0.2

Zinc (mg/l) 0 4 0 4 0 4 15 3 0.1 - 5.0

Boron (mg/l) 1 5 1 5 1 5


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Table 5.16: Results of analysis of effluents from Ngwerere River Areas

Parameters N1 SD N2 SD N3 SD

Recommended max concentrations (irrigation)

Recommended max concentrations for crops (Pescod)

pH 10 0.7 8 0.5 8 0.7

Conductivity 590 13 569 8 417 13

Water Temperature 18 0.4 16 0.4 18 1

Salinity (%) 0.02 0.00 0.02 0.00 0.01 0.00

Magnesium (mg/l) 36 10 36 9 43 15

Calcium (mg/l) 81 6 84 11 53 12

Sulphate (mg/l) 33 4 29 4 23 5

Total Nitrogen (as N mg/l) 3 7 5 6 1 0

Total Phosphates (as PO4-P mg/l) 3 1 3 1 0.5 1

Ammonia (as NH4-N mg/l) 4 0.1 4 0.1 0 0.1

Biochemical Oxygen Demand (O2 mg/l) 20 5 19 9 8 6

Chemical Oxygen Demand (O2 mg/l) 72 24 39 23 38 21

Total Suspended Solids (mg/l) 117 4 94 6 102 3


Nitrates (as NO3-N mg/l) 3 5 3 5 2 5

Iron (mg/l) 1 1 0.3 0.6 1 1 5 5

Sodium (mg/l) 232 11 219 9 219 9

Lead (mg/l) 0 0 0 0 0 0 5 5

Copper (mg/l) 0.0 0 0 0 0 0 0.2 0.2

Cadmium (mg/l) 0.0 2 0 2 0 2 0.01 0.01

Mercury (mg/l) 0 3 0 3 0 3 -

Zinc (mg/l) 0 4 0 4 0 4 2 2

Boron (mg/l) 1 5 1 5 1 5 0.5 - 15


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Table 5.17: Results of analysis of effluents from Ngwerere River Areas

Parameters N1 SD N2 SD N3 SD ECZ Effluent and Wastewater Standards

pH 10 0.7 8 0.5 8 0.7 6.0 - 9.0

Conductivity 590 13 569 8 417 13 4300

Water Temperature (oC) 18 0.4 16 0.4 18 1 40

Salinity (%) 0.02 0.00 0.02 0.00 0.01 0.00

Magnesium (mg/l) 36 10 36 9 43 15 500

Calcium (mg/l) 81 6 84 11 53 12

Sulphate (mg/l) 33 4 29 4 23 5 1500

Total Nitrogen (as N mg/l) 3 7 5 6 1 0 5.0

Total Phosphates (as PO4-P mg/l) 3 1 3 1 0.5 1 6

Ammonia (as NH4-N mg/l) 4 0.1 4 0.1 0 0.1 10

Biochemical Oxygen Demand (O2 mg/l) 20 5 19 9 8 6 50

Chemical Oxygen Demand (O2 mg/l) 72 24 39 23 38 21 90

Total Suspended Solids (mg/l) 117 4 94 6 102 3 100


Nitrates (as NO3-N mg/l) 3 5 3 5 2 5 50

Iron (mg/l) 1 1 0.3 0.6 1 1 2.0

Sodium (mg/l) 232 11 219 9 219 9

Lead (mg/l) 0 0 0 0 0 0 0.5

Copper (mg/l) 0 0 0 0 0 0 1.5

Cadmium (mg/l) 0 2 0 2 0 2 0.5

Mercury (mg/l) 0 3 0 3 0 3 0.002

Zinc (mg/l) 0 4 0 4 0 4 10.0

Boron (mg/l) 1 5 1 5 1 5 0.5

5.9.2.3.2 Kafue Lagoon Area For NCZ according to table 5.18, the parameters measured were within the ECZ recommended limits. This was very different from the situation in 1996 under the study of Sinkala et al, which reported higher levels of magnesium, calcium, total suspended solids and total dissolved solids. The difference may be attributed to slowed or no production at NCZ at the time of the present study. In fact the water in the effluent canal was visibly clear. At the time of sampling the farmers were mixing this water with that from Lee Yeast factory and Shikoswe stream through diversion canals. For Lee Yeast the conductivity was higher than the recommended standard of 4300uS/cm (ECZ) as shown in table 5.20. The phosphate and calcium levels were abnormally higher that the recommended limits by ECZ although this was just for one sample. High calcium and conductivity (as TDS) levels were also reported by Sinkala et al (1996) (Annex XIV). The concentration of heavy metals and boron in the water at all the sampling points were below the detection limit of the method of analysis which is also far below the recommended maximum concentrations.


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Table 5.18: Results of analysis of effluents from Nitrogen Chemicals of Zambia

Parameter 11.08.04 18.08.04 ECZ Limit (point source)

pH 7.7 6.8 6.0 - 9.0

Conductivity (uS/cm) 223 258 4300

Water temp 21.6 22.1 40

Salinity (%) 0.00 0.00

Magnesium (mg/l) 16.08 500

Calcium (mg/l) 31.6

Sulphate (mg/l) 36.6 1500

Total Phosphates (as PO4-P mg/l) 0.48 6.0

Ammonia (as NH4-N mg/l) 0.20 10

Total Suspended Solids (mg/l) 4 100

Iron (mg/l) 0.44 0.01 2.0

Sodium (mg/l) 109.2 124.05 200*

Lead (mg/l) <0.01 <0.01 0.5

Copper (mg/l) <0.003 <0.003 1.5

Cadmium (mg/l) <0.002 <0.002 0.5

Mercury (mg/l) <0.0002 <0.0002 0.002

Zinc (mg/l) 0.0695 0.0555 10

Plat 5.7: NCZ effluent channel near the footbridge on the Left side of the picture (Sampling point)


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Table 5.19: Table 5. : Results of analysis of effluents from Shikoswe Stream

Sampling Date 08.07.2004 20.07.2004 11.08.2004 18.08.2004 ECZ Limit (point source)

pH 7.9 8.2 7.8 6.3 6.0 - 9.0

Conductivity 343 390 348 324 4300

Temperature 19.4 20.1 24.8 25.2 40

Salinity 0.01 0.01 0.01 0.01

Sulphate (mg/l) 29.2 27.2 1500

Ammonia (as NH4-N mg/l) 3.32 4.598 3.1 4.88 10

Total Suspended Solids (mg/l) - 45 56 100

Bicarbonates (as CaCO3 mg/l) 198 230 203

Nitrates (as NO3-N mg/l) - 0.69 50

Magnesium (mg/l) 29.5

Calcium (mg/l) 29.6

Total Phosphates (as PO4-P mg/l) 15.6 6

Iron (mg/l) 0.54 0.60 <0.01 2.0

Lead (mg/l) <0.01 <0.01 0.5

Copper (mg/l) <0.01 1.5

Cadmium (mg/l) <0.002 0.5

Mercury (mg/l) <0.0002 0.002

Zinc (mg/l) <0.001 1.5

Boron (mg/l) <0.5 0.5

Plat 5.9: Shikoswe stream carrying sewerage effluent near NCZ going into the lagoon (NCZ right side of the picture)


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Table 5.20: Table 5. : Results of analysis of effluents from Lee Yeast

08.07.2004 20.07.2004 11.08.2004 18.08.2004 ECZ Limit (point source)

pH 8.0 8.9 8.9 7.9 6.0 - 9.0

Conductivity 5600 6420 6400 6350 4300

Temperature 16.3 18.3 25.5 27.3 40

Salinity 0.30 0.34 0.34 0.33

Ammonia (as NH4-N mg/l) 2.85 2.18 0.965 2.685 10

Total Suspended Solids (mg/l) - 242 220 100

Magnesium (mg/l) 224.4

Calcium (mg/l) 7812.85

Total Phosphates (as PO4-P mg/l) 62.65 6

Bicarbonates (as CaCO3 mg/l) 328 334 329

Nitrates (as NO3mg/l) - 1185 50

Iron (mg/l) 1.43 1.1 1.36 2.0

Lead (mg/l) <0.01 0.08 0.5

Copper (mg/l) <0.01 1.5

Cadmium (mg/l) <0.002 0.5

Mercury (mg/l) <0.0002 0.002

Zinc (mg/l) <0.001 1.5

Boron (mg/l) <0.5 0.5


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5.9.2.4 SEDIMENT ANALYSIS FROM NGWERERE RIVER AND KAFUE LAGOON AREAS

Table 5.21: ANALYSED SEDIMENTS FROM NGWERERE AREA from Ngwerere Sampling Points Sample Id N1 N1 N2 N2 N3 N3 Dutch sediment

quality guideline

Parameter (Class I)

Sampling Date 07.07.2004 13.07.2004 07.07.2004 13.07.2004 07.07.2004 13.07.2004

Lead (mg/kg) 0.13 1.38 0.5 1.57 1.17 0.62 <530

Copper (mg/kg) 0.16 7.51 0.33 1.85 1.85 1.27 <35

Cadmium (mg/kg) <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 <2

Mercury (mg/kg) <0.0002 <0.0002 <0.0002 <0.0002 <0.0002 <0.0002 <0.5

Zinc (mg/kg) 0.969 8.8 1.266 1.838 1.636 0.185 <480

Iron (mg/kg) 75 1,596.30 282 480.93 1,310 312.63

Table 5.22: ANALYSED SEDIMENTS FROM KAFUE LAGOON Lab No. 40451 40455 40456 Dutch sediment quality guideline

(Class I)

Sample Id Shikoswe stream Shikoswe stream Lee Yeast

Parameter

Sampling Date 08.07.2004 20.07.2004 20.07.2004

Lead (mg/kg) - 0.82 0.85 <530

Copper (mg/kg) 0.04 58 1.51 <35

Cadmium (mg/kg) <0.002 <0.002 <0.002 <2

Mercury (mg/kg) <0.0002 <0.0002 <0.0002 <0.5

Zinc (mg/kg) <0.001 15.6 11.2 <480

Iron (mg/kg) 8.62 1,503 1,175

The sediment samples were analysed at both sites for exploratory purposes. Detailed investigations may be carried out in future.


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CHAPTER 6

DISCUSSION OF RESULTS AND FINDINGS

6.1 Water Quality

From the results it is clear that the main problem with respect to the risk to human health is the pollution by microorganisms in the watercourses where the farmers draw water for irrigating their crops. This common for both studies –Ngwerere River and Kafue Lagoon Areas. For Ngwerere River only the last point (N3 about 23 km from source) qualifies for unrestricted

irrigation according to the WHO guideline value of 1000 faecal coliform/100ml, if only the mean value for July 2004 is considered (900 faecal coliform/100ml). Under unrestricted

irrigation vegetables and salad crops can be grown using water with 1000 faecal coliform/100ml. Therefore, the growing of vegetables at the other sites (N1 and N2) poses a health risk to workers (or producers) and the consumers. On the other hand the water in the Ngwerere River is only fit for restricted irrigation whereby the crops that can be safely grown are cereal crops, industrial and folder crops, and pasture and trees (fruit trees). The reduction in pathogens at the lower reach of the river (Kasisi Mission) evidenced by the reducing counts of E.coli and Faecal streptococci. At all the stations on the river the water was not suitable for drinking. Previous studies also demonstrated a similar pattern especially that the sampling points used in this study were also used in the past. In Kafue Lagoon Areas, the Shikoswe and Lee Yeast effluent streams also had their mean values above the WHO guideline of <1000 faecal coliforms/100ml. 6.2 Plants For mercury, which was also not found in significant quantities (<0.0002 mg/l) in the sediments, it could mean that it was not present as a waste product, hence not a threat to human health in these areas. Any detectable quantities of Hg could also be from natural sources. Given the high pH values copper could have precipitated out of solution into the sediments and so not much of it was available for the plant uptake after irrigation. A previous study by Sinkala et al (1996) reported less than 0.02 mg/l (detection limit) of Cu in the wastewater from NCZ and less than 0.011 and 0.018 mg/l (detection limits) of Cu in Lee Yeast effluents. Literature indicated that cadmium could be present in the water column at very low concentrations and yet build up in the plant tissue to levels that are harmful to human health. Annex IV shows recommended maximum trace element concentrations in irrigation water. For Cd the recommended maximum concentration is 0.01 mg/l in water. Others like Pb it is 5.0 mg/l, Zn 2.0 mg/l and Cu 0.20 mg/l. There were no reliable guideline values for heavy metals in plants against which comparisons could have been made. However, a study (workshop presentation) used 50 mg/kg as maximum concentration of Cu and Zn, and 5mg/kg Pb in plant tissues. 6.3 Sediments The spot samples analysed brought out interesting findings, which would help to explain or confirm variations in the other sample types in limited mass balance terms. Two samples were collected on different days at both sites. After about a week, there was a high increase in the


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concentration of Zn, Fe, Pb and Cu at the first two sites (N1 and N2) on the Ngwerere River. For instance for Cu it was over 6 times and for Zn it was over 9 times. But at the last site (N3), there was a marked concentration decrease in all the metals. However there seems to be no consistent trend in the data sets that can explain fully the variations, especially, given the variation in effluent discharges to the river and the seemingly high rates of deposition or removal of sediments. What is generally expected is that when the flow velocity of the river reduces the amount sediment deposition increases and vice-versa. At Kafue lagoon, there was also an increase in the heavy metal content after 12 days at the Shikoswe stream site, also indicating a relatively high rate of deposition. Cd and Hg concentrations were below the detection limit at all the sampling points in the two study sites, indicating that very little quantities of both metals are introduced in the watercourses and so may not be a serious threat to the environment. Moreover, on the Ngwerere River there are no known industrial discharges. Since there are no local guidelines for heavy metals in sediments, the results in this study were compared with the standards in the Netherlands although this country is more industrialized than Zambia. From the comparison with Class I (best class) out of four classes, all the samples are way below the maximum heavy metal class concentrations except for Cu (58 mg/kg) at Shikoswe stream, which was very high. But this was a one off value, which would require further verification. 6.4 Physicochemical Parameters Generally the physicochemical parameters for Ngwerere river are within the limits of the ECZ, WHO, DWA and EU guidelines for water quality. However, the pH was higher than the recommended upper limit of 9 in a few cases especially at Kasisi orphanage. Ammonia levels at N1 and N2 (that is urban and peri-urban areas) was higher than the WHO drinking water guideline value of 0.5mg/l. On average sodium was higher than the guideline value of 200mg/l which can lead to the problem of specific ion toxicity. TSS at N1 and N3 were also higher than the ECZ guideline value of 100mg/l. All the other parameters measured were lower than the recommended maximum concentration in irrigation water, according to Pescod (1997). The concentration of heavy metals and boron in the water at all the sampling points were below the detection limit of the method of analysis which is also far below the recommended maximum concentrations. The parameters measured at NCZ, were within the ECZ recommended limits. This was very different from the situation in 1996 in the study of Sinkala et al, which reported higher levels of magnesium, calcium, total suspended solids and total dissolved solids. The difference may be attributed to slowed or no production at NCZ at the time of the present study. In fact the water in the effluent canal was visibly clear. At the time of sampling the farmers were mixing this water with that from Lee Yeast factory and Shikoswe stream through diversion canals. For Lee Yeast the conductivity was higher than the recommended standard of 4300uS/cm (ECZ). The phosphate and calcium levels were abnormally higher that the recommended limits by ECZ although this was just for one sample. High calcium and conductivity (as TDS) levels were also reported by Sinkala et al (1996) (Annex XIV). The source of the calcium is mainly the geology of the area. The high conductivity corresponds to high sodium content of the effluent. The Shikoswe effluent had relatively high levels of ammonia and phosphate, the reason being that it carries mainly sewage effluents. As in Lee Yeast effluents, Shikoswe had also high levels


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of iron. The iron was also high in the sediments. However with respect to human health, through crop production, it does not pose a threat. The high salt content (as conductivity) of the irrigation water used at both study sites, threatens the well being of the soil in the fields under irrigation. The sodium adsorption ratio (SAR) are N1, N2 and N3 and at Kafue Lagoon Areas (NCZ) are 31, 28, 32 and 22, respectively. The values are higher than the Ayers and Westcot (1985) guideline value of 9 (Annex III) beyond which the fields under irrigation would experience severe specific ion toxicity affecting sensitive crops and also increasing soil salinity problems. High salinity leads to reduce uptake of water and nutrients by plants. The concentration of heavy metals and boron in the water at all the sampling points were below the detection limit of the method of analysis which is also far below the recommended maximum concentrations.


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CHAPTER 7

CONCLUSION AND RECOMMENDATIONS

CONCLUSION The growing and selling of crops in both study areas is the main source of cash income and food for most of the peasant farmers for many years. The high unemployment levels and the general poor state of the economy in Zambia have left them with few or no alternatives for earning a living. For example all the respondents (30) in Kafue Lagoon are unemployed. The average income earned from sale of crops ranges from K400, 000 to K1,000, 000 in Kafue Lagoon and K400, 000 to K2, 500, 000 in the Ngwerere River Area although these figures have not been cross-checked with other reliable data. The relevant parameters were measured in water, plants and sediments from the Ngwerere River and Kafue Lagoon Areas and compared with ECZ, WHO, EU, DWA, ZABS and others to determine the suitability of the water for various uses especially irrigation. It was found that the water in the Ngwerere River and Kafue Lagoon Area is suitable for restricted irrigation of folder crops, and fruit trees with to microbiological contamination. In the rural area of Ngwerere (Kasisi Mission) the water may be suitable for unrestricted irrigation of salad crops and vegetables. The water at all sampling points is not suitable for drinking. Heavy metals in the water at all the sampling points were below the detection limit and so generally poses no threat to human health through crop production. The heavy metals in plant tissue and to some extent in the sediments were way below the maximum recommended limits although bioaccumulation capacities of cadmium and lead need to be considered further. There is no evidence of pollution with heavy metals that may pose a threat to irrigated crops. Health risks associated with the use of water in the Ngwerere and Kafue Lagoon Area can be reduced if the sources of pollution are eliminated but this may not be possible in both situations because the contaminated water is also the water used for irrigation by the peasant farmers in these areas and is their main source of income and food. Other options could be in improving the efficiency of wastewater treatment plants (especially desludging since this has not been done for a long time) upstream. The sludge in the maturation ponds may be reducing the retention time of the water for the pathogen to die off before it is discharged into the environment. Maturation ponds are primarily used to ensure the removal of faecal bacteria and viruses to safe levels so that the effluents can be used without risk to public health for crop irrigation. Other parameters being acceptable, the water from the two study areas could be

used for irrigation according to the WHO guidelines value of 100, 000 per 100 ml for restricted irrigation. The WHO guidelines for microbiological quality of wastewater use/or reuse for irrigation are intended as a guide for the design of treatment plants The peasant farmers value wastewater for irrigation as the only alternative available. Literature also reviewed that in many places the pre-treated or untreated wastewater is their only source of irrigation water—so their livelihoods depend on it. The main irrigation method currently practiced is the use of containers that accentuate the risk of contamination of the plants and farmers. Literature revealed that lettuce irrigated with watering cans has higher levels of contamination by faecal coliforms and streptococcus than lettuce irrigated by hosing water into the furrow. Another way of mitigation would be to practice restricted irrigation as recommended by the WHO. Thus the latter method would be more preferred. In the Zambian context this may be challenging in that crops such as lettuce and


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tomatoes are some of the most profitable crops for peri-urban and urban agriculture. An education programme for farmers, the public, and municipal officials would be essential to effectively deal with this issue of peri-urban and urban agriculture. RECOMMENDATIONS At policy level the study‘s outcome would be used by the national government for purposes such as policy audit. Furthermore, stakeholder institutions like Department of Water Affairs and Ministry of Health can use the information obtained for effective routine water quality monitoring to inform users on the suitability of the water for the intended use. The results will be published into educational materials to inform users on the dangers of reusing raw wastewater and could also be a basis for routine monitoring of water quality and secure better health for farmers and consumers. It is expected that use of this water on a sustainable basis will result in enhanced crop production thereby contributing towards food security. In particular: The Ministry of Agriculture and Cooperatives (MAC) would incorporate reuse of wastewater

or nutrient enriched water, if found not hazardous, in the irrigation strategy aimed at improving food security and poverty alleviation in the country;

The Ministry of Health (MoH) will may the major findings for public awareness on health risks that may be associated with using and handling of untreated wastewater or pretreated wastewater;

The Ministry of Energy and Water Development and Ministry of Agriculture and Cooperatives could use the information generated from the study for demand management for sustainable use of the water resources;

NGOs and other interested public and private institutions may incorporate the findings in their projects, strategies etc to improve agriculture output, water management, prevention of water borne and helminth diseases and conservation of the environment.

If irrigation of agriculture is to continue contributing to the welfare of peri-urban and urban farming households, the following recommendations are appropriate: Policy changes need to be effected with a view to incorporate urban agriculture as a

legitimate urban land use because recent studies in several Asian and African cities have revealed that wastewater agriculture has accounted for over 50% of urban vegetable supply

Implementation of well-structured technical support to urban irrigators, not only regarding crop husbandry, but also on environmental implication;

Formation of urban farmers associations or co-operatives, which can deliberate, and act on issues such as marketing, input supply as well as credit

Another study need to be undertaken to check the seasonal variation of the parameters and prevalent of helminthes among irrigators and consumers from both study areas

There is need to sensitize the irrigators on the health implication associated with using water with high level of faecal coliforms

There is need to sensitize the peasant farmers on land use pattern and the dangers associated with river ban cultivation

There is also need to embark on an education programme for farmers, the public, and municipal officials that would be essential to effectively deal with this issue of peri-urban and urban agriculture.


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REFERENCES Blumentthal U. J., Mara D. D., Peasey A. and Ruiz-Palacios G. and Stott. Guidelines for the microbiological quality of treated wastewater used in agriculture: recommendations for revising WHO guidelines, Environment and Health, Bulletin of the World Health organization 2000, 78(9) 1105 Braden, John B. (2000), Value of valuation: Introduction. Journal of Water Resources Planning and Management, Vol. 126, no. 6, pp. 336-338. Cifuentes E.; M. Gomez; U. Blumenthal; M. M. Tellez-Rojo; I. Romieu; G. Ruiz-Palacios; and S.Ruiz-Velazco. 2000. Risk factors for Giardia intestinalis infection in agricultural villages practicing wastewater irrigation in Mexico. American Journal of Tropical Medicine and Hygiene. 62(3): 388-392. Cooper, R.C. 1991. Public health concerns in wastewater reuse. Water Science and Technology. 24(9):55-65. Cornish G. A., Mensah E and Ghesquire P (1990), Water quality and peri-urban irrigation: An assessment of surface water quality for irrigation and its implications for human health in peri-urnban zones of Kumasi, Ghana: KAR Project R7132, Report OD/TN95, HR Wallingford DFID (1998), Guidance Manual on water Supply and Sanitation Programme, WEDC Dubbeling M. and Santanddreu A. (2003), Urban Agriculture: A tool for Sustainable Municipal Development. Guidelines for Municipal Policymaking on Urban Agriculture, No 1 First Edition IWMI-RUAF E-CONFERENCE: AGRICULTURAL USE OF UNTREATED URBAN WASTEWATER IN LOW INCOME COUNTRIES 24 June - 5 July 2002 Egziabher A G, Maxwell D G, Lee-Smith D, Memon P A, Mougeot L J A, Sawio C J. 1994. Cities Feeding People. An examination of urban agriculture in East Africa. IDRC, Ottawa, Canada. Ensink, J. H. J.; W. van der Hoek; Y. Matsuno; S. Munir; and M. R. Aslam. 2002. Use of untreated wastewater in peri-urban agriculture in Pakistan: Risks and opportunities. Research Report 64. Colombo, Sri Lanka: International Water Management Institute. Environmental Council of Zambia, Enviro – line, Issue No. 1, May – August 1998. Environmental Council of Zambia and Lusaka City Council (1997), Solid Waste Management Plan Project, Phase 1- Diagnosis Final Report Environmental Council of Zambia (1994), State of the Environment Report, Lusaka Feenstra S.; R. Hussain; and W. van der Hoek. 2000. Health Risks of Irrigation with Untreated Urban Wastewater in the Southern Punjab, Pakistan, IWMI Pakistan Report no. 107. International Water Management Institute, and Institute of Public Health, Lahore.


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Ghoshi B. N. (1992), Scientific Methods and Social Research, Sterling Publishers Private Limited, New Delhi, India GKW Consult (2001), Water Supply and Sanitation study in Central Province, Zambia. Sector Review and Design Criteria Report, Lusaka Hide J. M., Kimani J., and Kimani J. T. (2001), Informal irrigation in the Peri-urban Zone of Nairobi, Kenya: An Analysis of Farmers Activities and Productivity. Report OD/TN 104 Hide J. M., Hide C. F. and Kimani J. (2001), Informal irrigation in the Peri-urban Zone of Nairobi, Kenya: An assessment of surface water quality used for irrigation. Report OD/TN 105 Huang J. Y. C (1994), ‗Sewage Disposal’ Microsoft ® Encarta, Funk and Wagnall‘s Corporation Habbari, K.; A. Tifnouti; B. Bitton; and A. Mandil. 2000. Geohelminthic infections associated with raw wastewater reuse for agricultural purposes in Beni-Mellal, Morocco. Parasitology International, 48, 249-254. Hussain I.; L. Raschid; M. A. Hanjra; F. Marikar; W. van der Hoek. (2002), Wastewater use in agriculture: Review of impacts and methodological issues in valuing impacts. Working Paper 37. Colombo, Sri Lanka: International Water Management Institute. Idelovitch E and Ringskog K (1997), Wastewater treatment in Latin America, Old and New Options, World Bank, Washington DC

IWMI , Confronting the Reality of Wastewater Use in Agriculture; Water Policy Briefing Series No. 9, August 2003, Karpagma M (1999), Environmental Economics, Sterling Publishers Pvt. LTD, New Delhi. Kelderman P. (2001), Environmental Chemistry, with special emphasis to aquatic sediments. International Institute for Infrastructure, hydraulic and Environmental engineering. The Netherlands Khouri N., Kalbermatten J. M. and Bartone C. R. (1994), Reuse of Wastewater in Agriculture: A guide to Planners, UNDP-World Bank Water and Sanitation Programme: The World Bank, Washington, DC Mara, D. D. 1977. Wastewater treatment in hot climates. In Water, wastes and health in hot climates, ed. R. Feachem, M. McGarry and D. Mara. Chichester, United Kingdom: John Wiley and Sons. Mara, D. D. (2000), The production of microbiologically safe effluents for wastewater reuse in the Middle East and North Africa. Water, Air, and Soil Pollution. 123(1-4): 595-603. Ministry of Finance and National Planning (2002), Poverty Reduction strategy Paper, Lusaka Ministry of Energy and Water Development (1994), Zambia National Water Policy, Lusaka. National Scientific Research (1983), Pollution Surveillance in Zambia – Ngwerere-Chongwe River System, Lusaka


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Naser Faruqui, Mark Redwood and Malick Gaye (2002), Reuse of Untreated Wastewater in Market Gardens in Dakar, Senegal, UA-Magazine December 2002 pp 35-36 Nicholas O'Dwyer and Partners Consulting Engineers, (1978), Extension of Present Sewage Treatment Plant, Main Sewage and Associated Pumping Station at Kafue, Kafue Township Council Pescod M (1992), Wastewater treatment and use in agriculture. FAO, irrigation and Drainage Paper no. 47. Rome: FAO. ISBN 92-5-103135-5. 125pp Price J. (2003), Treatment and Use of Wastewater in Urban Agriculture: Guidelines for Municipal Policy makers on Urban Agriculture. Paper No. 6 First Edition March 2003 Prof Duncan Mara: ‗Low-cost wastewater treatment and reuse‘ Water, DFID, issue 5, November, 1997 pp7 Rose G. D. (1999), Community-Based Technology for Domestic Wastewater Treatment and reuse: options for urban agriculture. CITIES FEEDING PEOPLE CFP REPORT SERIES Report 27 Scott C. A., Zarazua J. A. and Levine G. (2000), Urban-Wastewater Reuse for Crop Production in the Water-Short Guanajuato River Basin, Mexico. Colombo, Sri Lanka, International Water Management Institute. Shuval H. I. (1991), Health Guidelines and Standards for Wastewater reuse in Agriculture: historical perspectives. Water Science and Technology 23:2,073-2,080 Sinkala T., Kanyomeka L., Simukanga S., Mwasa M., Sikazwe O. N., Nsomi C. M., Mwase-Ngulube E. T., Lewanika M., Kasuta E., Mwale M. S. and Musonda M. M. (1996), Control of Aquatic Weed in the Kafue River Basin between Iteshi-teshi Dam and Kafue Gorge (March 1996 – March 1997), (draft) Final Report Smakhtim V. U (2000), Estimating Daily Flow Duration Curves form Monthly Stream Data, Water SA, Vol. 14, 13-18 Steenvoorden J., Van Lier J., and Huibers F. (2004), Wastewater Re-use and Groundwater Quality, IAHS Publication No. 285 Tembo J. M., Bolsius M., Handia L. and De Koning J. (1997), Preliminary research on the Ngwerere River Water Quality, Delft University of Technology, Department of Water Management and Department of Civil Engineering – University of Zambia, Lusaka

USEPA (United States Environmental Protection Agency). 1992. Guidelines for water reuse. Washington, U.S.A.: USEPA.

UNESCO (1982), Methods of Computing Low Stream Flow, Imprimerie de la Manutention, Mayeme, Paris Westcot D (1997), Quality control of wastewater for irrigated crop production. FAO. Water Report No. 10. Rome: FAO 86p ISBN 92-5-103994-1


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World Health Organization (1989), Reuse of Effluents: Methods of wastewater in agriculture and aquaculture. Geneva: Tech. Report Series 778 WWI, Wastewater Treatment in Egypt, Vol 4, No 4 (August 1989) Zambia Bureau of Standards (1990): Zambian Standard Specification for Drinking Water Quality (ZS 190:1990 ICS 13.060.20) Zambezi River Authority (2003), Zambezi River Authority Water Quality Guidelines for Livestock Watering, Irrigation and Aquatic Biota


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APPENDICES


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ANNEX I

QUESTIONNAIRES FOR THE PROJECT ON THE USE OF NUTRIENT ENRICHED WATER FOR GROWING FOOD CROPS IN THE NGWERERE RIVER CATCHMENT AND AT THE

KAFUE LAGOON This questionnaire is part of a research project looking at the use of nutrient enriched water of the Ngwerere River for growing food crops and to assess how this can contribute to poverty alleviation. The information collected will be kept with strict confidentiality and used strictly for the development of the community. Dear Respondent Kindly answer the following questions. Do not reveal your name. INSTRUCTIONS Where options are given circle the letter representing the option you choose. Write answers to questions in the spaces provided where there are no options given. Section A: General Demographic information on households using the nutrient enriched water 1) Farmer‘s sex

a) Female b) Male

2) Age a) 15-25 b) 26-35 c) 36-45 d) Above 45

3) Academic qualifications a) Primary b) Secondary c) College/University d) None e) Other, specify……………………………………………………………

4) Marital status a) Single b) Married c) Separated d) Divorced e) Widowed

5) Number of children………………….Dependants……………………………….. 6) Number of members of household above 16 years ………………………………


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7) Total household size ……………………………………………………………... 8) Employment status

a) Formal b) Informal c) Unemployed

9) Main occupation of farmer ……………………………………………………….. 10) Second occupation of farmer ……………………………………………………… 11) Main source of household income ………………………………………………………………………………………… 12) Alternative sources ………………………………………………………………………………………… Section B: Agricultural Practice Provide the following information for each irrigated field under the control of the farmer: If the farmer has more than one irrigated plot at different locations consider only the most important. If a single plot is divided into several fields and more than one is irrigated, give information for each field within the plot.

1. Field Identification

2. Approximate size of field (acres)

3. Distance of land from house (miles)

4. How many years have you farmed the field

5. Does flooding occur 1. Never 2. In some years 3. Every year

6. How many months a year is field flooded

7. Do you continue to farm the field on raised beds when it is flooded? (Yes/No/NA)

8. For how much of the year do you irrigate crops on this field?

1. All through the year 2. Indicate the months

9. How long has the field been cultivated under irrigation? [if known] (Years)

10. Current tenure? 1. Freehold 2. Leasehold 3. Communal 4. Traditional

11. Amount paid in rent

12. Terms if cash rent (months)

13. Terms if share cropped

14. Who often does the irrigation? (Male or Female)

13) Do you farm the land in partnership with another person or persons? Yes/No 14) If the answer is ‗yes‘ what is the contribution from the partners and how is the profit

shared?

Contributions: Self (%) Partner 1 (%) Partner 2 (%)

1. Land


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2. Labour

3. Inputs

Share of Profits

Section C: Water Management 15) Water Source

i. Main supply (pipe) ii. Stream/river (perennial) iii. Stream pool iv. Shallow dug out v. Stream pools and later dug outs vi. Deep well of borehole vii. Natural pool/pond viii. Gutter ix. Other (specify) ……………………………………………………

16) Conveyance from source to field

i. Manually bucket/watering can ii. Pumped iii. Manually but occasional pump hire iv. Stand-pipe and hoses v. Other specify

17) Field application method. More than one method may be circled

1. From watering can/bucket/tin filled at the source 2. From watering can/bucket/tin filled from field-side oil drum 3. From hose pipe without sprinkler 4. From hose and shallow held in the hand 5. From hose and mounted sprinkler 6. Other (specify) …………………………………………….

18) How much water do you use for irrigation? ……………………………………... 19) Do you think this is enough? Yes/No 20) If ‗No‘, what do you think should be done to increase the amount of water? ……………..…………………………………………………………………………… 21) Does your access to water limit the area that you cultivate in any part of the year because a. The source may dry up b. Requires too much effort to carry more water c. No 22) Do you think your yield is reduced because you cannot apply enough water to your crop?

Yes/No 23) Would you drink the water you use for irrigation? Yes/No 24) If [20] is ‗No‘, why ………………………………………………………………. 25) Does water quality influence your choice of irrigation crops? Yes/No 26) If the quality or quantity of water has been a significant problem what efforts have you

made, individually or jointly with others, to improve the situation? …………………………………………………………………………………………………………


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……………………………………………………………………………………………………………………………………………………………

27) Do you pay for water? Yes/No 28) Are you able to apply much water, as you would like to your crops? Yes/No 29) If ‗No‘ what is it that limits the amount you apply?

1. Cost of labour to carry or apply water 2. Cost of water tariff 3. Cost of pump hire or operation 4. The work is too hard 5. Not enough available at the source 6. Water quality any fear of crop damage 7. Other (specify) ……………………………………………

30) Have you received any formal training in vegetable production? Yes/No 31) If ‗Yes‘ describe training, when ……………and where ………………………… 32) If answer was ‗No‘ how did you learn able irrigated vegetable cultivation? ………………………………………………………………………………………… 33) Are some of your crops stolen from your field? Yes/No 34) If ‗Yes‘ is this

1. A major problem 2. 2. Minor problem

Section D: Crop marketing 35) How do you sell the crops?

1. Take produce to a market (where) …………………….. 2. Individual consumers buy from the field (where do they came

from)………………… 3. Traders buy from the field (where do they came from) …. 4. Other (specify) ………………………………...

36) Do you market your produce as: 1. An individual? 2. A member of an informal group? 3. A member of a co-operative?

37) How much do you earn from the sale of the crops?…………………………… (a) Per day ………. (b) Per Week …………… (d) Per months ……………..

38) Are you satisfied with the income?…………………………..………….……………. 39) What problems do you face in selling the produce? ………………………………………………………………………………………… ………………………………………………………………………………………… Section E: Public health issues 40) Do you see the use of this type of water as a threat to human health? Yes/No 41) Do you want an improvement in the sanitation of the stream so that the water can be safer

for both the producer and the consumer? Yes/No 42) If asked to pay for this improvement would you agree? Yes/No 43) Have you or any one of your household suffered from any illness related to the use of the

water or crops grown using the same water in the last 12 months? Yes/No


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44) If ‗Yes‘, how frequent were these illnesses? 1. Few times 2. Sometimes 3. Often

What type of disease(s) ………………………………………………………………. Section G: Attitudes toward organizations responsible for delivery of water related services. 45) Are you aware of any organisation/community project/association, which addresses water

issues in the area? (if answer is ‘No’, skip to Next section) Yes/No 46) If ‗Yes‘, are you a member of any? Yes/No: If ‗Yes‘, which one? ………………………………………………………………………………………… 47) Do you think most of the strategies put across have been beneficial to you in terms of

being adequately provided with adequate and safe water? ………………………………………………………………………………………… 48) Do you relate very well with programme/project implementers or is this done through

representative members? Yes/No. Reason? …..…………………………………………………………………………………….. 49) Are you satisfied with the current performance of the organisation/project/association?

1. Satisfied 2. Not satisfied

50) If ‗not satisfied‘ with the performance what improvements do you want to see? ………………………………………………………………………………………… ………………………………………………………………………………………… Section H: Perceived problems and possible solutions 51) Do you have plans to expand the acreage?

1. This year 2. Next year 3. Sometime 4. Never

52) Is the growing of crops using nutrient enriched water an activity you want to continue with? Yes/No

53) Do you experience any harassment because you are growing crops in this location? Yes/No

54) If ‗Yes‘ from whom? ……………………………………………………………… 55) What problems have you faced so far in the following areas as far as the use of the nutrient

enriched water is concerned? a) Quantity of water…………………………………………………………… b) Quality of water…………………………………………………………….. c) Maintenance of infrastructure (if any)……………………………………… d) Paying for water services (if any)………………………………………… e) Accessing water…………………………………………………………... f) Dialogue with implementers and relevant authorities…………………….

56) What are your suggestions in each of the above areas?


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a) ……………………………………………………………………………… b) ……………………………………………………………………………… c) ……………………………………………………………………………… d) ……………………………………………………………………………… e) ……………………………………………………………………………… f) ………………………………………………………………………………

Field identification …………………………………………………………..

Crop S O N D J F M A M J J A Area (acres)

Yield Unit Price per unit


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ANNEX II Table A.1: Wastewater treatment and quality criteria for irrigation (State of California 1978)

Treatment level Coliform Limits Types of use

Primary Surface irrigation of orchards and vineyards, Fodder, fiber, and seed crops.

Oxidation and disinfection , <23/100ml

Pasture for milking animals; landscape impoundments; Landscape irrigation (golf courses, cemeteries, etc.)

< 2.2/100 ml Surface irrigation of food crops (no content between water and edible portion of crop)

Oxidation, Coagulation, clarification, filtration And disinfections

< 2.2/100ml max. =23/100ml Spray irrigation of food crops Landscape irrigation (parks, playgrounds, etc.)

Source: Pettygrove and Asano 1985. a. The turbidity of filtered effluent cannot exceed an average of two turbidity units during any 24-hour period.


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ANNEX III: Irrigation Water Quality Guidelines Table B. 1: Guidelines for Interpreting Water Quality for Irrigation

Potential Irrigation Problem units None Slight to Moderate Severe

Salinity (affects crop water availability) ECw Or TDS

Ds/m Mg/1

< 0.7 <450

0.7 – 3.0 450 – 2,00

3.0 > 2,000

Infiltration (affects infiltration rate of water into the soil; evaluate using ECw and SAR together) SAR=0- 3 and ECw = 3-6 =6-12 =12-20 =20-40

=ds/m =ds/m =ds/m =ds/m =ds/m 0

>0.7 >1.2 >1.9 >2.9 >5.0

0.7 – 0.2 1.2 – 0.3 1.9 – 0.5 2.9 – 1.3 5.0 – 2.9

< 0.2 < 0.3 < 0.5 < 1.3 < 2.9

Specific ion toxicity (affects sensitive crops) sodium (Na)

Surface irrigation Sprinkler irrigation

SAR Me/l

<3 <3

3 - 9 >3

>9

Chloride (Cl) Surface irrigation Sprinkler irrigation

Me/l Me/l

<4 <3

4 – 10 >3

>10

Boron (B) Trace elements (see Table B.2)

Mg/1 <0.7 0.7 – 3.0 >3.0

Miscellaneous effects (affects susceptible crops) Nitrogen (NO3- N) Bicarbonate (HCO3) (overhead sprinkling only) pH

Mg/l Me/l

<5 <1.5

5 - 30 1.5 – 8.5 Normal range 6.5 – 8.4

>30 >8.5

Ecw means electrical conductivity, a measure of water salinity reported in decisiesmens per meter at 25o C (ds/m)or in milliohms per centimeter (nmho/cm). Both are equivalent. TDS means total dissolved solids, reported in milligrams per liter (mg/l). SAR sodium adsorption ratio. 1 me/1 = 1 milliequivalent per liter, where 1 me Na = 11 mg; 1 me Cl = 17mg; 1 me HCO3 = 31 mg. Source; Adapted from Ayers and Westcot 1985, to which he reader may refer for detailed assumptions in and justification of the guidelines presented above.


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ANNEX IV: TABLE 2B: Recommended Maximum Concentrations of Trace Elements in Irrigation Water

Element Recommended maximum concentration (mg/1)

Remarks

AL 5.0 Can cause nonproductivity in acid soils (pH <5.5), but more alkaline soils at pH > 7.0 will precipitate the ion and eliminate any toxicity.

As 0.10 Toxicity to plants varies widely, for example, < 0.5mg/1 for Lemon, 1.0 mg/1 for rice. B 0.5 - 15 Toxicity to plants varies widely: for example, < 0.5 mg/1 for lemon, 1.0 mg/1 for wheat, 6.0

mg/1 for tomato, and 15mg/1 for cotton. Be 0.10 Toxicity to plants varies widely, ranging from 5.0 mg/1 for kale to 0.5 mg/1 for bush beans. Cd 0.01 Toxic to beans, beets, and turnips at concentrations as low as 0.1 mg/1 in nutrient

solutions. Conservative limits recommend because of its potential to accumulate in plants and soils to concentrations that may harm humans.

Co 0.05 Toxic to tomatoes at 0.1 mg/1 in nutrient solution. Tends to be inactivated by neutral and alkaline soils

Cr 0.10 Not generally recognized as an essential growth element. Conservative limits recommend because of lack of knowledge about its toxicity to plants.

Cu 0.20 Toxic to a number of plants at 0.1 to 1.0 mg/1 in nutrient solutions. F 1.0 Inactivated by neutral and alkaline soils. Fe 5.0 Not toxic to plants in aerated soils, but can contribute to soil acidification and loss of

availability of essential phosphorus and molybdenum. Overhead sprinkling may result in unsightly deposits on plants, equipment, and buildings

Li 2.5 Tolerated by most crops up to 5.0mg/1; mobile in soil. Toxic to citrus at low concentration (<0.075mg/1). Acts similarly to boron.

Mn 0.20 Toxic to a number plants at a few tenths to a few mg/1, but usually only in acid soils. Mo 0.01 Not toxic to plants at normal concentrations in soil and water. Can be toxic to livestock if

forage is grown in soils with high concentrations of available molybdenum. Ni 0.20 Toxic to a number of plants at 0.5mg/1; reduced toxicity at neutral or alkaline pH Pb 5.0 Can inhibit plant cell growth at very high concentrations. Se 0.02 Toxic to plants at concentrations as low as 0.025mg/1 and toxic to livestock if forage is

growth in soils with relatively high levels off added selenium. An essential element to animals but in very low concentrations.

V 0.10 Toxic to many plants at relatively low concentrations. Zn 2.0 Toxic to many plants at widely varying concentrations; reduced toxicity at pH 6.0 and fine-

textured or organic soils.

This is not an exhaustive list of the effects of all trace elements found in wastewater, especially if industrial wastes are discharged directly into it. If industrial wastes are found in the wastewater, the trace elements contribute need to be identified and information obtained about their effects on a site-specific basis. The maximum concentration is based on a water application rate consistent with good irrigation practices (10,000m3/ha/yr). If the rate greatly exceeds this, the maximum concentrations should be adjusted downward accordingly. No adjustment should be made for application rates less than 10,000 m3/ ha/yr. The values given are for water used on a continuous basis at one site. Source: Ayers and Westcot 1985.


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ANNEX V: Table C. 3: Constituents of concern in wastewater treatment and irrigation using reclaimed municipal wastewater

Constituents Measured parameters Reason for concern

Suspended solids Suspended solids, including volatile and fixed solids

Suspended solids can lead to the development of sludge deposits and anaerobic conditions when untreated wastewater is discharged into the aquatic environment. Excessive amounts of suspended solids cause plugging in irrigation systems.

Biodegradable organics

BOD, COD Composed principally of proteins, carbohydrates, and fats. If discharged into the environment, their biological decomposition can lead to the depletion of dissolved oxygen in receiving waters and to the development of septic conditions.

Pathogens Indicator organisms, total and fecal coliform bacteria

Communicable diseases can be transmitted by the pathogens in wastewater: bacteria, viruses, and parasites.

Nutrients Nitrogen, Phosphorus, potassium

Nitrogen, phosphorus and potassium are essential nutrients for plant growth, and their presence normally enhances the value of the water for irrigation. When discharged into the aquatic environment, nitrogen and phosphorus can lead to the growth of undesirable aquatic life. When discharged in excessive amounts on land, nitrogen can also lead to groundwater pollution

Stable (refractory) organics

Specific compounds (e.g., phenols, pesticides, chlorinated hydrocarbons)

These organics tend to resist conventional methods of wastewater treatment. Some organic compounds are toxic in the environment, and their presence may limit the suitability of the wastewater for irrigation.


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ANNEX VI: Questionnaire results Section A: General Demographic information on households using the nutrient enriched water 1) Farmer’s sex (see tables below) 2) Age (see tables below)

Table 1a: Ages of Farmers in Ngwerere River Area Ngwerere Area Gender

Males % Females %

Age

15-25 7 17 -

26-35 15 36 1 2

36-45 6 14 2 5

Above 45 6 14 5 12

Totals 34 81% 8 19%

Table 1b: Ages of Farmers in Kafue Lagoon Areas Kafue Lagoon Gender

Males % Females %

Age

15-25 - - - -

26-35 2 7 3 10

36-45 2 7 4 13

Above 45 8 27 11 36

Totals 12 41% 18 59%

3) Academic qualifications: (see table below)

Primary

Secondary

College/University

None Table 2a: Ngwerere River Area (Academic qualification, marital status and employment status)

Single % Single Married % Married Divorced % Divorced Widowed % Widowed

Primary 4 10 18 43 - -

Secondary 5 12 8 19 - -

College 1 2

None 1 2 4 7 1 2 1 2

Totals 11 26 30 69 1 2 1 2



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Employed - - 1 2 - - -

Unemployed 11 26 28 67 1 2 1 2

Totals 11 26 29 69 1 2 1 2

Table 2b: Kafue Lagoon Areas (Academic qualification, marital status and employment status)


Primary 3 10 9 30 1 3 4 14

Secondary - 5 17

College - - - -

None 4 13 4 13

Totals 3 10 18 60 1 3 8 27


Employed - - - -

Unemployed 3 10 60 1 3 8 27

Totals 3 10 60 3 8 27

4) Marital status (see table above)

Single

Married

Separated

Divorced

Widowed

5) Number of children………………….Dependants……………………………….. 6) Number of members of household above 16 years ……………………………… 7) Total household size ……………………………………………………………... 8) Employment status (see table above)

Formal

Informal

Unemployed

9) Main occupation of farmer: (see table below) Table 3a: Ngwerere River Areas

Gardening % Farming % Others %

Main occupation 35 83 3 7 4 10

Second occupation 3 7 - - 39 93

Table 3b: Kafue Lagoon Areas

Gardening % Farming % Business/ piece work % Keeping cattle %

Selling charcoal % Others %

Main occupation 21 70 2 7 3 10 4 13

Second occupation 1 3 1 3 - - 1 3 1 3 26 87

10) Second occupation of farmer: (see table above)


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Main source of household income of farmers in Kafue Lagoon Areas: gardening, selling of vegetables and sugar canes

Main source of household income of farmers in Ngwerere River areas: gardening and selling of vegetables

11) Alternative sources of income for farmers in:

Kafue Lagoon Areas: gardening, selling of vegetables and sugar canes

Ngwerere River Areas: rental from houses, business and piece of work, gardening, selling of pesticides and vegetables.

Section B: Agricultural Practice Provide the following information for each irrigated field under the control of the farmer: If the farmer has more than one irrigated plot at different locations consider only the most important. If a single plot is divided into several fields and more than one is irrigated, give information for each field within the plot.

1. Field Identification Kafue Lagoon area Ngwerere River Area

2. Approximate size of field (acres)

3. Distance of land from house (miles)

4. How many years have you farmed the field

5. Does flooding occur 4. Never 5. In some years 6. Every year

6. How many months a year is field flooded

7. Do you continue to farm the field on raised beds when it is flooded? (Yes/No/NA)

8. For how much of the year do you irrigate crops on this field?

3. All through the year 4. Indicate the months

9. How long has the field been cultivated under irrigation? [if known] (Years)

10. Current tenure? 5. Freehold 6. Leasehold 7. Communal 8. Traditional

11. Amount paid in rent K120000 per year

12. Terms if cash rent (months) Six months

13. Terms if share cropped

14. Who often does the irrigation? (Male or Female) Male and Female Male and Female

12) Do you farm the land in partnership with another person or persons?

Yes: 5% of the respondents’ farm in partnership with either the husband and the friend in Ngwerere River Area. The partnering is 50% each.

No: partnering of farmers in Ngwerere River is at (95%) and Kafue Lagoon Areas (100%) 13) If the answer is ‗yes‘ what is the contribution from the partners and how is the profit

shared?

Contributions: Self (%) Partner 1 (%) Partner 2 (%)


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1. Land

2. Labour 50% 50%

3. Inputs 50% 50%

Share of Profits 50% 50%

Section C: Water Management 14) Water Source

Stream/river (perennial) - 88% use stream and 12% used both stream and hand dug out wells in Ngwerere Areas

Gutter – from NCZ discharge canal, Shikowse stream and Lee Yeast effluent canal 15) Conveyance from source to field

Manually bucket/watering can - Manually using bucket/watering can (88%) in Kafue Lagoon Area

Manually bucket/watering can - Manually using bucket/watering can (93%) and 7% use engine/pump in Ngwerere River Areas

16) Field application method. More than one method may be circled

From watering can/bucket/tin filled at the source – Manually bucket/watering can - Manually using bucket/watering can (88%) and engine/pump and hose pipe (12%) in Ngwerere areas

17) How much water do you use for irrigation?

20, 18 or 10 litres containers are used to irrigate the field crops; 20-litre container per 20 square meters - Ngwerere River Areas

18) Do you think this is enough?

Yes (93%); No (7%)- Ngwerere River Areas 19) If ‘No’, what do you think should be done to increase the amount of water?

More water should be released 20) Does your access to water limit the area that you cultivate in any part of the year because

The source may dry up

Requires too much effort to carry more water 21) Do you think your yield is reduced because you cannot apply enough water to your crop?

Yes/No 22) Would you drink the water you use for irrigation?

No (100%) 23) If [20] is ‗No‘, why?

The water is dirty (Ngwerere River and Kafue Lagoon Areas 100% 24) Does water quality influence your choice of irrigation crops?

No – the water is good for irrigating the crops (100% at Kafue Lagoon Areas and Ngwerere Area)


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25) If the quality or quantity of water has been a significant problem what efforts have you

made, individually or jointly with others, to improve the situation? 26) Do you pay for water?

No (100% at Kafue Lagoon Areas and Ngwerere Area) 27) Are you able to apply much water, as you would like to your crops?

Yes 28) Are able to apply as much water as you would like to your crops?

Yes (100% at Kafue Lagoon Areas and Ngwerere Area) 29) If ‗No‘ what is it that limits the amount you apply?

Does not apply to all the study areas 30) Have you received any formal training in vegetable production? Kafue Lagoon Areas

None received any training on how to grow crops. The farmers learnt how to grow crop and vegetables from parents, friends, through experience etc.

Ngwerere River Areas

83% of the farmers have not received any type of training. Learnt how to grow crops from either parents, friends, through experience, worked on a farm, and from school

17% of the farmers have received some training in growing of agricultural crops from various institutions e.g. FAO Agricultural Extension Officers, Chamba Valley cooperative, Kasisi Training Centre, Kafue, Chamba Valley Partnership Forum. One farmer had only acquired skills in citrus fruit farming and rearing of animals.

31) If ‗Yes‘ describe training, when ……………and where …………… (see above) 32) If answer was ‗No‘ how did you learn able irrigated vegetable cultivation? (see above) 33) Are some of your crops stolen from your field?

Yes 34) If ‗Yes‘ is this

A major problem because crops are uprooted by thieves

Minor problem Section D: Crop marketing 35) How do you sell the crops?

Take produce to Soweto, Chaisa, Ngombe, Chipata, Kabanana, Kaunda Square and Katambalala markets (69%)

Individual consumers buy from the field: come from surrounding areas (12%)

Traders buy from the field: come from surrounding areas 14%

Other (specify) Fresh Mark (5%).

36) Do you market your produce as:

An individual?- yes

A member of an informal group?- yes

A member of a co-operative?- yes


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37) How much do you earn from the sale of the crops? Table 4a: Farmers’ income in Kafue Lagoon and Ngwerere River Areas

Amounts in Zambian Kwacha

Per plot Per day Per week Per year Per 50 kg bag

Kafue Lagoon Areas

100, 000 8 000 - 60 000 8 000 – 500 000 800 000-1, 000, 000 K4 000 – K10 000

Ngwerere river Area

K30 000 – 40 000

K5, 000-K40, 000 K15 000 - K400 000 - K5000 – K10 000

38) Are you satisfied with the income?

Yes

No 39) What problems do you face in selling the produce?

The crops may rot or get spoilt or the agents overcharge Section E: Public health issues 40) Do you see the use of this type of water as a threat to human health?

Yes (26%)- Ngwerere River area

No (74%)- Ngwerere River area 41) Do you want an improvement in the sanitation of the stream so that the water can be safer

for both the producer and the consumer?

Yes- Ngwerere River area

No- Ngwerere River area 42) If asked to pay for this improvement would you agree?

Yes

No 43) Have you or any one of your household suffered from any illness related to the use of the

water or crops grown using the same water in the last 12 months? Yes/No 44) If ‗Yes‘, how frequent were these illnesses?

Few times (5%)- Ngwerere River area

Sometimes (12%)- Ngwerere River area

Often (24%)- Ngwerere River area

No (49%)- Ngwerere River area

Yes (10%)- Ngwerere River area What type of disease(s): malaria, bilharzias and diarrhoea Section G: Attitudes toward organizations responsible for delivery of water related services.


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45) Are you aware of any organisation/community project/association, which addresses water issues in the area? (if answer is ‘No’, skip to Next section) Yes/No

46) If ‗Yes‘, are you a member of any? Yes/No: If ‗Yes‘, which one? ………………………………………………………………………………………… 47) Do you think most of the strategies put across have been beneficial to you in terms of

being adequately provided with adequate and safe water? ………………………………………………………………………………………… 48) Do you relate very well with programme/project implementers or is this done through

representative members? Yes/No. Reason? …..…………………………………………………………………………………….. 49) Are you satisfied with the current performance of the organisation/project/association?

1. Satisfied 2. Not satisfied

50) If ‗not satisfied‘ with the performance what improvements do you want to see? ………………………………………………………………………………………… ………………………………………………………………………………………… Section H: Perceived problems and possible solutions 51) Do you have plans to expand the acreage?

1. This year 2. Next year 3. Sometime 4. Never

52) Is the growing of crops using nutrient enriched water an activity you want to continue with? Yes/No

53) Do you experience any harassment because you are growing crops in this location? Yes/No

54) If ‗Yes‘ from whom? ……………………………………………………………… 55) What problems have you faced so far in the following areas as far as the use of the nutrient

enriched water is concerned? a. Quantity of water…………………………………………………………… b. Quality of water…………………………………………………………….. c. Maintenance of infrastructure (if any)……………………………………… d. Paying for water services (if any)………………………………………… e. Accessing water…………………………………………………………... f. Dialogue with implementers and relevant authorities…………………….

56) What are your suggestions in each of the above areas? a. ……………………………………………………………………………… b. ……………………………………………………………………………… c. ……………………………………………………………………………… d. ……………………………………………………………………………… e. ……………………………………………………………………………… f. ………………………………………………………………………………


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Field identification …………………………………………………………..

Table 5a: Crops grown in Ngwerere River Area, yields, unit and price per unit Crop Months

S O N D J F M A M J J A Area (acres) Yield Unit Price per unit (Kwacha)


per head 1000

Tomato 1 acre 2-6 boxes 1 box 10000-70000

Spinach 0.25 ha 3 bags 50-75kg 40000-60000

Sweet potato leaves


Nchembele 1 acre - 0.25 ha 4-6 bags 50 kg sack 15000-30000

Chinese cabbage 0.25 acres - 0.5 acre 5-9 bags 50 kg sach 30000

Lettuce 0.25 acres 10 bags 50 kg sack 20000

Lettuce per head 500

Onion 0.5 ha 10kg porch 35000


Rape 0.25 acre - 0.25 ha 6-12 bags 50kg sack 15000-60000

Carrot 0.25 -0.5 acre 5-9 bags 300 kg 2000-2500/kg

Green pepper per kg 1500

Potatoes 4 bags 50 kg 48000

Pumpkin leaves 15meters*20meters 8*50kg bags 50 kg sack 15000-35000

Okra 1 acre 1 bag 50 kg sack 7000

Maize 1 acre 10 cobs @ K3500

Table 5b: Crops grown in Kafue Lagoon Area, yields, unit and price per unit Months

Crop S O N D J F M A M J J A Area (acres) Yield Unit Price per unit (kwacha)


Tomato 0.25-1.5 acre 2-10 boxes 1 box 5000-25000


Chinese cabbage 0.25 acres - 0.5 acre 5-9 bags 50 kg sach 7000


Rape 0.25 acre - 0.25 ha 1-2 bags 25-50kg sack 5000-35000

Pumpkin leaves 0.25 acre 6 bags 50 kg sack 5000-10000

Chikolowa 50 kg sack 18000

Cassava

Bananas per bunch 2000

Guava

Beans per bundle 500

Sugar cane 1 acre 50 bundles Portion 8000 per portion

Maize 1 acre 200-500 per cob

300 per cob


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ANNEX VII: ANALYZED WATER QUALITY DATA FROM NGWERERE SAMPLING POINTS

N1

Ngwerere Area 0 1 5 6 9 19 20

Sampling Date 07.07.04 08.07.04 12.07.04 13.07.04 16.07.04 04.08.04 05.08.04 AVERAGE SD

pH 8.74 8.93 8.6 8.43 7.46 7.9 7.25 8.2 0.7

Conductivity 601 613 567 586 583 610 603 595 17

Water Temperature 17.5 18.3 18.3 17.4 18.1 19.5 20.4 19 1

Salinity 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.00

Magnesium (mg/l) 35.52 53.76 26.9 29.76 34.56 30.4 24.2 34 10

Calcium (mg/l) 89.6 80 72 83.2 78.4 36 46 69 20

Sulphate (mg/l) 33.8 29.2 28.2 39.4 32.3 33 4

Total Nitrogen (as N mg/l) 10.8 0.96 4.16 4.075 5 4

Total Phosphates (as PO4-P mg/l) 1.79 4.96 2.39 2.24 3.94 2.14 2.47 3 1

Ammonia (as NH4-N mg/l) 4.39 4.47 3.83 3.18 4 1

Biochemical Oxygen Demand (O2 mg/l) 19 18 28 18 15 24.5 16 20 5

Chemical Oxygen Demand (O2 mg/l) 96 96 66 41 61 60.5 37.5 65 23

Total Suspended Solids (mg/l) 114 120 50 36.5 80 43


Nitrates (as NO3-N mg/l) 5.2 0.01 0.01 0.01 11.86 0.01 0.01 2 5

Iron (mg/l) 0.38 0.67 3.3 0.9 0.24 1 1

Sodium (mg/l) 239 225.3 227 222.2 248.7 232 11

E.coli (#/100ml) 120 96 6,200 2,200 2,200 500 520 1691 2185

Faecal coliforms (#/100ml) 12,000 9,000 9,300 4,000 3,100 18000 17500 10414 5890

Faecal Streptococci (#/100ml) 900 70 500 1,000 220 8000 8500 2741 3781

N2

0 1 5 6 9 19 20

07.07.04 08.07.04 12.07.04 13.07.04 16.07.04 04.08.04 05.08.04 AVERAGE SD

pH 8.5 8.4 7.5 8.4 7.7 8.0 7.1 7.9 0.6

Conductivity 567 576 576 571 556 590 564 571 11

Water Temperature 16.5 16.3 16.3 15.6 16.4 18.2 19.2 17 1

Salinity 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.00

Magnesium (mg/l) 44.2 22.08 38.4 29.76 43.2 23.1 27.9 33 9

Calcium (mg/l) 76.8 100.8 78.4 89.6 72 57.6 48 75 18

Sulphate (mg/l) 34.3 24.7 28.2 27.8 31.9 29 4



Ammonia (as NH4-N mg/l) 3.75 3.91 3.525 3.16 3.6 0.3

Biochemical Oxygen Demand (O2 mg/l) 24 30 20 15 5 29.5 19.5 20 9

Chemical Oxygen Demand (O2 mg/l) 98 96 75 44 62 51 45 67 23

Total Suspended Solids (mg/l) 98 90 48.5 8 61 42



Iron (mg/l) 0.01 0.03 1.3 0.01 0.26 0.3 0.6

Sodium (mg/l) 223.6 225.3 212.8 206.6 226.3 219 9

E.coli (#/100ml) 100 100 1,000 4,000 1,200 453 470 1046 1368

Faecal coliforms (#/100ml) 4,000 5,000 1,700 8,500 2,000 12350 15000 6936 5179


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Faecal Streptococci (#/100ml) 400 388 100 1,500 210 5500 7500 2228 3010

N3

0 1 5 6 9 19 20

07.07.04 08.07.04 12.07.04 13.07.04 16.07.04 04.08.04 05.08.04 AVERAGE SD

pH 9.5 9.8 8.9 10.6 8.9 7.8 8.05 9 1

Conductivity 440 410 412 411 413 423 418

418 11

Water Temperature 17 17.8 18.4 18.1 18.1 19.5 21.4 19 1

Salinity 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.00

Magnesium (mg/l) 55.5 60.8 26.9 29.76 43.2 24.55 48.1 41 14

Calcium (mg/l) 54.4 44.16 56 41.6 71.2 61.6 12.4 49 19

Sulphate (mg/l) 28.7 17 19.8 20.8 26.4 23 5



Ammonia (as NH4-N mg/l) 0.12 0.03 3.475 0.18 1 2

Biochemical Oxygen Demand (O2 mg/l) 14 6 15 4 3 29.5 20 13 10

Chemical Oxygen Demand (O2 mg/l) 96 96 63 53 57 35 44.5 64 24

Total Suspended Solids (mg/l) 104 100 23 15 61 48



Iron (mg/l) 0.08 0.01 1.7 2.3 0.21 1 1

Sodium (mg/l) 216.6 229.4 212.3 207.6 227.3 219 9

E.coli (#/100ml) 90 90 400 500 1,000 313 175 367 320

Faecal coliforms (#/100ml) 340 380 1,200 1,400 1,200 7850 9000 3053 3708

Faecal Streptococci (#/100ml) 70 10 400 300 190 1385 1805 594 707


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ANNEX VIII: ANALYZED WATER QUALITY DATA FROM KAFUE LAGOON AREAS

Kafue Lagoon July 2004 Shikoswe

Shikoswe Lee Yeast Lee Yeast

Sampling Date 08.07.04 20.07.04 08.07.04 20.07.04

pH 10.89 11.19 11 11.87

Conductivity 343 390 5600 6420

Temperature 19.4 20.1 16.3 18.3

Salinity 0.01 0.01 0.3 0.34

Sulphate (mg/l) 29.2 -

Total Nitrogen (as N mg/l) - -

Total Phosphates (as PO4-P mg/l) - -

Ammonia (as NH4-N mg/l) 3.32 4.598 2.85 2.180

Biochemical Oxygen Demand (O2 mg/l) - -

Chemical Oxygen Demand (O2 mg/l) - -

Total Suspended Solids (mg/l) - -

Bicarbonates (as CaCO3 mg/l) 198 230 328 334

Nitrates (as NO3-N mg/l) - -

Iron (mg/l) 0.54 0.60 1.43 1.11

Sodium (mg/l) 989.5 160.9

Lead (mg/l) <0.01 <0.01 <0.01 0.08

Copper (mg/l) <0.01 <0.01

Cadmium (mg/l) <0.002 <0.002

Mercury (mg/l) <0.0002 <0.0002

Zinc (mg/l) <0.001 <0.001

Boron (mg/l) <0.5 <0.5

Bacteriological Results

E.coli (#/100ml) 5,000 1200 76 2000

Feacal coliforms (#/100ml) 8,000 3300 8,000 4000

Feacal Streptococci (#/100ml) 96 800 120 1000

Total coliforms (#/100ml) 4500 7000


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ANNEX IX: ANALYSED SEDIMENTS FROM NGWERERE AREA FROM NGWERERE SAMPLING POINTS Lab No. 40448 40452 40449 40453 40450 40454

Sample Id N1 N1 N2 N2 N3 N3

Parameter

Sampling Date 07.07.2004 13.07.2004 07.07.2004 13.07.2004 07.07.2004 13.07.2004

Lead (mg/kg) 0.13 1.38 0.5 1.57 1.17 0.62

Copper (mg/kg) 0.16 7.51 0.33 1.85 1.85 1.27

Cadmium (mg/kg) <0.002 <0.002 <0.002 <0.002 <0.002 <0.002

Mercury (mg/kg) <0.0002 <0.0002 <0.0002 <0.0002 <0.0002 <0.0002

Zinc (mg/kg) 0.969 8.8 1.266 1.838 1.636 0.185

Iron (mg/kg) 75 1,596.30 282 480.93 1,310 312.63


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ANNEX X: ANALYSED SEDIMENTS FROM KAFUE LAGOON Lab No. 40451 40455 40456

Sample Id Shikoswe Shikoswe LY

Parameter

Sampling Date 08.07.2004 20.07.2004 20.07.2004

Lead (mg/kg) - 0.82 0.85

Copper (mg/kg) 0.04 58 1.51

Cadmium (mg/kg) <0.002 <0.002 <0.002

Mercury (mg/kg) <0.0002 <0.0002 <0.0002

Zinc (mg/kg) <0.001 15.6 11.2

Iron (mg/kg) 8.62 1,503 1,175


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ANNEX IX: BASEFLOW INDEX CALCULATION FOR NGWERERE ESTATE WEIR

BASEFLOW INDEX CALCULATION

Station Number: 5016

Name: Ngwerere River at Estate Weir

Time-Series: Mean Daily Flow

Period of analysis from: 1-Oct-1970 to 30-Sep-2004

BFI calculated over whole period

Number of days in period = 12389

Number of days with data = 12226

Number of days for BFI = 12152

Total volume (mm/year) = 234.587

Baseflow volume (mm/year) = 198.768

BFI = 0.8473

BFI in each hydrological year

Year start Days Data Days BFI days Years Total (mm) Baseflow (mm) Surface runoff BFI

Oct-70 365 365 360 Oct-70 168.266 146.637 21.629 0.8715

Oct-71 366 366 366 Oct-71 181.685 169.805 11.88 0.9346

Oct-72 365 365 365 Oct-72 155.835 139.143 16.692 0.8929

Oct-73 365 365 365 Oct-73 185.09 169.875 15.215 0.9178

Oct-74 365 365 365 Oct-74 202.398 186.673 15.725 0.9223

Oct-75 366 366 366 Oct-75 198.493 180.843 17.65 0.9111

Oct-76 365 365 365 Oct-76 192.981 178.909 14.072 0.9271

Oct-77 365 365 365 Oct-77 281.092 222.468 58.624 0.7914

Oct-78 365 365 365 Oct-78 546.066 476.88 69.186 0.8733

Oct-79 366 366 366 Oct-79 406.846 367.31 39.536 0.9028

Oct-80 365 365 365 Oct-80 535.992 467.806 68.186 0.8728

Oct-81 365 365 365 Oct-81 243.704 208.81 34.894 0.8568

Oct-82 365 365 365 Oct-82 203.039 187.343 15.696 0.9227

Oct-83 366 366 366 Oct-83 183.026 162.267 20.759 0.8866

Oct-84 365 365 365 Oct-84 240.364 218.739 21.625 0.91

Oct-85 365 365 365 Oct-85 321.747 244.184 77.563 0.7589

Oct-86 365 365 365 Oct-86 33.86 33.86 0 1

Oct-87 366 366 366 Oct-87 272.086 223.201 48.885 0.8203

Oct-88 365 365 365 Oct-88 88.673 76.294 12.379 0.8604

Oct-89 365 365 365 Oct-89 247.417 206.466 40.951 0.8345

Oct-90 365 365 365 Oct-90 318.628 296.212 22.416 0.9296

Oct-91 366 366 366 Oct-91 82.33 77.802 4.528 0.945

Oct-92 365 365 365 Oct-92 33.86 33.86 0 1

Oct-93 365 365 365 Oct-93 102.869 90.846 12.023 0.8831

Oct-94 365 365 365 Oct-94 166.894 146.879 20.015 0.8801

Oct-95 366 366 366 Oct-95 173.494 152.47 21.024 0.8788

Oct-96 365 365 365 Oct-96 253.931 195.273 58.658 0.769

Oct-97 365 365 365 Oct-97 402.35 314.597 87.753 0.7819

Oct-98 365 365 354 Oct-98 228.488 132.155 96.333 0.5784

Oct-99 366 253 243 Oct-99 188.72 151.968 36.752 0.8053

Oct-00 365 365 365 Oct-00 314.836 170.899 143.937 0.5428

Oct-01 365 365 365 Oct-01 251.368 224.648 26.72 0.8937


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Oct-02 365 364 353 Oct-02 240.118 200.038 40.08 0.8331

Oct-03 336 287 250 Oct-03 158.25 145.608 12.642 0.9201

ANNEX XII: CURRENT NATIONAL WATER QUALITY STANDARDS IN USE IN ZAMBIA

CONSTITUENT ZNBS*/DWA^ Permissible Limit

(mg/l)

DWA^ Desirable Limit (mg/l)

Water Aid Zambia Adopted Standard

(mg/l)

Bacteriological

A) Unpiped water

Faecal coliforms (per 100ml) 0 Not specified HDW/TS^^: 10 Hand pump: 0

Total coliforms (per 100 ml) 20 Not specified N/A

B) Piped water

Faecal coliforms (per 100ml) 0 Not specified N/A

Total coliforms (per 100ml) 0 Not specified N/A

Arsenic 0.05 0.01 N/A

Fluoride 1.5 0.7-1.1 1.5

Nitrate 10 5 N/A

Nuisance elements

Iron 1.0 Not specified 1.0

Magnesium 150 50 150

Taste/odour Unobjectionable Not specified Unobjectionable

*Zambia Bureau of Standards (ZS 190:1990) ^ Department of Water Affairs (from The National Water Resources Master Plan, 1995) ^^ HDW = Hand dug well with bucket and windlass; TS = traditional water source


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ANNEX XIII: RESULTS OF EFFLUENTS FROM NITROGEN CHEMICALS OF ZAMBIA (NCZ)

Parameters Analysis ECZ Limit (point source)

pH 7.35 6.0-9.0 Cu, mg/L <0.02 1.5 Pb, mg/L <0.24 0.5 Zn, mg/L <0.017 10 Co, mg/L <0.15 1.0 Mg, mg/L 133.6 500 Fe, mg/L 12.1 2.0 Total solids, mg/L 1005 100 Total Dissolved Solids, mg/L 729.5 3000 Suspended Solids, mg/L 275.5 Ca, mg/L 336.3 Nitrates, mg/L 65.84 50 Sulphate, mg/L 174.3 1500 Phosphate, mg/L 0.079 6 Chlorine, mg/L 21.2 800

Sources: Sinkala et al (1996), Control of Aquatic Weed in the Kafue river Basin between Iteshi-teshi Dam and Kafue Gorge (March 1996 – March 1997), (draft) Final Report


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ANNEX XIV: CHEMICAL ANALYSIS OF EFFLUENTS FROM LEE YEAST FACTORY

Parameter Sample 1 Sample 2 ECZ Specification

pH 7.3 4.1 6.0-9.0 TH (mg/l) 348.57 159.91 TS (mg/l) 6438 8768 100 TDS (mg/l) 6382 8580 3000 SS (mg/l) 56 188 Cl- (mg/l) 434 44 800 NO3- (mg/l) 0.13 0.04 50 Free NH3 (mg/l) Nil Nil 10 PO4- (mg/l) 0.42 0.05 6 SO4- (mg/l) 0.75 900 1500 Pb (mg/l) <0.41 <0.246 0.5 Cu (mg/l) <0.011 <0.018 1.5 Zn (mg/l) <0.016 <0.49 10 Co (mg/l) <0.13 0.12 1.0 Fe (mg/l) <0.11 13.63 2.0 Cd (mg/l) <0.022 <0.024 Ca (mg/l) 265.82 140.09 Mg (mg/l) 82.75 19.82 Total coliforms per 100ml 81818 25000

Sources: Sinkala et al (1996), Control of Aquatic Weed in the Kafue river Basin between Iteshi-teshi Dam and Kafue Gorge (March 1996 – March 1997), (draft) Final Report


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Zamsif Utilization of Nutrient Rich Water Report 02092004 Edited Everything

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