WASTE SEGREGATION

The public is not allowed to enter the disposal site due to the risk of disease and danger from operating machinery and is supposed to be fenced to deter people and animals from entering the premises. This also ensures that people and animals do not salvage the valuables and edibles from the disposals site.

It is well understood that not all waste is waste, as some can be reused or recycled according to Table 4.1 which indicates the types of waste found at the dumpsite. The principle of waste separation at sources is widely practiced in Europe, America, and other developed countries to ensure that valuables and edible waste are separated or salvaged before being mixed with the useless waste. This approach reduces the risk of valuable waste stream contamination and increases the salvaging capacity by the people.

In practice, segregation is the sorting of waste to make sure the right waste goes to the right place, that is, what is to be recycled, what goes to the landfill, and what needs special handling, like anti-freeze. Waste segregation requires the cooperation of the citizens and businesses for it to work. Often three color-coded bags or bins are put on a collection site. Each one is for a specific type of waste, such as organic waste, non-recyclables, and recyclables.

TABLE 4.1

The Municipal Waste Composition (Masocha, 2004)

Waste Category

Paper and cardboard

Organic wastes

Plastics

Glass and ceramics

Metals

Clothes and textiles

Leather and rubber

Miscellaneous/inert materials

Composition (%)

  • 34
  • 26
  • 15
  • 6
  • 5
  • 4
  • 2
  • 8

Waste segregation is the best solution to garbage woes and requires land space for composting of the biodegradable waste.

The 3-R policy - Reduce, Re-use, and Recycle leads to segregation of degradable and non-degradable waste. However, in the town at the moment, solid wastes are being disposed of either by the formal route i.e. to the designated dumpsite and informally on illegal dumpsites.

ENVIRONMENTS THAT MAY BE AFFECTED (BASE LINE STUDY)

Topography

The town and the surrounding rainforest are preserved as a 23.4-kilometer national park and form one of Zimbabwe’s four world heritage sites. The Zimbabwe Parks and National Wildlife Management Authority has maintained the town and the surrounding rainforest virtually as they were when Livingstone first saw them almost 140 years ago.

Climate

The weather is mainly divided into summer, rainy, and winter seasons. Winter runs from May to mid-August and is mild and dry. During this time the temperatures range from highs of 25-27°C to lows of 7-10°C. The summer is from mid-August to the end of April and is generally hot to very hot and wet during the rainy season. The rainy season runs from mid-November to April. Average temperature ranges from highs of 32-34°C to lows of 15-19°C. From the end of August, the temperatures start rising, and from September through to November, it is very hot and dry. At this time, the typical African landscape turns very brown and can feel a bit harsh.

The bird life is superb all year round, but in September it is exceptional with the arrival of numerous migrants. Among these are the spectacular carmine bee-eaters arriving en masse and nesting in the sand cliffs along the Zambezi River. November is when you can expect the rains to start. It becomes hot, wet, and quite muggy. The area does not experience rains day after day, but rather thunderstorms that build up in the late afternoon, followed by a torrential downpour which is over in about an hour. Although some very exciting electrical storms can be experienced, the rains make some of the roads in the national parks inaccessible, resulting in park closures. The rainy season normally lasts until about March/April. The climatic data for the town is described in Table 4.2.

Geology

The recent geological history of the town can be seen in the form of the gorges below the falls. The basalt plateau over which the Upper Zambezi flows has many large cracks filled with weaker sandstone. In the area of the current falls the largest cracks run roughly east to west (some run nearly northeast to southwest), with smaller north-south cracks connecting them.

TABLE 4.2

Climatic Data for The Town (Weather Source, 2011)

Daily Average

Daily Average

Mean Total

Mean Number of

Month

Maximum (°C)

Minimum (°C)

Rainfall (mm)

Rain days

Jan

30

18

168

14

Feb

29

18

126

10

March

30

17

70

7

April

29

14

24

2

May

27

10

3

1

June

25

6

1

0

Jul

25

6

0

0

Aug

28

8

0

0

Sept

32

13

2

1

Oct

33

17

27

4

Nov

32

18

64

8

Dec

30

18

174

13

Over at least 100 000 years, the falls have been receding upstream through the Batoka Gorges, eroding the sandstone-filled cracks to form the gorges. The river’s course in the current vicinity of the falls is north to south, so it opens up the large east-west cracks across its full width, it then cuts back through a short north-south crack to the next east-west one. The river has fallen in different areas into different chasms which now form a series of sharply zigzagging gorges downstream from the falls.

Apart from some dry sections, the Second to Fifth and the Songwe Gorges each represents a past site of the falls at a time when they fell into one long straight chasm as they do now. Their sizes indicate that we are not living in the age of the w'idest-ever falls. The falls have already started cutting back the next major gorge, at the dip in one side of the "Devil’s Cataract" (also known as "Leaping Waters") section of the falls. This is not actually a north-south crack, but a large east-northeast line of weakness across the river, where the next full-width falls will eventually form.

Soils

The area is underlain by basalt which is exposed in the area adjacent to the Zambezi River. Most of the land is overlain by Kalahari sands which are gently undulating. The most spectacular feature of the Zambezi River is a 300 m deep gorge cut into the basalt. The site for the future disposal site was analyzed by soil specialist. The objective was to ascertain the compatibility of the soil to the structure to be built. Basically, the clay content is the aspect which is under consideration. Visual and texture analysis reflected that the soil is capable to arrest leachate pollutants into the immediate and adjacent ground.

Hydrology

The drainage of the town is dominated by the Zambezi River with its numerous tributaries, braided valleys, islands, swamps, and dramatic ziz zag gorges, which constitute principal landscape features. The main tributary river, which drains into the Zambezi from Victoria Falls Town is the Masuie river. The Masuie is about 200 m to the south of the current municipal waste dump. Also close to the municipal dump is a stream, which flows into the Masuie. Although the stream is dry for the greater part of the year, there is a danger that in summer it transports contaminants from the dump to the Masuie, which is a cause for environmental concern. The municipality collects samples from the river for quality analysis. The latest analyses are reflected in Table 4.3.

Flora and Fauna

Mopane woodland savannah predominates in the area, with smaller areas of Miombo and Rhodesian teak woodland and scrubland savannah. Riverine forest with palm trees lines the banks and islands above the falls. The most notable aspect of the area’s vegetation, though, is the rainforest nurtured by the spray from the falls, containing plants rare for the area such as pod mahogany, ebony, ivory palm, wild date palm, and a number of creepers and lianas. Vegetation has suffered in recent droughts, and so have the animals that depend on it - particularly antelope.

The national parks have abundant wildlife including sizable populations of elephant, buffalo, giraffe, zebra, and a variety of antelope. Lion and leopard are only occasionally seen. Vervet monkeys and baboons are common. The river above the falls contains large populations of hippopotamus and crocodile. Elephants cross the river in the dry season at particular crossing points.

Although the gorges are mainly known for 35 species of raptors, klipspringers and clawless otters can be glimpsed there as well. The taita falcon, black eagle, peregrine falcon, and augur buzzard breed there. Above the falls, herons, fish eagles, and numerous kinds of waterfowl are common. The river is home to 39 species of fish below' the falls and 89 species above it. This illustrates the effectiveness of the falls as a dividing barrier between the upper and lower Zambezi. The old dumpsite is regularly visited by vultures and stock birds. There is a challenge to keep these birds away but the new disposal site will not present access to these birds.

TABLE 4. 3

Masuie River Water Sample Analysis

Aspect

Temperature

Turbidity

Total dissolved solids

Conductivity

Ph

Quantity

  • 31 °C
  • 12.19 NTU
  • 272 ppm
  • 96.7 mV
  • 8.55

Comment

Entropy too high

It’s above acceptable at around 5 NTU Higher than expected at around 90 ppm Within acceptable limits Not neutral as expected

SITE SELECTION

Introduction

For a landfill to be built, the proponent has to make sure that certain steps are followed. In most parts of the world, there are regulations that govern where a landfill can be placed and how it can operate. The whole process begins with someone proposing the landfill.

In Zimbabwe, taking care of trash and building landfills are local government responsibilities. Before a city or other authority can build a landfill, an EIA must be completed on the proposed site to determine:

  • • The area of land necessary for the landfill
  • • The composition of the underlying soil and bedrock
  • • The flow of surface water over the site
  • • The impact of the proposed landfill on the local environment and wildlife
  • • The historical or archaeological value of the proposed site

It is required that feasible, reasonable alternatives to the project site are identified, investigated, considered, and evaluated in terms of various factors such as social, economic, and biophysical. Based on the exclusionary approach, the areas in which the potential sites can be located were determined. The town could only avail of an area within the vicinity of the current dumpsite. Besides that, the area identified is in the windward direction, it is the area surveyed for future town expansion. Within the area, three sites were identified. These sites were investigated thoroughly, and the following sections provide brief descriptions of each and their advantages and disadvantages. During the EIA, three sites were identified as candidate sites and were subjected to survey. In determining the most appropriate site a number of criteria were considered - such as economic, environmental, as well as public influenced criteria - and analyzed. Based on these analyses, the most suitable site for the future development was identified.

Site Selection and Alternatives Ranking Criteria

A ranking approach was used to select the most appropriate disposal site based on the exclusionary approach. Within the area, three different locations were identified for a future development of a waste disposal facility from a theoretical perspective. All the other potential sites were dropped since they were located in the windward direction.

The three potential locations were studied with regard to various aspects which impact on economic, environmental, and pubic criteria, which include:

  • • Distance - the further from the area of generation the more expensive are the collection/transportation costs
  • • Size - must be large enough to last until the middle term life span in order to justify the capital expenditure
  • • Access - new roads would have a high cost and environmental implications
  • • Availability of soil on site to reduce the cost for the possible provenance of cover material
  • • Visibility of the site should be as low as possible in order to avoid unnecessary cost implications
  • • Distance and availability of surface and groundwater need to be as far as possible in order to avoid environmental pollutions e.g. leachate impact
  • • Distance of the site to settlements needs to be known. A displacement of inhabitants should not be seen as a solution to the problem
  • • Are there any wind directions disturbing inhabitants in nearby settlements

As Table 4.4 shows, a ranking was done, whereby marks were allocated based on the required criteria. A mark of 5 was the highest achievable mark for a criterion and a site, whilst a mark of 1 indicated the minimum.

As Table 4.4 represents, Site 1 achieved the highest score with regard to the site suitability or good condition. It was therefore recommended to develop Site 1 as the future waste disposal facility.

 
Source
< Prev   CONTENTS   Source   Next >