COMMUNITY LEVEL COMPOSTING OF MUNICIPAL SOLID WASTE

RISE-AT Waste Management Factsheet 2 

Community Level Composting of Municipal Solid Waste 

FACTSHEET 

2 COMMUNITY LEVEL COMPOSTING OF MUNICIPAL SOLID 

WASTE 

This factsheet provides information on Community Level Composting of Municipal Solid 

Waste. It is for communities who wish to process waste in the range of 1 – 50 tons per 

week. (For information on small-scale composting, (less than 1 ton per day), at individual 

household level or small neighborhood scale, see RISE-AT Waste Management Factsheet 1 

- A Simple Guide To Small Scale Composting). 

The information describes how to plan, set-up and run a low cost, labour intensive 

composting operation. This factsheet concentrates on solutions that keep the 

requirement for expensive equipment, maintenance and technical skills to a minimum. 

Composting is a way to help reduce the amount of waste placed in a landfill site. It is a 

natural process that breaks down food waste and garden materials into a dark, soil-like 

material called ‘Compost’. The product is an excellent soil conditioner that improves soil 

quality and helps plants to grow. 

WHAT IS SO GOOD ABOUT COMPOST 

v 

v 

v 

v 

It acts as a good soil conditioner, improving plant, garden and lawn 

growth, 

It acts like a sponge, helping soil retain moisture and nutrients. 

It helps to break down heavy clay soils or binds together sandy 

soils. 

It returns nutrients to the soil and reduces the need for expensive, 

chemical fertilizers. 

HOW DOES COMPOSTING IMPROVE A LANDFILL 

Organic material makes up between 1/3 and 1/2 of household garbage. By 

composting the organic waste and recycling it into a useful soil 

conditioner, the organic material is removed from the garbage and so 

reduces the volume of material sent to the landfill site. 

Organic waste is also the fraction of the garbage that causes unpleasant 

odors and attracts vermin to the landfill sites. 

Therefore removing organic waste improves conditions at the landfill site. 

Composting on a community level becomes more complicated than on an individual household 

level due to the size of the unit, the amount of compost produced and the subsequent 

Page 1



costs involved. The aim of this factsheet is to provide sufficient information to guide you 

through the decisions that must be made when considering building a community 

composting site. Every community is different and will have its own requirements for the 

composting plant. With this information you should be able to design a facility that is 

right for the situation in your area. 

A composting facility can be developed without the purchase of specialised equipment and 

this factsheet explains how it can be done. 

1 - INVESTIGATE THE MARKET FOR COMPOST 

Before starting any work on building a community composting facility, it is essential that 

some time is spent investigating the economics of composting and the potential market for 

the compost in the local area. 

The compost is not precisely a fertilizer and the market for it in agriculture can be more 

potential than real. 

Therefore you must first find answers to the following questions:- 

What is the existing market for compost - 

Who buys it 

What do they use it for 

How much do they buy 

How much do they pay 

What is the potential for the msw compost product 

Who would be interested in the product 

How much would they be prepared to pay 

How much of the compost product would they buy 

At what time of year would they use the compost 

How could the market be increased 

What is the current situation with use of chemical fertilizers 

Who uses it 

How much do they pay 

What subsidies do they receive 

Would they be interested in changing to compost 

If the results of this study show that there is a market for the compost, the next step is 

to assess the waste situation in the area to decide on the size of the plant and the quality 

of product that can be produced. 

If the results show that there no real market for the product, there are steps that can 

be taken by local authorities to create a market. 

Page 2



MARKET DEVELOPMENT 

It has been found in many areas where composting has become part of the msw system, 

that active development of the compost market is essential. Government/Local Authority 

action to stimualte the market can include: 

♦ Use of the compost in all public works projects, including some high profile projects in 

parks and gardens. 

♦ Giving compost away free to garden centres and businesses. 

♦ Require that nurseries that supply plants to government funded projects use the 

compost. 

♦ Removing or modifying subsidies on chemical fertilizers that compete with the compost. 

Once you know how much you can sell the compost for and how much you are likely to be 

able to sell, you can use this information to estimate the income from the composting 

facility. This needs to be considered and compared to the expenditure and operating costs 

when designing the plant. Experience has shown that many plants using high cost 

machinery fail, as construction and operating costs exceed the revenue received from the 

sale of the compost. If the primary purpose of the composting facility is to reduce the 

amount of waste sent to a landfill, it may be possible to justify the composting facility 

that does not make a profit but covers the costs of producing the compost and breaks 

even. 

It is also important to note that during the composting process the organic waste will 

reduce in weight by up to 50%, so 2 tons of organic waste will produce 1 ton of compost. 

2 – CALCULATE THE REQUIRED SIZE FOR THE PLANT 

The next thing to consider is how much waste the community produces and how much of 

this will be composted. This can be used to calculate how many tons of waste per day the 

facility will receive. 

Consider the size of the community now and also the potential for growth over the next 

few years. A life-span of 8-10 years is a good basis for the calculation. Ideally the chosen 

site for the facility should have the area to expand as the amount of waste produced by 

the community increases. 

HOW MUCH OF THE WASTE IS ORGANIC WASTE THAT CAN BE COMPOSTED 

The following list gives an idea of the types of materials that can be used. 

• DRIED BROWN GRASS 

• STRAW 

• PRUNINGS AND CUTTINGS 

• DRY LEAVES 

• HAIR 

• CARDBOARD/PAPER 

• SAWDUST 

Page 3



• BARK CHIPS 

• GREEN GRASS/ GREEN LEAVES 

• FOOD SCRAPS (SEE NOTE BELOW) 

• VEGETABLE AND FRUIT PEEL 

• TEA BAGS/ COFFEE GROUNDS 

• WEEDS (BEFORE THEY GO TO SEED) 

• CRUSHED EGG SHELLS 

• BREADS/COOKED RICE AND PASTAS 

• FLOWERS 

FOOD SCRAPS - In a small scale composting unit it is not advisable to add fish/meat/bone 

food scraps or oil/dairy products to the pile, to avoid attracting pests and to reduce odor 

problems. However for large scale composting these problems can be avoided by mixing 

the waste with the large amount of other organic material available. 

MATERIALS TO AVOID -There are a few organic materials that should not be 

composted:- 

CAT OR DOG WASTE 

PLANTS OR GRASS CLIPPINGS THAT HAVE BEEN TREATED WITH CHEMICALS 

DISEASED OR INSECT INFECTED PLANTS 

CHARCOAL OR COAL ASHES 

WEEDS WITH MATURE SEEDS 

NAPPIES 

Obviously inorganic materials should not be included in the compost materials. These items 

include all Plastics/ Glass/Metals/Batteries/Electronic equipment etc. 

It may be necessary to take some samples of garbage to get an idea of the percentage of 

organic material in the waste. Usually between 30 – 50% of the waste is organic and can 

be composted. 

From this information you can calculate the amount of waste in tons/day, that you need to 

compost in the facility. Taking into account future potential growth in the community will 

allow you to design a plant that can grow to meet the increased waste requirements over 

the next few years. 

3 - QUALITY OF THE COMPOST 

The quality of the product will have a big influence on the success of the plant, but the 

process becomes more complicated and costly as the quality of the product increases. A 

balance must be reached between producing a good quality product that can be sold and 

the costs involved in the process. 

The quality of the compost is mainly dependent on the materials that are added to the 

composting mixture. If materials such as glass, metals, plastic, chemicals, etc are not 

removed from the waste they will remain in the finished compost product and contaminate 

it, reducing its potential for use as a soil conditioner for crops. These materials can be 

Page 4



dangerous and contaminate the soil that they are added to, rather than acting to improve 

it. 

The quality of the compost is therefore dependent on the system of separation that is 

used. There are a variety of separation methods and these are explained in the table 

below, with their advantages and their disadvantages. 

Method How This Is Achieved Advantages Disadvantages 

Source 

Separation 

Householders within the 

community separate the 

organic waste that can be 

composted into a special 

bin. This bin is collected 

separately from the other 

garbage and taken 

directly to the composting 

site. The waste is sorted 

by hand to remove any 

problem items before 

being composted. 

A clean, uncontaminated 

waste stream is produced 

for composting – which 

will produce a good quality 

compost. 

The amount of sorting 

that needs to take place 

at the composting site is 

small, and is therefore low 

cost and takes little time. 

Householders need to be 

educated and motivated to 

source separate the waste. 

An additional waste collection 

is required. 

An alternative to collection 

from individual houses can be 

to have community collection 

bins for organic waste. 

Mechanical 

Separation at 

The un-separated waste 

stream is delivered to the 

Health hazards from 

human exposure to 

High cost solution. 

the Composting 

composting site where it 

dangerous wastes is 

Generally found to suffer 

Site 

is passed through various 

mechanical separation 

reduced. 

from mechanical problems. 

machines (such as 

rotating drum screens, 

Small workforce required 

to operate separation 

Fails to produce a clean 

stream of compostable 

magnetic separators, etc), 

process. 

materials, so compost 

to separate the inorganic 

materials from the waste 

produced is contaminated and 

low quality. 

stream. 

Recyclable materials 

recovered are contaminated 

and difficult to sell. 

Hand Separation 

at the 

The un-separated waste 

stream is delivered to the 

Low cost solution 

compared to mechanical 

Health hazards from human 

exposure to dangerous wastes 

Composting Site 

composting site where it 

is sorted by hand to 

separation. 

is high. 

separate the inorganic 

Provides work for waste 

Large workforce required to 

materials and recyclables 

from the waste stream. 

pickers and other 

scavengers who may have 

operate separation process. 

previously sorted waste at 

the dump site. 

Difficult to produce a clean 

stream of compostable 

materials, so compost 

produced may be 

contaminated and lower 

quality. 

Recyclable materials 

recovered are contaminated 

and difficult to sell. 

Page 5



Method How This Is Achieved Advantages Disadvantages 

No Separation No separation occurs. The Low cost 

Produces a very contaminated 

contaminated waste 

compost product, which will be 

stream is composted as it 

is delivered to the site. 

The final compost product 

can be sieved to remove 

large contaminating items 

at the end of the 

composting process. 

Can be used as a method 

to stabilise the waste 

before it is added to the 

landfill site. Could be 

used as a daily or final 

cover for the landfill site. 

(Particularly useful where 

soil cover for landfill is in 

short supply and needs to 

be excavated and 

transported to the site). 

difficult to sell and may cause 

health hazards if used on 

crops. 

May operate successfully 

if only waste collected 

from markets is used, as 

this should have a high 

organic content. 

The two recommended methods of separation are:- 

1) Source Separation by Householders – This is the ideal option and is operated 

successfully in many countries. It will produce the best quality compost and simplify 

the preprocessing operations that are performed at the composting site. The key to 

successful implementation is educating the community on what to separate and 

motivating them so that they will bother to do it. This can be encouraged with financial 

incentives, such as increasing the collection fees for those who do not separate the 

waste. 

2) Hand Separation at the Composting Site - This is the best option if source separation 

cannot be achieved in the community, It requires several people to sort the waste by 

hand and can produce a reasonably clean stream of organic materials, the quality of the 

sorting depending on the number of people sorting the waste and the time taken. It is 

however impossible to completely remove all contaminants by hand separation and the 

compost will have more contamination than that produced from source separated waste. 

4 - SITING OF THE COMPOSTING FACILITY 

The compost system needs to be positioned on open land to allow sufficient room to 

establish and manipulate the compost piles. It should be a site that has:- 

i) Suitable access for transportation of the waste to the site. 

ii) A ‘buffer area’ between the site and nearby land-users, this is to minimize the 

nuisance of waste and compost odors. 

iii) Appropriate soil for absorption or collection of leachate. 

iv) Room to accommodate the amount of material that requires composting plus room to 

store finished compost material. 

v) A level, well drained surface. 

Page 6



vi) 

vii) 

Easy access to a source of water for wetting the compost piles. 

Adequate fencing and control to prevent it from becoming an open dump site and to 

keep unauthorized waste pickers out of the site. 

It may be appropriate to have the compost facility close to the landfill site. This will allow 

ease of transportation of rejected inorganic waste to the landfill and lower quality 

compost can be used as cover material at the landfill site. 

5 – DEFINE PRE-PROCESSING OPERATIONS 

Mechanical pre-processing is often the most costly part of a composting system, as well as 

the most vulnerable to breakdown. Therefore, if you are looking for a low cost, simple 

system it is recommended that pre-processing is minimized and manual labor is used 

wherever possible. 

Preprocessing can be split into two parts, separation of the compostable parts of the 

waste and chopping of the waste to ensure it is a suitable size for composting. 

SEPARATION – As discussed previously, the better the separation the better the quality 

of compost produced. Even if source separation can be organized, there is still a 

requirement for some level of sorting at the composting site, (although this will be a much 

smaller operation than if unsorted waste is delivered). 

Methods for sorting the waste by hand are:- 

1) For a low cost operation, the waste can be delivered to a sorting area, which consists of 

a concrete floor or paved area. Here the waste can be sorted by operators who pick 

out any recyclable goods or residues that cannot be composted. The sorting can be 

organised so that one person delivers the waste to the sorting area, a number of people 

sort the waste and one person takes the sorted organic waste to the next preprocessing 

stage. 

2) The waste can be placed on a moving belt and transported past stationary workers who 

hand pick the inorganic and uncompostable materials from the waste stream. 

The speed of the belt should not exceed 15m/min and its width should not be more 

than 1m, unless it is being worked from both sides. The belt should be flat and spillage 

prevented by retaining boards of wood or metal along both sides. The belt should be 

the height above the floor equal to the average elbow height of the workers. Boxes or 

baskets should be provided for workers to deposit the different waste fractions 

picked from the belt. The length of the belt and number of workers depends on the 

amount of waste being sorted and the amount of contamination in the waste stream. 

• It is recommended that workers wear gloves, adequate clothing and safety glasses 

to protect against injury from sharp objects. These should be supplied by the site 

management and rules that require the wearing of the safety items during all 

sorting activities should be strictly enforced. 

Page 7



CHOPPING - Materials should be chopped before they are added to the piles, the smaller 

the material the faster it will decompose. Carbons, in particular should be chopped into 

pieces 3-5 cm in size. Dried leaves can be shredded to reduce the volume before being 

added. It is not so important to shred Green materials as they will compost quickly 

anyway. However, it is IMPORTANT to remember that the pile needs to consist of particles 

of different sizes for the composting to work effectively. If all the particles are one size 

they will tend to clump together and decrease the flow of oxygen and moisture through 

the pile. 

Chopping can be done by hand using shears/axes etc or a small shredding machine can be 

used, operated by a small motor. 

6 – HOW TO COMPOST 

For waste to compost it needs the following:- 

- to be mixed with sufficient air, (if not it will decompose anaerobically, start to smell of 

bad eggs and produce methane, a flammable gas). 

- to have sufficient water 

- to have the right mixture of brown (carbon) and green (nitrogen) materials within the 

waste. 

If these things are controlled the decomposition of the waste into matured compost can 

be accelerated so that the compost is ready in about 8 weeks. As waste composts it 

heats up and this temperature rise is used to monitor the composting process and to kill 

any disease causing organisms that may be in the waste. 

There are many different methods that can be used to compost organic waste. For a low 

cost, community level composting facility treating up to 50 tons per week, it is 

recommended that a windrow system is operated with manual turning of the piles. A 

’windrow’ is simply an elongated pile of waste, as shown in figure 1. 

The composting methods proposed basically consist of building piles of waste, adding 

sufficient water and turning the piles at intervals to mix air into waste mixture. The 

following steps explain :- 

- How to build the pile to be the optimum size and design to increase the rate of 

decompositon. 

- How to monitor the pile to ensure that sufficient water is present. 

- How to monitor the temperature of the pile to see when the pile needs to be turned, so 

that more air is mixed with the waste. 

- How to turn the pile to ensure that the waste is well mixed with air and that all of the 

waste will at some time be in the centre of the pile and heated up to kill any disease 

causing organisms. 

Page 8



STEP 1 – HOW TO BUILD THE PILE 

Pile Design:- Two methods are described below, you can select either based on your 

requirements and the size of the composting facility. 

1) Standard Windrow Design 

Build elongated piles of waste, as shown in figure 1. Ideally they should be built on a well 

drained, impermeable surface, such as a paved or concrete surface. The ideal shape is a 

semicircular profile. The pile size should follow these guidelines:- 

Height – 1.5 to 2 m high. Any lower and the temperatures inside the pile will reduce, Any 

higher than 2m and the chances of anaerobic pockets developing in the pile are likely. 

Note the size of the pile is also important when turning. The higher the pile, the more 

difficult the manual turning process will be. 

Width – 1.5 to 2.0 m wide. 

Length – The length of the pile will have no effect on the biological composting process. It 

should be determined depending on the amount of waste being processed, the space 

available and the practicalities of the plant layout. It is sometimes convenient to have 

each windrow containing one days waste, this will simplify the turning rota. 

Figure 1 – Standard Windrow 

1.5 - 

2.0 

Length - not 

critical 

1.5 - 2.0 

m 

Page 9



2) Aeration Tunnel 

A small windrow is built on top of an aeration tunnel, as shown in figures 2 to 4. The 

aeration tunnel is made from bamboo and is used to assist with the aeration process by 

allowing air to circulate to the underside of the compost pile. Working to the dimensions 

shown below, each pile will contain 2-3 ton of waste. The pile still requires turning at 

regular intervals but the additional aeration can assist in speeding up the composting 

process. (This method has been operated successfully in Jakarta, Indonesia). 

0.5m 

2m 

3m 

Figure 2: 

Bamboo Aeration Tunnel 

Figure 3: 

Building the Pile 

Page 10



1.5 

1.7 

2.0 

Figure 4: The Finished Pile 

This system involves extra work in building the aeration tunnels but can benefit from a 

reduced composting time. 

Building The Pile:- The sorted, chopped waste should be piled up but should not be 

compacted as this will remove oxygen from the mixture. Water needs to be added to 

ensure that the waste is sufficiently wet and that the moisture is evenly distributed. One 

method of ensuring this is to add water after each layer of waste, about 30cm thick, has 

been added to the pile. The water content should be 45-50% by weight of the pile. 

To check the water content of the waste, pick up a handful of the material and squeeze. 

It should feel damp and be sufficiently wet that one or two drops of water are produced. 

STEP 2 - HOW TO MONITOR THE PILE 

The waste in the windrows needs to be turned regularly to ensure sufficient air is mixed 

with the material. This will keep any odors produced to a minimum. If there is a lack of 

oxygen in the pile it will begin to smell of bad eggs. Regular turning will also increase the 

decomposition rate of the waste. 

The temperature of the pile can be monitored and this will determine when it should be 

turned. The method for doing this is described below 

Page 11



Temperature and Composting:- 

If a compost pile has enough water and oxygen and a good balance of organic material, 

temperatures in the pile will rise and can reach 65°C. Heat is the result of the microorganisms 

that are decomposing the organic material. 

After building the pile it should heat up within a few days – this shows that it is working. 

If it does not it may not contain enough green materials or may be too dry. As the oxygen 

in the pile is used up the decomposition will slow down and so the temperature in the pile 

will drop. This drop in temperature is a good indication that it is time to turn the pile and 

add more oxygen. 

It is important to note that a temperature of 55°C or above is required for about 3 days 

to kill any pathogens, (disease causing organisms), that may be present in the waste. 

When starting a composting facility it is recommended that pilot tests are performed at 

first to determine the how often the piles should be turned and the time it will take 

before composting is complete. No definite figures can be provided here as these 

parameters will vary from place to place depending on the pile design, climate, waste 

contents, etc. These times can be determined by monitoring the temperature of the first 

few piles built and using the drop in temperature to determine when the piles should be 

turned. . Once the system has been running for a while, the regularity of turning the piles 

will become apparent and constant monitoring of every pile should not be necessary. 

Temperature Monitoring:- 

If you want to monitor the temperature of the pile accurately a thermometer can be used 

to take the temperature in the middle of the pile. It is often more accurate to take 

several readings at different points around the pile and to use the average of these 

values. In general the temperature should be between 45 – 65°C and if the temperature 

drops below 45°C the pile should be turned. 

An example of temperature monitoring is shown in Figure 5. Poles are used to make holes 

in three points around the pile, the thermometer should be placed in the hole and left for 

a few minutes, if the thermometer is small, it should be connected to a piece of string so 

that it can be pushed into the centre of the heap. The hole can then be covered to stop 

heat loss, and the string can be used to pull the thermometer out when ready. The reading 

must be taken as soon as the thermometer has been removed. If there is any delay the 

temperature reading will drop rapidly as it is affected by the ambient temperature. 

Page 12



Figure 5: Temperature Monitoring 

A more simple, non-technical method is to allow a metal rod to heat up in the middle of the 

pile. Take it out and hold the hot end. If it can be held comfortably in the hand for only 3 

seconds, the heap is hot enough and should be left. If it can be held comfortably for 

longer than 3 seconds the pile should be turned. 

You should find that the turning is required once every 5 to 7 days for piles of the size 

described in this factsheet. 

STEP 3 – HOW TO TURN THE PILE 

As the pile is turned: 

- Fresh air is mixed with the waste material 

- Excess heat is released 

- The material is broken up into smaller particles 

- The moisture content can be monitored and excess water added if necessary 

- Material from the outside of the pile is turned to the middle, where it will heat up. 

This will ensure that all of the material sees the higher temperatures at the middle of 

the pile. This will kill disease causing organisms in the waste and will also help to kill 

the fly larvae which often accumulate under the surface of a compost pile, see figure 6. 

Page 13



Cross-Section Through Windrow 

Area of Windrow that 

may be inhabited by fly 

larvae after about 5 days 

Figure 6 – Fly Larvae accumulate under the surface of a compost pile 

In order to ensure that the material from the outside is placed to the middle of the pile, a 

standard turning procedure should be used. Examples for both the standard windrow and 

the aeration tunnel piles are shown in Figures 7 –9. Note that available space around the 

pile is necessary when turning. Turning a windrow means that the pile is rebuilt in an 

adjacent windrow location, in a particular way, as shown in Figure 7. The pile can be 

turned by hand by a crew using spades and forks. To make the turning as easy as possible 

the old and new windrow positions should be close together. A gap of approximately 1m is 

suggested as a suitable distance. 

As the pile is being turned, if the compost is too dry, water should be added. The 

moisture content should continue to be 45-50% of the pile, and the moisture level can be 

checked using the technique explained in step 1. 

Page 14



Figure 7 

Turning Procedure for a Windrow 

Section Through Windrow Ready for Turning 

Section Through New 

For 

transverse 

turning 

Vacant Space at Side of 

Existing Windrow 

1 

1 

2 

2 

1 

3 

3 

2 

1 

4 

4 

3 

2 

1 

If mechanical turning is preferred, it can be done using a bulldozer, tractor or specialized 

windrow turning machine. (However, costs of purchasing and maintaining these machines 

are high). 

Page 15



Figure 8 : Turning Procedure for Aeration Tunnel (method 1) 

Section Through Pile Ready for Turning 

1 

2 

Area required either 

side for turning 

2 

1 

1 2 

1 

2 

2 

1 

Page 16



Figure 9 : Turning Procedure for Aeration Tunnel (method 2) 

Section Through Pile Ready for Turning 

Section Through New 

Pile 

1 

2 

gap approx 1m 

Vacant Aeration Tunnel 

1 

2 

1 

2 

1 

STEP 4 – HOW TO SCREEN AND MATURE THE COMPOST 

The compost is ready when it has become a dark, crumbly texture and has a fresh, slightly 

sweet smell. Very little of the original organic material should be identifiable. A constant 

temperature, below 45°C, also indicates that the process is complete. Depending on 

conditions, (moisture level/ number of times the compost has been turned, etc), the 

compost should be ready after about 4 – 5 weeks. Again, pilot tests monitoring 

temperature should be used to determine the time accurately for a new composting 

facility. 

Following the completion of this composting stage the compost must enter a maturing 

stage, which should be at least 2 weeks. This ensures that the compost is completely 

matured and safe to use. 

For the maturing stage the compost can be left in the pile or removed from the 

pile/windrow and moved to another area. In this way the windrow area can be used for 

new incoming waste. The size of the maturing pile is not so critical and the compost can be 

left in the pile until it is required for use. 

After the maturing phase the compost will require screening before it is ready to be sold 

as a soil conditioning product. (Alternatively this screening can be done before the 

maturing process if preferred.) This screening phase will remove any large pieces of 

cloth/plastic/glass etc that may not have been removed in the initial sorting process. This 

Page 17



will make the compost more marketable and remove contamination. Screening can be done 

in several ways. The most simple is to pass the compost through a metal screen. The size 

of the holes being selected to provide the required compost particle size. 

For general agricultural compost the screening size should be in the range of 25 - 40mm. 

Fragments of inert material, such as stones, plastic etc that are below this size are 

unlikely to interfere with the cultivation process and can remain in the finished compost. 

The most simple screening process is a manual process where compost is sieved through a 

screen by hand. If the amount of compost is too great for this a Rotary Screen or 

Vibrating Screen can be used. A Rotary Screen can be a simple perforated drum, setup at 

an angle, which is rotated by hand operation through a geared drive. The compost is 

placed in the upper end of the drum and as it rotates the compost is sieved through the 

holes. It can be placed at a height so that it can easily be loaded from the ground. The 

screened material can be discharged into a hand cart. 

Figure 10: 

Rotary Drum/Screen 

Drum Rotates 

Unscreened 

Compost In 

Residue 

Out 

Compost collected 

in handcart 

7 - LAYOUT OF COMPOST FACILITY 

The compost facility should be contained within a fenced area with a controlled gate to 

restrict access to the site. 

A receiving area and sorting/chopping area needs to be positioned so that it can be 

accessed easily for waste deliveries to the site and from where the sorted waste can be 

easily moved to the windrow area. The windrows need to be positioned sufficiently far 

apart so that they are easy to access for building but close enough to vacant areas for 

turning purposes. There should ideally be some cover for the piles to shade them from the 

Page 18



hot sun, (to prevent them from drying out) and to protect them from getting too wet 

during the rainy season. 

The number of windrow spaces required depends on the amount of waste received each 

day and the retention period of the waste in the windrows. The site needs to be designed 

so that there is always space around the windrows that require turning. 

To help with the supply of water an underground water pipe can be laid under the site with 

hose connections at various intervals. These must be below ground level and covered with 

metal flaps to prevent damage by vehicles or equipment on the site. 

There should also be adequate area for storing and bagging the finished compost product. 

Demand for compost is likely to be seasonal, so a storage area for stock build-up will be 

useful. 

OTHER POINTS OF INTEREST 

• The site should be kept clean and tidy at all times. After windrow turning, building or 

dismantling operations the area should be swept to clear any debris. The will keep 

smells to a minimum and stop the site from looking like a dump site. 

• Inorganic residues sorted from the organic waste should be removed from the site 

regularly. They should not be allowed to build up in unsightly piles around the site. 

• Waste that is delivered to the site should be sorted, processed and built into a new 

pile on the same day, wherever possible. This prevents the waste from decomposing 

anaerobically and smelling before it gets to the compost piles. 

• Safety Regulations for all workers should be strictly enforced. This should include the 

wearing of appropriate safety clothing and the correct use of all equipment and 

machinery. 

Page 19



EXAMPLES OF COMPOSTING SYSTEMS IN OPERATION:- 

Example 1 – Manual Windrow composting 

The facility processes approximately 3 tonnes of organic waste per day. Therefore each 

day a windrow is built consisting of the days waste input. Each windrow is about 2m wide, 

1.5m high and 2-3m long, with a volume of approximately 9m 3 and is turned on the 6 th and 

11 th days. On the 16 th day the windrow is broken down and passed through a manually 

operated screen, before being taken to a maturing heap where it is left for 30 days to 

stabilize. 

A typical 16 day rota is shown below in Figure 11. Note that this is for a 16 day period 

after the facility is fully operating with 16 windrows. (At start-up the rota will build up 

slowly as each new windrow is made). 

Windrow No. 

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 

DAY 1 B F T2 T1 





DAY 6 T1 B F T2 





DAY 11 T2 T1 B F 





DAY 16 F T2 T1 B 

Figure 11: Typical Turning Rota (Example from ref 1) 

B = Build New Windrow 

T1 = First Turn of Windrow 

T2 = Second Turn of Windrow 

F = Finish Composting Stage – break down windrow and move to maturing stage 

Each day one windrow is built, two are turned and one is broken down and moved to the 

maturing stage. Note that this plant has a relatively short composting stage (16 days) and 

a longer maturing stage 30 days. 

The system requires 20 windrow spaces so that there is always sufficient space for 

turning. An example of a sequence of turning is shown in figure 12. 

Page 20



Figure 12: 

Example of turning sequence for windrows. 

Day 1 

Build 1 

Day 11 

Turn 

1 2 3 4 5 

Build 

11 

Turn 

6 

7 8 

9 

10 

Day 2 

1 

Build 2 

Day 

1 

11 

2 

Turn 

Build 

Turn 

3 4 5 

6 

7 8 

9 

10 

Day 3 

1 

2 

Build 3 

Day 

1 

11 2 1 

Tur 

3 4 5 

Tur 

Build 

13 

6 

7 8 

9 

10 

Day 4 

Day 

Turn 

1 

2 3 

Build 

1 

11 2 12 3 13 4 5 

Turn 

6 7 8 

9Build 

10 

Day 5 

1 

2 3 4 

Build 5 

Day 

1 

11 2 12 3 13 4 14 5 

6 7 8 9 

Turn 

Bld 

Turn 

1 

Day 6 

Turn 

Day 16 

Turn 

Build 6 

1 

2 3 4 5 

1 2 12 3 13 4 14 5 

Turn 

1 

6 

Build 16 

15 

7 8 9 10 

Day 7 

6 

1 

Build 

Turn 

2 3 4 5 

Day 17 Turn 

11 1 3 1 4 1 5 

2 

Turn 

Build 17 

6 1 7 8 

9 

1 

1 

Day 8 

6 

Turn 

1 2 3 4 5 

7 

Build 8 

Day 

1 1 13 4 14 5 

3 

Turn 

6 1 7 17 8 

Tur 

Build 18 

9 

15 

1 

Day 9 

Turn 

Day 

Turn 

6 

1 2 3 4 5 

7 8 

Build 9 

11 12 13 1 5 

6 16 7 17 8 

18 

4 

9 

Build 19 

Turn 

15 

10 

Day 10 

Turn 

Day 20 

Tur 

6 

1 2 3 4 5 

7 8 9 

Build 10 

1 

12 13 14 15 

6 16 7 1 8 

18 9 1 

5 

1 

0 

Build 20 

Tur 

Page 21



You can see that after day 16, when the facility is operating at full capacity, each day one 

windrow is removed, one is turned into the free space created, another is turned and the 

free space created is used to build that days new pile. This can be organised so that the 

sequence of activities is such that the first activity of the day is to turn the windrow that 

creates the free space for building the new pile. Then the new pile can be built while the 

other activities are going on. Also the pile to be removed and passed on to the maturing 

phase needs to be removed before the second pile can be turned into the free space. 

There are many other sequences and layouts that can be used, such as placing the 

windrows in a circle. Each will have its own requirements for organisation and turning and 

needs to be considered and planned at the beginning of the project. The plan may require 

changing/updating once the pilot tests have been carried out and more precise data is 

available on the composting times and turning periods that are to be used. 

Example 2 – Aeration Tunnel Method used in Jakarta, Indonesia (Ref 2) 

Several facilities in Jakarta use the Aeration Tunnel method to process piles of 2-3 ton of 

waste. The piles are left for 35 days to compost, turning each pile once every 7 days. 

Therefore each pile is turned 4 times before it is dismantled and taken to the maturing 

phase. Maturation takes 14 days, after which the compost is manually screened and 

packed, ready for sale. The compost is sold in bags from 1 to 10 Kg. 

Due to the longer composting time, if one pile is built per day there is a total of 35 piles 

once the system is fully operating. 

REFERENCES 

Information for this factsheet was compiled form a number of sources including:- 

Updated 22/12/98 

1. Management of Solid Wastes in Developing Countries, F.Flintoff, World Health 

Organisation, 1984. ISBN 9290221011 (Available from CMU Medical Faculty Library 

- WA 778 F623m). 

2. Practical Handbook on Composting, UDPK Composting Technique. (Available from 

RISE-AT Library). 

3. Organic Waste, I.Lardinois, A. van de Klundert, TOOL 1993. (Available from RISE-AT 

Library 369). 

4. Low Cost Composting, E.I Stentiford et al, University of Leeds, 1996. (Available from 

RISE-AT Library 363). 

5. Municipal Solid Waste Management Handbook, Sound Practices - Composting, UNEP 

International Environmental technology Centre. (Available from 

www.unep.or.jp/ietc/ESTdir/pub/MSW/index). 

Page 22

COMMUNITY LEVEL COMPOSTING OF MUNICIPAL SOLID WASTE

Create successful ePaper yourself

Delete template?

Save as template?