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This manual has been produced by SANDEC, the Department of Water and Sanitation in Developing Countries, which is part of the Swiss Federal Institute for Environmental Science and Technology (EAWAG). The main principles for strategic sanitation planing have been adopted from the guide “Strategic Planning for Municipal Planning” from GHK Research and Training Ltd. SANDEC has carried out a case study of fecal sludge management in order to enlighten the issues specific to planning of fecal sludge management. This study took place in the City of Nam Dinh, in Vietnam. The corresponding study report “Septage Management Study Nam Dinh” has been issued by SANDEC and the Nam Dinh Urban Development Project (funded by the Swiss Agency for Development and Cooperation).
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Fecal Sludge Management
in Developing Countries
A planning manual
Florian Klingel, Agnès Montangero, Doulaye Koné, and
Martin Strauss
1st Edition, April 2002
Swiss Federal Institute for Environmental Science and Technology
Department for Water and Sanitation in Developing Countries
Planning of Fecal Sludge Management
I
Foreword
This manual has been produced by SANDEC, the Department of Water and Sanitation in
Developing Countries, which is part of the Swiss Federal Institute for Environmental
Science and Technology (EAWAG).
The main principles for strategic sanitation planing have been adopted from the guide
“Strategic Planning for Municipal Planning” from GHK Research and Training Ltd.
SANDEC has carried out a case study of fecal sludge management in order to enlighten
the issues specific to planning of fecal sludge management. This study took place in the
City of Nam Dinh, in Vietnam. The corresponding study report “Septage Management
Study Nam Dinh” has been issued by SANDEC and the Nam Dinh Urban Development
Project (funded by the Swiss Agency for Development and Cooperation).
This manual is a first approach to provide guidance on strategic planning of fecal sludge
management. It is intended to further develop this manual. Therefore SANDEC will highly
appreciate your comments and suggestions on the manual.
For further information and comments, please contact Mr. Martin Strauss at:
Swiss Federal Institute for Environmental Science and Technology (EAWAG)
Water and Sanitation in Developing Countries (SANDEC)
Management of Sludge from On-site Sanitation Facilities (SOS)
P.O. Box 611
8600 Duebendorf
Switzerland
E-mail: Strauss@eawag.ch
Planning of Fecal Sludge Management
II
Contents
1 About this Manual _______________________________________ 1
Why fecal sludge management?________________________________________________ 1
When is it important to plan fecal sludge management? _____________________________ 1
What is the scope of this manual? ______________________________________________ 2
Who is this manual for?_______________________________________________________ 3
And how to use this manual? __________________________________________________ 3
2 Planning _______________________________________________ 4
2.1 The process of planning_________________________________________ 4
2.2 Establish the need to plan _______________________________________ 4
2.3 Explore the situation____________________________________________ 5
2.3.1 Introduction ________________________________________________________ 5
2.3.2 Explore the local context (geography, society, infrastructure) _________________ 5
2.3.3 Explore the situation of fecal sludge management __________________________ 7
2.3.4 Explore stakeholders’ needs and perceptions ____________________________ 10
2.3.5 Data collection_____________________________________________________ 13
2.3.6 Understand the problems ____________________________________________ 14
2.4 Develop the management concept _______________________________ 15
2.4.1 Planning principles _________________________________________________15
2.4.2 Define objectives and criteria _________________________________________ 16
2.4.3 Develop the time frame______________________________________________ 18
2.4.4 Design fecal sludge collection_________________________________________ 18
2.4.5 Design fecal sludge treatment_________________________________________ 21
2.4.6 Design fecal sludge reuse or disposal___________________________________ 23
2.4.7 Define responsibilities, communication and co-ordination mechanisms_________ 24
2.4.8 Develop financial arrangements _______________________________________ 25
2.5 Choose technologies __________________________________________ 26
2.6 Implement the concept _________________________________________ 28
3 Engineering Tools ______________________________________ 30
3.1 Fecal sludge management and health_____________________________ 30
3.1.1 Disease transmission through poor fecal sludge management _______________ 30
3.1.2 How to cut the transmission pathways __________________________________ 31
3.2 Data collection________________________________________________ 33
3.2.1 Sludge sampling and analysis_________________________________________ 33
3.2.2 Monitoring ________________________________________________________ 36
3.3 Technological options__________________________________________ 37
3.3.1 Technologies for vault or pit emptying and sludge haulage __________________ 37
3.3.2 Technologies for fecal sludge treatment _________________________________ 39
4 Sources of Further Information ___________________________ 47
Planning of Fecal Sludge Management
III
Glossary
Biosolids The solids fraction of fecal sludge or of sewage sludge, which is
biochemically stable and hygienically safe and, hence, can be used
in agriculture as a soil conditioner and fertilizer.
Composting latrine Latrine designed to receive both feces and vegetal matter with the
aim of reducing moisture content of the waste and to achieve a
carbon to nitrogen ratio that encourages its rapid decomposition.
Note that “composting” is a misleading term, because thermophilic
composting with pathogen destruction does not happen in
composting latrines.
Fecal sludge Sludge removed from all kind of on-site sanitation systems such as
septic tanks, bucket latrines, pit latrines etc.
Septage Fecal sludge from septic tanks (settled solids, scum and liquid).
Septic tank A tank or container, normally with on inlet and one outlet, that
retains sewage and reduces its strength by settlement and
anaerobic digestion of excreta.
Abbreviations
BOD Biochemical oxygen demand, unit for organic pollution
COD Chemical oxygen demand, unit for organic pollution
FS Fecal sludge
SANDEC Swiss Federal Institute for Environmental Science and Technology,
Dept. of Water and Sanitation in Developing Countries
STP Sewage treatment plant
SW Solid Waste
TS Total Solids (dissolved + suspended solids)
TVS Total Volatile Solids (ignitable part of TS)
Figures
Figure 1: Dumping of fecal sludge in the outskirts of Ouagadougou, Burkina Faso ____ 1
Figure 2: Stages of the planning process, adapted from ________________________ 4
Figure 3: Traditional fecal sludge management in China_________________________ 9
Figure 4: Interview with householders in Nam Dinh, Vietnam.____________________ 11
Figure 5: Interview with a rice-farmer in Nam Dinh, Vietnam_____________________ 13
Figure 6: The problem tree helps identifying the cause-effect relations_____________ 14
Figure 7: Appropriateness of technologies in Accra, Ghana:_____________________ 16
Figure 8: Several small steps are easier than on big jump ______________________ 18
Figure 9: Learning from existing facilities and pilot plants _______________________ 28
Figure 10: Environmental classification of excreted infections____________________ 30
Figure 11: Important sludge parameters and recommended analysis______________ 35
Figure 12: Truck mounted sludge tank and vacuum pump ______________________ 38
Figure 13: Mini-vacuum tug together with a intermediate-storage-tank ____________ 38
Figure 14: Small sludge tank connected to a hand-driven vacuum pump ___________ 38
Figure 15: Overview of “simple” fecal sludge treatment technologies ______________ 40
Photo record
All photos: SANDEC.
Planning of Fecal Sludge Management About this Manual
1
1 ABOUT THIS MANUAL
Why fecal sludge management?
In most urbanized areas in developing countries excreta are disposed off in facilities
located on the housing plot itself. Whether these facilities are septic tanks, dry latrines,
bucket latrines, communal toilets, or other types, they all accumulate fecal sludge,
which needs to be removed periodically. If this sludge is not properly managed, negative
impacts on the urban environment and on public health may result:
Environmental pollution is caused by effluents of not regularly de-sludged
septic tanks or community toilets;
Large amounts of fecal sludge removed from sanitation facilities are dumped
indiscriminately into the environment due to lacking disposal facilities;
Fecal sludge is used in unhygienic way in agriculture because no sludge
treatment is available.
All these problems can be avoided by a proper management of fecal sludge, which
may include adequate de-sludging of sanitation facilities, safe handling and transport of
sludge, treatment of sludge, and its safe disposal or reuse.
Figure 1: Dumping of
fecal sludge in the
outskirts of
Ouagadougou, Burkina
Faso
When is it important to plan fecal sludge management?
When inadequacy in sludge management causes problems
In absence of any orderly municipal sanitation planning, on-site sanitation facilities are
most commonly developed by their users themselves. Those are little concerned about
the problems with sludge removed from their facilities. Sludge management is usually
limited to a de-sludging service that is provided by municipal agencies or the private
sector, proper solutions for sludge disposal are generally lacking. This situation may have
less serious impacts when the population density is low. However, in urban areas the
negative impacts on the urban environment become too high and actions have to be
Planning of Fecal Sludge Management About this Manual
2
taken. Instead of leaving the responsibility completely to individuals, the public relevance
of fecal sludge management must be recognized and a strategy for better management
of fecal sludge be developed.
When a comprehensive sanitation plan is being developed
Ideally, fecal sludge management must be integral part of every sanitation plan,
which builds on on-site sanitation facilities. Sludge management is a indispensable part of
the maintenance of these facilities. However, in reality sludge management is often
neglected in sanitation planning because the need for it is less apparent than it is for the
provision of water supply or toilet facilities. Even when a sanitation plan foresees a
component for sludge management, its implementation is often impaired for the same
reasons.
Sanitation planners and decision-makers must recognize the importance of sludge
management whenever they deal with on-site sanitation facilities. It is for example
irresponsible to promote septic tanks without providing in the same time solutions for
regular de-sludging of the facilities and for safe disposal of the sludge.
On-site sanitation systems are often perceived as cheap in comparison to sewered
systems, because the investment costs are covered by individuals and not by the public
bodies. However, fecal sludge management is an important cost factor, which cannot
be neglected and which has always to be taken into account when sanitation systems are
planned.
What is the scope of this manual?
The present manual deals with one component of sanitation planning only. It is
specifically meant for the case where on-site sanitation facilities are already existing, or
are part of a sanitation plan. It explains how to manage the sludge produced from these
facilities. The choice of the toilet facilities themselves and the question of the overall
sanitation system are not discussed in this document. Abundant literature is already
existing about general sanitation planning, however most with very little emphasis on
sludge management. This document wants to contribute to close this gap.
Although this document concentrates on fecal sludge management, one should never
consider sludge management independently of the other components of a
sanitation system. Fecal sludge management is one component of a sanitation system,
which has many repercussions on the other components and vice versa.
“Conventional” on-site sanitation includes facilities like pit latrines, communal pit or
bucket toilets, flush toilets connected to septic tanks, etc. In these sanitation systems,
feces, urine, and in some cases greywater are mixed and the sludge produced can be
quite diluted. The efforts for sludge collection, transport and treatment are high, because
the sludges are of important volume and difficult to handle. The present manual is mainly
designed for managing sludge from conventional on-site sanitation facilities.
So called “ecological sanitation” is based on the minimization of waste at the source and
its re-circulation into the natural cycles. Feces are kept separately from urine and water,
and then dehydrated or decomposed in facilities such as double vault latrines,
composting latrines and others. The aim is to transform the waste on-site in a product
easier to handle, to treat and to reuse than sludge from conventional on-site sanitation
facilities where feces and liquids are mixed. This manual may also be helpful to plan the
management of waste from “ecological sanitation” systems.
Planning of Fecal Sludge Management About this Manual
3
Sewered sanitation transports feces, urine and toilet paper, diluted in large amounts of
water, in sewers with self cleaning flow velocities. This type of sanitation produces no
fecal sludge. However, in the case of sewage treatment, the handling of sewage sludge
may require high management expenses too. Sewage sludge is usually even more
problematic than fecal sludge from household toilet facilities, because it concentrates
contaminants from industrial effluents. This document does not treat management of
sewage sludge.
This manual is based on the results and the experiences of a detailed study of fecal
sludge management in Nam Dinh City (200,000 inhabitants), in northern Vietnam.
Therefore it is most applicable for projects in middle-sized cities in Vietnam and
other Southeast Asian countries. We hope it may prove useful, though, in similar
contexts in other countries and for larger cities too.
Who is this manual for?
This manual intends to provide practical guidance for the elaboration of fecal sludge
management concepts, whether current problems with sludge management have to be
solved or a future sanitation plan has to be established. It is mainly addressed to
environmental planners and engineers, but will be useful as well for politicians and
decision-makers.
And how to use this manual?
The manual is divided into two main parts: planning and tools. The “planning” chapter
contains the strategic approach of the planning process. Step by step, the planning
process is followed and the possible actions are explained. It is meant to be a checklist
for what is necessary to do and which points are important to consider. The different
steps will be accompanied by concrete examples from the case study in Nam Dinh.
The “engineering tools” chapter contains a collection of detailed technical
information assisting the planning process. These engineering tools are essentially the
result of SANDEC’s research and development activities. The planner using this manual
will certainly need other non-technical tools too, for instance for organizing workshops,
developing institutional and financial solutions etc. SANDEC does not develop such tools
because of its technical orientation. The last chapter therefore provides a list of useful
sources covering important issues that have not been included in this manual.
Planning of Fecal Sludge Management Planning
4
2 PLANNING
2.1 The process of planning
The planning process should follow logical stages. First a consensus about the need to
plan has to be established among the involved parties. Then the situation has to be
analyzed thoroughly to allow the identification of all existing problems and to define the
objectives of improvement measures. The core piece of the planning process is to
develop a future management concept. Finally the different components of this concept
will be implemented.
It is very important not to consider the planning process as a one-way process. It does
not end with its implementation. Experiences during planning and from implementation
and operation should always be considered and plans be revised if necessary.
Figure 2 visualizes the different planning stages. The feedback loops illustrate the fact
that plans are amended in the light of experience. During the elaboration of solutions,
further need for information will be identified and this information then collected in a
targeted way. The implemented components will be monitored and achievement of set
objectives be evaluated. More precise information about adequacy of proposed solutions
and about formerly unidentified problems will help developing better solutions.
Figure 2: Stages of the
planning process,
adapted from [2].
2.2 Establish the need to plan
The first step must be to develop a consensus on the need to plan fecal sludge
management. No plan will work if those responsible for its implementation are not
convinced of the need to plan. It is necessary to talk to the various stakeholders and, if
necessary, to convince them of the benefits of fecal sludge management.
The main initiative for improvements in fecal sludge management is more likely to come
from the authorities, than from the individual citizens. This is because the latter will not
benefit directly of improved fecal sludge management, but more in indirect way, through a
general environmental betterment. Therefore the support from authorities and decision-
makers will be decisive for the success of better fecal sludge management. However, it is
essential that the other stakeholders can agree upon the need to plan too.
Planning of Fecal Sludge Management Planning
5
Source of further information: [4] Annotated references on participatory approaches
and communication for water and sanitation programming. [5] Methodology for
participatory assessment with communities, institutions and policy makers.
2.3 Explore the situation
2.3.1 Introduction
The thorough understanding of the existing situation is essential to tackle the right
problems and to consider the right constraints while developing solutions. The first
approach should be to gather a broad understanding of the situation and to know about
all relevant issues and the relations between them.
Do not spend too much effort gathering technical data that may be of no practical use.
Always ask yourself what you will do with the information you collect. The requirements
for technical data will become apparent later, when specific solutions are envisaged.
Beside the basic goal of understanding the situation, you should always seek to identify
the main problems with FS management and their causes.
2.3.2 Explore the local context (geography, society, infrastructure)
A good knowledge of the general context around the specific problem is very important.
This is especially valid if you are a representative of an external agency and not yet
familiar with the local context.
The general conditions of the local situation set the frame within which potential solutions
are possible. Basically, the planner should achieve enough knowledge of the situation to
develop a good feeling for what is possible in the local context and what might be
problematic.
Useful and easily available sources for information might be reports of projects located in
the studied area and country reports issued by governmental or external agencies.
Political, legal and institutional issues are best explored through various interviews with
representatives of the different political levels and of discussions with persons outside
these institutions. It is often necessary to be careful with official descriptions of these
issues, as reality may look different. Environmental regulations for instance often have
little effects on practice due to lacking awareness and enforcement.
Case Study Nam Dinh
The case study named “Septage Management Study Nam Dinh” was carried out in
2001 within the Nam Dinh Urban Development Project. This project, financed by
Swiss and Vietnamese Governments, includes components for infrastructure
development, public administration reform, community participation and economic
development. The study aimed to provide a concept for septage management as part
of the project’s wastewater management strategy. SANDEC participated in the study
as part of their research mandate for fecal sludge management.
!
Planning of Fecal Sludge Management Planning
6
Geography
Geographical factors such as topographical situation, geology or climatic conditions may
have considerable influence on sanitation problems. They are major constraints
influencing the feasibility of technological and organizational solutions.
Socio-economic situation, health and cultural aspects
Socio-economic and cultural aspects tell about the populations’ ability and willingness to
contribute or to accept proposed measures. It is very useful to assess the situation and
potentials of private entrepreneurship in provision of public services. Health data may
indicate problems related to sanitation and how urgent it is to solve them.
Nam Dinh - The general situation
" Geographic and socio-economic
Nam Dinh is situated in Northern Vietnam, in the Red River delta. The climate is
tropical and flooding of the city after torrential rainfalls is frequent due to the flat
topography.
The city of Nam Dinh has a population of about 230,000. The economy of the
province is still largely based on agriculture (rice), whereas the city functions as local
center for administration, industry, service and trade. The overall growth of the
population in Nam Dinh City with an estimated 1.25 % per year is very low, caused by
falling birth rates and a steady migration flow to Hanoi. The average monthly income
per person is 50 USD.
" Public services
Three public companies provide public services for water supply, fecal sludge and
solid waste collection and disposal, and maintenance and cleaning of the drainage
system. All have general weak capacity, including low staff skills, inadequate
information systems and accounting procedures. Financial capacity is very limited,
revenues are insufficient to meet the operational cost, and capital investment in new
equipment or facilities remains low.
" Sanitation infrastructure
On-site sanitation is prevailing. The drainage system, conceived for the evacuation of
storm waters, de-facto acts as a combined sewer system for both domestic
wastewater, industrial wastewater and storm water. Domestic wastewater pretreated
in septic tanks or greywater cannot infiltrate due to low soil permeability, and sooner
or later ends up in the drainage system. The drainage system is not a closed system
but is connected at numerous points to the irrigation system and to fishponds. The
health risks through spreading the pathogen organisms and worse the industrial
wastewater in the environment are high.
Roughly 60 % of the domestic solid waste is collected and disposed off on a new
landfill. The landfill is sealed with a clay layer and is equipped with a basic drainage
system for leachate extraction. Stabilization ponds are foreseen for leachate
treatment.
Planning of Fecal Sludge Management Planning
7
Political and legal framework
Good knowledge of the political system, the administration system, planning procedures
etc. is essential for a planner. Legislation concerning environmental and construction
issues, including discharge standards and construction policies need to be taken into
account when planning treatment and disposal facilities.
Sanitation infrastructure and services
Wastewater management, solid waste management, urban drainage and other
environmental and sanitary services are closely related to FS management, or they could
be so in future. Public utilities or private enterprises are responsible for the provision of
those services. It is important to know what are the different enterprises’ activities, how
the enterprises are organized, what are the available human and financial resources, and
how are they equipped. Cost-recovery of services or the percentage of subsidizing are
other important issues to explore. It is essential to know how responsibilities for the
different services are shared among the different enterprises, which enterprises are
involved in FS management, and which are their weak points in management.
A good overview about the existing infrastructure like toilet facilities, sewers and drains,
treatment facilities, disposal or dumping sites, should be achieved. Find out what are
currently the sanitation problems of highest priority, and how are they connected to
problems related to FS management.
Existing plans
The different municipal or state departments and the public utilities may already have
their own plans dealing with sanitation and fecal sludge management. These plans
should be taken into account when preparing a new plan. Try to find out about the
strengths and the weaknesses of existing plans. Pay particular attention to the way in
which these plans deal with operation and maintenance and their financing. It is very
useful to explore how earlier plans have been implemented or why they have not been
implemented.
Land availability
The construction of facilities for FS management, e.g. for sludge treatment or storage will
require land. It would be useful to have at early planning stages an overview on the
general availability of land for this purpose, and on the cost or constraints of the land
acquiring processes. Try to find out if the municipality already possesses land potentially
suitable for sludge treatment, and what are the local constraints on these sites regarding
accessibility, possible odor emissions or wastewater discharge.
2.3.3 Explore the situation of fecal sludge management
The next step must be to find out more in detail about the current and the expected future
situation of FS management and all aspects that are related to it or may influence it.
Toilet facilities
Knowing the distribution of the various types of toilet facilities helps estimating what kind
of fecal sludges you have to deal with. Don’t assume that the distribution of different
sanitation systems is stable, the situation may be quite dynamic, with some systems
replacing others.
Planning of Fecal Sludge Management Planning
8
It might be rather difficult to obtain exact figures about the distribution of different toilet
facilities and the on-going developments. The best sources of information are usually
household surveys where a statistically representative number of households are
questioned about their situation regarding sanitation infrastructure, habits and awareness.
Conducting such a survey is, however, a major exercise, which can rarely be justified for
Nam Dinh - The situation of fecal sludge management
" Toilet facilities
Excreta disposal in Nam Dinh is based on on-site sanitation facilities in individual
houses such as bucket latrines, pit latrines, double vault latrines, pour-flush or WC
toilets connected to a septic tank.
The construction of septic tanks has started only in the late eighties and then rapidly
increased within the past years. 1997, the coverage was already 50 % with roughly
22,000 septic tanks, in the year 2010 the coverage will probably reach 90 %.
Bucket toilets were the second most important sanitation facilities in 1997. Pour-flush
or WC toilets, mostly connected to a septic tank increasingly replace these systems.
The increasing propagation of septic tanks is part of a generalized tendency observed
all over Vietnam: more and more people can afford to build an own toilet in-house.
" Sludge collection
Septic tanks in Nam Dinh are usually emptied only when problems like blocking of the
toilet occur. The owner mandates either URENCO (the public company providing de-
sludging services) or privates with the emptying of the septic tank. URENCO does the
work by its single vacuum tanker and charges 20 USD for the service. Private
emptiers are workers of URENCO doing this as second job out of working time,
bucket collectors or others. They evacuate the sludge manually with shovels and
buckets, and dispose it nearby into the drains. As no statistics exist, it is impossible to
assess the number of septic tanks emptied in this way. Approximately one third of the
houses are located in narrow lanes, out of the range of the vacuum tanker.
Bucket toilets and many public toilets are emptied by private collectors in daily to
weekly intervals. These collectors are either farmers or intermediates selling the
sludge to farmers for fertilizing purpose.
" Disposal and reuse
No assigned disposal point exists. Septage is dumped in fishponds, on fields or
wherever the driver of the vacuum tanker finds a location to dump it. Sometimes the
sludge can be sold to a farmer, but generally the money is not worth the effort
necessary to find a person willing to take a load. Bucket sludge is very welcome by
farmers practicing aquaculture as well as in agriculture. However, it is becoming
increasingly unavailable and more expensive, due to the replacement of bucket
latrines by septic tanks.
" Potential for reuse of treated fecal sludge
Following the National Institute for Agronomic Science in Hanoi, the lack of organic
fertilizer in rice cultivation is a limiting factor for rice production in the Red River Delta.
Compost from solid waste or treated fecal sludge is currently not traded, but all
farmers state that such a product would be very welcome if price and effectiveness
were satisfying.
Planning of Fecal Sludge Management Planning
9
the purpose of FS management only. If no data from earlier surveys is available, you will
need to conduct a smaller, “qualitative” survey by the mean of key interviews. It is not of
primary importance to have at hand statistically significant data. Rather you should try to
obtain, with a reasonable input of time and resources, a realistic picture of the current
situation and the main tendencies.
A large household survey is usually conducted when a city wide sanitation plan,
comprising overall sanitation, not FS management only, is going to be developed. In that
case, the large number of information, which can be collected from the household
questionings, justifies usually the high expenses for a large survey in the inception phase.
FS collection
The removal of sludge from toilet facilities, and the transport to the site of treatment or
disposal, is the first important component of FS management. You need to understand
well the current practice and what are the problems with it.
Who is collecting the FS - a municipal agency, private companies, individual
entrepreneurs, farmers, or others? Why the facilities are emptied - on demand of the
owners, on initiative of the authorities? How they are emptied - manually, or by vacuum
tanker? How frequently they are emptied? How is the collection financed - by fees for the
households, or by municipal subsidizes? How much is the fee? How much is the actual
cost for the collection? What are the problems with FS collection - are facilities difficult to
access, are the fees too high? Are transport distances a problem? These and more
questions need to be answered to get a good picture of the situation.
The best way to get a complete impression on how is working the FS collection is to talk
to the implicated persons. Don’t limit the interviews to municipal officials. Ask as well the
workers of municipal agencies, householders, private FS collectors and so on. Very
useful is to visit several households and to accompany the workers on a few collection
tours.
Figure 3: Traditional fecal sludge management in China: Buckets from bucket latrines are
collected by private entrepreneurs and sold to farmers, the fecal sludge is then diluted
and used untreated for crop fertilizing.
Planning of Fecal Sludge Management Planning
10
FS treatment, disposal or reuse
The second main component of the FS management is what is being done with the
sludge after collection from the facilities. The sludge may be disposed off, or used in
agriculture, untreated or after having received a treatment.
How the sludge is treated, disposed off or used is best found through interviews with the
agencies or individuals that are carrying out the collection. Observation of the disposal,
treatment or reuse and visiting corresponding sites is essential. Be aware that the sludge
may be treated, disposed or used in different ways, depending on the sludge type and
who collects it. For example, if there is a municipal agency and individual entrepreneurs
active in emptying toilets, the former may use a specific dumping site, whereas the latter
may dump sludge into the drainage channels, or sell it to farmers.
It is important to analyze the existing treatment, disposal or reuse system on its strengths
and weaknesses. Where are the main problems? Which components work well and
should be preserved? Try to understand the money flow: How is treatment or landfilling is
financed? Are farmers paying for fecal sludge?
Finding out what actually happens with the sludge is a crucial point, because it’s there
where most of the environmental pollution and health risks are generated.
Lessons from neighboring cities
It may be very helpful to visit a few neighboring cities to get informed about the situation
of fecal sludge management in similar places. You may find situations where fecal sludge
is managed in a much more satisfactory way, and get precious indications how you can
solve the problems on your location. You may also find similar problems in similar
contexts and though get confirmed the results of your only analysis.
Sources of further information: [3] Social survey methods. [4] Annotated references
on participatory approaches and communication for water and sanitation
programming. [5] Methodology for participatory assessment with communities,
institutions and policy makers.
2.3.4 Explore stakeholders’ needs and perceptions
Any solution works best if it satisfies as far as possible the interests of all involved
stakeholders, if everybody has a benefit through improvement of his individual situation or
through incentives provided for motivation purpose. Proposed measures are most
successful if they are able to solve the actual problems of all involved.
The above makes clear that it is indispensable to consider the perceptions, the needs,
the interests and the personal situation of all involved stakeholders. Therefore you have
to identify the stakeholders, all persons, groups or institutions who are directly or
indirectly involved in FS management, and you have to talk to them.
Exploring the stakeholders’ perceptions should not stand alone, but go along with
exploring the general situation and the practices of FS management. The most valuable
sources of information about the FS management situation are the involved stakeholders.
You will have to talk to them to learn about the facts, but in the same time you should ask
them about their personal point of view, situation and interests.
The most effective way to get representative information is to choose a number of
persons who all belong to the same group of stakeholders but have different positions
within this group. For example if you want to know about the situation of a municipal
!
Planning of Fecal Sludge Management Planning
11
service agency, talk to the director, to administrators, and to several workers. If you want
to know the problems of toilets users, ask people from different city neighborhoods and
people using different toilet types. Try to find those who know most and who are most
likely to tell what they know. Be always aware that the statements are very subjective and
may be incomplete for one or the other reason.
The following list gives possible stakeholders and their role in FS management. The list
may be not complete; you will find different stakeholders depending on every different
situation.
Householders
The householders are the ones using the toilet facilities in which sludge accumulates.
Usually it’s them who decide about the type of toilet facility they build, about the time
when they empty the toilet, and it’s them who have to pay for the emptying. They know
best who actually empties their toilet, what is the real price for it, and what are the
technical problems with the emptying. Also if shared or public toilets are used, the
householders, as their users, are able to provide corresponding information.
You should interview a number of people from different social classes, in different
neighborhoods, and with different sanitation facilities. Best is to visit them at home, see
their facilities and talk about their experience and problems with the emptying. Try to find
out about their awareness for environmental and health issues, and about their attitude
towards possible changes with the emptying regime.
Always keep in mind that the possible improvement measures need to be supported or at
least tolerated by the individual citizens. You should find out what are important aspects
for them, and where they might be lacking of knowledge to understand the necessity of
improvements. This may provide hints as to future needs for public awareness and
promotion activities.
A further important issue, which can be clarified through talks to individual citizens, is the
cultural attitude towards the handling of human waste and the acceptance of use of
human waste for
fertilizing of food crops.
Figure 4: Interview with
householders: Having
a tee and talking about
toilets in Nam Dinh,
Vietnam.
Planning of Fecal Sludge Management Planning
12
Community based organizations and non governmental organizations
There might by various groups being active in the sanitation and health sector of the
project area. These groups can be a valuable source of information representing the
community in which they are active, as they are well informed about the needs and
concerns of the community. On the other hand, these groups may facilitate the access to
the community, for example if you plan awareness raising campaigns or household
surveys.
Authorities
It is important to first identify all agencies potentially involved in the planning of FS
management. These might be the local government or specialist governmental agencies
on municipal, provincial or state level, responsible for planning, public services,
construction, health, environment, etc. Understand which agency is responsible for which
issue, and how responsibilities may interfere or where they are not clearly defined. Get
informed about the habitual procedures for decision making.
In the particular case of fecal sludge management, the initiative for citywide planning has
to come from the authorities. Therefore you have to explore how much the authorities are
aware of the existing problems, and if necessary, you have to make them understand the
need for actions. Try to make sure to have their continuous support for the planning, and
keep them informed about your work.
Public utilities
The opinion of the people doing the daily business of FS management is very valuable
and cannot be neglected while searching for improvements. Talk to representatives from
all utility enterprises which are currently active in FS management, or which could be
involved in future. Important is, again, to talk to persons from different hierarchic levels,
from the director to the workers. Does the director think his enterprise has sufficiently
support by the municipal government? What do the employees of the utility enterprises
think are the main problems for their enterprise and for the provision of an adequate
service? Try to get a feeling for the real interests of the people. For example: how do the
workers earn their main income – through the salary paid by the enterprise, or do they
earn money by emptying toilets on their own account, or by selling the sludge? Always try
to find out by what mean the workers could be motivated to act in the desired way. For
example: is it necessary to provide incentives to make sure that the driver of a vacuum
tanker will take his load to the treatment plant rather to sell it to a farmer or to dump it on
the next possible spot?
Private sector
The private sector active in FS management can be represented by companies operating
vacuum trucks or similar equipment, or by individual workers who usually empty the
toilets with shovels. You should ask them similar questions as to the public utility
enterprises. Learn how they earn money - by payment for the emptying, or by selling the
sludge. Try to find out, what kind of motivation or incentives it would need to make them
act in the desired way.
Whereas it should be no problem to contact companies, it may be difficult to actually find
the individual entrepreneurs. You could find some of them through the householders by
asking who has emptied their toilet. Be aware that private entrepreneurs might be at the
same time employees of the public enterprises and do empty toilets on their own account
as a secondary job.
Planning of Fecal Sludge Management Planning
13
Farmers
The farmers are the potential users of the treated fecal sludge. Exploring the current
reuse practice will tell you a lot about the general and cultural attitude towards use of
human waste in agriculture, about the current health risks, and about the potential for use
of treated sludge.
One main point to explore must be the acceptance by the farmers of a product from
sludge treatment. You should conduct a tentative market analysis. The main objective for
interviews with farmers is to get an idea if treated FS, and how much of it, could be used
in agriculture, how much the farmers would be willing to pay for it, and in which form they
would prefer to receive the product.
Agriculture services and state agencies can also be a valuable source of information on
this topic.
Figure 5: Interview with
a rice-farmer in Nam
Dinh, Vietnam
Sources of further information: [3] Social survey methods. [4] Annotated references
on participatory approaches and communication for water and sanitation
programming. [5] Methodology for participatory assessment with communities,
institutions and policy makers.
Useful tools: 3.2.1 Sludge sampling and analysis
2.3.5 Data collection
It will be necessary to collect more detailed data for the (pre-) design of components of
the future management concept. This requires that you already are familiar with the
situation, know about the problems, have defined the main objectives, and that you have
already pre-selected several potential solutions. Therefore, the data collection does not
follow directly the logical sequence of the other described points of the situation analysis.
Remember that the planning process cannot be treated as a one-way process (see 2.1),
that you should use the information collected in the initial stages to identify further needs
for more detailed information.
The data you need can be of very different nature: a more detailed survey to know about
the distribution of different toilet types; a thorough market analysis for a fertilizer from
treated FS; a detailed analysis of a specific sanitation service; a meaningful sludge
analyzing for the design of treatment facilities; etc.
!
Planning of Fecal Sludge Management Planning
14
Always try to maintain a reasonable balance between the expenses for the data collection
and the benefit from it. Detailed data is not always much more useful than already
available data from similar locations or even data from standard literature.
Sources of further information: [3] Social survey methods.
Useful tools: 3.2.1 Sludge sampling and analysis.
2.3.6 Understand the problems
At this stage, you should have achieved a good understanding of the current situation
with FS management and related sectors, you should be aware of the local constraints,
and of the different perceptions of the implicated parties. You should be able now to
identify the main problems of the current situation or the problems that are likely to occur
in the near future.
It is not enough to identify the problems, but you should understand as well the causes of
the problems. To solve problems you will need to understand how problems, causes and
effects are linked. A good way to carry out problem analysis is to develop a problem tree,
where you collect all problems and link them following their cause - effect relations.
Figure 6: The problem
tree helps identifying
the cause-effect
relations
Useful tools: 3.1.1 Disease transmission through poor fecal sludge management.
!
!
Planning of Fecal Sludge Management Planning
15
2.4 Develop the management concept
2.4.1 Planning principles
Involve stakeholders
The development of solutions should happen in close collaboration with all stakeholders.
You should continuously seek for feedback from the involved parties, to find out if your
ideas and propositions are acceptable and understandable to them, and to confirm if your
propositions satisfy the real needs.
Stakeholder involvement during the planning process may be of variable intensity. You
can limit yourself to work out components of the plan and to consult the stakeholders
from time to time. You can organize planning workshops in several stages of the planning
process, where all representatives come together and work collectively on decisive parts
of the plan. A workshop may be organized for problem analysis and definition of
objectives, where you present the results of your situation analysis, and seek for common
agreement on problems, objectives and priorities. Another possible workshop could be
organized for evaluation of options, where you present several previously developed
scenarios, which are then discussed together. The most intensive form of stakeholder
involvement would be the formation of a planning committee, where representatives of
the different parties regularly come together to work out solutions. Which way you go
depends on the project size, on the willingness to participate of the stakeholders and on
other aspects. More intensive involvement of stakeholders may slow down considerably
the planning process, however the chance that widely accepted solutions result are
correspondingly higher.
Have a global vision – think about concrete measures
Developing the management concept means developing a vision how fecal sludge
management could work citywide, and developing the individual components to be built
up step by step. You need always to keep an eye on both, how an idea can be part of a
whole, and how the idea can be concretely implemented in a small scale.
Appropriateness of measures and technologies
The paradigm of the appropriateness of measures and technologies has always to be
respected while planning sanitation or fecal sludge management in the context of
developing countries. The use of technologies and management concepts adapted to
local conditions is of prime importance. All proposed measures must match with available
human, technical and financial resources and have to be perfectly acceptable for the
population and the authorities.
Make the plan sustainable
Ensuring to sustain improvement measures over time means to ensure that all involved
stakeholders want to act in the sense of the plan, that they know how to do this, and that
they are able to do it. Appropriate incentive systems can make sure that the stakeholders
are motivated to act in the desired way. Information and training efforts are required to
increase knowledge and skills of the involved persons. Sound finances are required to
enable them to act in the desired way.
Planning of Fecal Sludge Management Planning
16
Make the plan official
Your concept for fecal sludge management will only be effective if the various
organizations that are expected to implement it, recognize it as their plan. You should do
everything that you can to have your concept accepted as the official plan for fecal sludge
management of the town. Everything possible should be done to ensure that the agreed
actions can be formally included in the programs and budgets produced by the various
stakeholder organizations.
Figure 7:
Appropriateness of
technologies in Accra,
Ghana:
Above a conventional
sewage treatment plant
(trickling filters and
secondary clarifiers)
that never operated.
Below a simple settling
tank for fecal sludge
treatment that is
operating successfully.
Sources of further information: [2] Strategic planning for municipal sanitation – a
guide. [4] Annotated references on participatory approaches and communication
for water and sanitation programming. [5] Methodology for participatory
assessment with communities, institutions and policy makers
2.4.2 Define objectives and criteria
The first step of developing solutions is to define where you want to go. You have to
define the main planning objectives, and to specify them, to set the targets for the various
measures to be developed. The simple rewording of the identified problems will already
!
Planning of Fecal Sludge Management Planning
17
deliver a more or less complete list of objectives, with the subordinated specific
objectives.
In most cases, one overall objective will be “to improve public health”, the protection of
the population from health risks through the transmission of pathogenic organisms
contained in human feces.
Once the list of specific objectives established, you should develop clear criteria how
these objectives are fulfilled. The proposed solutions can then be evaluated on their
adequacy to achieve the set objectives by the help of those criteria. Clearly measurable
indicators are helpful to evaluate the fulfilling of criteria.
Nam Dinh - Problem identification, objectives and planning horizon
" Main problems
Risk for public health due to lacking treatment or safe disposal: Septage is handled
without protection measures, dumped into the environment or used untreated in
agriculture.
Solids accumulation in drainage system because of lacking maintenance of septic
tanks: Septic tanks are often not emptied in the designed intervals. They become full
with sludge and cannot retain the solids any more. Increased solids accumulation in
the drainage system results, which contributes to blockage of drains and flooding.
" Causes of the problems
Municipality and population are not aware that septic tanks should be emptied more
often to maintain their function.
The public enterprises have insufficient financial and operational capacity to improve
septage collection.
There is no existing treatment facility or a safe disposal site.
" Principal objectives
Improvement of public health: Elimination of dumping of septage into the environment
and of use of untreated septage in agriculture.
Improving the functioning of the drainage system: Enhancing solids retention in septic
tank to reduce solids accumulation in the drainage system.
" Time frame
2 years: Collection capacity will be extended to 1000 septic tanks/yr by more efficient
use of the already existing equipment. Corresponding treatment capacity will be
provided. The plant for this first planning phase will be built as soon as possible (pilot
plant).
5 years: Collection and treatment capacity will be extended to 4 times of the current
capacity (4000 septic tanks/yr.). Design and proposed capacity of the treatment plant
will be revised using the experience gained with the first phase plant.
Planning of Fecal Sludge Management Planning
18
2.4.3 Develop the time frame
The formerly established objectives have to be translated into a concrete schedule that
defines the targets to be achieved in corresponding periods. For several reasons, it is
advisable to proceed in rather small steps instead of trying one big move forward:
Actions have to match with available resources. Too ambitious targets are
unlikely to be achievable. It is more encouraging for all involved, if realistic goals
can be achieved within the set period.
Practical experience with proposed solutions should be collected, and used in
planning, before solutions are introduced citywide.
It is often very difficult to make precise projections of the demand for periods of
10 to 20 years, like it is habitual for facility design in industrialized countries. In
developing countries, the data basis is often very imprecise and the situation is
too dynamic to allow good predictions. Planning and implementation in small
steps assures a higher flexibility to respond to the real demand.
Small-scale or pilot projects are more easily and quickly prepared and implemented with
already available resources. In this way, you can achieve immediate improvements. In
the same time, the experience with the first steps will help you to plan the further steps on
a more precise data basis. Positive experiences will help to convince the stakeholders of
the success of proposed measures, as you can directly show how it works.
Try to set realistic targets for short periods, such as one to three year periods. These
targets should be, however, part of a global and more long-term concept that will be
fulfilled step by step.
Figure 8: Several small
steps are easier than
on big jump, adapted
from [2].
2.4.4 Design fecal sludge collection
Demand-driven sludge collection or planned sludge collection
In general, the vault emptying and sludge collection is driven by the demand of the toilet
owners, and is financed by direct fees. This system usually works well and mostly there is
no reason to change it. Both, public utilities and the private sector can provide this
service.
However, in certain cases it might be impossible to leave the initiative for sludge
emptying to the householders. This is especially the case when environmental problems
are caused because sludge is not removed often enough. For example septic tanks may
Planning of Fecal Sludge Management Planning
19
loose their removal capacity when too much sludge is accumulated, leading to
considerable carry-over of pollutants into groundwater, drains and surface waters.
Introducing a planned sludge collection where the authorities take the initiative for
emptying facilities in the households is a complex task. You will need a considerably
increased management capacity of the service provider, comprising a detailed databank
about the city’s toilet facilities and their emptying dates, a good planning capacity, and the
corresponding technical equipment. You will need to achieve the necessary
understanding and the awareness of the householders for the duty to empty their facilities
more often. You will have to think if you need a different fee system, which can motivate
the owners to empty their facilities more frequently. And eventually you need to know if,
and how you can include the private sector in a directed sludge collection system.
Improve hygiene when sludge is handled
Hygiene with sludge handling is usually an important issue when manual pit or vault
emptying is common. The workers, whether independent or employees of private or
municipal enterprises, are seldom aware of the health risks and may use no protection
during their work.
You can follow different strategies to improve such a situation: The first would be to try
replacing manual by mechanical sludge removal. This means at the same time that you
will replace independent workers by companies, as only these can operate expensive
mechanical equipment. The main difficulty will then be how to prevent the independent
workers from doing their usual business and how to provide them with a new work.
The other strategy would rather be to accept the practice of manual removal and to
promote more hygienic practices, such as the use of protection measures. Stricter rules
and better enforcement concerning health protection of employees of municipal or private
enterprises would be necessary too.
Assure that sludge is transported to the desired site
One major cause of indiscriminate dumping of fecal sludge is the lack of a disposal site.
The collectors may dump the sludge in other sites or sell it to farmers, even if you are
providing a treatment plant or a safe disposal site. Therefore you will have to make sure
that the collected sludge actually reaches the desired site.
The most important aspect is that you have to locate the disposal sites in order that
transport to this site is neither expensive nor uncomfortable. Additionally you may need to
provide corresponding incentives to the workers, which motivate them to do what they
should actually do. Often workers may earn more from selling sludge to farmers than
from their salary. Workers also may dump the sludge as close to the area of collection as
possible to be able to make additional collection tours on their own account.
Indispensable condition that you can provide an effective incentive system is that you
previously understood very well the actual ways in which the workers earn money and
what motivates them.
Improve technical equipment and assure its operation and maintenance
Very common are technical problems with removal of sludge from sanitation facilities,
such as inaccessibility of houses by truck mounted vacuum tankers. Many types of
sludge evacuation pumps and vehicles have been developed for that kind of situation. To
solve these problems is mostly a matter of providing funds for investment in new
equipment.
Planning of Fecal Sludge Management Planning
20
A very frequent problem in developing countries is lacking capacities for operation and
maintenance of equipment. In many cases central government or external donors provide
the funds for investment in equipment and facilities, but the projects fail because
operation and maintenance has been neglected. It is therefore of prime importance to
make sure that revenues from the services cover the costs for operation and
maintenance. Think about arrangements on an efficient and reliable maintenance system
at the service provider.
Whenever new equipment is being purchased or new operation maintenance procedures
are being introduced, you have to make sure that staff receives sufficient training on the
new equipment and procedures.
Source of further information: [8] Practical tools to achieve effective Operation &
Maintenance.
Useful tools: 3.1.2. How to cut the transmission pathways. 3.3.1 Technologies for
vault or pit emptying and sludge haulage.
Nam Dinh - Proposed improvements of septage collection
The recommended equipment for septage collection consists of classical vacuum
tankers in combination with small hand-pushed vacuum tugs. These vacuum tugs
allow accessing septic tanks located in very narrow lanes, which are today still
emptied exclusively by hand. In this way, the public utility enterprise can extend its
emptying service to all households.
Mini vacuum tug in Haiphong City, Vietnam
The main problems with septage collection are institutional matters. These sensitive
issues must be discussed among decision-makers prior to the design of an effective
septage collection system: Should frequent septic tanks emptying become
compulsory? Should reduced monthly fees replace the high direct fees? How can the
responsibilities of the public utility enterprises be better defined?
The introduction of a systematic septic tank emptying and of monthly fees in selected
wards is recommended. In this way the septage collection rate can be increased
considerably and the experiences of the new system can be used in the political
discussions and the institutional reform process.
!
Planning of Fecal Sludge Management Planning
21
2.4.5 Design fecal sludge treatment
Provide an attractive disposal point
The first and main function of fecal sludge treatment is to get rid of the sludge. You want
to offer a reliable disposal point, where no harm is created to the environment and public
health. As already discussed under the previous point, you have to think carefully how to
make the disposal point attractive enough to achieve that all sludge reaches the facility.
The most important factor is the location. You must avoid that transport costs for
delivering sludge to the facility become too high. In the case of big cities with large
distances and much traffic, you should probably favor several decentralized treatment
facilities over one central facility.
Appropriate incentive systems should make sure that all collected fecal sludge reaches
the plant. For example, rather than excluding private companies from delivering sludge to
the plant, you should motivate them to do that. You will have to provide motivating
incentives to the workers if the sense of responsibility within the enterprises is low, or the
enforcement of corresponding rules is difficult.
When choosing the treatment sites, it is very important to take into account the resistance
or acceptance of the population neighboring the site or the access roads. Possible
negotiations for compensation measures should be held early in the plan. It is important
to include surface for possible extensions of the plant and for buffer zones when
purchasing or reserving land for sludge treatment.
Minimize impacts from treatment and treatment products
Products from a sludge treatment plant are in general odors, liquid effluents and dried
sludge.
Odors are more a problem for the public acceptance than a real danger for health and
environment. Nevertheless, this is reason enough to take the odor problem very serious.
You can reduce odor emissions by choosing the adequate treatment technologies or by
locating the plant at adequate distance from human settlements.
Agricultural reuse of the liquid effluent from sludge treatment is in most cases impossible
due to the high salt content. Therefore, the effluent will usually be discharged into the
environment and reduction of pollutant contents in the effluent is the main concern.
Authorities generally apply wastewater discharge standards as sludge treatment
objectives. However, it may hardly be possible to fulfill strict discharge standards with a
reasonable technological input because fecal sludge has 10-100 times higher and much
more variable pollutant concentrations than municipal wastewater. Nevertheless, treating
the sludge prior to discharge will, in itself, constitute substantial health and environmental
improvements, even if stringent effluent quality standards cannot be met. A pragmatic
approach concerning effluent standards is, though, often very difficult. Officials may insist
to apply wastewater standards because they are not familiar with fecal sludge and its
specificity. A possible compromise may be to set a removal percentage rather than an
absolute effluent concentration as treatment objective. For example, Ghana has applied a
90% BOD and fecal coliform removal standard for a sludge treatment plant in Accra [7].
The solid treatment product should at minimum have adequate moisture content (< 80%)
to allow safe disposal on sanitary landfills. Ideally it should have adequate quality for
agricultural reuse. Sludge to be used in agriculture has to be chemically safe and not
contain disease-transmitting organisms beyond tolerance limits. Excluding high-tech
treatments, complete pathogen destruction can only be achieved by thermophilic
Planning of Fecal Sludge Management Planning
22
composting or by storage over extended periods (½ to 1 year). Additionally, sludge to be
used in agriculture has to be delivered in acceptable form to the farmers. You have to
make sure that your product corresponds to what consumers wish. It would be favorable
to locate the treatment plant close to the sites of reuse to reduce transport costs.
However, the priority must still be to locate the plant close to the area of sludge collection.
Nam Dinh - Proposed septage treatment
A
septage treatment plant is proposed. The chosen technology is dewatering and
biochemical stabilization of septage in constructed wetlands. This treatment plant will
transform septage in a solids fraction with greatly reduced volume and very low
pathogen content, and in a liquid fraction suitable for discharge after treatment in
stabilization ponds. Constructed wetlands have been chosen as the preferred option
for Nam Dinh after a detailed evaluation of all available septage treatment
technologies.
It is proposed to construct a first treatment plant with modest capacity on the site of
the existing landfill. It is planned to treat the effluent from the sludge treatment
together with landfill leachate. This plant has then to be closely monitored. The gained
experiences and data will help to design the extensions of the plant for the next
planning phase.
Proposed constructed wetlands treatment plant for Nam Dinh
Proposed agricultural use of treated septage
The solids produced from septage treatment constitute an excellent organic fertilizer.
The commercialization of these “biosolids” is recommended, because it can generate
revenues, save landfill space and supply Nam Dinh's agriculture with urgently needed
soil-conditioner.
Intensive marketing efforts are necessary to achieve complete commercialization of
the biosolids. Trials of efficiency of the fertilizer product should be carried out in
collaboration with the provincial agricultural service. The agriculture cooperatives can
be used for initial commercialization. The cooperatives could later act as local agent
and inform farmers about the quality of the product.
Planning of Fecal Sludge Management Planning
23
Assure operation and maintenance of the plants
As already discussed for sludge collection equipment, you have to pay very much
attention on operation and maintenance of the proposed facilities. Choose technologies
that are adapted to the technological and financial means of the operator. Prepare for
corresponding training of staff. Always keep in mind, that lacking operation and
maintenance is cause number one for the failure of infrastructure projects in developing
countries.
Source of further information: [8] Practical tools to achieve effective Operation &
Maintenance
Useful tools: 3.1.2. How to cut the transmission pathways. 3.2.1 Sludge sampling
and analysis. 3.3.2 Technologies for fecal sludge treatment.
2.4.6 Design fecal sludge reuse or disposal
Reuse versus disposal
In general reuse of sludge should be preferred over disposal on landfill for several
reasons:
Commercialization of treated sludge can generate revenues
No use of landfill space
Fecal sludge, in contrast to sewage sludge has little chemical contamination
and can therefore be considered as valuable resource, which should be
valorized. In a long-term point of view, the recycling of waste is always the
preferable option.
You should only consider disposing the treated sludge if there is no need and market for
a soil conditioner, or if the additional expenses for providing a product suitable for
agricultural use can not be justified. Generally, the disposal of treated sludge is not
problematic, as long as the sludge is sufficiently dehydrated and a sanitary landfill is
available.
Develop market for treated sludge
When you consider the commercialization of the treated sludge, you will have to spend
sufficiently effort on developing the market for your product. You will have to identify
potential customers and analyze their needs and wishes. You should develop the
customer’s confidence by proofing the benefits of your product, best in collaboration with
an agricultural service or research institution. You have to find ways how to distribute the
product and how to promote it. It may be very useful to use existent structures such as
commercial fertilizer distributors or agricultural cooperatives. Never assume that the
farmers just will come and buy treated sludge without any effort from your side.
Useful tools: 3.1.2. How to cut the transmission pathways. 3.3.2 Technologies for
fecal sludge treatment.
!
!
Planning of Fecal Sludge Management Planning
24
2.4.7 Define responsibilities, communication and co-ordination
mechanisms
Define clear responsibilities
Who will do what in fecal sludge management? Each task should be very clearly
assigned to one of the involved parties. Best is when you can assign the responsibilities
in a logical way. For example one single municipal enterprise could carry out the sludge
collection, operate the treatment facilities and trade the fertilizer product. In a context
favorable to privatization of public services, these tasks could be assigned to different
private companies, which are responsible to a regulatory agency. In most cases,
however, you will have to be considerate of existing structures that are not easily
changeable. Important is to avoid that conflicts about competencies and responsibilities
can occur. Try as well to define clearly the role of other governmental organizations, of
NGO’s and of the community members. Everyone involved in fecal sludge management
should know clearly what he is meant to be doing and with whom he needs to liaise.
Develop mechanisms for co-ordination
Lack of co-ordination between the different involved groups may be a very important
problem. It may be advantageous to install a committee where all involved groups are
represented. However, you have to make sure that one organization will be responsible
for the leadership of this committee, and that the committee’s decisions result into
actions. It is essential that the committee’s authority be mutually recognized, best through
higher government levels too.
Don’t forget that fecal sludge management is not an isolated issue, it is closely linked and
interconnected to other sanitation issues. Co-ordination with the other sanitation services
is therefore indispensable during all stages of planning and day to day running. The
above mentioned committee should therefore best be a sanitation committee dealing with
all aspects of sanitation, including fecal sludge management.
Develop mechanisms for communication
An ongoing dialogue and consultation with service users should become part of the
routine of municipal service delivery. It may be best to assign this task to a third party
such as an NGO that is skilled in community liaison. Again, communication with service
users should not be limited to emptying of vaults and pits, but rather comprise all
sanitation issues.
Raise public awareness
For not well informed people, the need for fecal sludge management is less obvious than
the need for water supply and clean toilets. Nonetheless you will need the support of the
householders for improvements of sludge management, because they will participate in
its organization and financing. You should conduct awareness raising campaigns to
ensure the acceptance of the your measures and to achieve changes in the behavior,
favorable to better sludge management. Such behavior changes might be that people
know that they should empty the vault of their toilets or their septic tank more often, or
that they should not throw waste into the toilets, etc. Long lasting effects with awareness
raising are best obtained when promotion activities are institutionalized (e.g. hygienic
education in schools).
In many cases, you will need as well to awake the necessary awareness within the
authorities and service providers.
Planning of Fecal Sludge Management Planning
25
Sources of further information: [4] Annotated references on participatory
approaches and communication for water and sanitation programming. [5]
Methodology for participatory assessment with communities, institutions and policy
makers. [9] Just stir gently – The way to mix hygiene education with water supply
and sanitation.
Useful tools: 3.1.1 Disease transmission through poor fecal sludge management
3.1.2. How to cut the transmission pathways.
2.4.8 Develop financial arrangements
Ensure sound finances
The management of fecal sludge can only be successful in a sustainable way when its
financing is ensured. You have to pay very much attention to find stable arrangements for
covering running costs like salaries, operation and maintenance of equipment and
facilities. As far as possible, the running costs have to be recovered from the service fees
or revenues. Dependence on external subsidizing should be minimized.
Possible sources of financing for FS management can be the fees collected from
households, the municipal budget, and revenues from sludge commercialization or from
selling of licenses to private enterprises. Funding from central government or external
donors is generally limited to investments.
You have to think about a sound fee system, where fees sufficiently contribute to cost
recovery, are acceptable for the service users, and can be actually collected.
Be careful not to overestimate revenues from sludge commercialization. You need to
base your calculation on careful assumptions. This is especially true if the sold product is
new on the market and no experience with the willingness to pay of farmers exists.
Depending on the situation, it may be possible that you can generate revenues through
licensing private companies for sludge collection, or through fees for disposal at the
treatment site. In other contexts, however, fees for disposal a treatment site may be
repelling and entrepreneurs may rather dump the sludge elsewhere.
Always make the implementation of new components of fecal sludge management
dependent on available resources, both for investment and for operation costs. Better is
to implement small-scale components, which actually work in a sustainable way, than to
start too ambitious projects, which may fail soon due to lack of money for the day to day
running.
Use financing as steering instrument
Financial arrangements are not only about absolute coverage of costs, but as well about
intelligent ways how to use money for motivating workers to do what they are supposed
to do. Some examples how to provide incentives in different components of FS
management were already discussed earlier in this text. However, you will need to find an
arrangement working for the whole chain of FS management. Try to get a clear idea
where revenues are generated and whereto the money flows. It depends on the local
situation, how you should then arrange the money flows to achieve best effects. Factors
like the general sense of responsibility, the danger of corruption, the dependence of
workers on additional income, etc., play an important role. As an example, you could
make the workers participating at the income from sludge commercialization, which can
motivate them to actually deliver sludge to the treatment plant and to operate the plant
properly.
!
Planning of Fecal Sludge Management Planning
26
2.5 Choose technologies
Screen available technologies
When you start choosing the technologies for equipment and facilities, you should
consider all available and commonly used technologies in an objective way. With a first
screening, considering general criteria and obvious local constraints, you can already
select a reduced number of potentially feasible technologies, without going too much into
details. You should try to have at hand a small number of interesting options, which you
will then develop more in detail to make possible a thorough evaluation.
Pre-design potentially feasible technologies
To make possible an objective comparison between different scenarios, you have to
develop each scenario for the same situation, the same basic conditions, and for the
same targets. For example you will compare treatment plants using different
technologies, but all fulfilling the requirements for a certain planning horizon and for a set
treatment goal. You will have to develop preliminary designs and operating schemes, to
allow the detailed evaluation.
Evaluate the options
Once you have at hand several sufficiently detailed scenarios, you can evaluate them
following previously established criteria. Try to define clear criteria and indicators relative
performance, process reliability and cost of the examined technologies. Using the
preliminary designs, you will have to establish estimations regarding expected
performance, and investment, operation and maintenance costs. Try as well to predict
how reliable the technologies will be at the given local conditions. The final evaluation can
be done using a multi-criteria matrix, where you attribute to each scenario and each
criterion a valuation. In this way you will achieve a very objective selection of the
technologies, and you will have at hand a good data basis for further discussion with
stakeholders.
Sources of further information: [1] Nam Dinh Septage management study. [8]
Practical tools to achieve effective Operation & Maintenance
Useful tools: 3.3.2 Technologies for fecal sludge treatment.
!
Planning of Fecal Sludge Management Planning
27
Nam Dinh - Criteria for evaluation of treatment technologies
A list of criteria has been established for the evaluation of potential treatment
technologies. These criteria define how the fulfilling of treatment objectives by the
different options will be measured.
Specific objectives for septage treatment
Providing treatment capacity for 1000 septic tanks per year within 2 years.
Transforming septage into products suitable for safe disposal or reuse
Performance criteria
a) Achievable consistency of solids. The solids should be easy to handle and the
volume be reduced as much as possible. The parameter, which best expresses
this, is the achievable solids content. TS > 20-30 % should be achieved.
b) Hygienic quality of solids. The content of viable pathogens (worm-eggs) should be
very low or zero to allow safe reuse in agriculture. The requirement for post-
treatment to meet this criterion should be minimal.
c) Quality of liquid effluent. The content of pollutants should meet the Vietnamese
standard regulating discharge in surface waters.
Criteria regarding simplicity and reliability of process
d) O+M requirements. The process should require as little input as possible to
operate and to maintain it.
e) Skills required for operation and supervision. The skills required to operate the
plant should be as basic as possible.
f) Risk of failure: The estimated risk of failure through identified weak points should
be as low as possible.
Cost criteria
g) Minimal Land requirement.
h) Minimal Investment costs
i) Minimal Operation and maintenance cost
Planning of Fecal Sludge Management Planning
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2.6 Implement the concept
Implementation is part of the planning process!
The implementation should not be seen as the final stage of the planning process. You
and the stakeholders will learn a lot from the process of implementation and you should
use the learned lessons for future initiatives. This principle should be institutionalized
through fixed procedures for monitoring and evaluation of the implemented components
and for the use of the gained information before implementing further components.
Figure 9: Learning from existing
facilities and pilot plants: Sampling
from a settling tank in Accra, Ghana
Prepare proposals
For each component, you will have to prepare proposals and have them adopted for
implementation. For physical facilities such as a treatment plant, you will have to prepare
technical designs, drawings, estimates and contract documentation. For procurement of
equipment such as vacuum tankers, you will have to prepare detailed tender documents,
including components for training of staff. Proposals for components depending on
human resource input such as training programs or awareness campaigns should clearly
define who is going to do the work, how it will be financed, and how it will be linked to
other components. Be aware that procedures of adoption and tendering can take a lot of
time.
Planning of Fecal Sludge Management Planning
29
Implement components
Responsibility for carrying out the work for treatment facilities will usually be awarded to a
conventional contractor. If possible you should divide the work in relatively small
packages, which can be handled by smaller local contractors. This has the advantage of
better competition between contractors and that it helps to build local capacity. Good
supervision is very important to ensure the quality of work provided by contractors. If
possible, good work should be rewarded and supervision staff and implementing
organizations held to account when the quality of work is poor. One way to ensure that
this happens is to involve people from the benefiting communities in the supervision of
work.
Monitor and evaluate
The need for using experience from the implementation stage in planning has already
been enlightened. This suggests the need for effective monitoring and evaluation of
implemented components. Monitoring takes place throughout the life of the program, and
intents to provide information about how the monitored component is performing.
Evaluation takes place after the completion of the program and examines if the intended
objectives were achieved. You should make sure that monitoring efforts are targeted,
always think about what for you need the information you collect.
Minimum monitoring should include a general recording practice of the sludge collection
and monitoring the performance of the treatment plant.
Sources of further information: [2] Strategic planning for municipal sanitation – a
guide. [8] Practical tools to achieve effective Operation & Maintenance.
Useful tools: 3.2.2 Monitoring.
!
Planning of Fecal Sludge Management Engineering Tools
30
3 ENGINEERING TOOLS
3.1 Fecal sludge management and health
3.1.1 Disease transmission through poor fecal sludge management
Poor sanitation favors the transmission of diseases. Diseases related to poor sanitation
may be caused by viruses, bacteria, protozoa or parasitic worms (helminthes). For health
engineering purposes, these diseases are classified following their main transmission
pathways. The classification is resumed in Figure 10.
Environmental Classification of Excreted Infections and Control Measures
(after Feachem et al. 1983 and Mara 1996)
Category and
epidemiological features Prominent examples of
infection Dominant transmission
mechanisms
(in italics : partly related
to poor FS management)
Major control measures
(in italics: part of
improvement of FS
management)
I Non-bacterial (fecal-
oral)
Zero latency; low to
moderate persistence; low
infective dose; unable to
multiply; no intermediate
host
Rotavirus diarrhoea
Infectious hepatitis
Amoebiasis
Giardiasis
Cryptosporidiasis
Enterobiasis
Hymenolepiasis
Person to person contact
(or persons handling
excreta)
Domestic contamination
Improved water supply
Hygiene education
Improved housing
Improved excreta
disposal
II Bacterial (fecal-oral)
Zero latency; medium to
high infective dose;
medium to high
persistence; able to
multiply; no intermediate
host
Campylobacter infection
Cholera
Pathogenic E.coli infection
Salmonellosis
Shigellosis
Typhoid
Person to person contact
(or persons handling
excreta)
Domestic contamination
Water contamination
Excreta or wastewater-
fertilized crops
Improved water supply
Hygiene education
Improved housing
Improved excreta disposal
Treatment of excreta or
wastewater prior to use
or discharge
III Soil-transmitted
helminths
Latent; high persistence;
unable to multiply; low
infective dose; no
intermediate host
Ascariasis
Hookworm infection
Trichuriasis
Yard contamination
Fields, soil
contamination
Excreta or wastewater-
fertilized crops
Improved excreta
disposal
Treatment of excreta or
wastewater prior to use
or discharge
IV Tapeworm infections
Latent; persistent; unable
to multiply; low infective
dose; cow or pig as
intermediate host
Taeniasis
Yard contamination
Fields, soil
contamination
Fodder contamination
Improved excreta
disposal
Treatment of excreta or
wastewater prior to use
or discharge
Cooking of meat and meat
inspection
V Water-based
helminths
Latent; persistent; able to
multiply; low infective
dose; intermediate aquatic
host
Clonorchiasis (liver fluke)
Schistosomiasis Water contamination
Fish Improved excreta
disposal
Treatment of excreta or
wastewater prior to use
or discharge
Cooking of fish
Control of snails
VI Spread by excreta-
related insect vectors Infections in categories I-
III transmitted by flies or
cockroaches
Bancroftian filariasis
(transmitted by the Culex
pipiens mosquito
Insect breads in various
fecally contaminated
sites
Identification and
elimination of potential
breeding sites (Improved
domestic and peri-
domestic hygiene)
Improved sullage disposal
Use of mosquito netting
Figure 10: Environmental classification of excreted infections and control measures (after
Feachem et al. 1983 and Mara 1996)
Planning of Fecal Sludge Management Engineering Tools
31
Fecal sludge contains all infective organism excreted with human feces. These
organisms can survive outside the human body for a limited period. Pathogenic bacteria
die off within a few weeks (low persistence), whereas the eggs of parasitic worms can
survive up to three years in the environment (high persistence). Fresh fecal sludge from
public toilets contains the highest quantity of infective organisms. However, sludge from
septic tanks also contains bacteria from fresh excreta and a large number of viable worm
eggs. Fecal sludge needs to be considered as a very dangerous matter and requires
careful handling. Poor management of fecal sludge can contribute to transmission of
pathogenic organisms in various ways:
a) Careless handling of fecal sludge
Fecal sludge is handled during the removal from the facility and during transport and
treatment. The persons most likely to get in direct contact with fecal sludge are the
workers active in fecal sludge management. They are at very high risk to get infected by
organisms contained in fecal sludge. The usual way of transmission is the direct fecal-
oral way, which means that organisms contained in the sludge are ingested.
b) Discharge of fecal sludge into the environment
Once removed from a sanitation facility, fecal sludge often is discharged into the
environment. Sludge may be dumped into a dumping site, into surface waters, into
drains, or on the streets. In this way, the pathogenic organisms are dispersed into the
urban environment where humans can get in contact with the germs. Children playing
with contaminated water are especially at risk. A number of parasitic worms (geo-
helminthes) develop infective stades in humid soil and the larvae then penetrate the
human skin. All persons walking barefoot in areas where human excreta or fecal sludge
are spread are at risk to get infected.
c) Use of untreated fecal sludge in agriculture
Fecal sludge is a good organic fertilizer and soil conditioner and therefore frequently used
in agriculture. If the sludge is not adequately treated, pathogenic organisms contained in
the sludge are dispersed on the fields. Here they can infect the farmers working on the
fields as they permanently enter in contact with the contaminated soil and usually do not
use protection measures. Bacteria and worm eggs may also attach to the plants and
infect consumers if the crops are eaten raw and are not thoroughly washed.
3.1.2 How to cut the transmission pathways
The health risks from poor management of fecal sludge can be reduced by cutting the
pathways on which diseases are transmitted. The following measures can be useful,
depending on which of the above-described problems prevail:
a) Careful handling of fecal sludge
Manual handling of sludge is potentially dangerous and should be eliminated where it is
possible. Especially manual vault or pit emptying can be replaced by mechanical
emptying with vacuum suction units. Even in locations where conventional large
equipment cannot access, it is possible to use small vacuum pumps specially developed
for this situation. Use of adequate protection measures by workers is absolutely
necessary when it is impossible to exclude manual sludge handling.
Protection measures for handling of sludge include the use of protection clothes such as
gloves and masks and a good hygiene (washing hands after work etc.). Most important is
that workers be aware of the nature of the health risks to which they are exposed and that
they know how to protect themselves. Training of staff and targeted information may
Planning of Fecal Sludge Management Engineering Tools
32
therefore be the most successful measures. Companies and municipal enterprises
dealing with sludge should introduce rules for use of protection by their staff and care
should be taken to enforce those rules.
b) Eliminate discharge of fecal sludge into the environment
Elimination of indiscriminate dumping of sludge is the most important measure to avoid
that people get in contact with the pathogens contained in fecal sludge. It is important to
collect as much as possible of the sludge removed from vaults and pits and to dispose it
on sites designed for this purpose. It is absolutely necessary to make sure that nobody
can access the disposal sites and that contamination cannot spread from these sites.
Generally the latter requires that sludge has sufficiently reduced moisture content to
exclude percolation in the underground and that disposal sites be constructed as sanitary
landfills.
c) Treat fecal sludge before use in agriculture
Fecal sludge should always be treated prior to its use in agriculture. Treatment has then
to provide sufficient pathogen reduction in the sludge to guarantee the safety of its use.
The most resistant organisms in treatment are eggs of parasitic worms, in particular those
of Ascaris lumbricoides. These eggs can only be destroyed by exposure to temperatures
above 60°C, by desiccation at moisture contents lower than 10%, or by awaiting the
natural die off after at least ½ year. Pathogen destruction by heat or desiccation can
usually only be obtained with a considerable technological input, which is seldom
affordable for fecal sludge treatment in developing countries.
The only “low-tech” treatment that can provide satisfactory pathogen destruction in a
short time is termophilic composting. If composting is well done (the substrate has the
right composition, moisture content and aeration are optimized) the temperature in the
heaps usually rises above 55°C for several days and all pathogens are destroyed.
Storage of sludge over a period long enough to allow natural pathogen die off (minimum
6 months) is the other possibility to disinfect sludge without using expensive technologies.
Natural drying hardly can provide a moisture content sufficiently low for complete
pathogen destruction. Nevertheless, drying of sludge can enhance the pathogen
destruction during storage and therefore increase the security of this method.
d) Use untreated sludge only for non-food crops
Agricultural reuse of fecal sludge for non-food crops can be possible without prior
disinfecting treatment. In this way the health risks for consumers can be excluded.
However, the farmers handling the fecal sludge are still at risk. The risk to farmer has
then to be minimized through protection measures (a) or through hygienic education (e).
e) Hygienic education
Good personal hygiene breaks the direct contact routes by which pathogens are
transmitted and the full impact of the measures described in a) to d) will only be achieved
if they are accompanied by efforts to improve hygiene. Hygienic education should be
targeted on all aspects of hygiene and sanitation, and not only on issues related to fecal
sludge management.
Planning of Fecal Sludge Management Engineering Tools
33
3.2 Data collection
3.2.1 Sludge sampling and analysis
Why analyzing sludge?
Information about sludge characteristics is essential for design of treatment facilities.
Fecal sludge is in general much more concentrated than municipal wastewater (10-100
times higher contents of organic pollutants and suspended solids). Its characteristics are
very variable within one city because they depend on many factors such as the type of
sanitation facility from which the sludge is removed, the intervals of emptying, the
technique of emptying, etc. For this reason you cannot rely on literature data only for
design parameters such as pollutant concentrations and sludge production per capita. In
your specific situation these parameters may be quite different from other recorded
cases.
Estimation of fecal sludge production
Knowing the sludge volumes produced in a certain area is necessary to design collection
and treatment capacity. When estimating the volumes of sludge production, you should
be very careful to distinguish between two notions of “sludge production”:
a) Sludge accumulation in vaults and pits [liters sludge per capita and year]
The more familiar notion is the sludge accumulation in pit latrines, septic tanks and other
facilities, expressed in L/cap.yr. Standard values for this parameter appear commonly in
wastewater and sanitation literature, where they are usually meant for design of on-site
sanitation facilities (storage capacity for accumulating sludge). Using these values for the
prediction of sludge volumes that need be handled and treated would, however, not be
correct in most situations. It only would be admissible in the most ideal situation where all
sludge produced by the population actually reaches a treatment plant. This would require
that all on-site facilities be properly designed, be emptied in the designed intervals, and
that all sludge be collected and disposed in the treatment plant. This scenario is very
unlikely and it is therefore highly recommended to use the second notion of sludge
production as described in point b).
b) Sludge collection rate [m3 sludge collected per suction unit and year, or total volume
arriving on a disposal point per year]
To obtain a realistic estimation of the amount of sludge to collect and treat, you have to
take into account various aspects: Sanitation facilities may be improperly designed and
not accumulate the expected quantity of the produced sludge. Not all sanitation facilities
that accumulate sludge are actually emptied in regular intervals, or are emptied at all. Not
all sludge in vaults or pits is removed during the emptying as often part of the solidified
sediment remains in the facility. Not all sludge that is removed by companies or persons
will be delivered to the treatment facility; part of the sludge will be dumped elsewhere.
The sludge may be diluted during removal, volume and concentration be changed.
Hence, a realistic approach would be to base your estimations on the actual collection
rates. If you use records of the current sludge collection (or produce those records), you
will have at hand an estimation of the actual collection rate, which includes all the factors
mentioned above. You will then have consider which points of the sludge collection you
will seek to improve and you will have to try to quantify the repercussion of the
improvements on the volumes of sludge likely to be collected. Estimation made in this
Planning of Fecal Sludge Management Engineering Tools
34
way will be much more realistic than the ones based on literature values, even if they still
may contain a considerable uncertainty.
Sampling
Because of the variability of fecal sludge, you should try to take as many samples as
possible. If resources for sludge analyzing are limited, you may rather reduce the number
of analyzed parameters and take more samples instead. The minimum number of
samples necessary to obtain representative results is around 50 samples. Less than 30
samples can generally only indicate tendencies but not give statistically significant data.
The best way of sampling is directly from the vacuum tankers. When discharging the
tanker, you should collect sludge in a large bucket at the beginning of the discharging,
when the tank is half empty and short before the end of discharging. Mix the sludge in the
bucket thoroughly and take the sample from it. This way of sampling makes sure that you
analyze sludge in the composition that actually would reach the treatment plant.
Direct sampling from sanitation facilities or from existing discharge tanks or ponds is not
recommended. Suspended solids easily settle down when fecal sludge is stagnant. It is
then impossible to obtain a representative sample without mixing up the whole content of
the facility. Only sampling from the vacuum tanker takes into account that sludge may be
diluted with water during emptying of vaults and pits.
Analyzing
You should carefully consider what for actually you need the information when choosing
the parameters to analyze in sludge samples. Don’t bind resources for analyses that are
not absolutely necessary.
Design of primary sludge treatment (solid-liquid separation) facilities is usually based on
the solids content of the sludge, measured as suspended solids [SS] or total solids [TS].
The degree of stabilization of sludge indicates whether digestion of sludge is necessary
and is measured by the BOD/COD ratio or by the content of total volatile solids [TVS].
Nam Dinh – Estimation of fecal sludge volumes
The only de-slugging service likely to deliver sludge to a future treatment plant is the
municipal enterprise URENCO. URENCO operates two vacuum tankers (capacity 4
m3), which are used for de-sludging of septic tanks.
The average size of a septic tank is estimated to be 2.5 m3. This figure has been
estimated from an existent report of a household survey in Nam Dinh. It is considered
that the average volume evacuated from a septic tank is the full content of 2.5 m3,
which includes both sediment and liquid supernatant.
URENCO indicated that under normal conditions, one vacuum tanker could empty two
septic tanks per day. Currently only 100 to 150 tanks are emptied yearly. However, it
is planned to increase operational capacity, to promote de-sludging service and to use
the full capacity of the existent equipment.
The expected volume of fecal sludge volume is then estimated being 2500 m3/year
and the collection capacity can cover 1000 septic tanks or households per year (2.5
m3 sludge per septic tank, 2 septic tanks per day and unit of equipment, 2 existing
units, 250 operation days per year)
Planning of Fecal Sludge Management Engineering Tools
35
Recommended parameters for fecal sludge analyzing
Typical concentrations
in fecal sludge
Parameter Low-
strength
(septage)
High-
strength
(public
toilets)
Analyzing method
* Standard Methods for the Examination of
Water and Wastewater, APHA, AWWA,
WEF, 19th edition 1995
Minimum parameters
(very simple and cheap to analyze, sufficient for first characterization of sludge)
TS [%]
(total solids) 0.5-3 <3.5 Drying at 105°C during 2 h *
TVS [% of TS]
(total volatile solids) <60 >60 Ignition at 550°C during 2 *
Complementary parameters
(simple to analyze, complementary to TS and TVS)
total COD [mg O2/L]
6,000-
15,000 20,000-
50,000 COD, unfiltered sample *
Settling
characteristics,[mL/L] <300 Settling
disturbed by
gas-
production
Settling test in 1 or 2 L cylinder, note
settled volume after 2h
Other useful parameters
(analysis requires reliable lab, useful for detailed design of treatment facilities)
SS [mg/L]
(suspended solids) 5,000-
15,000 >30,000 Filtration of sample, drying of filter
residue at 105°C during 2 h *
dissolved BOD5, [mg
O2/L] <500 >500 BOD5 after filtration *
dissolved COD [mg
O2/L] <1,000 >1,000 COD after filtration *
BOD/COD ratio 5:1…10:1 2:1…5:1
NH4-N [mg/L]
(ammonia nitrogen) <1,000 2,000-
5,000 *
Figure 11: Important sludge parameters and recommended analysis.
Design of treatment of the liquid effluent from primary sludge treatment is based on the
habitual parameters for wastewater treatment, in particular BOD, COD, SS and NH4-N.
The parameters of fecal coliforms (for pathogenic bacteria) and viable helminthes eggs
(for parasitic worms) generally indicate the content of pathogen organisms. You don’t
need to analyze these parameters as you can assume with certainty that fecal sludge
contains dangerous concentrations of pathogens.
It is recommended to choose parameters that can be determined by simple laboratory
methods. It is likely that you will have to rely on low standard laboratories where it may be
difficult to produce reliable data for delicate parameters. Choosing parameters easy to
measure will increase the reliability of your data. In the same time it helps reducing cost
and enables you to analyze a higher number of samples, equally important for a reliable
data basis. You may therefore prefer to analyze total solids rather than suspended solids,
avoiding filtration that may be difficult with sludge samples. You may also prefer the
simple analysis of volatile solids instead of the more difficult analysis of BOD and COD.
Planning of Fecal Sludge Management Engineering Tools
36
Especially BOD analysis with unfiltered sludge samples is not recommended, because
the high solids content in the samples can cause erratic results.
3.2.2 Monitoring
General recording
Monitoring of implemented components should not only include technical aspects such as
fecal sludge collection and treatment, but also organizational, institutional and financial
matters. The most efficient way to do this is a good recording practice. Records about the
work done and about the finances should systematically kept and archived in a way that
allows easy access for those wanting to use the information. This is less obvious as it
may seem. Very often the recording practice and even more the archiving practice is very
poor and records are seldom really used for analyzing the quality of work. The most
important point may be that the persons doing the work and responsible for recording are
conscious that records will be needed and be used later. Some training of staff regarding
recording and archiving may be necessary.
Fecal sludge collection
The workers themselves best do monitoring of sludge collection by recording the
collection tours. Important points to record may be:
Location (address) and type of the emptied facility
Fee charged for the emptying
Volume of sludge removed from the facility
Date of emptying and date of last emptying
This data, if systematically recorded, is very valuable and can be used to establish a
database about on-site facilities and their characteristics.
Fecal sludge treatment
A monitoring program for the treatment plant should be installed to supervise its
functioning and to provide design information for extension phases. Regular analysis of
the influents and effluents of the treatment should be done, for example on a weekly
basis. An important monitoring parameter is the solids content (TS) of the sludge
throughout the different treatment steps. Additionally you should verify if the treatment
objectives are achieved and analyze the corresponding indicator parameters (for example
BOD and COD in the liquid effluent and CF or helminth eggs in the in the dried sludge).
Records of operation of the treatment plant should also be kept in the way described for
the fecal sludge collection. Entering fecal sludge volumes and leaving dry sludge volumes
have to be recorded, as well as particular observations or problems during the treatment
process.
Recording has to be done by the staff operating the treatment plant, whereas monitoring
could also be done by an external contractor.
Planning of Fecal Sludge Management Engineering Tools
37
3.3 Technological options
3.3.1 Technologies for vault or pit emptying and sludge haulage
Large vacuum tankers, truck or cart mounted
The classical technology for emptying of toilet vaults or pits is by suction with a vacuum
pump. A hose is introduced in the vault through a small opening and the content is
sucked out. Sometimes stirring of the vault content and addition of water prior to suction
may be required for loosening of the sediment layer. Sludge removal by suction pump
largely minimizes the direct contact of the workers with the sludge and is therefore the
safest technique available.
The pump is usually connected to a truck-mounted tank of variable capacity (1 to 10 m3).
In this way the truck can access the plot, empty the facility and then directly transport the
sludge to the disposal or treatment site. This type of equipment is the same that is used
in industrialized countries and is rather expensive (50,000 - 80,000 USD/unit). In
developing countries the tanks are often mounted on carts pulled by tractor or animals.
This version is considerably cheaper and technically equivalent to truck mounted
systems. The disadvantage is the reduced mobility and action radiant due to the slower
speed.
Mini vacuum tugs
Dwellings in urban centers of developing countries are often located in very narrow lanes
that are inaccessible to large vehicles. Large suction units as described above are
useless in this kind of situation and a large part of the households can therefore not be
serviced with modern equipment. For this reason smaller units have been developed in
various places, e.g. by UNCHS-Habitat in Nairobi, by WASTE in Dar Es Salaam or by
Urenco in Hai Phong. This equipment consists of smaller tanks (200-500 L) and a motor
or hand-driven vacuum pump. It can be hand-pushed or motor-driven. These units are
not appropriate to transport sludge over longer distances. They need therefore be
combined with truck mounted tankers or with intermediate storage and transportation
tanks transported by hook-lift trucks.
The ideal solution in many cases would be to combine large equipment for the normal
situations with smaller units for the areas difficult to access.
Manual emptying
Manual vault emptying will still be the final option when the use of vacuum pumps is
excluded for certain reasons. Manual emptying can be acceptable if two points are
respected: The health risk to workers must be minimized (see 3.1.2) and the transport to
the disposal site must be organized. Both are much more organizational than technical
problems. Good hygiene and protection clothes can reduce the health risks. Sludge can
be transported by carts or in buckets to the disposal site. However it might be especially
difficult to make independent workers bringing all the sludge to the desired site. Usually
they earn their money from the fees emptying of vaults and not for transportation of
sludge. Therefore they tend to dispose the sludge close to the emptying site in drains,
fields or on the street. The only way to achieve that workers bring the sludge to designed
site may be to provide appropriate incentive systems. Incentive systems should include
both rewards for taking the desired actions and sanctions against harmful actions.
Planning of Fecal Sludge Management Engineering Tools
38
Figure 12: Truck
mounted sludge tank
(7,5 m3) and vacuum
pump in Hai Phong,
Vietnam.
Figure 13: Mini-
vacuum tug (350 L) for
narrow lanes, used
together with a
intermediate-storage-
tank placed in the next
accessible road, Hai
Phong, Vietnam.
Figure 14: Small
sludge tank connected
to a hand-driven
vacuum pump in
Mapet, Congo.
Planning of Fecal Sludge Management Engineering Tools
39
3.3.2 Technologies for fecal sludge treatment
Advanced treatment technologies are not described here
Treatment of fecal sludge in industrialized countries is usually based on technologies
habitual for treatment of sewage and sewage sludge. Frequently used technologies
include extended aeration, anaerobic digestion, mechanically stirred sludge thickeners,
centrifuges, belt presses, vacuum filter presses, heat drying, pasteurization and others.
However, all the mentioned technologies are not considered being adapted to most
conditions in developing countries, because they are very expensive and have high
operation and maintenance requirements. These “high-tech” options are therefore not
described in this chapter.
Knowledge about simple treatment technologies is limited
A word of caution is needed before going into the details of available “low-tech” options
for fecal sludge treatment. Knowledge about this type of treatment technologies is very
limited. The research efforts for technologies adapted to conditions in developing
countries always has been focussed on wastewater treatment exclusively. SANDEC has
scientifically followed various fecal sludge treatment plants in several countries in order to
contribute to close this knowledge gap and to develop design guidelines. The description
of treatment technologies and the recommended design parameter given in this chapter
are based on SANDEC’s research activities. Be aware that many of these
recommendations are based on experiences from a single treatment plant and that you
still have to use your own common sense when designing facilities. So far there isn’t
existing a design manual for fecal sludge treatment that is used in practice.
Principles of fecal sludge treatment
Fecal sludge has several characteristics that make it difficult to handle. Fecal sludge
cannot be discharged into surface waters or be treated like wastewater because its
pollutant concentrations are too high. It cannot be landfilled or treated like solid waste
because its moisture content is too high. It cannot be directly used for crop fertilizing
because its pathogen content is too high.
The first stage of fecal sludge treatment thus mostly involves the stabilization of the
sludge and the separation of the solid phase and the liquid phase. In this way the liquid
part can be treated specifically, usually with wastewater treatment technologies. The solid
part can further be treated to enhance its characteristics for either landfilling or
agricultural reuse. Hence, sludge treatment involves different treatment steps where
available techniques can be combined in various ways depending on the existing
constraints and the treatment objectives.
Figure 15: gives an overview on the described treatment processes and some possible
combinations.
Planning of Fecal Sludge Management Engineering Tools
40
Figure 15: Overview of “simple” fecal sludge treatment technologies and their possible
combinations
Receiving tank
Fecal sludge arriving at the treatment plant will usually first be discharged into a receiving
tank. This tank should be equipped with a grid for removing the coarse objects.
Additionally the receiving tans can function as buffering tank, receiving the sludge in a
strong flush and passing then in a lower continuous flow on the primary treatment facility.
All primary treatments expect ponds hardly tolerate loading in a strong flush.
a) Co-treatment of raw fecal sludge with sewage or sewage sludge
If a sewage treatment plant is
existing or planned, FS can be co-
treated with sewage. FS is mixed
with sewage before treatment, or is
mixed with sewage sludge before
sludge treatment (if the STP is an
activated sludge plant).
When to use? Condition is the
existence or the project of a sewage
treatment plant. The STP needs to
have sufficient capacity to receive the additional load from FS.
Advantages: FS, when diluted with sewage, can be treated with well-known and reliable
sewage treatment technologies. Co-treatment of FS and sewage may be economic.
Disadvantages: FS is mixed with chemically more contaminated sewage or sewage
sludge. Agricultural reuse might be impossible and the resource FS be wasted.
Design: It is necessary to verify if the STP has sufficient capacity to treat the additional
pollution load from FS. The most critical parameter is usually suspended solids (SS).
Other design parameters are COD, BOD5, NH4-N.
Planning of Fecal Sludge Management Engineering Tools
41
Primary treatment of fecal sludge
Primary treatment, in this context, designates further stabilization of the fecal sludge and
the separation of solid and liquid phases. The quality of solids and liquids after primary
treatment depends on the process. Post-treatment of solids and/or liquids may be
necessary to achieve treatment objectives.
b) Digester for biogas production
Fresh FS rich in biodegradable
organic matter is digested
anaerobically, alone or together with
animal dung or vegetal waste. The
methane produced during the
digestion is captured and can be
used for cooking, lightening
electricity generation. Liquid effluent
and accumulated sludge leaving the
digestion process are then treated
separately.
When to use? Digestion of FS for biogas production can be interesting when there is a
potential for use of the biogas. Only fresh FS (like from public toilets) is appropriate for
biogas production. FS collected from septic tanks, pit latrines, etc. cannot be used for
biogas production. The sludge needs to have a minimum solids content of 3%. Mixing
with animal dung or with vegetal waste may increase solids content and content of
digestible organic matter.
Advantages: Production of combustible and generation of revenues. Stabilization of fresh
sludge. Little land requirements.
Disadvantages: The primary function of a biogas reactor is biogas production rather than
sludge treatment. The biogas reactor is therefore generally an additional treatment
process. Settling in digesters is incomplete and effluents require more extensive
treatment efforts than effluents from other primary FS treatment processes. The structure
is rather expensive, and operation requirements are quite considerable. Removal of
settled and thickened solids can cause difficulties.
Design: Design is aimed at biogas production, reactor volumes usually are smaller
compared to digesters for sewage sludge. Many different types of biogas reactors have
been developed throughout the world. An example is the digester with floating gas dome
as it is widely used in India for FS digestion. Following design values are frequently used:
solids content (TS) in influent: 5–8 %; hydraulic retention time: 30 – 50 d, organic loading:
1.6-2.2 kg volatile solids (VS) /m3.d.
c) Imhoff tank (settling and digestion)
The Imhoff tank allows settling of solids in presence of digestion processes. Inclined walls
make sure that rising gas bubbles produced by anaerobic digestion do not disturb the
settling process. Solids will accumulate on the bottom, be stabilized by digestion and
thicken. The digested sludge will be removed periodically by pumping or hydrostatic
pressure and further be treated. The clarified supernatant generally requires further
treatment.
When to use? The Imhoff tank can be used for insufficiently stabilized FS to allow settling
and digestion in one single stage. It can be used when conditions are not favorable for
biogas digesters and when no space for stabilization ponds is available.
Planning of Fecal Sludge Management Engineering Tools
42
Advantages: Settling and digestion in a
single step. Little land requirement.
Disadvantages: Expensive structure. Risk
of obstruction of sludge draw-off pipe by
thickened sludge when draw-off is not
done in adequate frequency.
Design: The Imhoff tank has been
developed for pre-treatment of wastewater
in small treatment systems. Larger storage
volumes for sludge and shorter sludge
removal intervals have to be considered
when adapting the design to FS treatment.
The volume foreseen for settling (above the inclined walls) can be kept similar to the
design for wastewater. Recommended design values: overall depth 2-3m; sludge
accumulation depth 0.5–1 m; hydraulic retention time in settling compartment 4-8 h;
sludge removal intervals 1-4 weeks, volume of accumulated sludge per incoming solids
load 5-9 L/kg TS.
d) Settling/thickening tanks
In settling or thickening tanks, the
solids accumulate at the bottom and
the clarified supernatant can further
be treated. The accumulated sludge
is removed periodically through
draw-off pipes. Another possibility of
sludge removal is manually or by
front-loaders after removal of the
liquid column and a period of drying.
Removed sludge generally requires
further treatment.
When to use? Settling tanks can be used for partly stabilized FS such as sludge from
septic tanks and most other sanitation facilities. Settlings tanks are not appropriate for
very fresh sludge from public toilets, but may still be suitable if the fresh sludge is diluted
with more stabilized sludge.
Advantages: Simple and reliable process. Little land requirement.
Disadvantages: Not suitable for fresh FS.
Design: Settling tanks need sufficient volume for sludge accumulation and sufficient
depth of the liquid column (> 1.5m) to allow good settling. The tanks should be equipped
with baffle walls to maintain hydraulic conditions favorable to good settling and to retain
floating scum. Design varies depending on the way of sediment removal. If sediment is
removed by pumping or hydrostatic pressure, the tank should have a sludge hopper from
where the sludge will be drawn off. If sediment is removed manually or by front-loaders
the tank will be equipped with an access ramp. At least two parallel tanks will then be
needed to assure continuos operation when one of the tanks is due for emptying. The
tank size is estimated by choosing the sludge removal interval (2 weeks to 2 months) and
with the assumed rate of accumulated sludge volume per incoming solids load of 5-9 L/kg
TS.
Planning of Fecal Sludge Management Engineering Tools
43
e) Sedimentation/stabilization ponds
The sedimentation ponds use the same principle
of sedimentation of solids as the settling tanks.
Ponds are larger and have longer sediment
removal intervals. Due to the high volume and
long retention time, they provide a good
stabilization capacity for fresher sludge. The
sediment is removed after removal of the liquid
column and a period of drying. Both liquid and
sediments require further treatment.
When to use? Sedimentation/stabilization ponds
can be used as first FS treatment stage when
land availability is not a problem. They can receive fresh FS. Often they are the first stage
in a sequence of stabilization ponds.
Advantages: Simple operation, cheap construction, better sedimentation properties as
settling tanks, stabilization capacity.
Disadvantages: High land requirements.
Design: Sedimentation ponds are designed as anaerobic ponds with a sufficient storage
volume for sludge accumulation. Sludge is removed once, twice or more often per year.
At least two parallel ponds are required to assure continuos operation. The organic load
of anaerobic ponds is 250-350 gBOD/m3.d; the volume of accumulated sludge per
incoming solids load is 0.8-2 L/kg TS.
f) Drying beds
Drying beds consist of a gravel-
sand filter, equipped with a drainage
system. Raw or pre-settled FS is
loaded on the bed and the water is
evacuated mainly by percolation
through the filter and to a minor part
by evaporation. The dewatered
sludge is suitable for disposal.
Further treatment for pathogen
removal is necessary if the dried
sludge is to be reused. Percolate
quality improves through filtration
but may still require a polishing
treatment.
When to use? Drying beds can be used as first treatment stage and as second stage for
dewatering of settled sludge removed from facilities such as described in b), c), d) and e).
Drying beds cannot receive undiluted fresh FS (poor dewatering characteristics, odor
emissions).
Advantages: Low moisture content of dried solids and relatively good percolate quality
(compared to settling facilities). Technology is well known and reliable.
Disadvantages: Solids are not yet hygienically safe (unlike constructed wetlands)
Design: Various designs have been developed for drying of digested sewage sludge. The
most frequently used type is the sand drying bed (see drawing above). They can be
Planning of Fecal Sludge Management Engineering Tools
44
designed for a loading rate of 150-200 kg total solids (TS) per m2 and year. Dried sludge
can be removed after 7 to 14 days, depending on climatic conditions.
g) Constructed wetlands
A vertical-flow constructed wetland
is a bed equipped with a drained
gravel and sand filter and planted
with marsh plants. The sludge is
loaded on the bed and dewatered
by percolation in the filter and by
evapotranspiration through the
plants. The root system of the
plants maintains the permeability of
the sludge layer and sludge can be
added continuously. Sludge has to
be removed only once every few
years. The long solids retention
period favors further mineralization and pathogen die-off and allows direct reuse of solids
in agriculture. Percolate quality considerably improves but may still require a polishing
treatment.
When to use? Constructed wetlands can be used when the sludge is to be reused in
agriculture.
Advantages: Include dewatering, stabilization and hygienization in a single treatment
stage, unlike all other treatment techniques. Dewatered sludge can be used in agriculture
without further treatment. Percolate quality compares favorable to other primary
treatments.
Disadvantages: Experiences from pilot plants only are available so far. Requires care for
plant growth.
Design: The filter and drainage system of constructed wetlands is similar to a drying bed.
The plants should be local marshland species that are tolerant to a wide range of
environmental conditions (varying humidity, salinity). A freeboard for sludge accumulation
of up to 1 m should be provided. Optimal performance has been observed for the loading
rate of 250 kg total solids (TS) per m2 and year. The sludge accumulation is then
approximately 20 cm per year.
Post treatment of liquids
Post treatment of liquid effluents from primary treatment assures that the final effluent can
be discharge into surface waters with no harm for the environment and public health.
h) Co-treatment of liquids with sewage
Effluents from primary FS treatment can be treated together with sewage if a sewage
treatment plant is existing or planned. The primary treatment mainly eliminates the
suspended solids and the STP can then treat much higher volumes of liquid effluent than
of raw FS (compare to option a).
When to use? This option can be considered when there is existing or planned a sewage
treatment plant, and when its capacity is not sufficient to treat raw FS.
Advantages: Co-treatment can save resources. The solids fraction is separated during
the primary treatment and can be reused in agriculture (unlike option a).
Planning of Fecal Sludge Management Engineering Tools
45
Design: It is necessary to verify if the STP has sufficient capacity to treat the additional
pollution load from pre-treated FS. Generally the greatest part of suspended solids will be
removed in primary treatment. Removal of organic pollutants is minor during primary
treatment, best in constructed wetland and rather poor in settling facilites. The critical
parameters will therefore be BOD5 and COD, further important are remaining SS and
NH4-N.
i) Stabilization ponds
Stabilization ponds for FS effluent treatment can be anaerobic or/and facultative ponds
depending on the organic pollutant concentration. The first anaerobic pond after the
primary treatment will still receive some suspended solids that will accumulate on its
bottom. After occasional removal, the sediments can be treated together with the solids
that have been separated in primary treatment
When to use?
Ponds can be used when sufficient land is available. High ammonia concentrations in the
effluent, for example in FS from public toilets, may inhibit growth for algae and bacteria
and thus the functioning of ponds.
Advantages: Simple, well-known and reliable technology.
Disadvantages: High land requirements. Possible inhibition of functioning through
NH3/NH4 in case of very fresh FS.
Design: Stabilization ponds are designed for organic loading rates. Anaerobic ponds have
2-3 m depth, remove 60-70 % of BOD and produce no bad odors when loaded with 250–
350 gDBO/m3.d. Facultative ponds are 1-2 m deep and loaded with 350 kgDBO/ha.d.
Post treatment of solids
Post treatment of solids assures the necessary quality corresponding to the treatment
goals. If the solids are to be reused for food crop production, the treatment of solids has
to provide hygienic safety of the solids. If solids will be used for non-food crops, be
disposed off, or used for other purposes, the treatment basically has to provide adequate
consistency of the solids.
j) Co-composting with solid waste
Pre-treated Fs (with reduced moisture content) is composted together with organic solid
waste. If the composting is well done, temperatures in the heaps reach 55-60°C and all
pathogens are destroyed. The produced compost constitutes a very good soil conditioner.
When to use?
Planning of Fecal Sludge Management Engineering Tools
46
Composting is a very interesting
option when agricultural reuse of
fecal sludge and solid waste is
desired. Solid waste needs to be
available in sufficient quantity and
quality (sorting).
Advantages: Allows producing a
good and pathogen free soil
conditioner in relatively short time.
Co-treatment can safe resources.
Disadvantages: Contaminants in solid waste may reduce compost quality.
Design: It is important that the mixture of SW and FS are optimal for composting. A
moisture content of 50-60% and a C:N ratio of 30-35 should be guaranteed. Good
aeration by frequent turning of the heaps is required to maintain thermophilic conditions.
The composting process is generally completed after 6 weeks to 2 months.
k) Storage and natural drying
Storage over at least 6 months allows natural pathogen die-off in dewaterd sludge from
settling facilities or drying beds. Further drying of sludge contributes to pathogen die-off
and increases the safety of the method.
When to use? Storage and natural drying will be used if the fecal sludge is to be reused
in agriculture and if co-composting or constructed wetlands (other processes delivering
hygienically safe biosolids) are not favored.
Advantages: Cheap and simple.
Disadvantages: High land requirements.
Design: Protection against rain may be required depending on the climatic conditions.
Planning of Fecal Sludge Management Sources of Further Information
47
4 SOURCES OF FURTHER INFORMATION
Case study of fecal sludge management planning
[1] Nam Dinh Septage management study
Florian Klingel; Nam Dinh Urban Development Project; SANDEC; November 2001
Download: http://www.sandec.ch/sos/references.html
This manual is based to a large extend on the practical experiences of the Nam Dinh
Septage management study. The study aims to propose a feasible concept on how to
improve the collection of fecal sludge and how to introduce adequate sludge treatment.
The first part describes the thorough assessment of the situation, the problem analysis
and definition of objectives. The main part deals with the development of the future
management concept, including a discussion of technical and institutional ways to
improve septage collection and an in-depth evaluation of various septage treatment
technologies.
Sanitation planning
[2] Strategic planning for municipal sanitation – a guide
GHK Research and Training Ltd.; First edition; July 2000
Download: http://www.ghkint.com/pub_pub2.htm
The strategic planning approach of the present manual has largely been adopted from
this guide. This guide contains the characteristics of a strategic approach for sanitation
planning and step-by-step guides for policy development, for sanitation planning on
municipal level and on local level. The last section of the guide contains a collection of
tools for health and sanitation promotion, on sanitation technologies and sewage
treatment, for sanitation choice, for information gathering, analyzing and sharing, for
planning and management tools, and training modules
Community assessment
[3] Social Survey Methods - A fieldguide for development workers
Paul Nichols; Oxfam; ISBN 0-85598-126-1; 1991
Order: http://www.oxfam.org
A readable guide to selecting an appropriate, affordable research method, implementing
the research, and communicating the results. Formal and non-formal survey methods are
detailed, and advice provided on statistical analysis of results, design of survey forms and
interview methods. This valuable tool is designed for those without formal training in
statistics.
[4] Resources on Participatory Approaches and Communication for Water and
Sanitation Programming: annotated references
Dick de Jong, Veera Mendonca and Silvia Luciani; IRC; 1997
Planning of Fecal Sludge Management Sources of Further Information
48
Available: http://www.irc.nl/themes/communication/comres/index.html
This resource package on participatory approaches and communication tools aims to
serve planners, implementers and field workers who are dealing with advocacy, social
mobilization and program communication for change in water and environmental
sanitation programming. This document incorporates a variety of annotated information:
important publications, training manuals, workshops, training courses and other
resources available.
[5] Metguide – Methodology for participatory assessment with communities,
institutions and policy makers. Linking sustainability with demand, gender
and poverty.
Rekha Dayal, Christine van Wijk, Nilanjana Mukherjee; WSP; 2000
Download: http://www.wsp.org/pdfs/global_metguideall.pdf
The metguide mainstreams gender and poverty indicators into a participatory
methodology that can be used to monitor key aspects of sustainability. It provides a
means for stakeholders at various levels – community, project and service provider, and
policy – to clearly visualize how actions can contribute to the goal of sustainability. It uses
quantitative statistical methods to analyze qualitative data obtained from communities
through participatory techniques.
Technologies
[6] Fecal sludge treatment
Agnes Montangero, Martin Strauss; Lecture notes IHE Delft; February 2002
Download: http://www.sandec.ch/sos/references.html
These lecture notes summarize SANDEC’s to date research results in fecal sludge
treatment. Current practices and problems in fecal sludge management, strategic and
regulatory aspects are addressed at first. The main part is about fecal sludge treatment,
including descriptions of various treatment options and investigated facilities in different
countries. The paper concludes with chapters about option evaluation and about land
requirements.
[7] Solids separation and pond systems for the treatment of fecal sludges in the
tropics - lessons learnt and recommendations for preliminary design
Udo Heinss, Seth A. Larmie, Martin Strauss; SANDEC Report No. 5/98
Download: http://www.sandec.ch/sos/references.html
The report sets out to provide guidelines for the preliminary design of fecal sludge
treatment schemes comprising solids-liquid separation and stabilization ponds. The
document is based on the results of field research conducted on full and pilot-scale fecal
sludge treatment plants located in Accra, Ghana. The authors first inform on fecal sludge
quantities and characteristics. Effluent and solids quality standards for fecal sludge
treatment plants are discussed and a set of guideline values proposed. The document
then proceeds to discuss results of field research conducted on FS pretreatment; i.e.,
solids-liquid separation in sedimentation/thickening tanks, dewatering/drying beds and
anaerobic pond technology and the results of field investigations conducted with
anaerobic ponds.
Planning of Fecal Sludge Management Sources of Further Information
49
[8] Practical tools to achieve effective Operation & Maintenance
WHO; Operation and Maintenance Working Group; 2001
Download: http://www.who.int/water_sanitation_health/wss/o_m.html, WHO CH-1211
Geneva 27, Switzerland
The Working Group Operation and Maintenance has developed a series of tools which
can be used at the country level to improve O&M performance. The tools have been
developed in response to the demand for practical solutions to the sector's problems.
They include guidelines, manuals, training packages, and case studies.
Those currently available are:
Tools for Assessing the Operation and Maintenance Status of Water Supply and
Sanitation in Developing Countries. These comprehensive guidelines show how
to assess O&M performance in both rural and urban areas.
Operation and Maintenance of Urban Water Supply and Sanitation Systems: A
Guide for Managers. This publication examines the factors, which may prevent
existing urban water supply systems working efficiently, and provides guidelines
and solutions for optimization.
Operation and Maintenance of Rural Water Supply and Sanitation Systems. This
package contains resource material for training courses aimed at improving the
management of O&M in rural areas.
Models of Management Systems for the Operation and Maintenance of Rural
Water Supply and Sanitation Systems. This document evaluates the factors
which influence the development of O&M management systems for rural facilities.
It describes models in eight representative countries and offers guidance to
planners and designers in selecting the most appropriate one.
Linking Technology Choice with Operation and Maintenance. This document
helps users to make more appropriate technology choices by providing
information on the O&M implications - particularly the costs - of selecting a
specific technology.
Hygiene promotion
[9] Just stir gently – The way to mix hygiene education with water supply and
sanitation
IRC; Technical Paper Series No. 29; ISBN 90-6687-016-8; 1991
Order: http://www.irc.nl/products/publications/index.html or IRC, P.O. Box 93190, 2509
AD The Hague, Netherlands
Provides options and methods for integrating hygiene education with water supply and
sanitation projects. Illustrations and examples are used to reinforce the text and to give
some ideas from 'real life' situations. Target audience is those responsible for the
development and implementation of hygiene education components in water supply and
sanitation projects.
______________
Article
Full-text available
This review paper covers the issues of pit latrine emptying national policies and regulations with a focus on Malawi and Zambia. With 2.4 billion people worldwide still lacking improved sanitation facilities, developing countries need to look at policy, regulation and practice for household sanitation service provision with a new lens. What happens “next,” when improved sanitation facilities eventually become full? An emphasis on faecal sludge management has multiplied this important issue in the past few years. The authors compare the pit latrine emptying situation in Malawi and Zambia with a focus on status, challenges and opportunities. To build this comparison, a desk review of national policies, local regulations and peer-reviewed journal papers was conducted. The paper concludes that existing national policies and regulations taking faecal sludge management into account are weak and have wide gaps in the two study countries. For the future, it is recommended, first, that household pit latrine emptying should be seen as an opportunity to address national sanitation gaps and, second, national policies and regulations need to be evaluated and updated. Key words: Faecal sludge management, pit latrine, policy, private sector, sanitation.
ResearchGate has not been able to resolve any references for this publication.