EAWAG SANDEC 2008 Module 4 Sanitation Systems and Technologies - Presentation

Eawag: Swiss Federal Institute of Aquatic Science and Technology

Sandec Training Tool 1.0 Module 4

Sanitation Systems & Technologies

Sandec Training Tool

Module 4: Sanitation Systems & Technologies

Review

Non-technicalaspects such as

socio-cultural, politicaland financial

Systems and technologies classified

and described

Introduction to global sanitation situation

and the characteristicsof the system

Definitions and objectives of sanitation

systems and technologies



Module 4: Chapter 1


Definition: Interventions to reduce peoples exposure to disease by providing a clean environment in which to live, with measures to break the cycle of disease.Involves both behaviours and facilities which work together to form a hygienic environment. Simpson-Hebert and Woods, 1998)

What is water supply & environmental sanitation?

Water supply(Water treatment

& storage)

Water supply(Water treatment

& storage)

Sanitation (Waste-water & excretamanagement)

Sanitation (Waste-water & excretamanagement)

Solid wastemanagementSolid wastemanagement

Stormwaterdrainage

Stormwaterdrainage

Definitions & Objectives


What waste, resource and management systemsare we dealing with?

Storage Transport Treatment Disposal ReuseStorage Transport Treatment Disposal Reuse

Wastewater

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Planning Financing ImplementingOperation & Maintenance Regulation & Enforcement


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Houshold waterhandling


Waste generation

Waste generationSanitationSanitation DrainageDrainage

ProcessesProcesses

Management Management

Sources of waste

Sources of waste

Water supplyWater supply



What is our focus in this course?

Storage Transport Treatment Disposal ReuseStorage Transport Treatment Disposal Reuse

Wastewater

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Waste generation

Waste generationSanitationSanitation DrainageDrainage

ProcessesProcesses

Management Management

Sources of waste

Sources of waste

Water supplyWater supply



What are the objectives of sanitation systems?

Protect and promote health

Protect and promote health

Protect the environment Protect the

environment

Be simple Be simple

Be affordableBe affordable

Be culturally acceptable

Be culturally acceptable

Work for everyoneWork for everyone

Sanitation programmes have to comply with all these aspects to become functional, appropriate and sustainable.Sanitation programmes have to comply with all these aspects to become functional, appropriate and sustainable.



What is considered as access to basic sanitation?

How can we measure these criteria?How can we measure these criteria?

Healthful environment Access to sanitationservices

Respect of privacy & dignity

Access to sanitationfacilities

The Millennium Development Task Force on Water defined access to basic sanitation based on the following criteria:



What is considered as access to improved sanitation?

bucket latrines public latrines open latrines

not improved technologies:

connection to a public sewer connection to a septic system pour-flush latrine simple pit latrine ventilated improved pit latrine (VIP)

improved technologies:

For monitoring purposes access to improved sanitation is defined in terms of the types of technology and levels of service afforded.

This classification is used to measure coverage and progress of global sanitation.This classification is used to measure coverage and progress of global sanitation.



Module 4: Chapter 2

Review




and described






Can we achieve the sanitation targets of the MDG?

MDG Goal 7: Halve, by 2015, the proportion of people without sustainable access to safe drinking water and basic sanitation.

What progress have we made so far? (1990-2002)

2.6 billion people still lack improved sanitation !

Introduction

(WHO&UNICEF 2004))


Why is sanitation coverage not increasing? Introduction

Lack of political will Low prestige and recognition Ineffective promotion and low public awareness

No coordination among stakeholders Poor institutional frameworks

Poor policy, at all levels

Inadequate and poorly-used resources Neglect of consumers willingness/ability to pay

based on their preferences

Inappropriate approaches Insufficient enforcement Insufficient capacity&expertise

Awareness and priority:

Legislative and policy issues:

Economic issues:

Capacity and Expertise:

Institutional issues:


The Bellagio-Principles, to improve environmental sanitation

Slum household, Manila Stakeholders, Africa Compost sieving, India Urine sep., China

Responsive and accountable to local needs and demands Decision making should involve the participation of all stakeholders Waste should be considered as a resource Waste should be managed as close as possible to its source

Introduction


What products are we dealing with?

Greywater:wastewater

from kitchen, bath, shower.

Yellow-water:separated

urine

Blackwater: urine, faeces

& flush

Faecal sludge:solids and liquids accumulating in

sanitation systems

A sanitation system must manage all products generated !A sanitation system must manage all products generated !

Excreta:urine & faeces

Introduction


47%12%41%30kg/capyrCOD

0*

54%

60%

85%

500

Urine

107-109 /100ml104-106 /100ml-Faecal coliforms

12%34%1.4 - 2.0 kg/capyr

Potassium

30%10%**0.3 - 0.8 kg/capyr

Phosphorous

10%5%2 - 4 kg/capyrNutrientsNitrogen

5025000-10000025000-100000Volume [l/capyr]

FaecesGreywater***Total

* healthy people** can be as high as 50%, depending on washing and dish-washing powder used*** values representative for industrialized countries

Characteristics of waste productsIntroduction


Characteristics of waste products

Good soilconditioner, but only littlenutrients

Nutrients(N, K and P etc.) => ideal fertilizer

Reuse potential for irrigation or municipal and non-potable domestic use

Value

Pathogensbacterias, viruses, helminths, protozoa

Almost sterile i.e. cross-contamination fromfeaces

Pathogensbacterias, viruses, helminths, protozoa

Biologicalcontamination

Micro-contaminantse.g. Heavy metals

Micro-contaminantse.g. hormons & antibiotics

Fats, oils and toxic substances org. compounds, chlorides, metals

Chemical contamination

FaecesUrineGreywater

Introduction


Module 4: Chapter 3

Review




and described






What are the Functional Groups through which theproducts flow?

User Interface

e.g. Dry Toilet orPour Flush Toilet

Collectionand Storage/

Treatment

e.g. SepticTank

(Semi-) CentralisedTreatment

e.g. AnaerobicBaffled Reactor

or Waste Stabilisation

Pond

Conveyance

e.g. SimplifiedSewer or

Tank Lorries

Use and/or

Disposal

e.g. Compostingor Leaching Field

Input products

Input products

safe & valuable output productssafe & valuable output products

Systems and Technologies

Technologies which perform the same, or similar function, are grouped into Functional Groups


How can the Functional Groups belinked?

Collection and Storage/Treatment e.g. Septic Tank

User Interfacee.g. Flush-Toilet,

Pit Latrine

Conveyancee.g. Simplified

Sewer, Tank LorriesSemi-Centralised

Treatmente.g. Anaerobic Baffled

Reactor, Waste Stabilisation Pond

Use and/or Disposale.g. Composting or Leaching Field


Functional Groups have to be linked to a functional systemFunctional Groups have to be linked to a functional system


Which technologies can perform which function?

Dry Toilet Urine Diverting

Dry Toilet Urinal Pour-Flush Toilet Flush Toilet Urine Diverting Flush Toilet

Single Pit Single VIP DehydrationVaults

Septic Tank CompostingChamber

AnaerobicBaffled Reactor

Anaerobic Filteretc.

Human-PoweredEmptying andTransport

Motorized Emptyingand Transport

Simplified Sewers Small-Bore Sewer Conventional

Gravity Sewer Jerry Can/Tanketc.


Anaerobic Filter Trickling Filter WasteStabilisationPonds

Activated Sludge ConstructedWetland

Co-compostingetc.

Application ofUrine

Application ofDehydr. Faeces

Compost Irrigation Aquaculture Soak Pit Leach Field Land Application Surface Disposaletc.

User Interface

Collection and Storage/

Treatment Conveyance

(Semi-) Centralised Treatment

Use and/orDisposal

Only selected combinations of technologies will lead to functional systems.Only selected combinations of technologies will lead to functional systems.



How can sanitation systems be classified?

Waterless Systems Water based Systems

Determined mainly by the user interface, there are 8 technically feasible system templates, classified in two categories:

System 1: Single Pit SystemSystem 2: Waterless Alternating

Double PitsSystem 4: Waterless Urine

Diversion

System 3: Pour Flush with Urine Diversion

System 5: Decentralised Blackwater Treatment

System 6: (Semi-) Centralised Blackwater Treatment

System 7: Sewerage with (Semi-) Centralised Treamtent

System 8: Sewerage with (semi-) centralized treatment

Most system templates have several alternative configurations. The most appropriate system option has to be selected on a case-to-case basis.

Most system templates have several alternative configurations. The most appropriate system option has to be selected on a case-to-case basis.



Technologies for the user interface

Conveyance (Semi-) CentralisedTreatment

Use and/orDisposal

User Interface Collection and Storage/

Treatment















Co-compostingetc.

Application ofUrine




Output Products

User InterfacesInput Products

Technologies for the user-interface

UrineUrine

FaecesFaeces

BeigewaterBeigewater

ExcretaExcreta

Dry Toilet

(1) (2)


UrineUrine

FaecesFaeces

Urine Diverting Dry Toilet

UrineUrine

FaecesFaeces

(3)BeigewaterBeigewater


Out ProductsUser InterfacesInput Products

Technologies for the user-interface

Cistern-Flush Toilet (2)


UrineUrine

FaecesFaeces

FlushwaterFlushwaterBlackwaterBlackwater


Pour-Flush Toilet (1)UrineUrine

FaecesFaecesBlackwaterBlackwater

FlushwaterFlushwater



Technologies for collection and storage/treatment


Use and/orDisposal

User Interface Collection and Storage/

Treatment















Co-compostingetc.

Application ofUrine




Collection and storage / treatment technologiesVIP latrine (ventilated improved pit latrine)

mesh traps flies (1.2-1.5 mm mesh) size

mesh traps flies (1.2-1.5 mm mesh) size

Should extent > 0.5 m above superstructure

Should extent > 0.5 m above superstructure

Naturally induced ventilation with screened ventilation pipe

removes odor and prevents escape of flies

+ odors and flies reduced

- difficult to construct properly

- more expensive than simple pit latrine

+ odors and flies reduced

- difficult to construct properly

- more expensive than simple pit latrine

Flies are attracted by light from pipe

Flies are attracted by light from pipe



+ no waste, but fertilizer+ simple to design + little flies or odours if used

correctly+ easy and safe handling of

dried material

Requires:- special squatting pan- education and acceptance - constant source of ash,

sand etc.- a use or discharge point for

urine

+ no waste, but fertilizer+ simple to design + little flies or odours if used

correctly+ easy and safe handling of

dried material

Requires:- special squatting pan- education and acceptance - constant source of ash,

sand etc.- a use or discharge point for

urine

Urine diversion latrines with double deyhdration vaults

Urine is collected in tanks and is reused as liquid fertilizer

Urine is collected in tanks and is reused as liquid fertilizer

Faeces are dehydrated in 2 alternating chambers and used as soil conditioner

Faeces are dehydrated in 2 alternating chambers and used as soil conditioner

Urine and Faeces are separatedUrine and Faeces are separated

Add ash, sand or lime

Add ash, sand or lime


Collection and storage / treatment technologies


Alternating water-based pits

flushing of excreta with 2-3 L using a syphon (water seal) permanent pit(s) constant operation

+ reduced odour- higher investment costs- water must be available

+ reduced odour- higher investment costs- water must be available

single pit latrine with water-sealed pan for pour-flush



Pour-Flush toilets with double pit


most frequent onsite treatment unit worldwide

Consists of 2 to 3 compartments

Septic tank

+ simple, little space required because of being underground

+ low O&M costs- little removal of dissolved

and suspended matter (COD removal approx. 50%)

- high investment costs

+ simple, little space required because of being underground

+ low O&M costs- little removal of dissolved

and suspended matter (COD removal approx. 50%)

- high investment costs

= sedimentation tank in which settled sludge is partially stabilised by anaerobic digestion




Anaerobic baffled reactor (baffled septic tank)

+ simple, high treatment efficiency, hardly any blockage+ high removal efficiencies, also for suspended and dissolved solids

- construction and maintenance more complicated than conventional septic tank

+ simple, high treatment efficiency, hardly any blockage+ high removal efficiencies, also for suspended and dissolved solids

- construction and maintenance more complicated than conventional septic tank

Sedimentation chamber for removal of solidsSedimentation chamber for removal of solids

intensive contact between resident sludge and fresh influent

intensive contact between resident sludge and fresh influent

2 to 5 anaerobic chambers for removal and digestion of organics2 to 5 anaerobic chambers for removal and digestion of organics

Improvement of a septic tank Treatment efficiency: 65 to 90% COD removal




User Interface Collectionand Storage/

Treatment


Use and/orDisposal

Conveyance technologiesSystems and Technologies


Dry Toilet Urinal Pour-Flush Toilet Flush Toilet Urine DivertingFlush Toilet












Co-compostingetc.

Application ofUrine




Conveyance technologiesSolids free sewer

especially adequate where septic tanks already exist.

strict design criteria- relies on good solid removal in

septic or interceptor tanks

less strict design standards (e.g. fewer manholes, smaller pipe dia-meters, flatter gradients, shallow etc.)

sewers laid inside housing blocks or under pavements.

+ cheaper

Simplified sewer


Conveyance technologiesMotorized emptying & transport Human-powered emptying & transport

+ High efficiency- High O&M and capital cost- Spare parts often lacking- Difficulty in manoeuvring (vehicle

size, traffic congestion, infrastructure)

+ High efficiency- High O&M and capital cost- Spare parts often lacking- Difficulty in manoeuvring (vehicle

size, traffic congestion, infrastructure)

+ Low-cost operation and maintenance

+ Maintenance skills and spare parts available

- Limited efficiency

+ Low-cost operation and maintenance

+ Maintenance skills and spare parts available

- Limited efficiency


Semi-centralised treatmenttechnologies

Conveyance (Semi-)CentralisedTreatment

Reuse andDisposal

User Interface Collectionand Storage















Co-compostingetc.

Application ofUrine




Constructed wetlands (here: horizontal sand filter)

+ high treatment efficiency (up to 95% COD removal), no WW above ground, no nuisance of odour, high nutrient removal

- high space requirement, costly (gravel), great care required during construction

+ high treatment efficiency (up to 95% COD removal), no WW above ground, no nuisance of odour, high nutrient removal

- high space requirement, costly (gravel), great care required during construction

For treatment of (pre-settled) domestic or industrial WW(COD < 500mg/l and low solids)

sand & gravel filter,permanently soaked with watersand & gravel filter,permanently soaked with water

phragmitesand typhaphragmitesand typha

Inlet pipeInlet pipe

Outlet pipeOutlet pipe


Semi-centralised treatment technologies


Maturation Ponds

A pond-system comprises:

Waste stabilization ponds

Facultative PondAnaerobic Pond

Final sedimentation of suspended solids, bacteria mass and pathogens

hygienization

Aerobic degradation of suspended and dissolved matter (BOD reduction 50-70%) degradation

Sedimentation and anaerobic stabilisation of sludge (BOD reduction 40-50%) settling

Function

Hydraulic retention time: 10 days

Hydraulic retention time: 10 to 20 days

Hydraulic retention time: 1 to 3 days

Flow

Shallow (



Degradation of organic substances in facultative ponds:





Pros and Cons

Ideal for developing countries if enough space and supervision available !Ideal for developing countries if enough space and supervision available !


+ Can treat high strength wastewater to high quality effluent+ Generally reliable and good functioning+ Very inexpensive compared to other centralized options

- Not always appropriate for colder climates- Potential for bad odours if poorly designed- Requires expert design and supervision - Requires a lot of space

+ Can treat high strength wastewater to high quality effluent+ Generally reliable and good functioning+ Very inexpensive compared to other centralized options

- Not always appropriate for colder climates- Potential for bad odours if poorly designed- Requires expert design and supervision - Requires a lot of space



Use and/or disposal technologiesConveyance (Semi-)

CentralisedTreatment

Use and/orDisposal

User Interface Collectionand Storage/

Treatment


Dry Toilet Urinal Pour-Flush Toilet Flush Toilet

Single Pit Single Pit VIP Alternating Dry Double Pit

Alternating Wet Double Pit

Double Dehydr.Vaults

Aquaprivy Septic Tank CompostingChamber

Manual Emptying Mechanical

Emptying Simplified Sewers Small-Bore Sewer Conventional

Gravity Sewer Jerry Can/Tank

Imhoff Tank AnaerobicBaffled Reactor


Finishing Pond ConstructedWetland

Co-compostingetc.

Application ofUrine


Compost Irrigation with

Wastewater Aquaculture Soak Pit Leaching Field Incineration Land Application Surface Disposal



Wastewater disposal technologies

clean rock

perforated distribution pipe

sand and/ortopsoil

= system of trenches that is used to dissipate the effluent from a septic tank for discharge of non-solid septic tank effluent

Leach fields


+ little maintenance required - Space and skills required !+ little maintenance required - Space and skills required !

fabric, to preventplugging of pipe


Soak pits= covered, porous-walled chamber that allows water to slowly soak into the ground. for non-solid septic tankeffluent (clogging!)

Between 1.5 and 4 m deep

+ simple and cheap+ little space required

- not adequate for shallow ground water table (>1.5 m)

- not adequate in clay or rocky soils

+ simple and cheap+ little space required

- not adequate for shallow ground water table (>1.5 m)

- not adequate in clay or rocky soils

Wastewater disposal technologiesSystems and Technologies


Use of output productsWastewater irrigation

Recommendations to limit health risks on farm: Use of wastewater only after secondary treatment (i.e. physical and biological)

Wastewater can be used for irrigating agricultural land, if appropriate precautions have been taken.Wastewater can be used for irrigating agricultural land, if appropriate precautions have been taken.


Use of appriopriate irrigation system:1) Drip irrigation (ideal, but more costly)2) Furrow irrigation (cheap, but more evaporation loss) Crop restriction: Growing e.g. fibres (cotton), tobacco or fruit trees is generally safer than vegetables or salad Increasing the period between wastewater irrigation and harvesting/consumption Farmer fetching faecal sludge


Quality standards for use of output products

6 month storage(20C)

Irrigation of all crops

Aquaculture

Agriculture (Soil conditioner)

Restricted irrigationUnrestricted irrigationLocalized irrigationRestricted irrigationUnrestricted irrigation

Irrigation of food and fodder crops to be processed, fodder crops unprocessed

Irrigation of food and fodder crops to be processed

Reuse Application



Dry Toilet Urinal Pour-Flush Toilet Flush Toilet

Single Pit Single Pit VIP Alternating Dry Double Pit

Alternating Wet Double Pit

Double Dehydr.Vaults

Aquaprivy Septic Tank CompostingChamber

Manual Emptying Mechanical

Emptying Simplified Sewers Small-Bore Sewer Conventional

Gravity Sewer Jerry Can/Tank

Imhoff Tank AnaerobicBaffled Reactor


Finishing Pond ConstructedWetland

Co-compostingetc.

Application ofUrine


Compost Irrigation with

Wastewater Aquaculture Soak Pit Leaching Field Incineration Land Application Surface Disposal

User Interface


Treatment Conveyance


Use and/orDisposal

How to design a sanitation system?

How to proceed:How to proceed:

3.) Select the specific technologies for each product for each process in each of the system templates identified.

3.) Select the specific technologies for each product for each process in each of the system templates identified.

2.) Select the most appropriate system templates.2.) Select the most appropriate system templates.

Remember: Only selected combinations of technologies result in functional systems !

1.) Identify the types of products that are generated.1.) Identify the types of products that are generated.

4.) Select the most site-specific system option based on the social, economic, and resource aspects.

4.) Select the most site-specific system option based on the social, economic, and resource aspects.



1st Example: Waterless system with urine diversion

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Urine Diverting Dry Toilet & Urinal

Double DehydrationVaults

Human Powered Emptying and Transport

Applicationof Faeces

Applicationof Urine

StorageTank

Jerry Can / Tank

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User Interface


Treatment

Conveyance Use and/or Disposal



2nd Example: Water-based, alternating double pit

Pour Flush

Twin Pits for Pour-Flush

Compost/EcoHumus

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Greywater Treatment


User Interface


Treatment

Conveyance Use and/or Disposal


Human Powered Emptying and Transport


3rd Example: (Semi-) centralised blackwatertreatment system

Pour Flush Toilet

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Simplified Sewers

Human-Powered E &T

Greywater Treatment

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Cistern Flush

Septic Tank Solids-free Sewers

Motorized E&T

IrrigationTrickling FilterUASBWaste Stabilisation PondsAerated PondConstructedWetlandsFloating Plant Wetland

Surface DisposalCo-Composting

Thickening Ponds (Un-)plantedDrying BedsBiogas Reactor

AquaculturePonds

Land application.


User Interface


Treatment

Conveyance Use and/orDisposal

ABR

Anaerobic Filter

Disposal/ Recharge


Select the most appropriate system configuration !


Emergency sanitation

Construction of an emergeny latrine



Immediate action measures

Design criteria: Far from water source (50 m)

and storage Downhill of settlements

(leakage) Far from public buildings and

roads Security screen to provide

minimum privacy Including hand washing

facilities Better suited for hot dry

climates

Open field defecation

+ rapid and easy- lack of privacy+ rapid and easy- lack of privacy

First clearing of scattered excreta !



Immediate action measures

Design criteria: 15-60 cm deep 20-30 cm wide provide shovels to allow each

user to cover its excreta with soil

Shallow trench defecation

+ rapid (1 worker can dig 50 m of trench per day)

+ covered with soil

- limited privacy- considerable space required

+ rapid (1 worker can dig 50 m of trench per day)

+ covered with soil

- limited privacy- considerable space required

Shallow trench



Immediate action measures Bucket / container latrines Urinals with soakage pit



Emergency sanitation planning

1 cubicle/space to 20 persons



Quantity

25m (one way) 50m (one way) 70m (one way)Maximum walking

distance Technically very appropriate Very socially and culturally acceptable

Technically appropriate Socially and culturally acceptable

Technically basic Barely socially and culturally acceptable

Quality

95% of affectedpopulation



Access to facilities

Long-term(3 years)

Short-term(max. 6 months)

Immediate(max. 1 month)

Recommended minimum objectives for safe excreta disposal

Household pit latrines

Communal pit latrines

Open/trench defecation field



Criteria influencing the selection of sanitation systems

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political & institutionalaspects

political & institutionalaspects

Non-technical Aspects


Criteria influencing the selection of sanitation systemsPhysical aspects

Narrow alley: pit emptying difficultFlooded yard


Availability of space (pit emptying) Groundwater level Water availability Climate (temperature, rainfall) Ground conditions (rock, sand, loam, ...)


Criteria influencing the selection of sanitation systemPolitical & institutional aspects


Regulations and standards

Organizational setup and responsibilities

Political will and support

Bureaucracy


Criteria influencing the selection of sanitation systemsFinancial & economical aspects

Construction of baffled reactor

Availability of local skills, manpower & resources

Availability of local materials and tools

Affordable technology

Willingness to pay and appropriate service level

Operation and maintenance

Availability of credits and loans



What are financial and economic costs?

Cost shaped to allow accounting and comparison of treatment plants and management systems.

Cost relevant only for individualhousehold, enterprise or institution. e.g. Price charged to household for pit emptying

Financial costs Economic costs

?


Tank lorry

VIP latrine


How to finance a sanitation programme?

Expensive (realistic?)Feeling of ownership and

responsibility?

Who will get loans? Is money lent actually

spent on sanitation? Organisation and control

needed !

Loans

Two financial tools:

Paid directly to user? Subsidising only components? Subsidising only overhead costs of

sanitation programme?

Concerns:

Can users pay interest rate?Possibility: Subsidized rate of interest

Subsidies



Permits stepwise development

and investment of sanitation system

Permits stepwise development

and investment of sanitation system

Potential of decentralized sanitation systems

Responsiveness to local demandsResponsiveness to local demands

Permits waste segregation

at source

Permits waste segregation

at source

Increases local wastewater reuse

opportunities

Increases local wastewater reuse

opportunities

Tailoring to local conditions

Tailoring to local conditions

Minimizes waste of freshwater

for transportation

Minimizes waste of freshwater

for transportation

Lower risks system failsLower risks system fails



Module 4: Chapter 6

Review




and described






Review

Sanitation involves both, facilities and behaviour. A sanitation system should include all waste products,

from cradle to grave. Only selected combinations of technologies result in a

functional sanitation system. The most appropriate system option has to be selected on

a case-to-case basis, considering hard and soft aspects. Decentralized systems are often more appropriate in

developing countries. Waste products are valuable and should be considered

as resources.

Review


CreditsCredits

Publisher: Eawag, Sandec: Department of Water and Sanitation in Developing Countries, P.O. 611, 8600 Dbendorf, Switzerland, Phone +41 (0)44 823 52 86, Fax +41 (0)44 823 53 99

Editors: Elizabeth Tilley

Concept and Content: Manuel Henseler and Karin Gdel

Layout: Manuel Henseler and Karin Gdel

Copyright: Eawag/Sandec 2008Eawag/Sandec compiled this material, however much of the text and figures are not Eawag/Sandec property and can be obtained from theInternet. The modules of the Sandec Training Tool are not commercialproducts and may only be reproduced freely for non-commercial purposes. The user must always give credit in citations to the original author, sourceand copyright holder. This Powerpoint presentation and its matching lecture notes are availableon the CD of Sandecs Training Tool and can be ordered at: [email protected]

EAWAG SANDEC 2008 Module 4 Sanitation Systems and Technologies - Presentation

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