Geotube – Filtration – October 2018

Organization : Solidarités International

 

Location of the case study


Bangladesh - Cox's Bazaar - Unchiprang camp [get_field_info_custom field='location' type='placeholder']

Main treatment objectives


BOD/COD reduction, Pathogen reduction, Solid/liquid separation, TSS and TDS reduction [get_field_info_custom field='main-treatment-objectives' type='placeholder']

Capex per design input flow


0.05 USD/m3/day

Opex per real input flow


70 USD/m3

Required space


0.15 [get_field_info_custom field='required-space' type='placeholder']

Description of the treatment process

This approach uses a combination of Hydrated Lime Treatment, Geotextile Tubes known as ‘Geotubes’ and Filtration. In the first step, the faecal sludge is pumped out of the pit latrines using mechanical sludge pumps. The sludge is emptied into barrels with a lime (calcium hydroxide: Ca(OH) mix. The stabilised sludge is then poured into a Geotube from barrels through a mesh screen to remove any solid waste. A Geotube consists of a permeable membrane which allows for dewatering of the sludge. The liquid portion of the sludge drains out of the Geotube into a primary filtration unit consisting of three layers of filtration media. This effluent then flows into a secondary filtration unit after which it can be discharged into the environment. The solid fraction of the sludge is retained inside the Geotube and then can be transported to a disposal site or incinerated.

The dried sludge and effluent are not fully stabilized and may require further treatment or storage, depending on the desired end-use.

Short description of the emergency context

Main treatment objectives

BOD/COD reduction, Pathogen reduction, Solid/liquid separation, TSS and TDS reduction

Technologies employed

Geotubes, Gravel filter, Sand filter

Design population

13000 Persons

Design input flow

4 m3/day

Design life

Short term (months)

Source of sludge

Pit latrines affected by groundwater infiltration, Public toilets, Septic tanks

Types of output

Effluent, Sludge

Required space

0.15 [get_field_info_custom field="required-space" type="placeholder"]

Local constraints

Flood prone area, Mountainous topography, Only locally available material

Skills level

Communitarian operation

Capex per design input flow

0.05 USD/m3/day

Real input flow

4 [get_field_info_custom field="real-input-flow" type="placeholder"]

Resources needed for operation

Chemicals [get_field_info_custom field="resources-needed-for-operation" type="placeholder"]

Opex per real input flow

70 USD/m3

COD reduction

97[get_field_info_custom field="cod-reduction" type="placeholder"]

The latrines provided for the refugees are simple pit latrines. Pits are emptied approximately every 4 to 8 weeks depending on the number of users.

In the hilly terrain of Cox’s Bazaar, the transportation of the sludge is challenging and time consuming. The pit latrines are desludged by trained operators using an Oxfam pump (Atalanta Pelican 351 Diaphragm sludge pump with Lombardini 15LD225 diesel engine) with a capacity of approximately 10 min for a 500 L pit. The sludge is transported in a 50 L barrel fixed to a pole and jointly carried by two emptiers (manual transport, see pictures below).

The Lime treatment is carried out in 50 L barrels. Prior to the collection and transport of faecal sludge, 15 g/l lime (CaOH2, 2 kg per barrel) is added to the empty barrels. The faecal sludge from the pit latrines is removed from different ways: manual using buckets, manualy pumped using submersible pump and pumping with dedicated Oxfam trash/sludge pumps, which facilitates the mixing of the lime and the faecal sludge. Bucket desludging is used in place where it’s difficult to access with the heavy Oxfam pump. The lime creates a highly alkaline environment, which results in the inactivation of pathogens and stabilizes the sludge (if the alkaline environment of pH>12 is sustained for at least 1 hour).

From the barrels, the sludge is poured through a screen (to remove any solid waste) and into the Geotube. The time the leachate filters into the sand portion of the filtration unit still need to be determined. The primary filtration units are comprised of three layers of filter media. The bottom layer is 17 cm of coarse gravel 1’’ the second layer is 14 cm of medium size gravel ½’’, topped off by a 20 cm of 2.5 fineness modulus (FM) sand appropriate for filtration. After this filtration phase, the liquid drains through a 6’’ pipe installed below the filtration media and flows through gravity force to a secondary filtration unit comprised of a 20 cm layer of medium size gravel ½’’. The effluent from the secondary filtration phase is then discharged into the environment. The Geotube and primary filtration unit are protected with a roof to keep rain water out of the system. The solid phase of the faecal sludge is retained in the Geotube and is then emptied after a time to be determined. The Geotubes are single use and a new one must be installed after it is emptied. For the final disposal, two options are planned, depending on the final characteristics of the sludge. The first one is direct disposal of the remaining dried sludge into onto land in a nearby area and the second is, incineration of the dried sludge with basic equipment.

The system was developed and designed by the Sanitation Technical Advisor of Solidarités International in coordination with the Faecal Sludge Management Technical Working Group of the WASH Cluster.

There is a risk of contamination of ground water through the discharge effluent, hence the technology needs to be placed in a safe distance from boreholes, wells and other drinking water sources.

Permanent infrastructure is not permitted by the government, therefore WASH infrastructure needs to be able to be decommissioned and the use of construction materials such as bricks or cement is not accepted in the context of Cox’s Bazaar.

The Geotubes are made from membrane material that is either woven and non-woven material. The project team initially piloted the non-woven membrane as it is easily available in Bangladesh and shipping time for woven material is expected to be time consuming (material pictures below). However, woven membranes have been successfully tested and may therefore be preferred, if available. Non-woven materials have mainly been used for dewatering purposes and have less been used for the treatment of sludge. Further materials required are all available in the local market such as: sand, gravel, cement, drainage pipes, bamboo, roofing, tarpaulins and fitting materials.

One Geotextile unit costs approximately 60 USD and has the capacity to treat 60m3 of sludge.

The plant will be decommissioned as it was designed for the relief and early recovery phase only.

The overall operation and maintenance of the system is simple.

Hydrated Lime Treatment requires a barrel to prepare the lime slurry (e.g. a 50 L plastic barrel). For an even distribution of hydrated lime throughout the sludge, constant mixing is required (either manually or with a mixing pump).

A significant amount of manual labor is required, especially for the transport of sludge from the latrines to the treatment site.

At field level, the program manager and the sanitation team (supervisors, officers) are in charge of the implementation and the monitoring. Specific daily operation and maintenance is being conducted by local desludging contractors who manage the transportation of the sludge to the site where the system is located.

The system does not require Energy.

The costs of the locally available Hydrated Lime, geotextile and filter material (sand, cement, gravel) is relatively inexpensive. Salaries are very low. However because of the hilly terrain, transport of the materials adds additional cost and time to the implementation and must be considered. As part of an appropriate health risk management, costs for personal protective equipment and staff trainings need to be considered.

Due to potential health risks when handling Lime, and removal of the dewatered sludge, the process requires trained personnel following health and safety protocols and wearing proper personal protective equipment (PPE). Daily washing and disinfection of all used equipment is required.

Hydrated lime is a powder and corrosive to skin, eyes and lungs. Therefore, adequate PPE must be worn when handling hydrated lime to prevent irritation to eyes, skin, respiratory system, and gastrointestinal tract. Protection from fire and moisture must also be ensured. Lime is an alkaline material that reacts strongly with moisture. Workers must be carefully trained to follow health and safety protocols. The incoming and dewatered sludge of the Geotube contains pathogens; therefore, workers should be equipped with proper PPE. There is no washing facilities available.

The site is protected by a fence and drainage is implemented.

Strengths

  • Low complexity and cost of the system,
  • Non-permanent infrastructure,
  • Rapid implementation,
  • Possibility of scaling up of capacity by adding more geotextile tubes and filter units.
  • Can be constructed using local available material, as long as geotextile is available.

Weaknesses


NC

Lessons learned

It is essential that the community is informed about the risks related to faecal sludge before the desludging process is initiated. The community needs to be aware of the need to keep a safe distance during the operations, for them and their children and can be part of the planned hygiene promotion activities. Additional awareness raising measures are required to avoid pit latrines being used for solid waste. PPE should be worn and training for involved staff is needed to ensure safety and the proper functioning of the technology.

This technology is appropriate for the stabilisation of faecal sludge in the acute phase of an emergency and can be implemented quickly, where the appropriate geotextile and good quality lime (CaOH2) is available. The infrastructure is not permanent. Once there is land available, the capacity of the system can easily be scaled up by increasing the number of barrels, geotextile tubes and infiltration beds. It is effective in decreasing the sludge volume (through dewatering) which is especially important when sludge needs to be transported elsewhere for end-use or disposal.

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Valentina

Hello, I would like to check with you the management cost. As of 21 February 2019 is reported: 70 USD/month/person.
What is this cost including? If “person” is considered number of beneficiaries, it seems not realistic or not sustainable.
Thanks in advance for the clarification

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Location

Definition of the indicator

Country, state and town where feacal sludge management activities are taking place.

References, tips, examples

Bangladesh, Cox’s Bazar
Myanmar, Rakhine State, Sittwe camps

Why is it important to measure it

The case studies are gathered and sorted by location on the website.

Main treatment objectives

Definition of the indicator

The objectives are the main desired treatments or modifications of the input sludge before disposal or reuse.

Unit/value

Solid/liquid separation
Pathogen reduction
BOD/COD reduction
TSS and TDS reduction
Nutrient reduction
Biogas production
Compost production
Other

How to measure or calculate it

Review the design documents or ask the design team or consultant: the objectives are considered to design the faecal sludge treatment site. Usually, the objectives are related to the quality of input sludge and the environmental conditions of disposal sites or the desired output reuse.

References, tips, examples

If the aim is to reuse the wastewater outlet in agriculture, the treatment objectives are solid/liquid separation and pathogen reduction.

Why is it important to measure it

It is a requirement to design the faecal sludge treatment plant and to evaluate the efficiency of the treatment of the wastes by the plant.

Capex per design input flow

Definition of the indicator

This indicator defines the total cost the construction works, including:

– Preliminary and general items (Office and transport contractor and supervisors, security, insurance, electricity supply connection, etc.)
– Purchase of land if relevant
– Civil works
– Electromechanical works: pumps, GenSet, etc.
– Design (typically 5% of Civil & Electromechanical costs)
– Supervision of implementation (typically 5-15% of Civil and Electromechanical costs)

divided by the design input flow.

Unit/value: USD/m3/day

How to measure or calculate it

Review the purchase documents and include the HR costs related to construction. All the expenditure for the construction and installation of a sludge faecal treatment system has to be considered and divided by the design flow (see indicator).

References, tips, examples

Capital expenditure per design flow for faecal sludge treatment sites differs from place to place and depends mostly on transport costs. A treatment plant in inaccessible areas where cement bags need to be flown in can be 10 times more expensive than the same plant in areas where cement can be purchased ‘off the shelf’.

Why is it important to measure it

This indicator is useful to know the cost of construction of a treatment solution, in relation to the volume of sludge treated. This enters in the decision-making process to choose a treatment solution as the amount of money available for construction can be limited.

Opex per real input flow

Definition of the indicator

Operation expenditure includes the daily average of:

– Staff costs
– Energy costs (especially high when electricity needs to be generated separately)
– Chemical costs
– Transport costs
– Administration costs
– Water for cleaning / operating costs
– Personal Protection Equipment costs
– Etc.

divided by real input flow.
This doesn’t include the desludging costs.

Unit/value: USD/m3

How to measure or calculate it

Review the operation and maintenance SOPs, the purchase documents and ask the staff. All the expenditure for operation has to be considered and divided by the real input flow (see indicator). Expenditure for daily, weekly and monthly operation, as well as yearly and extraordinary maintenance should be considered as a daily average. It includes the cost of human resources involved in the operation and maintenance of the plant, but it doesn’t include the costs related to desludging activities.

References, tips, examples

Typical O&M costs for faecal sludge treatment plants around the world are 6-10 USD/m3.

Why is it important to measure it

This indicator is useful to know the economical efficiency of a faecal sludge treatment system.

Required space

Definition of the indicator

This is the space occupied by the faecal sludge treatment site in relationship with the design beneficiary population (see indicator).

Unit/value: m2/person

How to measure or calculate it

Measure in the field (on site) or in the project designs, the total area of the faecal sludge treatment site and divide it by the design population (see indicator).

References, tips, examples

Example:
If the total area of the plant is 500 m2, and the design population is 1600 persons, the required space is 500/1600 = 0,31 m2/person.

Why is it important to measure it

This indicator is useful to know the amount of land needed to implement treatment technologies depending on the design population. In humanitarian contexts, where the population is often obliged to settle in crowded areas with unfavourable environmental conditions, the space available for faecal sludge treatment sites may be limited.

Technologies employed

Definition of the indicator

List of all the treatment technologies employed and making up the fecal sludge treatment plant.

Unit/value

Unplanted drying beds
Planted drying beds
Anaerobic Baffled Reactor
Anaerobic filter
Lime treatment
Constructed wetland
Stabilization ponds
Upflow filters
Geotubes
Activated sludge
Biogas reactor
Trickling filters
Settling-thickening tank
Sedimentation pond
Co-composting
Vermi-composting
Disinfection
Incineration
Infiltration
Other

How to measure or calculate it

Observe on-site or review the design documents or the manual operator to have an exhaustive list of all the treatment modules of the plant. If a module is not on the list, indicate it with the ‘other’ choice.

Why is it important to measure it

This indicator is important to compare treatment plants and evaluate their efficiency.

Design population

Definition of the indicator

Number of people to benefit from the faecal sludge treatment service that was used for the design of the treatment plant.

Unit/value: Persons

How to measure or calculate it

Analyse the current population, its growth and movement trends. In a stable growing population, population to be served can be calculated as follows:
Pn = P0 * (1+i)^n
Pn = Population in year ‘n’
n = design period (refer to design life indicator)
P0 = Population in year 0
i = annual growth of the population
However in humanitarian context, this will usually depend on the security context (forecast of the population affected by the crisis).

References, tips, examples

n = design period = 5 years
P0 = Population in year 0 = 1,000 persons
i = annual growth of the population = 10% influx per year
P5 = 1,000 * (1+0.1)^5 = 1,610 persons, say 1,600

Why is it important to measure it

It is necessary to know the size of the population that needs to be served in order to design the treatment plant correctly and accordingly. It is important to forecast the population growth to better size the facility (tanks, pumps, drying beds, etc.) so that it can answer to the future needs of the population. If the facilities are not designed according to the needs, the construction and operation costs can end up being unnecessarily increased (plant overdesigned) or the treatment results can be poorer (plant underdesigned).

Design input flow

Definition of the indicator

This indicator defines the quantity of sludge per day that the facility can receive according to the design.

Unit/value: m3/day

How to measure or calculate it

Review the design documents or ask to the design team or consultant: the input flow is considered to design the faecal sludge treatment plant. It is based on the design population, knowing that an average individual produces between 0.12 – 0.40 litres of faeces and 0.6 – 1.5 litres of urine per day. For small networks (small bore sewerage, solids free sewerage) where domestic drinking water network is available: it is estimated that 80% of the drinking water supply ends up in the sanitation system.

Why is it important to measure it

This indicator is important to know what inlet flow the plant can receive (mean and maximum). It is used to design the whole facility (tanks, pumps, drying beds, etc.).

Design life

Definition of the indicator

This indicator defines how long the faecal sludge treatment site was designed to last and cover the population needs.

Unit/value:

Short term (months)
Long term (years)

How to measure or calculate it

Identify for how long the plant will cover the population’s needs (see Design population indicator). It depends on immediate and long term needs, population growth and movement trends, donors and implementing actors’ commitments for the future.

Why is it important to measure it

The design life determines the appropriate building material to use and helps planning for upgrades of the plant.

Source of sludge

Definition of the indicator

It defines the type of sanitation infrastructures which the sludge comes from.

Unit/value

Public toilets
Flush latrines
Dry latrines
Septic tanks
Unlined pit latrines
Lined pit latrines
Pit latrines affected by groundwater infiltration
Health facilities
Pits or tanks connected to greywater
Urine diversion toilets
Other

How to measure or calculate it

If they exist, analyse the documents on desludging which report this information, otherwise observe the desludging activities and the sanitation infrastructures which the sludge comes from. Talk with people in charge of desludging.
It is possible to select several answers.

References, tips, examples

For example, the sludge can come from different types of latrines – lined and unlined pit latrines, all being dry latrines and some being public toilets. All four responses need to be ticked.

Why is it important to measure it

This indicator is important to estimate the sludge’s characteristics as it varies depending on the origin of the infrastructure (flush vs dry latrines, affected by groundwater or not, from health facilities, etc.). The design of the plant should be based on the sludge characteristics. For example, the sludge from hospitals is likely to be more hazardous and will need a special treatment.

Types of output

Definition of the indicator

The indicator defines what the main outputs of the faecal sludge treatment site are:
Sludge is a mixture of solids and liquids, containing mostly excreta and water, in combination with sand, grit, metals, trash and/or various chemical compounds.
Effluent is the general term for a liquid that leaves a technology, typically after blackwater or sludge has undergone solids separation or some other type of treatment.
Biogas is the common name for the mixture of gases released from the anaerobic digestion of organic material.
Compost is decomposed organic matter that results from a controlled aerobic degradation process, and is an earth-like, odourless, brown/black material.

Unit/value

Sludge
Effluent
Biogas
Compost

How to measure or calculate it

Review the design documents or observe what the different outputs of the plant are. Several responses can be selected.

References, tips, examples

For example, if there is a solid/liquid separation of the sludge with drying beds followed by a constructed wetland for the liquid outlet treatment, the outputs of the plant are sludge (from the dewatered sludge of the drying beds) and effluent (from the outlet of the constructed wetland).

Why is it important to measure it

Knowing the different outputs enables the creation of specific disposal or end-use systems.

Local constraints

Definition of the indicator

This indicator defines the constraints faced in the area where the treatment plant is located.

Unit/value

High water table
Rocky ground
Flood prone area
Earthquakes
Mountainous topography
Only locally available material
Other

How to measure or calculate it

High water table: check, at the end of rainy season, the groundwater table at the faecal sludge site by digging a pit and/or checking dug wells nearby (in the early morning before water is taken and water level drops). If it’s not possible to do it at the end of the rainy season, ask for information from the local population about the water level in the wells during the year. If there is less than 1m between the water table and the ground level, consider that it is a high water table.
Rocky ground: check if the ground is rocky where the plant is located, thanks to local knowledge of the population, reference documents or by digging a hole next to the treatment plant.
Flood prone area: verify with litterature and local knowledge if a flood occurred in the area next to the faecal sludge treatment site, in the last period equivalent to the design life (see indicator).Take in consideration only the faecal sludge treatment site and not the access to it or the latrines.
Earthquakes: verify with litterature and local knowledge if an earthquake occurred in the area next to the faecal sludge treatment site, in the last period equivalent to the design life (see indicator). Take into consideration only the faecal sludge treatment site and not the access to it or the latrines.
Mountainous topography: the area where the plant is implemented is not flat, there are hills or mountains.
Only locally available material: analyse the purchase documents for the faecal sludge treatment site and identify if only locally available material and equipment were used. Don’t tick the box if material and equipment from abroad were used.
Other: indicate any other constraints faced locally.

Why is it important to measure it

All these constraints will influence the chosen technologies for the treatment plant: construction in areas with a high ground water table requires more complex structures as faecal sludge is composed of contaminants that spread easily and quickly in water; rocky ground will make digging work more complex and expensive; plants in flood prone areas will need extra work to be protected against flooding, as flooding may stop operations for several weeks and/or spread faecal contamination out of the faecal sludge treatment site; plants in earthquake-prone areas will need extra work and consolidation in order to be resistant to earthquakes; a mountainous topography may determine the type of treatment facilities to be built and may influence the transportation and pumping costs; plants contructed and operated only with locally available material reduce costs and are easier to replicate in the same area.

Skills level

Definition of the indicator

This indicates if the knowledge and experience level of an FSM specialist is required to be able to design, contruct, operate and maintain the faecal sludge treatment site successfully.
Communitarian operation means the faecal sludge treatment system is operated exclusively by the beneficiary community without constant external support.

Unit/value: 

FSM specialist for design
FSM specialist for construction
FSM specialist for operation and maintenance
Communitarian operation

How to measure or calculate it

For design: the indicator is determined by assessing the design process and understanding if specialists were involved or not.
For construction: the indicator is determined by assessing the construction process (including selection of contractors or construction staff) and understanding if specific contractors and specialists for special supervision, know-how, equipment use were involved or not.
For operation and maintenance: analyse the CV of the manager of the O&M of the faecal sludge treatment site and identify if he/she has completed higher education related to FSM and if this education is strictly necessary for his/her role.
For community operation: analyse responsibilities and tasks of the faecal sludge treatment site management. Identify if they are covered by the beneficiary community. If there is occasional external support, still consider that the site is completely operated by the community.

References, tips, examples

Example of different design skills in the same context: the design of Oxfam’s large scale faecal sludge treatment site in Cox’s Bazaar was implemented in collaboration with Borda (sanitation experts); Oxfam’s small lime stabilization faecal treatment site was implemented by WASH officers (not FSM specialists).

Why is it important to measure it

This indicator is important to know what kind of skills are needed to have a properly functioning treatment plant, to be able to hire the right people for the task and to select the technologies according to the local skills available.

Real input flow

Definition of the indicator

This indicator is required to know how much sludge is currently treated at the faecal sludge treatment site. It can differ from the design flow and be lower.

Unit/value: m3/day

How to measure or calculate it

Calculate the real input flow by measuring the sludge volume in transport tanks arriving to the faecal sludge treatment site or by measuring the pump flow rates and their time of use (duration of usage) during desludging. Consider an average value including also the days the faecal sludge treatment activities are not running.
If it’s not possible to measure in the field, the input flow is estimated as follows:
For emergency simple pit latrines emptied at regular intervals and with poor pit infiltration: it is estimated to 2.2 lcd (litres per capita per day) (1 for anal cleansing and toilet cleaning + 1.2 for faeces)
For emergency simple pits where effluent can infiltrate and latrines are emptied at regular intervals consider the following sludge accumulation rates:
– Wastes retained in water where water is used as anal cleansing material: 25 litres per capita per year (lcy);
– Wastes retained in water where degradable anal cleansing materials are used: 40lcy;
– Wastes retained in water where non-degradable anal cleansing materials are used: 60lcy;
– Wastes retained in dry conditions where degradable anal cleansing materials are used: 60lcy;
– Wastes retained in dry conditions where non-degradable anal cleansing materials are used: 90lcy.
For pour-flush facilities where water cannot infiltrate and be emptied at regular intervals: it is estimated at 4.2 lcd (2 for additional flush water),
For small networks (small bore sewerage, solids free sewerage) where domestic drinking water network is available: it is estimated that 80% of the drinking water supply ends up in the sanitation system.

References, tips, examples

Examples:
Simple pit latrines emptied at regular intervals and with poor pit infiltration: only water used for anal cleansing and cleaning the toilet enters the receptacle together with the volume of urine and faeces. Typical volume for anal cleansing is 1 litre per person per day (lcd or litres per capita per day). Typical volume of fresh urine and faeces is 1.2 lcd. Hence, for 1.000 people: 1.000 * (1+1.2) = 2,200 litres or 2.2 m3/day;
Pour-flush facility where water cannot infiltrate, emptied at regular intervals: water used for anal cleansing and for manually flushing the toilet enters the receptacle. A typical volume for pour-flush is 2-3 lcd. Hence, for 1,000 people: 1,000 * (3+1.2) = 4,200 litres or 4.2 m3/day;
Small network (small bore sewerage, solids free sewerage) where domestic drinking water network is available: when wastewater is collected, conveyed and treated, usually 80% of the drinking water supply ends up in the system. Hence, if for example drinking water is 25lcd, wastewater is 25 * 0.8 = 20lcd. Hence, for 1,000 people: 1,000 * 20 = 20,000 litres or 20 m3/day.

Why is it important to measure it

The real input flow can be compared with the design flow and upgrades or flow increases can be planned accordingly.

Resources needed for operation

Definition of the indicator

This indicator defines if any resources are needed to operate the treatment plant.

Unit/value

Electricity
Water
Chemicals
Other

How to measure or calculate it

Review the O&M documents or ask the staff to find out if electricity (from solar panels or a generator), addition of water (from wells or piping system) or addition of chemicals (lime, chlorine, etc.) are required to run the regular operation of the plant. Indicate if any other kind of input is needed.

References, tips, examples

Electricity can be required to run aeration in tanks, water can be needed for co-composting, lime can be needed to neutralize pathogens.

Why is it important to measure it

It is useful to decide if a treatment solution is adequate for a specific context, as the resources need to be available and they can increase the cost and complexity of operation.

COD reduction

Definition of the indicator

Chemical oxygen demand (COD) is an indicative measure of the amount of oxygen that can be consumed by reactions in a measured solution. It is commonly expressed in mass of oxygen consumed over volume of solution  (mg/L) and is composed principally of proteins, carbohydrates and fats.
The reduction is related to the COD concentration of the effluent exiting the faecal sludge treatment site in comparison to the COD concentration of the influent entering the faecal sludge treatment site.

Unit/value: %

How to measure or calculate it

The reduction is calculated as a relative percentage of the average COD value of the effluent exiting the faecal sludge treatment site over the average COD value of the influent entering the faecal sludge treatment site in the same period.
% = (1-Ce/Ci) x 100
with Ce = effluent COD concentration (mg/l)
Ci = influent COD concentration (mg/l)

The laboratory test protocol can be found at:
The STeP Global Testing Protocols & Parameters – A best practices guide for testing sanitation technologies in the field
http://stepsforsanitation.org/?smd_process_download=1&download_id=4171

References, tips, examples

If the influent COD concentration of the treatment plant is 3000 mg/l and the effluent COD concentration is 1000 mg/l:
(1-1000/3000) x 100 = 66% of COD reduction.
Influent values example from Zambia: 50,000-100,000mg/l for pit latrines and 10,000-20,000mg/l for septic tanks

Why is it important to measure it

Faecal sludge characteristics vary widely between cities, types of on-site sanitation systems and types of emptying system used. Samples taken from the same pit latrine can have significant variations in standard physio-chemical testing, which impacts how sludge must be treated.
The COD parameter monitors the available oxygen which has a direct impact on aquatic life. If biodegradable organics are discharged untreated to the environment, their biological stabilisation can lead to the depletion of natural oxygen resources and to the development of septic conditions.

Objective

Definition of indicator

The objective, in this case, is the desired treatment or modification of the input sludge before disposal or reuser.

How to measure or calculate it ?

If possible, revise design  document and ask to the design team or consultants: the objective should have been considered to design and dimension the faecal sludge treatment site. Usually, the objective is related to the quality of input sludge and the environmental conditions of disposal sites or the desired reusing methodology.

Why it is important to measure it

This is very important to design the faecal sludge treatment site and to evaluate the efficacy of the treatment.

Organization

Definition of the indicator

Name of the organisation filling in the case study information.

References, tips, examples

Solidarités International
Oxfam

Why is it important to measure it

It gives visibility to the organisation that implemented the treatment plant, and gives the opportunity to contact the NGO for more information.

Faecal coliforms reduction

Definition of ithe ndicator

Faecal coliforms are pathogenic organisms that can transmit diseases. They include genera that originate in feces (e.g. Escherichia) as well as genera not of faecal origin (e.g. Enterobacter, Klebsiella, Citrobacter). It is an indicator of faecal contamination, indicating the presence of other pathogens. E.Coli are part of the feacal coliforms that can be tested. They are commonly expressed in colony forming units over 100mL volume of solution  (CFU/100mL), or in Log (1 log = 1000 CFU/100mL).
The reduction is related to the faecal coliforms concentration of the effluent exiting the faecal sludge treatment site in comparison to the faecal coliforms concentration of the influent entering the faecal sludge treatment site.

Unit/value: Log Reduction

How to measure or calculate it

The reduction is calculated as COMPLEMENTARY PERCENTAGE of the average faecal coliforms of effluent exiting the faecal sludge treatment site over the average faecal coliforms of influent entering the faecal sludge treatment site in the same period.

References, tips, examples

If the number of faecal coliforms in the influent of the treatment plant is 1*10^6 and the number of faecal coliforms in the effluent is 1000:
log10(1*10^6)-log(1000) = 3  Log Reduction.
Example values from Zambia: 2*107 CFU/100ml for pit latrines and 1*105 CFU/100ml for septic tanks

Why is it important to measure it

Faecal sludge characteristics varies widely between cities, types of on site sanitation systems and type of emptying system used. Even samples taken from the same pit latrine have been shown to have significant variation in standard physio-chemical testing.  Such characteristics impact how sludge can be processed following removal. Stabilised sludge is very poor in terms of gas release in an anaerobic digester.

Time construction and commisionning

Definition of the indicator

This indicator refers to the time needed to construct the treatment plant and for the treatment process to be effective.

Unit/value

Days
Weeks
Months
Year

How to measure or calculate it

Consider the whole time needed for the construction of the plant, and add the time needed for the treatment modules to be effective (development of bacteria in ABR, starting period of stabilization ponds, etc.). Provide an estimate: does the whole period approximate to days, weeks, months or one year?

References, tips, examples

The construction of an Anaerobic Baffled Reactor can last a few weeks, but its commissioning time (= time for the treatment to be fully effective) is of about 9 months, with the time needed for the bacteria to develop. So the total time considered will be in months.

Why is it important to measure it

It is an important parameter when choosing the treatment technology, as the time constraint may be critical in the first phases of an emergency.

TS reduction

Definition of the indicator

Total solids is the measurement of the concentration of particulate solids that can dissolve or suspend in wastewater. It is commonly expressed as mass of solids in comparison to volume of solution  (% weight-volume).
The reduction is related to the total solids concentration of the effluent exiting the faecal sludge treatment site in comparison to the total solids concentration of the influent entering the faecal sludge treatment site.

Unit/value: %

How to measure or calculate it

The reduction is calculated as a relative percentage of the average total solids value of the effluent exiting the faecal sludge treatment site over the average total solids value of the influent entering the faecal sludge treatment site in the same period.
% = (1-Ce/Ci) x 100
with Ce = effluent TS concentration (mg/l)
Ci = influent TS concentration (mg/l)

The laboratory test protocol can be found at:
The STeP Global Testing Protocols & Parameters – A best practices guide for testing sanitation technologies in the field
http://stepsforsanitation.org/?smd_process_download=1&download_id=4171

References, tips, examples

Septage (contents of a septic tank) usually has a low percentage of solids (typically 1-2 %) and faecal sludge from pit latrines usually has a high percentage of solids (typically 10-15%). Example values from Zambia: 7-15% for pit latrines and 1-2% for septic tanks.
For example if the influent TS concentration of the treatment plant is 1000 mg/l and the effluent TS concentration is 400 mg/l:
(1-400/1000) x 100 = 60% of TS reduction.

Why is it important to measure it

Faecal sludge characteristics vary widely between cities, types of on-site sanitation systems and types of emptying system used. Samples taken from the same pit latrine can have significant variations in standard physio-chemical testing, which impacts how sludge must be treated.
Suspended solid can lead to the development of sludge deposits and anaerobic conditions when untreated wastewater is discharged in the aquatic environment.
Moreover, as an example, solids content is an important parameter to estimate the volume of dried sludge to be removed from the drying beds of sludge treatment plants.

Indicators notice

Definition of indicator

The objective, in this case, is the desired treatment or modification of the input sludge before disposal or reuser.

How to measure or calculate it ?

If possible, revise design  document and ask to the design team or consultants: the objective should have been considered to design and dimension the faecal sludge treatment site. Usually, the objective is related to the quality of input sludge and the environmental conditions of disposal sites or the desired reusing methodology.

Why it is important to measure it

This is very important to design the faecal sludge treatment site and to evaluate the efficacy of the treatment.

Definition of Indicator

This indicator defines at the moment of design how long the faecal sludge treatment site should be operational..

How to measure or calculate it ?

Identify immediate and long term needs. Analyse population growth and movements trends (see design beneficiary indicator), donors and implementing actors commitments.

References, tips, examples

The size of the population today might be 1,000 persons (often referred to as ‘capita’), but in 1 year this may double and in 5 years this might increase ten-fold; moreover it is important to know how long the facility will need to last to determine the building materials to use.

Why it is important to measure it ?

It is important to know the design period as this will help to calculate the designed beneficiary population (see indicator) of the faecal sludge treatment site. Moreover, it is important to know how long the facility will need to last to determine the building materials to use.

Definition of indicator

This indicates the level of knowledge and experience required to be able to design faecal sludge treatment site successfully.

How to measure or calculate it ?

The indicator is determined by assessing the design process and understanding if specialists were involved or not.

References, tips and/or examples

Example of different design skills in the same context: Design of large scale faecal sludge treatment site of Oxfam in Cox Bazar was implemented in collaboration with Borda (sanitation experts). The small lime stabilization faecal treatment site of Oxfam was implemented by the ‘regular’ WASH officers.

However it’s always preferable to check designs with FSM specialists as in practice the law of Murphy rules: anything that can go wrong, will go wrong.
So for example also during the design of a simple facility such as a septic tank the following mistakes are common:
– inlet and outlet are mixed up;
– plans and cross-sections are mixed up;
– capacity of the facility is far too large;
– absence of ventilation pipes;
– absence of infiltration facilities;
– leaking tanks;
Etc., etc. etc.

Why it is important to measure it ?

Faecal sludge is a potentially dangerous material: a simple mistake impacts the lives of many people
This indicator is important for actors interested in implementing faecal sludge treatment for planning reasons.

Definition of indicator

The indicator defines if the technology also works well if ground-water is less than 1 metre from ground levelat least for a part of the year

How to measure or calculate it ?

Check, at the end of rainy season, the groundwater table at the faecal sludge site by digging a pit and/or checking dug wells nearby (in the early morning before water is taken and water level drops).
If it’s not possible to do it at the end of rainy season, ask for information from the local population about water level in the wells during the year.

References, tips, examples

In areas with high water tables, it might be a challenge to dig pits/ tanks as pumps for keeping the pit dry might be absent. Even if pumps are available, care must be taken to avoid floating of empty tanks. Floating can be avoided by adding enough weight (stones, concrete) to the tank to prevent floating. Hence, above ground / raised facilities are advised such as raised Oxfam tanks.

Why it is important to measure it ?

Faecal sludge is potentially dangerous material and when in contact with water, contaminants will spread easily and quickly. Moreover, construction in areas with high ground water table requires extra measures and more complex structures (expensive).

Definition of indicator

It defines the type of sanitation infrastructures from which the sludge comes from

How to measure or calculate it ?

If existing, analyse the documents of desludging which report this information, otherwise observe the desludging activities and the sanitation infrastructures from which the sludge comes from. Talk with people in charge of desludging.

References, tips, examples

Hospitainer has developed specific solutions for hazardous hospital waste in the framework of S(p) eedkits : https://hospitainer.com/add-ons/sanitation/ . Both IBBK and A-aqua have developed sludge pasteurizers: http://www.a-aqua.no/Products-Services/Humanitarian-Aid/Hygieniser100-Sludge-Pasteurising-Unit ;

Why it is important to measure it ?

It is important to know the source to estimate the characteristics of the sludge and likeliness of contamination with pathogens (of course, any faecal sludge needs to be treated as hazardous material but waste from hospitals is likely to be more hazardous and needs special attention.)

Definition of indicator

Number of people who can benefit from the faecal sludge treatment service.

How to measure or calculate it ?

Analyse current population, its growth and movement trends. In a stable growing population, population to be served can be calculated as follows:
Pn = P0 * (1+i)^n
Pn = Population in year ‘n’ (refer to life expectancy indicator)
n = design period
P0 = Population in year 0
i = annual growth of the population
However in humanitarian context, this will usually depend on the security context (forecast of the population affected by the natural /manmade disaster).

References, tips, examples

Example:
n = design period (say 5 years)
P0 = Population in year 0 (say 1,000)
i = annual growth of the population (say 10% influx per year)]
P5 = 1,000 * (1+0.1)^5 = 1,610 persons, say 1,600

Why it is important to measure it ?

When the population is known, there is a solid basis for sizing the facility: sizing of the tanks AND sizing of any pumps, drying beds, etc.

Definition of indicator

This is the space occupied by the faecal sludge treatment site in relationship with the design beneficiary population (see indicator).

How to measure or calculate it ?

Measure in the field, or in the project designs, the total area of the faecal sludge treatment site and divide it by the design beneficiary population (see indicator).

Why it is important to measure it ?

In humanitarian contexts, the population is often obliged to settle in crowed areas with unfavourable environmental conditions. This has a consequence also on the availability of space for faecal sludge treatment sites and sanitation facilities in general.

Definition of indicator

This indicator, in this case, defines the general slope of the area of the sludge treatment site.

How to measure or calculate it ?

If some types of topography are equally present, please provide multiple answers.

Why it is important to measure it ?

The topography may determine the type of treatment facilities to be built and may influence the transport and pumping costs.

Definition of indicator

This indicator defines for which sludge flow the facility has been designed.

How to measure or calculate it ?

If possible, revise design calculation document and ask the design team or consultants. The design input flow should have been considered for dimensioning. Usually, if it’s not possible to measure in the field, the input flow is estimated as follows:
For emergency simple pit latrines emptied at regular intervals and with poor pit infiltration: it is estimated 2.2 lcd (1 for anal cleansing and toilet cleaning + 1.2 for faeces)
For emergency simple pits where effluent can infiltrate and latrines are emptied at regular intervals consider the following sludge accumulation rates:
 Wastes retained in water where water is used as anal cleansing material: 25 litres per capita per year (lcy);
 Wastes retained in water where degradable anal cleansing materials are used: 40lcy;
 Wastes retained in water where non-degradable anal cleansing materials are used: 60lcy;
 Wastes retained in dry conditions where degradable anal cleansing materials are used: 60lcy;
 Wastes retained in dry conditions where non-degradable anal cleansing materials are used: 90lcy;
For pour-flush facilities where water cannot infiltrate, emptied at regular intervals: it is estimated 4.2 lcd (2 for additional flush water),
For small network (small bore sewerage, solids free sewerage) where domestic drinking water network is available: it is estimated 80% of the drinking water supply ends up in the sanitation system.
For some environmental conditions and infrastructures, groundwater infiltration inside the sanitation facilities should have been considered.

References, tips, examples

Example:
Simple pit latrines emptied at regular intervals and with poor pit infiltration: only water used for anal cleansing and cleaning the toilet enters the receptacle together with the volume of urine and faeces. Typical volume for anal cleansing is 1 litre per person per day (lcd or litres per capita per day). Typical volumes of fresh urine and faeces 1.2 lcd. Hence, for 1.000 people: 1.000 * (1+1.2) = 2,200 litres or 2.2 m3/day;
Pour-flush facility where water cannot infiltrate, emptied at regular intervals: water used for anal cleansing AND manually flushing the toilet enters the receptacle. Typical volume for pour-flush is 2-3 lcd. Hence, for 1,000 people: 1,000 * (3+1.2) = 4,200 litres or 4.2 m3/day;
Small network (small bore sewerage, solids free sewerage) where domestic drinking water network is available. When wastewater is collected and conveyed and treated, usually taken as 80% of the drinking water supply ends up in the system. Hence, if for example drinking water is 25lcd, wastewater is 25 * 0.8 = 20lcd. Hence, for 1,000 people: 1,000 * 20 = 20,000 litres or 20 m3/day.

Why it is important to measure it ?

When the design flow is known, there is a solid basis for sizing the facility: sizing of the tanks AND sizing of any pumps, drying beds, etc. Sludge can easily be much more than the volume of urine and faeces and has a big impact on the sizing. If this is neglected, the facilities are too small and retention / treatment times are shortened, resulting in poor results.

Definition of indicator

The indicator defines if the main outputs of the faecal sludge treatment site are composed only of sludge, effluent or both

How to measure or calculate it ?

Observe if two different outputs originating from solid/liquid separation mechanisms can be distinguished on the basis of their density and solids content.

References, tips, examples

For example, the ratio between the two in the simplest treatment system (sludge drying beds) has been assessed as following:
septage (contents of a septic tank) % of solids (typically 1-2 %)
faecal sludge from pit latrines with a high % of solids (typically 10-15%).
Solids content is an important parameter to estimate the volume of dried sludge to be removed from the drying beds of sludge treatment plants. After 2 weeks drying period the typical solids content is 40% dry solids. Hence, 1 m3 (1,000 litres) of septage containing 1% of dry solids has been decreased to 1,000 *1%/(40%) = 25 kg of biosolids. The remainder (typically 1,000-25 = 975 litres has partially evaporated, partially drained away. The drainage water, say max 975 litres, needs to be treated in a filter / pond system. Also, 1 m3 (1,000 litres) of faecal sludge containing 15% of dry solids has been decreased to 1,000 *15%/(40%) = 375 kg of biosolids. The remainder (typically 1,000-375 = 625 litres has partially evaporated, partially drained away. The drainage water, say max 625 litres, needs to be treated in a filter / pond system

Why it is important to measure it ?

Knowing if there are different outputs enables the creation of specific different treatment chains and disposal mechanisms.

Definition of indicator

Locally available material is material that doesn’t need to be imported.

How to measure or calculate it ?

Analyse the purchase documents for the faecal sludge treatment site and equipment and identify material imported from abroad.

References, tips, examples

Typical imported materials are the raised latrines discussed above, Oxfam tanks for sludge treatment (e.g. lime treatment) and a ‘plug-and-play’ wastewater treatment plant for a hospital.

Why it is important to measure it ?

During the first few days of an emergency, it might be difficult to source local material. Hence, these need to be flown in. However, locally available material should as much as possible be sourced to reduce construction costs.

Definition of indicator

Barrier which doesn’t allow entrance to the faecal sludge treatment site for people, animals, vehicles who are not involved in the treatment operations.

How to measure or calculate it ?

Observe if a fencing is in place all along the perimeter of the faecal sludge treatment site. Identify if there are any weak points which allow people, animals, or vehicles who are not involved in the treatment operations to enter the site.

Why it is important to measure it ?

Adequate fencing is a must under all circumstances in conjunction with 24/7 guards: septage, wastewater and faecal sludge are hazardous material and can easily be used to contaminate the entire community. Think of vandalism by punching a hole in a bladder full of sludge.

Definition of indicator

Drainage are all the systems that avoid water logging and the entrance of run-off water to the faecal sludge treatment site.

How to measure or calculate it ?

Observe if there are specific infrastructures for drainage in the faecal sludge treatment site. Identify if there is any major waterlogging or water run-off which causes surface water contamination or makes the treatment operations difficult.

Why it is important to measure it ?

Adequate drainage is a must under all circumstances to prevent flooding and lead storm water away from the site without major contamination.

Definition of indicator

The indicator defines if the area of the faecal sludge treatment site is affected by flood.

How to measure or calculate it ?

Verify with literature and local knowledge when last flood occurred in the faecal sludge treatment site. The indicator defines if the area of the faecal sludge treatment site has been affected in the last period equivalent to the life expectancy (see indicator) and nothing has been done to avoid flood in the area during construction. The indicator takes in consideration only the faecal sludge treatment site and not the access to it or to latrines.

Why it is important to measure it ?

Faecal sludge is a potentially dangerous material: flooding may stop operations for several weeks and/or spread faecal contamination out of the faecal sludge treatment site.

Definition of indicator

This indicator defines the total of:

– Preliminary and general items (Office and transport contractor and supervisors, security, insurance, electricity supply connection, etc.)
– Purchase of land
– Civil works
– Electromechanical works: pumps, GenSet,
– Design (typically 5% of Civil & Electromechanical costs)
– Supervision of implementation (typically 5-15% of Civil and Electromechanical costs)

divided by current flow.

How to measure or calculate it ?

All the expenditure for the construction and put in place of sludge faecal treatment system have to be considered and divided by the real input flow (see indicator). It includes also a quota of human resources involved in the conception and construction, that can have been involved also in other tasks.

References, tips, examples

A treatment plant in inaccessible areas where cement bags need to flown is easily 10 times more expensive than the same plant in areas where cement can be purchased ‘of the shelf’.

Why it is important to measure it ?

Capital expenditure per real input flow on any faecal sludge treatment site differ from place to place and depends mostly on transport costs.

Definition of indicator

This indicator defines the total of:

– Preliminary and general items (Office and transport contractor and supervisors, security, insurance, electricity supply connection, etc.)
– Civil works
– Electromechanical works: pumps, GenSet,
– Design (typically 5% of Civil & Electromechanical costs)
– Supervision of implementation (typically 5-15% of Civil and Electromechanical costs)

divided by current flow.

How to measure or calculate it ?

All the expenditure for the construction and installation of the faecal sludge treatment system (EXLUDING PURCHASE OF LAND) has to be considered and divided by the real input flow (see indicator). It includes also a quota of human resources involved in the conception and construction, that can also have been involved in other tasks.

References, tips, examples

A treatment plant in inaccessible areas where cement bags need to be flown in is easily 10 times more expensive than the same plant in areas where cement can be purchased ‘off the shelf’.

Why it is important to measure it ?

Capital expenditure per real input flow on any faecal sludge treatment site differs from place to place and depends mostly on transport costs.

Definition of indicator

This indicator defines the level of knowledge and experience required to be able to build a faecal sludge treatment site successfully.

How to measure or calculate it ?

The indicator is determined by assessing the construction process (including selection of contractors or construction staff) and understanding if specific contractors and specialists for special supervision, know-how, equipment were involved or not.

References, tips, examples

Skill level for construction can be reduced by standardization, use of kits and clear and univocal instruction materials.

Why it is important to measure it ?

Faecal sludge is a potentially dangerous material: a simple mistake in infrastructures construction may stop operations for several weeks and affect the sustainability of faecal sludge treatment.

Definition of indicator

Operation expenditure includes the daily average of:

– Staff costs
– Energy costs (especially high when electricity needs to be generated separately)
– Chemical costs
– Transport costs
– Administration costs
– Water for cleaning / operating costs
– Personal Protection Equipment costs
– Etc.

divided by real input flow.
It doesn’t include desludging costs.

How to measure or calculate it ?

All the expenditure for operations has to be considered and divided by the real input flow (see indicator). Also expenditures for extraordinary operations as a daily average should be considered. It also includes a quota of human resources involved in the operations, that can also be involved in other tasks.

References, tips, examples

Typical O&M costs for faecal sludge treatment around the world are USD 6-10 /m3.

Why it is important to measure it ?

It represents the economical efficiency of the faecal sludge treatment systems by comparing daily operational costs with real input flow.

Definition of indicator

This indicator defines the skill level of the manager of the O&M tasks of the faecal sludge treatment site.

How to measure or calculate it ?

Analyse the CV of the manager of the O&M of the faecal sludge treatment site and identify if he/she has an education higher than the compulsory one (high school, university) and if this education is strictly necessary for his/her role.

Why it is important to measure it ?

This indicator provides information on the staff to be hired for the management of the faecal sludge treatment site.

Definition of indicator

This indicator is required to know how much sludge is currently really treated at the faecal sludge treatment site.

How to measure or calculate it ?

Calculate the real input flow by measuring the sludge volume in transport tanks to the faecal sludge treatment site or by measuring the pumps flow rates and their time of use during desludging. Consider an average value including also the days the faecal sludge treatment activities don’t run.

Why it is important to measure it ?

When the real input flow is known, it’s possible to compare it with design input flow and with the output sludge production and give important indications about possible upgrading.

Definition of indicator

This indicator defines how much sludge is produced daily by the faecal sludge treatment site in comparison to real input flow for an average operational period

How to measure or calculate it ?

Measure weight of the sludge produced daily before disposal or reuse out of the sludge treatment site. Divide it by real input flow (see indicator). Consider an average value including also the days faecal sludge treatment activities don’t run.

References, tips, examples

Output sludge production in comparison to sludge input flow can vary a lot according to treatment processes:
Chemical treatment like lime where the volume of sludge does not change (volume sludge in = volume sludge out);
Physical and biological treatment (separation of solids from fluids, aerobic or anaerobic digestion of sludge). Here the volume of sludge decreases drastically to 5-15% of the original volume (see examples).

Why it is important to measure it ?

The volume of sludge is an important parameter in sizing the transportation and disposal system of processed sludge from the faecal sludge treatment site.

Definition of indicator

Biochemical Oxygen Demand (BOD, also called Biological Oxygen Demand) is the amount of dissolved oxygen needed (i.e. demanded) by aerobic biological organisms to break down organic material present in a given water sample at certain temperature over a specific time period. The BOD value is most commonly expressed in milligrams of oxygen consumed per litre of sample during 5 days of incubation at 20 °C (mg/L).
The reduction is related to the BOD of effluent exiting the faecal sludge treatment site in comparison to the BOD of influent entering the faecal sludge treatment site.

How to measure or calculate it ?

The reduction is calculated as COMPLEMENTARY PERCENTAGE of the average BOD of effluent exiting the faecal sludge treatment site over the average BOD of influent entering the faecal sludge treatment site in the same period.

References, tips, examples

The laboratory test protocol can be seen at:
The STeP Global Testing Protocols & Parameters – A best practices guide for testing sanitation technologies in the field
http://stepsforsanitation.org/?smd_process_download=1&download_id=4171
Influent example from Zambia: 25,000-40,000mg/l for pit latrines and 1,000-2,000mg/l for septic tanks
maximum concentration example of liquid effluent as per the ZEMA standard 50mg/l.

Why it is important to measure it ?

Faecal sludge characteristics vary widely between cities, types of on site sanitation systems and type of emptying system used. Even samples taken from the same pit latrine.

Definition of indicator

Chemical oxygen demand (COD) is an indicative measure of the amount of oxygen that can be consumed by reactions in a measured solution. It is commonly expressed in mass of oxygen consumed over volume of solution (mg/L).
The reduction is related to the COD of effluent exiting the faecal sludge treatment site in comparison to the COD of influent entering the faecal sludge treatment site.

How to measure or calculate it ?

The reduction is calculated as COMPLEMENTARY PERCENTAGE of the average COD of effluent exiting the faecal sludge treatment site over the average COD of influent entering the faecal sludge treatment site in the same period.

References, tips, examples

The laboratory test protocol can be seen at:
The STeP Global Testing Protocols & Parameters – A best practices guide for testing sanitation technologies in the field
http://stepsforsanitation.org/?smd_process_download=1&download_id=4171
Influent example from Zambia: 50,000-100,000mg/l for pit latrines and 10,000-20,000mg/l for septic tanks
maximum concentration example of liquid effluent as per the ZEMA standard 50mg/l.

Why it is important to measure it ?

Faecal sludge characteristics vary widely between cities, types of on site sanitation systems and type of emptying system used. Even samples taken from the same pit latrine have been shown to have significant variation in standard physio-chemical testing. Such characteristics impact how sludge can be processed following removal. Stabilised sludge is very poor in terms of gas release in an anaerobic digester.

Definition of indicator

Faecal coliforms are facultatively anaerobic, rod-shaped, gram-negative, non-sporulating bacterium. Coliform bacteria generally originate in the intestines of warm-blooded animals. Faecal coliforms are capable of growth in the presence of bile salts or similar surface agents, are oxidase negative, and produce acid and gas from lactose within 48 hours at 44 ± 0.5°C.The term “thermotolerant coliform” is more correct and is gaining acceptance over “faecal coliform”.
Coliform bacteria include genera that originate in feces (e.g. Escherichia) as well as genera not of faecal origin (e.g. Enterobacter, Klebsiella, Citrobacter). The assay is intended to be an indicator of faecal contamination; more specifically of E. coli which is an indicator microorganism for other pathogens that may be present in feces. They are commonly expressed in colony forming units over 100mL volume of solution (CFU/100mL).
The reduction is related to the faecal coliforms of effluent exiting the faecal sludge treatment site in comparison to the faecal coliforms of influent entering the faecal sludge treatment site.

How to measure or calculate it ?

The reduction is calculated as COMPLEMENTARY PERCENTAGE of the average faecal coliforms of effluent exiting the faecal sludge treatment site over the average faecal coliforms of influent entering the faecal sludge treatment site in the same period.

References, tips, examples

The laboratory test protocol can be seen at:
The STeP Global Testing Protocols & Parameters – A best practices guide for testing sanitation technologies in the field
http://stepsforsanitation.org/?smd_process_download=1&download_id=4171
Influent example from Zambia: 2*107 CFU/100ml for pit latrines and 1*105 CFU/100ml for septic tanks
maximum concentration example of liquid effluent as per the ZEMA standard 2500CFU/100ml.

Why it is important to measure it ?

Faecal sludge characteristics varies widely between cities, types of on site sanitation systems and type of emptying system used. Even samples taken from the same pit latrine have been shown to have significant variation in standard physio-chemical testing. Such characteristics impact how sludge can be processed following removal. Stabilised sludge is very poor in terms of gas release in an anaerobic digester.

Definition of indicator

Total solids are the total dissolved solids (TDS) + total suspended solids (TSS). They are commonly expressed as mass of solids in comparison to volume of solution (% weight-volume).
The reduction is related to the total solids of effluent exiting the faecal sludge treatment site in comparison to the total solids of influent entering the faecal sludge treatment site.

How to measure or calculate it ?

The reduction is calculated as COMPLEMENTARY PERCENTAGE of the average total solids of effluent exiting the faecal sludge treatment site over the average total solids of influent entering the faecal sludge treatment site in the same period.

References, tips, examples

The laboratory test protocol can be seen at:
The STeP Global Testing Protocols & Parameters – A best practices guide for testing sanitation technologies in the field
http://stepsforsanitation.org/?smd_process_download=1&download_id=4171
Septage (contents of a septic tank) is much easier to pump and treat due to the low % of solids (typically 1-2 %) than faecal sludge from pit latrines with a high % of solids (typically 10-15%). Solids content is an important parameter to estimate the volume of dried sludge to be removed from the drying beds of sludge treatment plants. After 2 weeks drying period the typical solids content is 40% dry solids. Hence, 1 m3 (1,000 litres) of septage containing 1% of dry solids has been decreased to 1,000 *1%/(40%) = 25 kg of biosolids. The remainder (typically 1,000-25 = 975 litres has partially evaporated, partially drained away. The drainage water, say max 975 litres, needs to be treated in a filter / pond system. Also, 1 m3 (1,000 litres) of faecal sludge containing 15% of dry solids has been decreased to 1,000 *15%/(40%) = 375 kg of biosolids. The remainder (typically 1,000-375 = 625 litres has partially evaporated, partially drained away. The drainage water, say max 625 litres, needs to be treated in a filter / pond system;
Influent example from Zambia: 7-15% for pit latrines and 1-2% for septic tanks.

Why it is important to measure it ?

Faecal sludge characteristics vary widely between cities, types of on site sanitation systems and type of emptying system used. Even samples taken from the same pit latrine have been shown to have significant variation in standard physio-chemical testing. Such characteristics impact how sludge can be processed following removal. Stabilised sludge is very poor in terms of gas release in an anaerobic digester.
Solids content is an important parameter to estimate the volume of dried sludge to be removed from the drying beds of sludge treatment plants.

Definition of indicator

pH is a logarithmic scale used to specify the acidity or basicity of an aqueous solution. It is approximately the negative of the base 10 logarithm of the molar concentration, measured in units of moles per litre, of hydrogen ions. Indeed it doesn’t have unit measure.
The variation is related to the pH of effluent exiting the faecal sludge treatment site in comparison to the pH of influent entering the faecal sludge treatment site.

How to measure or calculate it ?

The variation is calculated as positive (when effluent pH is higher than influent pH) or negative (when effluent pH is lower than influent pH) difference of the average pH of effluent exiting the faecal sludge treatment site in comparison to the average pH of influent entering the faecal sludge treatment site in the same period.

References, tips, examples

The laboratory test protocol can be seen at:
The STeP Global Testing Protocols & Parameters – A best practices guide for testing sanitation technologies in the field
http://stepsforsanitation.org/?smd_process_download=1&download_id=4171
Influent example from Zambia: 7.5-7.8 for pit latrines and 7.0-7.5 for septic tanks
Example range of liquid effluent as per the ZEMA standard 6-9.

Why it is important to measure it ?

Faecal sludge characteristics vary widely between cities, types of on site sanitation systems and type of emptying system used. Even samples taken from the same pit latrine have been shown to have significant variation in standard physio-chemical testing. Such characteristics impact how sludge can be processed following removal. Stabilised sludge is very poor in terms of gas release in an anaerobic digester.

Definition of indicator

Parasitic worms, also known as helminths, are large macroparasites, which as adults can generally be seen with the naked eye. Many are intestinal worms that are soil-transmitted and infect the gastrointestinal tract. It is an umbrella term that includes many species of worm from different genera. Helminth eggs of concern in wastewater used for irrigation have a size between 20 and 90 μm. They are commonly expressed in number of eggs per gram of solution (n/g).
The reduction is related to the Helminth eggs in the effluent exiting the faecal sludge treatment site in comparison to the Helminth eggs in the influent entering the faecal sludge treatment site.

How to measure or calculate it ?

The reduction is calculated as COMPLEMENTARY PERCENTAGE of the average Helminths eggs in the effluent exiting the faecal sludge treatment site over the average Helminth eggs in the influent entering the faecal sludge treatment site in the same period.

References, tips, examples

The laboratory test protocol can be seen at:
The STeP Global Testing Protocols & Parameters – A best practices guide for testing sanitation technologies in the field
http://stepsforsanitation.org/?smd_process_download=1&download_id=4171
It is very difficult to inactivate helminth eggs, unless temperature is increased above 40 °C or moisture is reduced to less than 5%.

Why it is important to measure it ?

Helminth eggs (or ova) are a good indicator organism to assess the safety of sanitation reuse systems for resource recovery because they are the most environmentally resistant faecal pathogens and they can in extreme cases survive for several years in soil.

Definition of indicator

The indicator defines if the faecal sludge treatment system is operated exclusively by the beneficiary community without any constant external support.

How to measure or calculate it ?

Analyse responsibilities and tasks of the faecal sludge treatment site management. Identify if they are all cover by the beneficiary community or part of it. If there is occasional external support, still consider that the site is completely operated by the community.

Why it is important to measure it ?

It is important to know the complexity of operations in relation to the skills of the community in order to plan the faecal treatment site management and forecast long-term sustainability.

Definition of indicator

The indicator defines if washing capacities are available for the faecal sludge treatment workers.

How to measure or calculate it ?

Analyse if washing capacity (with adequate privacy and supplied with enough water and soap/chlore) are available and accessible at the key moments (before eating or drinking and before leaving the faecal sludge treatment site).

Why it is important to measure it ?

Washing capacity is key to protect the health of faecal sludge treatment workers and their family.

Definition of indicator

The indicator defines if Personal Protection Equipment (PPEs) are available for the faecal sludge treatment workers and potential visitors.

How to measure or calculate it ?

Analyse if Personal Protection Equipment (PPE) are available, accessible and frequently washed or replaced.

Why it is important to measure it ?

PPEs are key to protect the health of faecal sludge treatment workers and their family.

Definition of indicator

This indicator defines the level of knowledge and experience required to be able to upgrade or decommission the faecal sludge treatment site successfully.

How to measure or calculate it ?

The indicator is determined by forecasting an eventual upgrading or decommissioning phase taking lessons learnt from the construction process (including selection of contractors or construction staff). Should specific contractors and specialists be involved for special supervision, know-how, equipment?

Why it is important to measure it ?

Faecal sludge is a potential dangerous material: a simple mistake in infrastructures construction may stop operations for several weeks and affect the sustainability of faecal sludge treatment. For the same reason, decommissioning and disposal of faecal sludge treatment infrastructures and equipment can contaminate the environment and affect population living around the disposal site or dismissed faecal sludge treatment site.