Difference between revisions of "Motorized Emptying and Transport"

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|{{Language-box|english_link=Motorized_Emptying_and_Transport|french_link=Vidange_et_Transport_motorisés|spanish_link=Vaciado_y_Transporte_Motorizado|hindi_link=coming soon|malayalam_link=coming soon|tamil_link=coming soon | korean_link=coming soon | chinese_link=Coming soon | indonesian_link=Coming soon | japanese_link=Coming soon}}
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sys4=[[ Sewerage System with Urine Diversion|8]]|
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Input1=Faecal Sludge|Input2=Urine |Input3=Blackwater| Input4= |Input5=|
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Input1=Sludge|Input2=Urine |Input3=Blackwater| Input4=Effluent |Input5=Stored Urine|
Output1= Faecal Sludge |Output2= Urine | Output3= Blackwater | Output4= | Output5=
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Output1= Sludge |Output2= Urine | Output3= Blackwater | Output4=Effluent | Output5=Stored Urine
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'''Motorized Emptying and Transport refers to a vacuum truck or another vehicle equipped with a motorized pump and a storage tank for emptying and transporting faecal sludge, septage and urine. Humans are required to operate the pump and manoeuvre the hose, but they do not lift or transport the sludge.'''
 
  
The pump is connected to a hose that is lowered down into a constructed tank (e.g. septic tank or aquaprivy) or pit, and the sludge is pumped up into the holding tank on the truck. Generally the storage capacity of a vacuum tanker is between 3,000 and 10,000L. Multiple truckloads may be required for large septic tanks.
+
'''Motorized emptying and transport refers to a vehicle equipped with a motorized pump and a storage tank for emptying and transporting faecal sludge and urine. Humans are required to operate the pump and manoeuvre the hose, but sludge is not manually lifted or transported.'''
  
Both the agencies responsible for sewerage and private entrepreneurs may operate vacuum trucks, although the price and level of service may vary significantly. Some public operators may not service informal settlements, whereas some private operators may offer a reduced price, but can only afford to do so if they do not empty the sludge at a certified facility. The cost of hiring a vacuum truck can sometimes be the most expensive part of operating a sanitation system for some homeowners.
+
A truck is fitted with a pump which is connected to a hose that is lowered down into a tank (e.g., [[Septic Tank | Septic Tank]], S.9) or pit, and the sludge is pumped up into the holding tank on the vehicle. This type of design is often referred to as a vacuum truck. Alternative motorized vehicles or machines have been developed for densely populated areas with limited access. Designs such as the Vacutug, Dung Beetle, Molsta or Kedoteng carry a small sludge tank and a pump and can negotiate narrow pathways.
  
===Vacutug===
+
===Design Considerations===
The UN-HABITAT Vacutug Project was conceived in 1995 with the goal of developing ‘fully sustainable system for emptying pit latrines in unplanned, periurban areas and refugee camps in the developing countries’. The Vacutug consists of a 500 litre steel vacuum tank connected to vacuum pump which is connected to a gasoline engine that has the capacity to remove sludge (or urine) at 1,700 litres a minute. On level ground, the vehicle is capable of around 5km/h. The waste sludge can be discharged under gravity or by slight pressurization from the pump. Recent results indicate that under certain circumstances (constant number of pits, transfer station, short transfer distance, etc.) the Vacutug can be sustainable and cover its operating and maintenance costs.
+
Generally, the storage capacity of a vacuum truck is between 3 and 12 m3. Local trucks are commonly adapted for sludge transport by equipping them with holding tanks and pumps. Modified pick-ups and tractor trailers can transport around 1.5 m3, but capacities vary. Smaller vehicles for densely populated areas have capacities of 500 to 800 L. These vehicles use, for example, two-wheel tractor or motorcycle based drives and can reach speeds of up to 12 km/h.
 +
 
 +
Pumps can usually only suck down to a depth of 2 to 3 m (depending on the strength of the pump) and must be
 +
located within 30 m of the pit. In general, the closer the vacuum pump can be to the pit, the easier it is to empty.
 +
 
 +
====Vacutug====
 +
The UN-HABITAT Vacutug Project was conceived in 1995 with the goal of developing ‘fully sustainable system for emptying pit latrines in unplanned, peri-urban areas and refugee camps in the developing countries’. The Vacutug consists of a 500 litre steel vacuum tank connected to vacuum pump which is connected to a gasoline engine that has the capacity to remove sludge (or urine) at 1,700 litres a minute. On level ground, the vehicle is capable of around 5km/h. The waste sludge can be discharged under gravity or by slight pressurization from the pump. Recent results indicate that under certain circumstances (constant number of pits, transfer station, short transfer distance, etc.) the Vacutug can be sustainable and cover its operating and maintenance costs.
  
 
A manually operated version of the Vacutug is the [[Human-Powered Emptying and Transport#MAPET|MAPET]].
 
A manually operated version of the Vacutug is the [[Human-Powered Emptying and Transport#MAPET|MAPET]].
  
{{procontable | pro=
+
<br>
- Fast, and generally efficient. <br> - Potential for local job creation and income generation. <br> - Provides essential service to unsewered areas. | con=
+
{{procontable  
- Cannot pump thick dried sludge (must be manually removed or thinned with water). <br> - Garbage in pits may block hose. <br> - Very high capital costs; variable operating costs depending on use and maintenance. <br> - Pumps can usually only suck down to a depth of 2 to 3m and the pump must be located within 30m of the pit. <br> - Not all parts and materials may be available locally. <br> - May have difficulties with access.
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| pro=
 +
- Fast, hygienic and generally effective sludge removal <br>
 +
- Efficient transport possible with large vacuum trucks <br>
 +
- Potential for local job creation and income generation <br>
 +
- Provides an essential service to unsewered areas
 +
| con=
 +
- Cannot pump thick, dried sludge (must be thinned with water or manually removed) <br>
 +
- Garbage in pits may block hose <br>
 +
- Cannot completely empty deep pits due to limited suction lift <br>
 +
- Very high capital costs; variable operating costs depending on use and maintenance <br>
 +
- Hiring a vacuum truck may be unaffordable for poor households <br>
 +
- Not all parts and materials may be locally available <br>
 +
- May have difficulties with access
 
}}
 
}}
  
==Adequacy==
+
===Appropriateness===  
 
+
Depending on the Collection and Storage technology, the sludge can be so dense that it cannot be easily pumped. In these situations it is necessary to thin the solids with water so that they flow more easily, but this may be inefficient and costly. Garbage and sand make emptying much more difficult and clog the pipe or pump. Multiple truckloads may be required for large Septic Tanks.
Although smaller more mobile vehicles have been developed, large vacuum trucks remain the norm for municipalities and sanitation authorities. Unfortunately, large trucks cannot access all pits/septic tanks especially in areas with narrow or non-driveable roads. Also, vacuum trucks can rarely make trips to peri-urban or rural areas since the income generated from emptying, may not offset the cost of fuel and time.  
 
  
Depending on the collection or treatment technology, the material that needs to be pumped can be so dense that it cannot be pumped easily. In these situations it is necessary to thin the solids with water so that they flow more easily, but this may be inefficient and costly. If water is not available, it may be necessary for the waste to be manually removed. In general, the closer the vacuum can be to the pit, the easier it is to empty. The critical velocity of the sludge required for pumping is dependent on the distance from, and strength of, the vacuum pump; sludge is extremely site specific. Garbage and sand also makes emptying the pit much more difficult.
+
Although large vacuum trucks cannot access areas with narrow or non-drivable roads, they remain the norm for municipalities and sanitation authorities. These trucks can rarely make trips to remote areas (e.g., in the periphery of a city) since the income generated may not offset the cost of fuel and time. Therefore, the treatment site must be within reach from the serviced areas. [[Transfer Station - Underground Holding Tank | Transfer Stations]] (C.7) and adequate treatment are also crucial for service providers using small-scale motorized equipment. Field experiences have shown that the existing designs for dense urban areas are limited in terms of their emptying effectiveness and travel speed, and their ability to negotiate slopes, poor roads and very narrow lanes. Moreover, demand and market constraints have prevented them from becoming commercially viable.
  
==Health Aspects/Acceptance==
+
Under favourable circumstances, small vehicles like the Vacutug are able to recover the operating and maintenance costs. However, the capital costs are still too high to sustainably run a profitable business. Both the sanitation authority and private entrepreneurs may operate vacuum trucks, although the price and level of service may vary significantly. Private operators may charge less than public ones, but may only afford to do so if they do not discharge the sludge at a certified facility. Private and municipal service providers should work together to cover the whole faecal sludge
 +
management chain.
  
The use of a vacuum tanker for emptying a pit latrine or [[Septic Tank]] presents two health improvements: (1) emptying maintains the Collection and Storage/Treatment technology and reduces the risk of overflows and (2) the use of a tanker reduces the need for manual emptying, which is quite unsafe and unhygienic. Still, those who operate vacuum trucks may be demonized by the community and may face difficulties with finding appropriate locations to dump and treat the collected sludge.
+
===Health Aspects/Acceptance===
 +
The use of a vacuum truck presents a significant health improvement over manual emptying and helps to maintain the Collection and Storage technology. Still, truck operators are not always accepted by the community and may face difficulties with finding appropriate locations to dump the collected sludge.
  
==Maintenance==
+
===Operation & Maintenance===
 +
Most pump trucks are manufactured in North America, Asia or Europe. Thus, in some regions it is difficult to locate spare parts and a mechanic to repair broken pumps or trucks. New trucks are very expensive and sometimes difficult to obtain. Therefore, older trucks are often used, but the savings are offset by the resulting high maintenance and fuel
 +
costs that can account for more than two thirds of the total costs incurred by a truck operator. Truck owners must be conscientious to save money for the purchase of expensive replacement parts, tires and equipment. The lack of preventive maintenance is often the cause for major repairs. The addition of chemical additives for desludging is not recommended because they tend to corrode the sludge tank.
  
Maintenance is a crucial part of vacuum truck operation. Trucks are not usually brand new and they often require constant attention to prevent breakdowns. The lack of preventive maintenance is often the cause for major repairs. Most pump trucks are manufactured in North America or Europe. As such, it is difficult to locate spare truck parts and a local mechanic to repair broken pumps and trucks. New trucks are difficult to obtain, very expensive and thus rarely purchased. Local trucks are commonly adapted to serve as vacuum trucks by equipping them with holding tanks and vacuums. Maintenance accounts for at least one quarter of the costs incurred by the operator of a vacuum truck. Fuel and oil account for another quarter of the total operating costs. Owners/operators must be conscientious to save money for the purchase of expensive replacement parts, tires and equipment, whose replacement could be essential to the working of the vacuum truck.
+
===References===
 +
* Boesch, A. and Schertenleib, R. (1985). [https://www.susana.org/en/knowledge-hub/resources-and-publications/library/details/3091 Emptying on-Site Excreta Disposal Systems. Field Tests with Mechanized Equipment in Gaborone (Botswana)]. International Reference Centre for Waste Disposal, Dübendorf, CH. (Comprehensive summary of technical components, performance with different sludge types, and maintenance)
  
==Acknowledgements==
+
* Chowdhry, S. and Koné, D. (2012). [https://www.susana.org/en/knowledge-hub/resources-and-publications/library/details/1662 Business Analysis of Fecal Sludge Management: Emptying and Transportation Services in Africa and Asia]. Bill & Melinda Gates Foundation, Seattle, US.
{{:Acknowledgements Sanitation}}
 
  
==References and external links==
+
* O’Riordan, M. (2009). [https://www.susana.org/en/knowledge-hub/resources-and-publications/library/details/1424 Investigation into Methods of Pit Latrine Emptying. Management of Sludge Accumulation in VIP Latrines]. WRC Project 1745, Water Research Commission, Pretoria, ZA. (Includes a detailed analysis of field experiences with the Vacutug)
  
* Brikké, F. and Bredero, M. (2003). Linking technology choice with operation and maintenance in the context of community water supply and sanitation: A reference document for planners and project staff. WHO and IRC Water and Sanitation Centre, Geneva. Available: http://www.who.int (Chapter 8 provides an assessment of vacuum emptying.)
+
* Strande, L., Ronteltap, M. and Brdjanovic, D. (Eds.) (2014). Faecal Sludge Management. Systems Approach for Implementation and Operation (book). IWA Publishing, London, UK.
  
* Boesch, A. and Schertenleib, R. (1985). Pit Emptying On- Site Excreta Disposal Systems. Field Tests with Mechanized Equipment in Gaborone (Botswana). IRCWD, Switzerland. Available: www.sandec.ch (Comprehensive summary of technical components, performance with different sludge types, and maintenance.)
+
===Acknowledgements===
 
+
{{:Acknowledgements Sanitation}}
* Issaias, I. (2007). UN-HABITAT Vacutug Development Project: Technical report of field trials 2003–2006. Water, Sanitation and Infrastructure Branch, UN-HABITAT, Nairobi, Kenya.
 

Latest revision as of 19:29, 24 February 2021

English Français Español भारत മലയാളം தமிழ் 한국어 中國 Indonesia Japanese
Applicable in systems:
1 , 4 , 5 , 6 , 7 , 9
Level of Application
Household XX
Neighbourhood XX
City X

 

Inputs
Sludge, Urine, Blackwater, Effluent, Stored Urine


Level of management
Household
Shared X
Public XX

 

Outputs
Sludge, Urine, Blackwater, Effluent, Stored Urine
Motorized emtying and transport.png




Icon motorized emptying and transport.png

Motorized emptying and transport refers to a vehicle equipped with a motorized pump and a storage tank for emptying and transporting faecal sludge and urine. Humans are required to operate the pump and manoeuvre the hose, but sludge is not manually lifted or transported.

A truck is fitted with a pump which is connected to a hose that is lowered down into a tank (e.g., Septic Tank, S.9) or pit, and the sludge is pumped up into the holding tank on the vehicle. This type of design is often referred to as a vacuum truck. Alternative motorized vehicles or machines have been developed for densely populated areas with limited access. Designs such as the Vacutug, Dung Beetle, Molsta or Kedoteng carry a small sludge tank and a pump and can negotiate narrow pathways.

Design Considerations

Generally, the storage capacity of a vacuum truck is between 3 and 12 m3. Local trucks are commonly adapted for sludge transport by equipping them with holding tanks and pumps. Modified pick-ups and tractor trailers can transport around 1.5 m3, but capacities vary. Smaller vehicles for densely populated areas have capacities of 500 to 800 L. These vehicles use, for example, two-wheel tractor or motorcycle based drives and can reach speeds of up to 12 km/h.

Pumps can usually only suck down to a depth of 2 to 3 m (depending on the strength of the pump) and must be located within 30 m of the pit. In general, the closer the vacuum pump can be to the pit, the easier it is to empty.

Vacutug

The UN-HABITAT Vacutug Project was conceived in 1995 with the goal of developing ‘fully sustainable system for emptying pit latrines in unplanned, peri-urban areas and refugee camps in the developing countries’. The Vacutug consists of a 500 litre steel vacuum tank connected to vacuum pump which is connected to a gasoline engine that has the capacity to remove sludge (or urine) at 1,700 litres a minute. On level ground, the vehicle is capable of around 5km/h. The waste sludge can be discharged under gravity or by slight pressurization from the pump. Recent results indicate that under certain circumstances (constant number of pits, transfer station, short transfer distance, etc.) the Vacutug can be sustainable and cover its operating and maintenance costs.

A manually operated version of the Vacutug is the MAPET.


Advantages Disadvantages/limitations
- Fast, hygienic and generally effective sludge removal

- Efficient transport possible with large vacuum trucks
- Potential for local job creation and income generation
- Provides an essential service to unsewered areas

- Cannot pump thick, dried sludge (must be thinned with water or manually removed)

- Garbage in pits may block hose
- Cannot completely empty deep pits due to limited suction lift
- Very high capital costs; variable operating costs depending on use and maintenance
- Hiring a vacuum truck may be unaffordable for poor households
- Not all parts and materials may be locally available
- May have difficulties with access


Appropriateness

Depending on the Collection and Storage technology, the sludge can be so dense that it cannot be easily pumped. In these situations it is necessary to thin the solids with water so that they flow more easily, but this may be inefficient and costly. Garbage and sand make emptying much more difficult and clog the pipe or pump. Multiple truckloads may be required for large Septic Tanks.

Although large vacuum trucks cannot access areas with narrow or non-drivable roads, they remain the norm for municipalities and sanitation authorities. These trucks can rarely make trips to remote areas (e.g., in the periphery of a city) since the income generated may not offset the cost of fuel and time. Therefore, the treatment site must be within reach from the serviced areas. Transfer Stations (C.7) and adequate treatment are also crucial for service providers using small-scale motorized equipment. Field experiences have shown that the existing designs for dense urban areas are limited in terms of their emptying effectiveness and travel speed, and their ability to negotiate slopes, poor roads and very narrow lanes. Moreover, demand and market constraints have prevented them from becoming commercially viable.

Under favourable circumstances, small vehicles like the Vacutug are able to recover the operating and maintenance costs. However, the capital costs are still too high to sustainably run a profitable business. Both the sanitation authority and private entrepreneurs may operate vacuum trucks, although the price and level of service may vary significantly. Private operators may charge less than public ones, but may only afford to do so if they do not discharge the sludge at a certified facility. Private and municipal service providers should work together to cover the whole faecal sludge management chain.

Health Aspects/Acceptance

The use of a vacuum truck presents a significant health improvement over manual emptying and helps to maintain the Collection and Storage technology. Still, truck operators are not always accepted by the community and may face difficulties with finding appropriate locations to dump the collected sludge.

Operation & Maintenance

Most pump trucks are manufactured in North America, Asia or Europe. Thus, in some regions it is difficult to locate spare parts and a mechanic to repair broken pumps or trucks. New trucks are very expensive and sometimes difficult to obtain. Therefore, older trucks are often used, but the savings are offset by the resulting high maintenance and fuel costs that can account for more than two thirds of the total costs incurred by a truck operator. Truck owners must be conscientious to save money for the purchase of expensive replacement parts, tires and equipment. The lack of preventive maintenance is often the cause for major repairs. The addition of chemical additives for desludging is not recommended because they tend to corrode the sludge tank.

References

  • Strande, L., Ronteltap, M. and Brdjanovic, D. (Eds.) (2014). Faecal Sludge Management. Systems Approach for Implementation and Operation (book). IWA Publishing, London, UK.

Acknowledgements

Eawag compendium cover.png

The material on this page was adapted from:

Elizabeth Tilley, Lukas Ulrich, Christoph Lüthi, Philippe Reymond and Christian Zurbrügg (2014). Compendium of Sanitation Systems and Technologies, published by Sandec, the Department of Water and Sanitation in Developing Countries of Eawag, the Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland.

The 2nd edition publication is available in English. French and Spanish are yet to come.