Virtual Environmental and Humanitarian Adviser Tool – (VEHA Tool) is a tool
to easily integrate environmental considerations in humanitarian response. Field Implementation guidances are useful for the design and execution of humanitarian activities in the field.

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VEHA - Field Implementation Guidance

Water supply, Sanitation and Hygiene Promotion (WASH)
Access to sanitation
Wastewater management (estimation, separation, transportation, treatment, reuse, discharge)
Use and rehabilitation of existing sewage systems

Use and rehabilitation of existing sewage systems


Environmental factors causing/contributing to the needs and affecting the humanitarian activity

Water pollution can affect people’s health. Bacterial, viral and parasitic diseases such as typhoid, cholera, encephalitis, poliomyelitis, hepatitis, skin infection, and gastrointestinal diseases can spread through polluted water increasing the probabilities of overloading the capacity of excreta management systems due to diarrhoeal and vomiting cases. This impacts efficiency and capacity (that is increased amount of excreta generated due to health burdens).

In addition, close proximity of water tubewells and latrines together with soil porosity, ground water table, topography, drainage, and stability of slopes, may result in pollution of wells from surface water, sewage, solid waste leachates, chemical spills, etc and subsequent sickness or disease.

Gender, age, disability and HIV/AIDS implications

People who have less power in communities are usually those who are served by the worst infrastructure. Septic tank and cesspit overflows, storm spillages, and failure of sewerage networks are more likely to impact the poor and vulnerable greatest.


Environmental impact categories

Air pollution
Soil pollution
Water pollution
Loss of biodiversity and ecosystems

Summary of Impacts
Summary of potential environmental impacts

Water and soil pollution due to spills and leakages caused by sewage system overflows (exceeding the carrying capacity of the system) or due to inappropriate disposal of waste.

Impact detail
Detailed potential environmental impact information

Depending on the design capacity of an existing sewerage system, it may become overloaded if there is an influx of people, or new connections are made to it, or if it is not regularly emptied and maintained. If a new connection is made at a point already subject to peak flows, or where specific retention times are required for the waste, sewage spillage can occur which can pollute the surface, surface water, and ground water.

Inappropriate disposal of waste (e.g. sanitary towels, nappies, or even toilet paper) may cause blockages, backflow, and spills or inhibit sewage processing in the case of septic tanks.


Summary of environmental activities

Consult local authorities and the water/sewerage utilities to identify critical points in sewerage systems that could be affected by a sudden increase in flows from the affected populations.

Otherwise, model existing sewerage networks to estimate capacities, and if possible use CCTV to investigate conditions prior to agreeing to rehabilitate, upgrade or add new connections.

Detailed guidance for implementing suggested environmental activities

Inspect the existing sewerage system and consult with local authorities and the water/wastewater utility regarding capacities, conditions, and any critical points in the system.

Otherwise, survey and model the sewerage network to identify conditions, necessary repairs, capacities, and potential for expansion.

Verify which are the most suitable points to make new connections in order to avoid overloading the system and causing any spillages to the surrounding environment.

Provide community awareness/sensitization regarding items that can / cannot be disposed of through sewage system and provide alternative disposal methods for them.

Lessons Learnt
Lessons from past experiences

In Bangladesh, there has been insufficient capacity to treat sewage and septage, and a lack of capacity to remove and treat sludge from sewage treatment facilities. This has led to much sewage being insufficiently treated and ground water pollution. This is being addressed with the gradual provision of water supply networks.

Activity Measurement
Environmental indicators/monitoring examples

Existing capacity and condition assessed prior to extending or increasing flows.

Activity status
Main Focus
Focus of suggested activities

Prevention of environmental damage

Resource implications (physical assets, time, effort)

Time to consult utility owners and assess sewerage system condition and capacity or inspect and model network to estimate capacities and condition.

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