VEHA
Guidance
Guidance
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.
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.
Soil and water pollution and eutrophication contaminants usually impact the poorest and most vulnerable members of society as they have less money and access to cleaner water.
Soil pollution
Water pollution
Eutrophication
Loss of biodiversity and ecosystems
Soil pollution and water pollution and eutrophication due to the indiscriminate discharge of wastewater.
Discharge of wastewater into water bodies can harm local aquatic ecosystems and prevent the water from being used for drinking, cooking, bathing, or agricultural purposes. Pollution of water bodies with untreated wastewater can result in eutrophication (loss of aquatic life) and can contaminate the soil.
Test any discharged water and capture or divert it and ensure either contaminants are removed at source or the wastewater is treated before discharge.
The quality of the wastewater should be tested to understand the potential health and environmental impacts and to inform the design of any drainage and wastewater treatment system. Wastewater quality should be compared to the relevant discharge standards and should be tested at the point of convergence.
As automated chemical wastewater treatment facilities are not always feasible, low-cost alternatives such as natural filtration beds or constructed wetlands could be explored.
Percolation beds, soak pits or infiltration basins (with vegetation) can enable groundwater recharge whilst filtering out some harmful contaminants, providing some protection to nearby surface water bodies and groundwater resources. 2-3m of unsaturated soil is required to provide some level of natural filtration.
Regular water quality testing should be performed to ensure that the discharge from the wastewater system complies with the relevant effluent standards. Strategies should be in place to manage or respond to situations where water quality is outside of permissible effluent standards, including the provision of additional treatment steps or source identification and prevention of water pollutants.
If cultivated in High Rate Algal Ponds (HRAPs), microalgae can both treat wastewater and be a source of biofuel. The algae grown in wastewater treatment processes can be extracted and used as feedstock for fuel through anaerobic respiration for biogas, lipids to biofuel, or carbohydrate fermentation to bioethanol.
This option is attractive for its reuse of resources: HRAP systems which exclusively cultivate feedstock for biofuel are more costly and resource-intensive than land-based biofuel sources, however, if combined with wastewater treatment, nutrients and water that would otherwise be wasted can be put to use (Park et al. 2011). Pittman et al. refer to a species of Chlorella grown in a municipal wastewater oxidation pond in India to demonstrate the effect that additional nutrient inputs have on biomass. Acting as a photoheterotroph, the algae produced biomass of 379 mg/L after 10 days, compared to 73.03 mg/L as a photoautotroph (Pittman et al. 2011). This suggests that in an HRAP system, algae could be a viable source of biomass production. Additionally, high CO2 content produces greater biomass.
If anaerobic digestion produces biogas on-site, the exhaust from that energy generation could be used as a CO2 input, making the system up to two times more productive with proper amounts of CO2 (Park et al. 2011). While a number of other factors contribute to algal biomass production including algal species, pH of the water, light saturation, lipid production, and nutrient availability, with proper design, experimentation, and implementation, these parameters can be addressed.
When cultivated in partnership with wastewater treatment, algae can be a feedstock source for biogas, simultaneously providing sustainable energy and reducing the effects of eutrophication. Though more research is needed to determine the practicality of joint wastewater-biogas projects, many high-rate algal ponds are currently used on a small scale for water treatment, particularly in small communities (Park et al. 2011). Potential lies within using the algae grown as a fuel source, which would reduce water and arable land used currently to grow soy and corn for bio-ethanol, and reduce the effects of eutrophication by consuming nitrogen and phosphorous before it reaches the ocean.
Percentage of water that is discharged into the environment following environmental guidelines
Mitigation of environmental damage
Time and budget for effluent testing and any additional treatment.