Sudden or progressive change in the environment adversely affects the lives or living conditions of people who may have been displaced from their origin. When environmental degradation occurs or sudden onset hazards impact vulnerable areas, people may be forced to move and relocate to areas that then require new infrastructure. The new infrastructure should be built to be resilient and strong enough to endure the impact of future natural hazards.

Excluded people hold the least power to influence decision-making. They should be consulted regarding potential environmental impacts and their personal needs and dependencies on the local environment.

Air pollution
Soil pollution
Water pollution
Deforestation
Desertification
Loss of biodiversity and ecosystems
Natural Resource depletion
Soil erosion

Soil loss
Air, water, soil pollution
Loss of water resources
Damage to fragile ecosystems
Health and safety hazards, soil loss, and disease spread from open trenches
Soil loss and disease spread from piled excavated soil

Soil excavation for WASH infrastructure sites can cause soil loss through excess removal of vegetation or ground surface reprofiling, both of which can lead to floods, water or wind erosion of soil, and/or degrading of soil quality. Excavation activities can pollute the air, water, or soil by uncovering toxins or pollutants already within a site or importing them into the construction materials used or crisis waste redistributed on a site. Excavation activities can block or divert watercourses or divert surface water causing excess soil erosion and deposition within watercourses. Poorly managed excavation activities can lead to the partial or total loss of water resources if surface water infiltration is reduced or watercourses diverted away from the site.

Fragile ecosystems can easily be damaged by construction activities through removing flora or fauna that other species rely on, interrupting food chains, disrupting watercourses or drainage pathways, or introducing pollutants (e.g. diesel spills, cement slurry) or pathogens that spread disease amongst flora and fauna.

Open trenches create hazards to adults, children, animals, and vehicles, who may fall into them. They can also lead to soil loss from water flow and disease spread if they harbor stagnant water.

Soil loss and disease spread can also ensue from uncovered piled excavated soil that is left on site for excessive periods.

Minimise soil excavation

Re-use excavated soil on-site wherever possible

Assess crisis or construction waste and imported materials for contaminants

Map and protect watercourses

Map and protect fragile ecosystems

Rebury excavated trenches within 4 days

Manage re-use of excavated soil to avoid excessive runoff or hosting disease vectors

Minimise soil excavation. This can be done by planning WASH facilities sites within existing ground profiles and contours, noting and avoiding watercourses and natural drainage channels and sensitive ecosystems, and minimising vegetation removal. Alternative construction methods can be used that minimise excavation, such as raft foundations or the use of short piles for buildings. Always plan to re-use any excavated soil on-site wherever possible, as long as this can be done without harming any fragile ecosystems on the site. Assess any re-used crisis or construction waste and any imported materials for potential contaminants and ensure contaminants identified are suitably removed and safely disposed of.

Map watercourses and ensure new structures and infrastructure do not divert them or cause excess surface water run-off to enter them. Map the presence of any fragile ecosystems and their specific fragilities and put measures in place to protect them from construction activities.

Excavated trenches should be reburied quickly (maximum 4 days open) to avoid hosting vectors or accidents within the affected communities. Excavated soil must be managed or disposed of to avoid excessive runoff or turning into a potential host for disease vectors. The soil should be re-used locally if possible, or transported to an off-site for another re-use (e.g. construction or landfill cover).

When people want to use a patch of land – for farming, development, or some other purpose – they cut down the trees in that area. Food production is the most common reason for land clearing. This land clearing, also known as deforestation, often occurs so people can raise cattle or other meat sources for consumption, or grow plants for palm oil or soya production.

Deforestation has devastating impacts on the environment on both a small scale and a global scale. In the immediate vicinity, land clearing destroys and fragments habitats, endangers animals, increases soil erosion, contributes to pollution, increases flooding risk, and even exacerbates the effects of climate change. This has happened in many countries including the Amazon and Congo rainforests.

Percentage of decrease in volumes of excavated soil

Prevention of environmental damage

Mitigation of environmental damage

Time for assessing ground conditions, and planning construction methods to reduce or avoid excavation