Groundwater is water that is present beneath the earth’s surface and is either contained within soil or cracks in rock formations. It includes significant deposits of water, as well as moisture and frost.
Groundwater is frequently used as a source of drinking water, both to supply private wells and for public water utilities.
Safeopedia Explains Groundwater
The structural integrity of soil is heavily influenced by the amount and type of groundwater that soil contains, as well as environmental effects that impact the interactions between the water and its container (e.g. temperature variability).
Groundwater is an important safety consideration on many work sites, particularly in construction, due to the many different ways it can impact the environment. For instance, the structural integrity of tunnels, trenches, and other excavation areas can be severely impacted by groundwater.
Most jurisdictions require the use of groundwater impervious barriers and soil stabilizers to be used in vulnerable excavation projects in order to reduce the risk of a collapse incident or disaster. Safety incidents in excavation areas are a major safety hazard; excavation collapses often lead to severe worker injury or death.
Changes in groundwater levels can also affect building foundations, including scaffolding, and thus pose a risk on construction sites where temperature changes or modifications to the environment may alter groundwater composition. Some building structures in moist soil may also be negatively affected (e.g. by corrosion, water pressure buildup, saturation) if they are not designed to allow trapped moisture to move through soil-facing structures.