Summary Water Supply and Waste Disposal

Water Supply and Waste Disposal
Groundwater Supply
Water Table – the upper limit of the saturated zone

Aquifer – a unit of permeable rock that can yield
significant amount of water e.g. sandstone or limestone

• Permeable
• Porous

Aquiclude – a unit of low permeability that controls
water flow from aquifers e.g. shale or mudstone

Aquifuge (Aquitard) – An impermeable rock, no water is
absorbed or transmitted e.g. granite

Recharge Area – water gets into the aquifer from an area where the permeable rock is unconfined

Spring – where water flows from an aquifer to the earth's surface, where the water table meets the surface

Perched Aquifer – occurs above the main water table in the unsaturated zone, when there is an impermeable
layer of rock or sediment above the main water table/aquifer but below the surface of the land

Unconfined vs Confined Aquifers:

Unconfined Aquifer Confined Aquifer




Water will seep directly into an underlying unit of Water can’t seep directly into the unit of permeable
permeable rock near the surface rock because it is bound by two layers of
impermeable rock

Flowing Artesian Well

• Confined aquifers cause the ground water to have a high pore pressure
• This means the projected water table is higher than the land surface
• This causes the water to passively up-well, so there is no need for pumping