Very permeable due to joints, water can infiltrate and percolate relatively quickly
3 main sources of water
Rivers
Reservoirs
Aquifers
Porous
A rock stores water in holes within it
Aquifers also contain the highest salt level other than sea water
Porosity
Determines how much water an aquifer can contain, measured as a % of rock volume
Water table
The level of saturated rock
Boreholes
Drilled into the aquifer rock to pump water out, the water is very clean (compared to rivers) because water filters through the rock removing suspended sediment
Aquifers have a relatively high temperature range because they are below the surface
Sandstone
Porous due to the grains stuck together
One third of the UK's drinking water comes from aquifers
Permeable
A rock allows water to move through it
Abstraction rate is greater than recharge rate
Ideal aquifers should have a high porosity and high permeability
The aquifer contains the highest calcium carbonate apart from sea water (lots of dissolved calcium carbonate)
