Groundwater is contaminated through a variety of sources. Chemicals and toxins that seep into the soil can make their way further underground until it makes its way into aquifers. Runoff that travels over roads and roofs before entering the ground can also pick up a massive amount of chemicals before it reaches soil and seeps into the earth.
If you're storing your groundwater in a lagoon, its important to use an impermeable liner and cover to prevent seepage. This keeps your water from being lost to evaporation or draining into the soil. Additionally, run-off or chemicals in the soil cannot directly touch and affect your stored water.
