Water that is safe to drink is called potable water - AQA - GCSE Chemistry Combined Science - Question 2 - 2022 - Paper 2

When comparing the two sources of potable water, ground water is generally easier to obtain than waste water.

1. Ease of Access:

   • Ground water can be accessed through wells or boreholes, typically requiring less processing to ensure cleanliness.
   • Waste water, however, must undergo extensive treatment processes to remove contaminants.

2. Processing Time:

   • Obtaining potable water from ground water usually takes less time compared to the lengthy processes involved in treating waste water to meet safety standards.

3. Treatment Methods:

   • Ground water may require basic filtration and chlorination to make it safe for consumption.
   • Waste water involves several stages including screening, biological treatment, and sterilization to eliminate harmful pathogens and pollutants before it can be considered potable.

4. Final Treatment:

   • Ground water can be sterilized simply using chlorine, ozone, or ultraviolet (UV) light.
   • Waste water treatments are more complex and may also involve anaerobic digestion to break down organic matter effectively.