10.1.2 Potable Water

In the UK, rain provides sufficient fresh water to meet the needs of the population. However, during the summer months, water reserves can run low in some areas, leading to water conservation measures such as hosepipe bans.

Sources of Fresh Water

• Rainwater: Collects in rivers, lakes, and underground rocks, forming natural reservoirs.
• Dissolved Substances: This water contains low levels of dissolved substances, making it suitable for further treatment.

Production of Potable Water

Most potable water in the UK is produced from naturally occurring fresh water through the following steps:

1. Filtration:

• Process: The water is passed through filter beds.
• Purpose: To remove insoluble particles and ensure the water is clear and clean.

2. Sterilisation:

• Process: The water is sterilised to kill any harmful microbes.
• Methods Used:
• Chlorine
• Ozone
• Ultraviolet Light These steps ensure that the water is safe for drinking and free from harmful contaminants.

Desalination of Sea Water

Challenges:

• Desalination is energy-intensive and costly, making it less viable in many parts of the world.
• Alternative Methods: Membrane systems are also used for desalination.

Considerations for Desalination:

• The process should use renewable energy to minimise environmental impact.
• Desalination plants need to be located near the sea to access seawater.

Global Considerations:

• The viability of desalination as a source of drinking water depends on factors such as proximity to the sea, availability of affordable energy, and a country's wealth.

Fluoridation

What is Fluoridation?:

• Fluoride is a naturally occurring ion found in water in varying amounts, depending on where in the UK you live.
• Fluoridation refers to the process of adding fluoride to the water supply to help prevent tooth decay. Controversy:

Fluoridation of water supplies is a controversial issue. You need to understand both the arguments for and against this process.

Benefits:

Fluoride helps to prevent tooth decay, which is why it is added to many brands of toothpaste and, in some areas, to the water supply.

Community Water Fluoridation

Current Practices:

• Most water supplies contain some fluoride naturally.
• In the early 20th century, levels of tooth decay were found to be associated with low fluoride levels in drinking water. This led to the introduction of water fluoridation schemes to improve dental health.
• Community water fluoridation schemes have operated for over 70 years, with the first being introduced in the US in 1945. The first substantive UK scheme was established in Birmingham in 1964.

⚠️ Safety Concerns: Is Fluoride Safe? ⚠️

Health Concerns:

• There have been some concerns that fluoride may be linked to a variety of health conditions.
• The link between fluoride ions and a reduction in the incidence of tooth decay has been established by surveying school children. The data is considered reliable because all school children are surveyed, and only absentees on the day are excluded.

Ethical Issues

• It is important to realise that science cannot address ethical issues directly. Science can only provide the facts and evidence needed for people to form their own opinions.
• You should be aware that information regarding the fluoridation of water supplies comes from many different sources, and some of these may be biased and may try to influence opinions.