Ammonia
Overview
Ammonia is a colourless, alkaline gas that dissolves easily in water. It can enter groundwater through natural processes or human activities such as agriculture, sewage, and industrial operations. Typical natural levels are below 0.2 mg/L, but some anaerobic sources may reach up to 3 mg/L.
Health Implications
Ammonia levels in drinking water are generally not high enough to pose health risks, so the World Health Organization (WHO) has not set a health-based limit. However, individuals with concerns should consult their local health authorities.
Reasons for Monitoring
Monitoring ammonia is important due to its potential to:
• Affect taste and odour: Levels above 1.5 mg/L can cause noticeable changes.
• Reduce disinfection efficiency: Ammonia reacts with chlorine, forming chloramines that may also affect taste and odour.
• Interfere with filtration: High levels can disrupt manganese removal filters.
• Cause nitrification: This process can increase water hardness and further affect taste and odour.
• Indicate contamination: Elevated ammonia may signal faecal pollution.
• Corrode plumbing: It can damage copper pipes, leaving stains.
• Support microbial growth: Ammonia can feed bacteria and algae, leading to nuisance growths and can cause further taste and odour issues.
Treatment Options
Ammonia can be removed using:
• Ion exchange
• Reverse osmosis
• Membrane filtration
The choice of method depends on water quality, ammonia concentration, and budget.
Further Information
More details are available from the World Health Organisation and national health websites.