The Ministry of Health, the PMU and other Government agencies are investigating water disinfection options in preparation for water quality discussions during community consultations in 2019. Factors under consideration include safety, complexity, reliability, capital cost, and ongoing operational and maintenance costs.
The five principles of water treatment
Minimise contaminants entering the water supply
Remove what you can through screens, filters etc.
Disinfect the water to make harmful microbes inactive
Disinfect the pipes to keep them free of harmful microbes
Continually maintain and operate the system to a high standard.
Disinfection options include:
UV - A complex system that uses ultraviolet (UV) energy. Maintenance costs are high, and specialist skills are required
Ozone - Used for niche applications where good technical support is available. Maintenance costs are high, and specialist skills are required
Chemical disinfection – Safe, cost-effective and easier to manage effectively. The most commonly used option, including in New Zealand and Australian water supply networks.