How Often Do New Zealand Schools Need to Clean Their Water Tanks?

Here in NZ, water tank maintenance for schools follow specific guidelines to ensure water quality for both staff and the kids.  Unlike years ago, the old ‘she’ll be right’ attitude won’t meet the water regulations in place. . . .

Legal Obligations

Under the Water Services Act 2021, schools, as drinking water suppliers, have a legal duty to ensure the safety of the water they provide. This includes developing and implementing a Drinking Water Safety Plan (DWSP) that outlines risk management strategies and compliance with the Drinking Water Quality Assurance Rules. 

Schools must also meet the Drinking Water Standards for New Zealand, which set maximum acceptable values for various contaminants and aesthetic qualities like taste, smell, and appearance of drinking water.

UV Filtration

Under the water regulations one of the main requirements of schools is to have validated UV filtration in place.  The combination of the sediment filters and UV treatment generally remove anything of risk to the students and staff at the school. 

 This requires the water to be free from sediment in solution that impacts the effectiveness of the UV light accessing the bacteria to neutralise them.  As a consequence regular tank cleaning combined with the UV filtration provides the best protection and opportunity for clean and safe water for all users.   

Regular Maintenance Schedule

Schools should clean their water tanks regularly to remove sediment, biofilm, and other contaminants that may accumulate over time. Ideally this should be done annually and from our experience of cleaning thousands of tanks at least every two years, to ensure that the required UV filtration can work effectively.  

Additionally, schools using rainwater tanks should ensure that debris from roof catchments is minimised through regular gutter cleaning and the installation of gutter whiskers or leaf guards where relevant.  Read more on the Ministry for Education website.

Monitoring Water Quality

Apart from regular cleaning, schools should regularly inspect and monitor their water tanks and the water for any signs of contamination or other issues. This means checking sediment levels and water clarity (remembering that the human eye generally cannot see what is in the water), making sure that all seals are intact and there are no holes or openings in and around the tank(s) and pipes, and testing water quality regularly. 

If water quality tests indicate contamination, immediate cleaning and disinfection are necessary before retesting is undertaken.

Preventative Measures

Implementing preventative measures can reduce the likelihood or frequency of contamination. For example, opening flush caps (if they are present) on the pipes feeding the tank during a rain event can help prevent the first flush of rain, which is often the most contaminated, from entering the tank. 

Keeping the gutters and roof clean and clear of overhanging vegetation can minimise the amount of organic material getting in your tank(s).  

Additionally, ensuring that tanks are properly covered and secured can prevent animal and insect intrusion.  This combined with regular maintenance tank cleans combine to reduce the risk that the UV filtration cannot do its job.

Using  Water Tank Cleaning Professionals

Schools will benefit from using  professional water tank cleaning services, such as Safe H2O to keep tanks clean.  

This is generally not a task for school caretakers.  These services often include detailed inspections, complete cleaning, and disinfection procedures that comply with water safety standards in Aotearoa.  Read more about the benefits of using a tank cleaning specialist.   

For more detailed guidelines and resources on water tank maintenance, visit Taumata Arowai, or feel free to reach out to our team for a free consultation.