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What to know about changes to New Zealand drainage and plumbing standards

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Drainage and plumbing standards play an important role in public health and safety, as well as property and environmental protection.  These standards help prevent drinking water contamination, cross-connection between potable and non-potable water sources, structural issues, exorbitant maintenance costs, and other invasive issues. 

Recently, New Zealand drainage and plumbing standards have undergone a change. This is to get all tradespeople on the same page while filling gaps related to safety and well-being. Not only does this ensure consistency across the board, making repairs and other maintenance requirements much more seamless, it means that residents like you can enjoy peace of mind knowing your infrastructure is safer. 

What drainage and plumbing standards have changed and why? 

Here are just some of the updates to the drainage system and plumbing building codes. 

Water temperature

According to Dr Dave Gittings, Manager of Building Performance and Engineering from the Ministry of Business, Innovation and Employment, tap water scalds are a common issue amongst the elderly and young children. In fact, 65% of severe scalds inflict children under 4. 

As a result, the maximum allowed temperature of hot water for personal hygiene plumbing fixtures has been reduced to 50-55̊C. In early childcare centres, it’s even lower at 40-45̊C. This aims to better protect those vulnerable to scalding from taps, baths and showers. 

Hot water systems 

A home using a hot water cylinder must now be heated to over 60̊C. This helps prevent the growth of Legionella bacteria, which can form biofilms within water systems and cause a severe kind of pneumonia. However, to remain compliant with water temperature regulations, the water needs to be tempered before making its way to outlets. 

This can be achieved through a system of values and controls that also regulate water pressure. The components of this system must have 500kpa pressure maximums for warranty purposes. 

Lead limits  

Amendments have also arisen that limit the maximum amount of lead content within any plumbing product containing copper alloys intended to be used for potable water. Pipe fittings, valves, taps, mixers, water heaters, water meters and more must not exceed 0.25%. To verify this, products require a testing report from an accredited laboratory. These assets must also be dezincification-resistant to limit corrosion. 

With these amendments in place, it will limit the potential consumption of lead and the associated health risks. 

What do the updated drainage and plumbing standards mean for you?  

These new plumbing and drainage standards have a transition period end data for 1 September 2025. This means that by this date, your plumbing and drainage infrastructure must be updated in accordance with the new regulations. This is not something you can do yourself as it risks your safety and the assets themselves. You must talk to an expert who understands the amendments to the current standards and has the capabilities to perform them to a high standard. 

Talk to Allen Plumbing today 

We pride ourselves on remaining up to date with the current trends and regulations of our industry. For help updating your plumbing assets and ensuring they are in correct working order, you can come to us. We have a specialist team with the knowledge and experience needed to ensure you are compliant with the new drainage and plumbing standards. Talk to us today.