New Zealand’s drinking water laws have changed.

New water regulator, Taumata Arowai took over responsibility for regulating drinking water from the Ministry of Health in November 2021, via the Water Services Act. Under the Act all registered water supplies must submit a Drinking Water Safety Plan (DWSP) as well as introduce a residual disinfectant, such as chlorine, by 15 November 2022 - unless awarded an exemption.

Chlorination is widely and safely used in New Zealand and globally as a preventative measure to kill bacteria and waterborne diseases.

Council supplies water to about 85% of the district’s population through its 16 water supply schemes. The water is treated before it enters your pipes, and levels of nitrate and other potential contaminants of interest are monitored. Chlorine adds an additional layer of protection while the water travels through the pipes on its way to your tap.

Taumata Arowai have reviewed and declined the exemption application for the Cust supply.

Specific reasons include:

• UV treatment installation will need to be completed
• Further source water investigations
• Leakage reduction work
• Additional backflow prevention requirements
• Further detailed explanations of historical contamination incidents
• The Council will need to meet all legislative requirements
• We need to upgrade the bore head to meet new requirements
• Disconnect supply from previous primary bore that is now a backup only
• Any other measures identified during ongoing discussions with Taumata Arowai.

This sets a precedent for our other supplies on the basis that supplies cannot currently be operated without chlorination in a way that is consistent with the main purpose of the Water Services Act.

In other words, chlorination now is required for Waimakariri District Council to be legally compliant with the New Zealand’s drinking water standards.

The Drinking Water Standards for New Zealand are issued by Taumata Arowai under the Water Services Act 2021 and set out the requirements water suppliers need to meet to provide safe water to their communities. The standards set out:

• Maximum amounts of substances, organisms, contaminants, and residues allowed in drinking water
• Criteria for demonstrating compliance with standards
• Action to be taken in the event of non-compliance with standards.

Chlorine is widely and safely used in New Zealand and globally both as a short-term treatment and as a permanent treatment to protect drinking water supplies against contamination. Most drinking water supplies in New Zealand are chlorinated.

The amount of chlorine added to a supply is carefully managed to ensure the smallest amount is ingested, while still maintaining a high level of effectiveness.

In Waimakariri, we use a small quantity, roughly 0.5 grams per cubic metre, minimising any taste or smell to the water as much as is possible. Levels are monitored continuously to ensure they are safe and appropriate.

Even before the law changes, all Waimakariri District Council schemes had chlorine equipment ready to be used if a change in water quality or the risk profile of a supply were to change.

The amount of chlorine added to a supply is carefully managed to ensure the smallest amount is used, while maintaining effectiveness.

In Waimakariri, we use a small quantity, roughly 0.5 parts per million. By the time it gets to your property the dosage is lower still at 0.2 parts per million (ppm). Another way to think about this is one teaspoon of chlorine per 10,000 litres of water.

Using a small quantity minimises any taste or smell to the water as much as possible. Levels are monitored continuously to ensure they are safe.

As chlorine is introduced to a supply, you may notice a slight change in taste as the chlorine begins to mix in.

This will generally decrease with time. We have very careful controls on the amount being added to ensure it remains within targets.

Chlorine can be removed by several methods.

For drinking water, one of the simplest ways to remove chlorine is to fill a jug of water and leave it in your fridge overnight – the chlorine will dissipate naturally over a few hours.

An alternative is to purchase an ‘under-sink’ filter that will remove chlorine from your tap.

If you don’t want to shower or wash your clothes in chlorinated water you can buy a filter that attaches to your water supply where it enters your property.

These are available from numerous retailers and can be installed by most plumbers at your own cost.

There are no known health impacts from drinking water effectively treated with chlorine. The use of filters will mitigate any risks for those on dialysis. This is arranged by Te Whatu Ora – Waitaha Canterbury.

While rarely experienced, chlorine can be an irritant for existing skin conditions such as eczema. If you feel your skin getting dry or itchy, use moisturiser after having a shower or bath. If you notice increased skin irritation, asthma symptoms or other symptoms, seek medical advice from your GP. You can also contact Healthline any time for free health advice on 0800 611 116.

The International Agency for Cancer Research (IARC) does not believe chlorinated water is either a probable, or even possible, cause of cancer.

Chlorine has been used safely all over the world for around 120 years. It keeps millions of people, including most of New Zealand, safe from waterborne illness.

The Journal of the National Cancer Institute acknowledges that “water chlorination is one of the major disease prevention achievements of the 20^th century”, and that it “has become the principal means of effectively reducing waterborne enteric diseases”.

Under the new Drinking Water Rules, the Council is required to closely monitor drinking water for chlorine by-products to ensure these are always within safe levels.

You can call your GP’s number after hours and your call will be put through to a nurse who can provide free health advice. You can also contact Healthline any time for free health advice on 0800 611 116.

Treated water is safe for household pets such as cats and dogs to drink.

If you have fish in outside ponds you will need to either turn down in-coming water to an absolute trickle (this dilutes the chlorine level to a safe amount for your fish) or fill up drums of water and let them sit for at least 24 hours before using (the UV of the sun removes chlorine).

For fish tanks or bowls inside, fill up a container of water, let it sit for at least 24 hours and then only replace 1/3 of this water at a time with what is in the tank already. If you’re still worried, you can buy de-chlorinating kits (sodium thiosulfate) at pet supply stores.

We use chlorine, not chloramine (chloramine is more toxic to fish).

Chlorination has been introduced to a lot of water supplies throughout the years with no issues.

There are always multiple factors that can lead to a hot water cylinder leaking, and then needing to be replaced. These include the chemical composition of the water, the age of the cylinder, the type of cylinder, whether there is any debris in the cylinder, and the particulars of the installation.

It appears most cylinders that fail are older, low-pressure copper cylinders.

There are specific cylinders that are sold for areas where pitting corrosion is prevalent. If you are replacing your cylinder talk to your plumber about the best option for you. Some options include enamel-lined steel or stainless steel cylinders.

The Council will continue to work with Taumata Arowai to determine a path forward where our drinking water can be chlorine-free. However, this is expected to take a significant amount of investment (additional to planned UV upgrades) which we would need to engage with the community on through future Long Term or Annual Plans.