Water - Hard and Soft


August Weather Event 2022

Information relating to the recent weather event in Marlborough

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Water - Hard and Soft

What is hard and soft water

When water falls as rain, it is "soft" and free of minerals. It picks up minerals as it passes through rock, sand and soil, so most water drawn from an aquifer will be ‘hard’. Hard water is high in mineral salts, especially calcium and magnesium. Hard water, generally, is not harmful to our health and may indeed be beneficial.

Hard water isn't bad water, any more than soft water is 'good' water. For example, many tea and coffee drinkers do not like their drink made with soft water, preferring a degree of hardness. Generally people used to soft water will find hard water difficult and vice versa.

The sum of all calcium and magnesium compounds in water results in the total hardness, measured in milligrams calcium carbonate per litre (CaCO3 mg/L).

This means a property that can adversely affect taste, colour or general appearance of water. Guideline values (GV) are applied to aesthetics – these are levels that if exceeded, may make the water unattractive to consumers. The GV for total hardness is 200mg/L CaCO3.

Certain house hold appliance installation instructions ask if your water is Hard or Soft or what is the pH level of your water.

Latest Chemical Analysis Reports

Drinking-water Standards

The new water services regulator is Taumata Arowai.

The role of drinking-water regulator shifted from the Ministry of Health to Taumata Arowai in November 2021.

They have consulted on a set of draft standards which will support the Water Services Act 2021.

The standards can be accessed on their web site. They are likely to be finalised in July 2022.

Go to the Taumata Arowai website

Go to the Water Services Act 2021