What's in your water

Hard water

Hardness in drinking water is mainly the result of the presence of large amounts of two minerals - calcium and magnesium.

• Hard water requires more soap than soft water to obtain a lather.
• It can also cause scale to form on hot water pipes and fittings.

Soft water

Soft water contains small amounts of calcium and magnesium.

It may lead to greater corrosion of pipes, although this will depend on other factors such as pH, alkalinity and dissolved oxygen concentration.

In our regions

• Sunshine Coast and Noosa drinking water is generally soft (less than100mg/L)
• Moreton Bay drinking water it is neither hard nor soft (less than 200 mg/L).

Useful things to know in relation to soft water:

• Leave your water-using appliances on factory settings
• You do not need to add salt to the water
• If a dishwasher supplier quotes results in mmol/L, then 1mmol/L = 100mg/L

Degrees of hardness

Degrees of hardness are described in the Australian Drinking Water Guidelines 2011 as:

Seqwater, the State Government bulk water supply authority, adds fluoride to the water at their water treatment plants, under the direction of councils. Unitywater does not add fluoride to the water supply.

Under the Water Fluoridation Act 2008, local councils in Queensland are able to choose to fluoridate the water supply. All three councils in Unitywater's service area (Moreton Bay, Sunshine Coast and Noosa) have elected to fluoridate.

For health information, visit the Queensland Health website, read the Changes to Water Fluoridation Act 2008 – Frequently Asked Questions or Seqwater’s fluoride factsheet.

Chlorine is commonly used around the world to disinfect drinking water supplies.

Chlorine is a simple, reliable, effective, relatively inexpensive and, above all else, safe way to disinfect drinking water supplies to protect against contamination by microbiological organisms.

When used at levels that comply with the Australian Drinking Water Guidelines, chlorine is effective against virtually all micro-organisms that could pose a threat to your health.

Normal chlorine concentrations in our drinking water pipeline systems will range up to 1.5 mg/L.

Chloramination is a disinfection process which involves adding controlled doses of chlorine and ammonia to the water supply.

• Chloramines stay in the water supply system for longer periods.
• This is an advantage for a water network as large as ours because it persists longer, providing longer lasting protection against microbiological organisms. 

However, chloramines are toxic to pet fish. To make the water safe for fish, you will need to:

• seek advice from your local aquarium
• test the water to determine chloramine and pH concentration
• treat the water with products from your local aquarium (if necessary)
• age tap water in a container overnight before adding to a fish tank
• replace less than one-third of the total volume of water in the tank at any one time.

What is pH?

• pH is a measure of the hydrogen ion concentration of water. It is measured on a logarithmic scale from 0 to 14.
• A pH of 7 is neutral, greater than 7 is alkaline, and less than 7 is acidic.

How is pH used? 

• One of the major objectives of controlling pH is to ensure the effectiveness of chlorine or chloramine. The optimal range is between 7 and 8.5. If the pH is above or below these values the disinfectant type becomes less ‘reactive’ and is less effective as a barrier against microorganisms.

• Another objective for controlling pH is to minimise corrosion in our pipes and fittings. To reduce this impact, the pH of drinking water should be between 6.5 and 8.5. Our 2018-19 Drinking Water Quality Performance Report shows the average pH results from various locations across the service area were between 7.4 and 7.9.