Clermont Water Treatment Update 25 February 2020

Council is committed to keeping community informed in relation to water discolouration in Clermont as new information becomes available.

What happened?

Clermont, including the catchment which supports the Theresa Creek Dam had experienced significant rainfalls in late January. This washed large volumes of sediment and organic matter into the dam which supplies the Clermont water treatment plant. This impacted the overall quality of raw water which has resulted in higher than normal turbidity and lower than normal pH levels supplied from Theresa Creek Dam. Our water treatment plant appeared to be operating satisfactorily until last Wednesday when we had initial reports of discoloured water.

In 2018 there was a discoloration of the Clermont water associated with a plant failure resulting in material not settling out of the water and a major effort to restore supply.

The discoloration which surfaced last week is associated with iron and manganese becoming visible as a result of the chemistry of water treatment. As soon as we were aware of the issue, staff responded and commenced flushing reservoirs and mains of the discoloured water. We also undertook some manual changes at the plant and last Friday evening believed we had resolved the issue as the plant was again producing clean water. We developed a plan for improvements at the plant to minimise the long term potential for discoloured water

On Saturday and Sunday we continued monitoring and flushing residual pockets of discoloured water.

On Sunday night we had another discoloration event which staff responded to immediately and with a recognition that we would need to review the treatment process and implement some changes immediately.

An independent water process specialist who was involved with the water treatment plant upgrade in 2017-18 was brought to site to review treatment processes and help assess options to improve these processes and find a long term solution to the discoloration issue.

A new pump has been installed at the treatment plant to address the current raw water levels of manganese, iron and organics by varying dosing locations and volumes of the chemicals used to ensure water is safe to drink. Additional water treatment is underway, with ongoing monitoring of the water quality changes and the process improvements.  

What makes the water discoloured?

The discolouration of the water is caused by the latent re-oxidation of manganese and iron in the treated water reservoir. In simple terms any residual iron and manganese available in the water can become visible on contact with additional chlorine.

Is the water safe?

The discolouration, is undesirable however the water is safe to drink. Samples have been independently tested at the National Association of Testing Authorities, Australia (NATA) accredited laboratory and are within the Australian Drinking Water Guidelines.

Regular internal testing is undertaken in accordance with our Drinking Water Quality Management Plan and is being undertaken every time a process change is made at the water treatment plant. We also have regular monitoring of the town network supply.

When will the water be clear?

Changing the treatment process takes time. We are doing this under live conditions as we still need to produce safe drinking water whilst we tweak the treatment process. Some changes take 4 to 5 hours to show results. We also have to flush any residual discoloured water from the network. We are also assessing all the options to ensure it doesn’t occur again.

We are actively engaged in implementing viable solutions however confirmation of successful changes is anticipated to take until the end of the week.

How to clean stained laundry?

The staining of your laundry from discoloured water is due to particles of sediment being lodged in the fabric caused by iron and manganese.  The stain is best removed by an acid-based cleaning agent. 

Council has ordered and will supply citric acid as a stain remover for laundry purposes. This will be available initially from Councils Offices corner Karmoo and Daintree Street Clermont from Wednesday 26 February 2020. We will assess other locations for distribution over the weekend and out of hours.

Council will supply a Citric Acid Factsheet with each bag of citric acid.

When water quality or quantity issues arise we have a 24 hour response capability. Often the solution is able to be implemented quickly if we are alerted to any issues that arise.

Please contact Council’s Customer Service Centre available 24 hours a day, 7 days a week on 1300 ISAACS (1300 472 227).

Council wishes to thank the public for their patience.

Gary Stevenson PSM

Chief Executive Officer