ISAAC Clermont Water Quality Response Plan - November2021

CLERMONT WATER QUALITY RESPONSE PLAN

ACCURATE AS OF NOVEMBER 2021

FOR MORE INFORMATION: ISAAC.QLD.GOV.AU | 1300 ISAACS (1300 47 22 27) isaacregionalcouncil

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CLERMONT WATER QUALITY RESPONSE PLAN Council has developed a plan to outline what changes and improvements are planned for the Clermont Water Treatment Plant and network.

INTRODUCTION Isaac Regional Council is committed to maintaining, renewing and expanding its water infrastructure to meet the present and future needs of our communities in the Isaac region.

In partnership with government and industry, Council continues to invest significantly in this vital function as part of a focus on improving water infrastructure and service delivery.

Council acknowledges the region’s communities have experienced past issues in relation to water supply (security and quality), but is working hard to deliver long-term solutions, particularly in the area of drinking water quality.

INVESTING IN WATER INFRASTRUCTURE Improving the quality and reliability of water supply in Clermont remains one of Council’s top priorities. In 20/21, Clermont received well over three-quarters of Council’s total budget spend on water projects – almost $4.9 million from the total $5.9 million. Another $768,000 investment has been made to reaffirm Council’s commitment to improving the water quality, safety and sustainability of Clermont.

As part of Clermont’s Water Quality Response Plan (Plan) a number of major projects are underway or have been completed last financial year, including, $1.39 million has been allocated for a water mains replacement program, almost $1 million for de-silting the area around the raw water offtake structure at Theresa Creek Dam and $2 million to construct Clermont’s five-megalitre treated water reservoir which is now online and in use.

REGULAR UPDATES Council committed to providing regular updates on the progress of the actions outlined in the Plan and these have been made via Council’s website.

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Since Council implemented the Plan in July 2020 a total of 12 actions have been completed.

As of November 2021, there were eight still in progress and Council is working hard to carry out these improvements within the agreed timeframes.

Each item outlined in the Clermont Water Quality Response Plan is updated regularly on the website so the Clermont community can keep track of our progress.

LOOKING BACK Between 16 and 29 November 2018 Clermont was subject to a water discolouration incident associated with high turbidity influent water from Theresa Creek Dam (TCD). This was caused by a long dry period followed by a large inflow of rain into the dam and the failure of an alum dosing pump whilst the plant was operating automatically after hours.

In February 2020, again following a period of dry weather followed by a high rainfall event and rapid filling of TCD, a discoloured water incident occurred associated with iron and manganese not being removed or stabilised through the treatment process. This resulted in very inconsistent water colour throughout the network. Even though we were able to adjust treatment processes and produce clear water from the Clermont Water Treatment Plant (WTP) on several occasions, the discolouration impacted some water customers up until early March 2020.

LOOKING FORWARD There should be no doubt about the quality of drinking water in any of our communities, and Council has put strategies in place to prevent further incidents from occurring.

Council committed to providing the community with regular updates on their website and provided an engagement opportunity for feedback via the

THE PLAN Pictured: Theresa Creek Dam desilting project

Action

What are we doing

Manganese (Mn) and Iron (Fe) removal pre-dose

Potassium Permanganate PP is very effective in oxidation (PP) dosing system to be removal and can remove 90% of installed. System to have fail the iron and manganese. safe and alarm.

Completed October 2020

Manganese (Mn) and Iron (Fe) removal pre-dose

Installation of sodium hydroxide dose point.

To improve pH and oxidation process.

Completed March 2020

This is a natural way to remove iron and manganese by allowing the air to pass through the water and oxidation to occur. This will reduce chemical costs and improve treatment process.

Following further investigation and the installation of the inline analysers Council has reduced the need to oxidise the raw water.

Oxidation of raw Raise the inlet pipe at the water at the raw raw water and clear water water reservoir reservoir to a level that still allows the balance tank to gravity feed correctly.

Why are we doing it

Expected completion

Sampling point upgrades

Raise the sampling point up Safety and ensuring the most accurate readings are collected. out of the pit so that staff are safe when collecting samples and to make certain the samples are at the best collection point.

Completed March 2020

New dosing pumps

New dosing units should be To allow the chemical to work able to be adjusted to dose as intended and ensure more chemicals for a large range accuracy in applied dosages. of water qualities.

Completed May 2020

Chemical line flow sensors

Installation of two sensors at all of the chemical dose systems to detect flow through the pump intake and delivery lines.

New equipment installed. Further review to occur to ensure it continues to meet our needs.

Flow sensors at the intake will detect blockages between the chemical tank and the pump.

Installation of the delivery line sensor at the dosing point will detect pump failure and delivery line failure.

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Action

What are we doing

Why are we doing it

Expected completion

Inline analysers

Installation of inline analysers that have the capacity to shut down the plant and monitor all water quality parameters required.

By installing analysers that can shut Project commenced down the water treatment plant, August 2021. issues such as water discolouration and other water treatment failures can be stopped before water quality is harmed. Parameters can be set as operational ranges and changes only made through operational protocol.

Supernatant pump station at the sludge ponds

Installation of a pumping station and delivery main to the raw water reservoir.

System installed must also be capable of taking flows from the clarifier.

By putting in a supernatant pumping Completed February station, the uncontaminated water will 2021. be returned to the raw water reservoir. An alternative solution has been sourced and activated.

Duty / Standby on all equipment

All current and future processes must include duty/standby so if one piece of equipment fails the standby unit starts.

By not having a duty standby system the water treatment process can fail when one piece of equipment fails.

Completed December 2020

Painting of the clarifier

Painting the clarifier with product which is chemical resistant and suitable for use in waster treatment.

This will assist the operator to understand how well the plant is operating visually as water clarity can be easily observed. It will also extend the life of the asset and allow for easier cleaning.

Completed March 2021.

Increased cleaning of the clarifier has been scheduled to improve water quality visability.

Additionally the inline analysers to be installed by June 2021 will provide further data on water quality.

Clarifier inlet design upgrade

Installation of larger bell This allows flocculation to occur mouth to the inlet pipe to without affecting the floc. reduce turbulence at centre cone.

Completed February 2021

Water An analysis on suitable Treatment Plant options to either build new undersized treatment plant or upgrade the existing facility.

Current plant is almost at full capacity for treatment of water to meet town demand and often has to be slowed to accommodate the treatment process.

Analysis and Scope Development 20/21 through 21/22 Proposed Project Submission 22/23

Flow calibration Drop down testing tubes test tubes with level increments - to be installed with flushing points and cleaning procedures.

To monitor pumps and ensure they are dosing what they say they are dosing.

Installation completed 2021.

Prevent stirring of settled contaminates

To prevent stirring of sludge that Install diversion pipe at will effect the water quality. inlet to the clear water reservoir to divert the inlet water away from the settled sludge at the bottom of the reservoir.

Completed February 2021

Aerial view of Theresa Creek Dam desilting project

Action

What are we doing

Why are we doing it

Expected completion

Improve circulation of water within the network to remove low flow sections of reticulation

Investigate ways to improve circulation in the network (possibly by consultant analysis).

To prevent a build up of settled solids in the network zones and improve water quality.

Completed March 2021.

Generator to power the entire Clermont Water Treatment Plant site including raw water reservoir

Investigations to be sought for either power supply to site or UPS that has full alarming when power is low.

To ensure all areas of the site have power to run during emergency outages.

Undertaking a risk assessment of all assets at the plant to determine criticality to inform need of backup generators.

Raw water valve fails to close at raw water reservoir

Investigate reasons and causes and then provide an acceptable solution.

Raw water reservoir overflows when valve fails to close.

Capital bid for floating offtake was successful and is anticipated to be installed in May/June 2022.

Flow paced dosing of all chemicals

Ensure the dosing units are flow paced.

To ensure that correct dosing of chemical is delivered to treat the water quality at all times.

Investigation and review of performance of existing chemical dosing systems to be completed.

Improved lighting at the Water Treatment Plant

Improve lighting to enable safe work at night.

For the safety of operators and to ensure work can be carried out efficiently.

Completed June 2021.

Termite damage and control

Assess termite damage and options for repair and/or replacement.

Significant asset/ Inspection completed and building deterioration rectification ongoing. due to termite damage.

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Council conducted engagement activities earlier this year for Clermont residents to have their say on the Clermont Quality Response Plan. Council would like to thank residents for their engagement and feedback regarding communications and information regarding their water.

For all the latest on the Clermont Water Quality Response Plan, please visit Council’s website at isaac.qld.gov.au/clermont-water-update

FOR MORE INFORMATION: ISAAC.QLD.GOV.AU | 1300 ISAACS (1300 47 22 27) isaacregionalcouncil

isaacregionalcouncil

isaacrcouncil