Our Plans for 2021/22 | Page 27

How we are managing the key operational risks - Sewerage

• A sewer main collapse

Risk

Roma ’ s sewerage network consists predominantly of reinforced concrete and asbestos cement with the expected life now exceeded ( pipes over 50 years old ).

The majority of the networks were constructed in the 50s and 60s . Following a significant investment in relining , and CCTV to obtain good quality information on condition , there are now 6.9kms of Roma ’ s gravity sewer pipes that have been classified in a Condition 5 state . This means that the pipes are at the point of failure and need to be addressed urgently .

If the sewer deteriorates beyond repair ( before relining can occur ) pipes will need to be replaced by open excavation . This is estimated to be close to double the cost of relining .

Actions

• The condition of the sewers are closely monitored and documented ;

• Sewers are condition rated from 1-5 with 5 being close to failure ;

• A program is in place to address all sewers with a condition of 5 as soon as possible ;

• Closed circuit television ( CCTV ) programs are implemented each year to gather data on the condition of sewers ;

• From the CCTV reports the condition of the sewers are updated to provide the most accurate data possible ;

• Sewers are renewed through relining , which is cost effective and less disruptive to customers .

Council previously committed a $ 3 million investment financed by a loan to address a large proportion of the relining works . Council also advocated to the Queensland Government for assistance with the balance of the funding needed ($ 1.6 million ), however was unsuccessful . We aim to carry out $ 500,000 + relining works each year .

Our plans for 2021 / 22

• Failure of a sewage pump station • The condition of the pump stations are closely monitored and documented ;

• Redundancy is built in through the installation of more than one pump at each station ;

• Pumps and pump stations are routinely serviced each year and any deficiencies addressed as soon as practical ;

• The installation of SCADA at each site will provide early warning of issues ;

• Generators are installed to provide backup power in the event of an electrical failure .

• Treatment failure resulting in breach of conditions can result in environmental damage and fines

• Suitably qualified / certified staff are operating the systems ;

• Personnel trained and competent for operations and maintenance tasks ;

• Records of training maintained ;

• Procedures are in place to ensure the correct operation of the systems ;

• Regular monitoring of results and acting with urgency when results are not normal ;

• Trade waste arrangements to control quality and volume of industrial wastes ;

• Controls on allowable discharges at the treatment plants ;

• Regular maintenance of the ponds such as de-sludging .

New initiatives in 2021 / 22

New or upgraded assets How we are reducing operational risks in 2021 / 22

Upgrade Mitchell and Surat sewage pump stations

Sewage pump station 1 Roma additional capacity / storage

Install flow meters at sewage pump stations - regional

Replace pumps Amby and Mungallala sewage pump stations

Replace pumps at Sewerage Pump Station ( SPS ) 6 , 7 and 8 , Roma

These works are required to provide safe access to the sewage pump stations .

Providing additional capacity at the pump station will reduce the current overflow issues that occur during significant rain events .

The installation of flow meters will provide better data to monitor the pump station operations .

The replacement of the pumps will provide better quality pumps and reliable operation .

Replacement of old pumps .

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