1.1 WATER How we are managing the key operational risks
Risk
• A major incident of E . coli in the drinking water
Council must meet the standards prescribed under the Public Health Regulation 2018 for E . coli in the reticulation system of the service . There are requirements to :
• monitor for E . coli
• monitor at the frequency of sampling relevant to the service
• achieve a nil colony forming units per 100mL ( nil cfu / 100mL ) value per sample
• achieve a 98 per cent annual value of samples ( i . e . 98 per cent of samples for a 12-month period must be nil cfu / 100mL )
• undertake a follow-up sample immediately where E . coli is detected in a sample .
Actions
• The water supplies are operated in accordance with Queensland Government ’ s Water Supply ( Safety and Reliability ) Act 2008 ( and Regulation 2011 ), and Public Health Act 2005 and Regulation 2018 ;
• The water supplies are operated in accordance with the Drinking Water Quality Management Plan ;
• Chlorine dosing has been installed on each water supply ;
• Regular chlorine sampling is taken to check the chlorine levels and ensure that they are appropriate ;
• Action is taken immediately if low chlorine levels are detected ;
• A programmed flushing program has been implemented ;
• Suitably qualified / certified staff are operating the supplies ;
• Personnel are trained and competent for operations and maintenance tasks ;
• Records of training are maintained ;
• Pressures in the reticulation are monitored to ensure they are adequate to prevent ingress of groundwater into the reticulation ;
• A proactive backflow prevention program is in place to prevent contamination from high risk consumers ;
• Procedures are in place to ensure the correct operation of the supply ;
• As far as possible staff are separated that work on water and sewerage to reduce the risk of cross contamination .
• The disinfection of water requires the storage and handling of corrosive substances , and the storage and handling of liquefied chlorine gas
As Maranoa Regional Council is the local authority responsible for the provision of water for the region , facilities across the region comprise a large number of groundwater bores which are chlorinated for disinfection purposes to supply safe drinking water to the community . Most of these use liquefied chlorine gas , while a couple of sites also use sodium hypochlorite dosing for disinfection . Furthermore , a number of these sites also require pH adjustment , using ~ 35 % sulphuric acid , to optimise the chlorine disinfection as the groundwater is alkaline .
A specialist firm has previously been engaged to undertake a Compliance Audit of Maranoa Regional Council Chlorine and Corrosives Chemicals Storage and Dosing Facilities against the Relevant Australian Standards :
AS3780:2008 The Storage and Handling of Corrosive Substances
AS2827:2001 The Storage and Handling and of Liquefied Chlorine Gas
Periodic audits ( internal / external ) assess progress and compliance .
The bulk chemical and chlorine storage systems are located in the following locations : 1 . Roma Sewerage Treatment Plant ( Sulphuric Acid and Chlorine dosing as well as chemical storage ); 2 . Roma Sewage Treatment Plant ( Gas Chlorine cylinder storage ); 3 . Roma Water Tower and Bore – 2 Gas Chlorine Dosing Sites ; 4 . Roma - 10 groundwater bores and Gas Chlorine Dosing and Acid Dosing sites ; 5 . Injune Ground Reservoir – Sodium Hypochlorite Dosing ; 6 . Surat Water Supply ( Surface Water Treatment System – Gas Chlorine Dosing ); 7 . Mitchell Water Supply ( 2 bore dosing sites & Ground Reservoir Bore – Gas Chlorine ); 8 . Amby , Jackson , Muckadilla , Mungallala , Wallumbilla , Yuleba - Sodium Hypochlorite Dosing .
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