How do we monitor our services and business?

Monitoring water quality

Sydney’s drinking water is among the best in the world. We often take for granted how easy it is to turn on a tap and have clean drinking water readily available. We continue to build on a great foundation and are committed to continuously improving our water quality monitoring.

Each year, IPART assesses our performance under our Operating Licence. This year it also looked at how we meet Australian Drinking Water Guidelines (ADWG).

In December 2011, the auditors commended us for our excellence in water quality during 2010–11 and gave us an overall grade of high compliance for drinking water quality for that period. They will release their report for 2011–12 around December. To earn this rating, we achieved full compliance on all elements except for how we apply the ADWG to water storages (reservoirs).

While we are international best practice when it comes to disinfecting the water from these reservoirs, there are some gaps where vermin and untreated rainwater could enter the reservoirs.

While this poses a low risk of contamination when it comes to public health, we reviewed all reservoir roofs and are sealing existing gaps. We also reviewed checklists and training for staff doing reservoir inspections.

Monitoring wastewater treatment system discharges

Sydney Water’s wastewater system transports and treats sewage through a network of pipes, pumping stations and treatment plants.

The pipes include emergency relief structures that prevent wastewater backing up in the pipes and discharging to properties, recreational parks and roads. This can occur during heavy rain if large amounts of stormwater enter the sewer or if the sewer becomes blocked.

In March 2012, Sydney experienced very intense rainfall of 120 mm over 12 hours. This activated the emergency relief structure on the North Georges River Submain at Oatley.

Unfortunately, part of the emergency relief structure became blocked and failed, causing the discharge to continue after the rainfall stopped. This meant stormwater containing a low amount of water and high amount of wastewater entered the nearby wetland and Lime Kiln Bay.

We worked to fix the problem immediately and restored the wetland to the satisfaction of Council and the Environment Protection Authority. We also communicated with the local community about this work. We received four customer enquiries and each expressed their satisfaction with our response and clean-up notices.

While we regularly inspect emergency relief structures, we did not inspect the part that became blocked because it is difficult to access and is not known to fail. To reduce the risk of another failure of this type, we are redesigning and replacing part of the structures. We are also working to increase the effectiveness of our environmental response.

In September 2011, we faced significant concern from the community when we submitted an application to the Department of Planning and Infrastructure to raise the levels of nutrients we release from Brooklyn Wastewater Treatment Plant.

We made the application to try and reduce costs for customers, as the high amount of chemicals we need to meet our licence requirements was greatly reducing the life of some of the equipment at the plant. Our water quality modelling indicated there would be little impact on the river; however, the Brooklyn community, and particularly the oyster farm industry, were very concerned by the application.

We listened to these concerns and withdrew our application. Instead, we will install extra filters, to meet our licence limits while still reducing the amount of chemicals we use.