Power and Water says it is actively delivering on water demand management measures in Katherine following the NT Government’s announcement of compulsory water conservation measures last month to help safeguard the town’s water supply.
The water conservation measures are part of Power and Water’s integrated water management strategy to minimise the amount of PFAS in Katherine’s water supply.
Power and Water’s executive general manager of Water Services Rob Brito said the treatment plant is operating at capacity.
“Our treatment plant is currently operating at capacity to keep PFAS levels below the Australian guidance values by maximising river water in the water blend. This reduces the reliance on bore water, which is now less than 1 per cent, to provide a safe drinking water supply for the Katherine community.”
A water treatment plant being provided by the Department of Defence with ability to selectively remove PFAS compounds is expected to be operational late October. This will provide some support in the efforts to reduce PFAS presence in the water supply.
Mr Brito said Power and Water’s Living Water Smart team is also assisting local residents after identifying that the Katherine community is one of the highest water users in the country.
“Living Water Smart’s Community Leak Check Program was rolled out to reduce water waste and help manage the town’s drinking water supply. During the upcoming peak demand period in September and October, water demand in Katherine increases by up to 50 per cent.
“Our leak checkers completed almost 2000 checks in Katherine. The average leak was 230,251 litres per year and costing $443 annually.
“A phenomenal 92 million litres of leaking water was identified. “
The first 10 Leak Find and Fix Rebates have been conducted by local plumbers fixing an estimated 5.2 mega litres per year of residential water leaks.
“Last week’s water use reduced to 62 megalitres, 20 per cent less than in the same week over the past two years. Daily consumption last week saw a reduction of 1.5 megalitres, which demonstrates the community’s positive response to the measures,” Mr Brito said.
Since notification last year by the Department of Defence of the presence of PFAS in the vicinity of some of its bases around Australia including Tindal, Power and Water has been testing for PFAS in the water supplies and included it as part of their annual drinking water quality monitoring program at the request of the Department of Health.
“Power and Water is continuing to work to understand the movement of PFAS in the Tindal aquifer and has undertaken additional sampling to better understand the impact on the production bores and manage the water supply.
“The Australian Drinking Water Guidelines are the primary reference on drinking water quality in Australia and PFAS test results are recorded in line with the reporting protocols of these guidelines.
“During this time the test results have been variable and on four occasions, Power and Water has reported to the Department of Health that four individual samples showed PFAS levels were slightly above health based guidance values,” Mr Brito said.
However, despite the occurrence of these four elevated results, the rolling monthly average for the Katherine public drinking water is still below the lifetime exposure health based guidance value or the tolerable daily intake.
The Commonwealth Deputy Chief Medical Officer, Dr Tony Hobbs has advised that there is minimal risk to human health posed by short term exceedances of the HBGV for drinking water.
Low levels of PFAS have been detected in some other Northern Territory areas and have not exceeded the health based guidance values.
PFAS test results to the end of August and will be published on Power and Water’s website.