The Northern Territory government insists water is still safe to drink after a reduction in standards of acceptable contamination from a potentially hazardous firefighting foam near three Top End military bases.
The daily tolerable intake level for people exposed to toxic chemicals found at a dozen defence sites across the country is now 7.5 times lower, following changes announced by the federal government on Monday.
"The Commonwealth is taking a precautionary approach to this emerging national issue, introducing some of the most conservative guidelines in the world to ensure Australians minimise their exposure," NT Health Minister Natasha Fyles said.
The foam was used from the 1970s and pollutants have since leeched into ground and surface water at RAAF base Tindal near Katherine and the RAAF Base and Robertson Barracks in Darwin.
The health risks are still unknown but the federal government continues to provide alternative drinking water to about 50 Katherine homes.
Katherine's water supply comprises 10-30 per cent of groundwater, while the rest comes from the Katherine River.
Ms Fyles said the town relies solely on bore water for a short period at the end of the dry season and residents could be impacted during this time.
Last November the NT government also urged people not to eat seafood from two Darwin creeks after contamination was detected in shellfish.
In light of the changes, those samples will be reviewed with results due later this month, while results from tests on fish, prawns and crabs are due in June.
Defence is providing voluntarily blood tests and counselling services to heavily contaminated towns such as Williamtown in NSW and Oakey in Queensland where property prices have dropped.
The NT government is lobbying the Commonwealth to provide similar resources to affected Territory communities and to fast track more groundwater testing.
There's no impact on commercial agriculture in those areas but the pollutants will affect people growing vegetables in their backyards, Ms Fyles said.
And fewer than 1000 of the Territory's 2.2 million cattle could potentially be contaminated.
