But independent testing has cleared the nearby Duralie coalmine as the source of the contamination.

Macquarie University researchers took samples from 101 houses last October in response to community concerns about the mine’s health impacts.

The results showed between 10 and 20per cent of the water samples contained levels of lead or zinc that were above the drinking water guidelines.

Some also revealed high levels of nickel and copper contamination.

Two soil samples – one from the yard and another from under the roof eve – were also taken at each property.

The yard samples were almost all clean, however, about 10per cent of the eve samples failed for zinc or lead.

The soil and water analysis did not show any spatial relationship with the coalmine.

‘‘The highest values are right beside the mine but so are the lowest values", Associate Professor Damian Gore, who will discuss the findings at a community forum today, said.

‘‘It all comes down to the age and individual construction of the house, rainwater tank and plumbing.’’

He said some residents were likely to be surprised at the water findings.

‘‘I suspect that some residents may be a bit dismayed, but we need to work through it with them and get to the fact that we still have to manage their metal problems because what they are drinking is pretty much unacceptable,’’ he said.

Associate Professor Gore said the issue of dust pollution was outside the study’s scope.

‘‘I don’t think the mines can walk away smug at all because the amount of dust that I’m seeing in some samples is inexcusable,’’ he said.

‘‘They certainly need to reduce their dust emissions.’’