TasWater has switched Winnaleah's water supply to the town's irrigation scheme as a temporary measure, after levels of lead above the maximum Australian Drinking Water Guidelines were detected in its bore water last month.

Winnaleah farmer Byron Cairns said yesterday that the town's water was now brown and contained E.coli and other micro- organisms.

Cr Jarvis said the irrigation solution was only a short-term answer.

"There needs to be an investigation from someone greater than TasWater from the state government or the Health Department into where the lead has come from," Cr Jarvis said.

"Anything to do with alternative water systems is costly ... so a little bit of money spent identifying why this is happening is needed.

"Why spend more money on a new bore system when you don't know if it is going to be contaminated? It may be from old mining activity in the area."

TasWater chief executive Michael Brewster said extending the $9.5 million Ringarooma pipeline could be a solution.

"We will look at how the economics of that stack up and what range of options we might have," Mr Brewster said.

"Do we effectively treat the bore water or take a supply from Herrick.

"At the end of the day you can take lead out of water."

Lead was found in Pioneer and Avoca's water supply in 2012.