Victoria's Fire Services Commissioner has ordered new tests on water used to fight the fire in the Hazelwood coal mine amid concerns for the safety of the firefighters battling the blaze.

The fire has been burning since February 9, sending thick clouds of smoke across Morwell, east of Melbourne.

The United Firefighters Union (UFU) paid $9,000 for independent testing of water used in the mine after 13 firefighters contacted the union with concerns about their safety.

One firefighter had to have surgery and 22 stitches in his hand after a small cut became infected.

The occupational hygienist who carried out the independent test was horrified because it revealed extreme levels of E-coli and other dangerous bacteria which could get into small cuts and cause septicaemia.

The union's Mick Tisbury says the safety of the firefighters is the paramount concern.

"There's been a lot of concern shown for the residents of Morwell, and rightly so," he told ABC local radio.

"There's been bugger all concern shown for the actual firefighters in the hole.

"Morwell South's been evacuated, but the firefighters, we've got not choice, mate. We've got to expose ourselves to this stuff."

Commissioner orders new test on water

Fire Services Commissioner Craig Lapsley says the tests done by the UFU were broader than the ones done by the Environment Protection Agency (EPA).

The unidentified firefighter had to have surgery and stitches to his hand after being exposed to the water. ( Supplied )

"We have asked EPA to change their test regime to do the same as what the UFU have done in their independent review and have a look at those samples as well," he said.

"We took advice and obviously have gone down a certain road.

"UFU have gone a little bit further. [We] give them credit for that. We'll change our regime to get that right.

"I think the critical thing about this is about firefighter safety."

Firefighters have now been directed to wear special gloves and eye protection.

Premier Denis Napthine says his thoughts are with the injured firefighter, but his advice is that the water and the air quality is clear.

Flood of information from public about cause of mine fire

Meanwhile, Victoria Police Chief Commissioner Ken Lay says police have received a flood of information from the public about the deliberately lit fire that spread to the coal mine.

The fire started at Driffield, south of the mine, on February 9 and spread across bush and grassland and into the open cut mine.

Commissioner Lay says police have had more than 100 calls from people with information.

He says investigators are piecing together how the fire started and the intent of the arsonist.

"I'm very positive that our investigation's moving forward in a positive manner," he said.

"Hopefully we'll get a result in the not too distant future."

Premier Napthine says the Government is close to finalising the details of an inquiry into the management of the mine fire.

The Government has agreed to an independent inquiry into the fire, but is yet to reveal its terms of reference, or whether it will hold public hearings.

Dr Napthine says the details are being finalised.

"There will be a proper inquiry into this fire, the cause of the fire which police indicate is most likely to have been deliberately lit.

"The management of the fire and the management of how the incident affected the Morwell community, all of those things will be examined," he said.