The federal government will pay as much as 50 per cent of the decontamination costs in Lac-Mégantic, Que., to a maximum of $95 million, Prime Minister Stephen Harper announced in the town Thursday.

The Quebec government has estimated the cleanup costs following the train derailment that devastated the small Quebec town in July at $190 million.

The federal government will split the cleanup costs 50-50 with the province of Quebec.

Harper praised the efforts of first responders who were called to the scene that tragic day in July and personally thanked them for their courage in the face of such terrible and personally tragedy.

The prime minister said today's financial contribution was "not final," and that the federal government is open to re-evaluating its share of the cleanup costs should the final price tag be higher than expected.

"It's very possible the final costs will be more than $190 million, but those are the initial estimates by the government of Quebec. We will be here for the entire rebuilding process," Harper said.

Harper was joined by International Development Minister Christian Paradis, who is also the MP for Mégantic-L'Érable, and Lac-Mégantic Mayor Colette Roy-Laroche.

72 tankers spilled

Meghan Plamondon, a resident of Lac-Mégantic, told CBC News on Thursday it will take at least a year or two for businesses to clean up the affected areas.

Today's financial support will help the town clean up up the estimated 31 hectares of affected soil in Lac-Mégantic and the Chaudière River.

The cleanup will consist of disposing of contaminated waste, helping to restore the sewer system, clean up buildings and infrastructure, and demolish contaminated buildings.

The federal government has already committed $60 million to support recovery efforts in the small town.

Since the derailment, the federal government has taken several measures to ensure railway owners are liable for losses and damages following an oil spill under federal legislation.

The government has also taken steps to increase rail safety and the transportation of dangerous goods across the country.​

Transport Minister Lisa Raitt announced on Wednesday that the federal government will now require railway companies to inform the communities their trains run through of the dangerous goods they are carrying.

Canadian Class 1 railway companies will have to report that information every three months while other companies will have to do so on an annual basis.

The train that derailed in Lac-Mégantic was carrying 72 tankers full of crude oil causing a series of explosions that killed 47 people and ripped the small community apart.

'Secret' Senate payment

Harper was asked by reporters in Lac-Mégantic about the latest allegations in the Senate expenses scandal, including whether his former chief of staff, Nigel Wright, came to him in February for approval on his decision to give Senator Mike Duffy $90,000 out of his own pocket to repay his ineligible expenses.

The prime minister did not answer the questions directly but simply reiterated what he has repeated in the past, that he took action when he found out about the deal on May 15.

"Mr. Wright, who made the secret payment to Mr. Duffy has not been in my employment for six months. Mr. Duffy has been sanctioned severely and removed from the payroll by the Senate of Canada."

The timing of Harper's announcement in Quebec will make it such that the prime minister will not be back in Ottawa to attend question period.

The Opposition New Democrats are expected to ask the Conservatives about the allegations contained in court documents filed by the RCMP about the Mike Duffy expenses scandal.

Harper's former chief of staff, Nigel Wright, and Duffy are alleged to have committed bribery, fraud on the government, and breach of trust between February and May 2013, according to the RCMP.

The prime minister was also asked about the credibility of Toronto mayor Rob Ford and whether he should resign given that he has admitted to smoking crack cocaine.

Harper said his government's tough-on-crime position is clear: "We do not endorse the use or purchase of drugs by officials in public office."