More than £50,000 is being spent every day tackling fires which have been started deliberately across Northern Ireland, the Belfast Telegraph can reveal.
Arsonists were responsible for 9,500 blazes in the last 18 months, with fire chiefs estimating the bill for dealing with the attacks is nearly £30m.
Yet in most cases the culprits escape justice, with police statistics revealing just one in 24 reported incidents resulted in someone being charged.
It has led to calls for tougher action against arsonists.
DUP MLA Paul Givan, who chairs the Assembly's justice committee, said the cost of arson was a waste of money.
"This is money that is literally going up in smoke," he said.
"This is causing a huge financial burden, never mind the public safety risk associated with arson attacks."
The Northern Ireland Fire and Rescue Service falls under the remit of the Department of Health, which is facing huge budget pressures. The near £30m spent on dealing with arson would go some way to meeting the £140m shortfall which Health Minister Edwin Poots said his department is facing.
According to figures from the fire service, firefighters responded to 9,501 deliberate blazes in the 18 months to July this year.
The total cost of responding to the fires was £28,954,979.
It averages at 17 fires each day, at a daily cost of £53,031.
The fire service pointed out that the figure includes normal day-to-day costs which would have been incurred while dealing with each incident.
Mr Givan, an MLA for Lagan Valley, added: "It is truly remarkable and shocking that the fire service is dealing with 17 deliberate blazes a day.
"There will be a criminal element where people are targeting property and people, but there is also an anti-social element which is causing a huge burden on our communities.
"The fire service itself is under pressure, put in the context of the Department of Health, which is under extreme pressure, and it is money going to complete waste."
SDLP MLA Alban Maginness, who also sits on the justice committee, said the costs of arson were not just financial.
"This is an enormous waste of money, particularly given that arson is a very deliberate, malicious and criminal act," he said.
"However, you also have to consider the impact on safety. Arson puts lives in danger and the effects of fire can be terrible."
The figures obtained by this newspaper include a number of high-profile arson attacks.
Last December more than £10,000 was spent dealing on a blaze after criminals drove a fuel tanker into the former headquarters of the Quinn Group in Fermanagh and set it alight.
A further £26,952 was spent putting out a blaze which engulfed the former site of St Peter's High School in Londonderry last September. The school closed in 2013 but has been targeted numerous times by arsonists.
And a blaze at Whiteabbey Methodist Church earlier this year cost the fire service £11,115.
Assistant Chief Fire Officer Dale Ashford said the 9,501 deliberate blazes included both primary fires such as buildings and secondary fires, for example gorse, wildland and rubbish.
"The number of deliberate primary fires has been decreasing year on year and over the past five years we have reduced the overall number of deliberate secondary fires by 41% with targeted education and engagement work with the community," he said.
However, Mr Ashford added that there had been a rise in the number of deliberate secondary fires, particularly gorse blazes, in the past year. In the first seven days of April 2013, for example, firefighters dealt with 387 gorse blazes.
He stressed that deliberate blazes put unnecessary strain on the fire service. "There is no doubt that attending such incidents puts additional pressure on our operational resources and we continue our community education and engagement work in relation to the serious consequences of deliberate fire-setting and targeting public awareness campaigns towards hotspot areas for gorse and wildland fires," he said.