It may take several weeks and more than €2m to extinguish an underground fire as big as 10 houses raging at an abandoned dump.
And yesterday health experts were due to visit householders living near the dump at Kerdiffstown, near Naas, Co Kildare, to advise on protection measures against respiratory illness.
An expert from British consultants SKM Enviros with experience in tackling fires below ground visited the site yesterday to assess the environmental emergency.
On Friday night public agencies, including the environmental Protection Agency (EPA), Health Service Executive (HSE) and Kildare County Council met with residents and local politicians to brief them on the difficulties posed by the underground fire, which has been burning since last week.
At least 30,000 people live in the shadow of the dump and the smell of burning has reached all parts of Naas and some surrounding areas.
The EPA has, from yesterday, provided 24-hour security on the site -- a measure that local residents have been seeking for more than a year.
Spontaneous combustion is the most likely cause of the main fire, including a build-up of flammable gases.
Air quality measurement in the area has been increased but, so far, tests have discovered no breach of permitted standards.
The HSE has advised householders in the path of the fire's smoke plume to close windows and doors as a precaution.
It also advises that people with existing respiratory or cardiac problems, young children and the elderly may experience problems. Anyone with symptoms should reduce their level of activity and consult their doctor, it says.
Smoke from the fire contains elevated levels of sulphur dioxide and some local residents have had to leave their homes. The council is also considering if a wider evacuation may be required should the fire get worse.