The NSW Department of Education has issued a further assurance about the safety of Cringila Public School students after a coal fire beneath the school reignited after a decade of inactivity.
The school department said air quality test were conducted over the school holidays, with results showing there was “no hazard to students, staff or the school community”.
“While some odours can at times be detected, these levels are far below the prescribed safe exposure limit and are therefore not considered a risk,” the department told the Mercury on Thursday.
Parents alerted the school and EPA to the re-ignition of the dormant underground fire three weeks ago, when they noticed smoke and a burning coal smell emanating from the earth.
The fenced-off site between the school and its sports fields last drew attention in 2007, when the NSW Education Department - which owns the land - undertook major remediation works to extinguish a fire burning several metres underground.
The fire had been burning for decades unnoticed until 2001.
It was caused by coal wash dumped on the site by BHP to create the school's playground in the 1970s.
The material was not compacted sufficiently, so the oxygen in the air reacted with the coal wash and spontaneous combustion kicked in.
The day after parent Paula Loustos raised the issue with the school on September 18, the Education Department launched an investigation with Fire and Rescue NSW, NSW Health and the EPA to find the source of the new smoke.
This revealed that a long spell of dry weather, and subsequent drop in the water table, had resulted in ignition of the underground coal.
Fire crews attended and flooded the area with water in an effort to stop the ground from smouldering.