A Hunter primary school has been immediately closed until the end of the week, after discovering a heavy metal contamination.
The Catholic Diocese of Maitland-Newcastle made the decision to close Glendale Holy Cross Primary School, after elevated levels of lead were detected in the soil near the fence line of play areas.
On Monday, about 150 students were moved to St Paul's Catholic College in Booragul, and will be there until at least Friday.
"It is important to recognise this is a concerning matter and we take it very seriously," a Diocese spokesperson said.
Health authorities say the risk to student and staff health is low, but will be on site this week to conduct further testing, while the affected areas have been cordoned off as initial remediation work gets underway.
"[Hunter New England Health] have assessed that the lead levels and exposure scenario would not be likely to elevate the blood lead levels of most students or staff," a Diocese spokesperson said.
"While some soil samples exceed the health investigation levels for lead in school soil, this does not mean there will be a health effect. The finding triggers an assessment of potential risk.
"School-wide blood lead testing is not being recommended due to the potential for unnecessary stress of testing in a low-risk situation."
The contamination was first discovered through routine testing in preparation for the construction of a proposed covered outdoor learning area.
At the moment, the contaminated soil has only been found in one area, however further testing will also establish the total extent of the contamination.
How the lead-containing soil ended up on school grounds remains unknown.
Lake Macquarie has a long history of 'black slag' - the product of the former Pasminco lead smelter - being found across the region.
From 1960 to 1995, more than two million tonnes of black slag was used throughout Lake Macquarie for landscaping.
A geofabric membrane will be used to cover the soil at the building site, which will be covered with topsoil and turf to minimise dust.
"The safety and wellbeing of our community is our priority, and we will continue to work with the relevant experts to confirm the safety of our school site," the Diocese spokesperson said.
"The Diocesan Property team is working on the immediate remediation of this area and has employed a qualified and independent occupational hygienist to undertake further soil samples to be confident that all steps are taken to safeguard the safety and wellbeing of our students and staff."
"This work, and all associated works, will be monitored by a qualified and independent occupational hygienist, with Safe Work notified."
