Swimming hole highly acidic
THE cobalt blue water and cliff face makes the swimming hole at the former Bexhill Brickworks hard to resist on a hot summer day, which is probably why locals regularly ignore the ‘no swimming’ sign.
So eager are people to cool down in the crystal clear water they have pulled away a large section of the barbed wire fence to gain access.
However, a chemical analysis of the water by Southern Cross University reveals swimmers are putting themselves at peril.
While there has been a slight improvement since last tested in 2002, Graham Lancaster, the manager of SCU-based Environmental Analysis Laboratory, said the water is still highly acidic.
Testing conducted this week showed the water has a pH level of 3.98, well below Australian guidelines of between 6.5 and 8.5, meaning it is highly acidic.
“The origin of the acidity and metals is due to an acceleration of natural processes similar to the acid sulphate soils in this region releasing acid and metals,” Mr Lancaster said.
The test also found the level of manganese was 17 times higher than safe levels and aluminium was six times higher – both regarded as very high concentrations.
He said last week’s results had shown an improvement from 2002 which he put down to dilution from rain water and ground water.
Eight years ago the pH level was almost as acidic as vinegar and more so than Coca Cola, with aluminium levels 2500 times greater than the guidelines.
Closed around 2002, the former brickworks is easily accessible from Bangalow Road, and the dramatic cliff wall is a popular jumping off spot for locals, despite the pit containing jagged metal left over from the old quarrying and brickmaking operation.
Now Crown land, a NSW Department of Lands spokesperson yesterday warned against swimming at the former industrial site.
“It is understood the bright blue colour comes from copper in the disturbed clay, and the water quality is unsuitable for swimming, hence the fencing and warning signage,” the spokesperson said.
The department, which inspected the site after inquires from The Northern Star, said the fence would be repaired and additional signs erected as soon as possible.