A KURRI Kurri civil works company has ensured an indigenous heritage site at Chinamans Hollow will be preserved.

Arogen devised a way to protect the site, which was discovered during the construction of a water main between Maitland and Cessnock.

The company used horizontal directional drilling (HDD) techniques to safeguard the indigenous history, extending the original Chinamans Hollow Crossing from 150 metres to 340 metres to prevent any disturbance of the site.

Hunter Water is undertaking the water main project  over 6.5 kilometers and including seven major  crossings.

Arogen has completed three of the crossings using its horizontal directional drilling technology.

"The advantage of HDD technology is that there is little to no impact on the community," Arogen business development director Tony O'Meley said.

"There are no extensive trenches to be dug, there is reduced construction time and the environmental impacts are reduced."