Traditional sources of aggregate and sand are nearly exhausted near Penrith. Consequently, multinational and smaller operators are blasting into a vast granodiorite resource to supply hard rock for building projects, including Sydney’s second airport at Badgerys Creek, new roads and rail links and housing projects.

Five quarries have either been upgraded or are being commissioned between Goulburn and the Hume Highway village of Marulan. The two major ones are Boral’s $200 million quarry and Holcim’s Lynwood quarry, a $250 million project.

Nathan O’Connor, an exercise science and sports management graduate from the University of Canberra, and surveyor Michael David hope to be among the 250 people who land long-term jobs at one of the quarries.

Mr David has worked on just about every wind farm in the region, but demand for his skills are limited in his home town of Goulburn, where there’s an annual exodus of school leavers.

In their early 20s, both men are prepared to do anything but hope to align their work with their skills when Holcim’s Lynwood mine is commissioned in late September with 115 staff.

Big machines being assembled including Hewatt earth movers sold this month after the Canberra firm went broke on the Majura Parkway construction.

Marulan Chamber of Commerce spokesman David Humphreys says auxiliary activities will generate more business beyond the initial investment.

''What dictates extractive industries is construction. The Reserve Bank is hoping and saying positively the construction industry is moving in to take up that slack (from the mining sector),'' he said.

Mr Humphreys, who belongs to a consultative committee with Holcim and Goulburn Mulwaree Council’s economic development committee, says the federal government’s new infrastructure agenda will drive demand.

''Holcim will have 150 truck movements a day - that’s 75 trucks, 75 drivers and somewhere along the line 75 people who are going to look after the trucks and supply them, fill them up with petrol, the whole bit.''

Eighty per cent of ore leaving Holcim will go by rail. The beginnings of an open-cut pit have already been drilled and blasted in a 17.5 metre-deep hole from which rock will be hauled to a crusher and reduced into various sizes.

Lynwood’s head of project Shannon Ladewig said Holcim was working with the Beacon Foundation, which helps school leavers, to expand its workforce.

''They have been very successful and we have been fortunate enough to help them supporting young people to develop career pathways, not only in our industry but others as well,'' Mr Ladewig said.

Goulburn Mulwaree Council economic development officer Debbi Rodden said the industry needed to educate young school leavers about solid, ongoing careers, including for professional people such as surveyors, geologists, environmentalists  and engineers.

''Quarrying may not be seen as a desirable industry for some people, but young people need to realise they get to blow stuff up,'' Ms Rodden said.

Twenty seven tonne of emulsion explosives is pumped into one blast, and when the 24-hour operation is in full swing 3.5 million tonne of milled hard rock will leave Lynwood to build homes, schools, hospitals, factories, railways and roads.