The federal and provincial environmental assessment process took nearly seven-years and KSM was only the second metal mine in five years to receive approval.

A new preliminary economic impact study released by Toronto-based Seabridge on Thursday, the already ambitious project takes another leap forward.

According to a statement, Seabridge now envisages a much larger operation than the one outlined in the preliminary feasibility study released last month and in the process improves both the environmental impact and economics of KSM.

The PEA calls for mill throughput of 170,000 tonnes per day, 40,000 tonnes more than the earlier study which Seabridge says can be done without significant redesign of facilities. Initial capital costs have been increased by just less than 10% to $5.5 billion.

In the PEA the bulk of the operations are moved underground and using the block-cave method Seabridge says it can reduce waste rock by a whopping 81% or 2.4 billion tonnes over the 51 year life of the mine.

By vastly increasing the amount of copper mined life of mine operating costs are now a negative $179 an ounce while all-in costs fall to just $358 an ounce.

Measured and Indicated Mineral Resources at KSM are estimated at 2.9 billion tonnes grading 0.54 grams per tonne gold, 0.21% copper and 2.7 grams per tonne silver which translates into 49.8 million ounces of gold, 13.6 billion pounds of copper and 253 million ounces of silver.

During the first seven years of operation annual gold output would top 1 million ounces and life of mine annual production is estimated at 592,000 ounces of gold, 286,000 pounds of copper and 2.8 million ounces of silver.

Seabridge (TSX:SEA) (NYSE:SA) is worth just over $530 million on the New York Stock Exchange, up 21% in value year to date.