He said Costco's store would offer Hunter residents a "different shopping experience than you're used to".
"We sell everything from champagne to fresh meat, Calvin Klein jeans and diamond rings - you can buy everything there," he said.
"It's a true market.
"We try and bring great brands from around the world, and Australia, and offer those at discount prices."
Construction of the 14,000 square-metre warehouse and service station is expected to generate about 80 full-time equivalent jobs.
Costco plans to employ between 225 and 250 people to work at the store in ongoing roles, Mr Noone said.
Lake Macquarie MP Greg Piper said those jobs, along with the hundreds that will be created by Green Capital's adjacent residential development, would offer local employment opportunities for Lake Macquarie residents.
The smelter, which operated at the site for more than 100 years until operations ceased in 2003, caused widespread contamination.
"It had a very controversial life, particularly towards the later years," Mr Piper said.
"I've been involved with that issue since 1988, so I can assure you it's been a very long journey to get to there.
"But as the local member and a former mayor, I'm very proud of the work that we have all done - as a community - to reclaim something excellent out of what was a very big legacy problem."
The NSW government took ownership of the site late last year after it passed legislation to make a compulsory acquisition.
The site was transferred to the Hunter and Central Coast Development Corporation, which managed and progressed the land sales with the two parties.
Both had previously had options on the lots, but the sales did not eventuate under Ferrier Hodgson.
Ms Pavey, who said Premier Gladys Berejiklian had made the Cockle Creek precinct "a very big KPI" for her when she became Property Minister, praised Mr Piper for his advocacy to progress the site over recent years.
She said the land sales and expected development "couldn't be happening at better time in relation to economic activity" and the state government was "pleased to part of it, and delivering it".
"This is hundreds and hundreds of jobs at a time when we need a little bit of positive news and opportunity," she said.
"Full-time equivalent jobs - 200 at Costco, 80 in the construction of the warehouse and we will see that finished by the middle of next year.
"So it's full steam ahead.
"As for the new homes, 500 new home sites, there could be 400 jobs during the construction of those homes.
"It's an amazing opportunity to live in a great location, near public transport, near magnificent Lake Macquarie.
"This community has been waiting a long time for this."
Lake Macquarie mayor Kay Fraser said council welcomed the opportunity to the developments.
"A $300 million investment by Costco and Green Capital, it's absolutely amazing," she said. "We know that Costco will make a huge impact in this city and they will bring other businesses here with them as well.
"With Green Capital, we know they're already talking about an additional 500 homes here. That will bring more people to our city and will make it vibrant and make it more livable."
Green Capital is working with council to progress its plans for the staged subdivision. It has already developed an adjacent lot it bought in 2015.
The state government has not revealed the value of its two land sales.
Swedish furniture chain IKEA, which was previously linked to the precinct, is understood to no longer be interested in establishing a store at the site. HCCDC is yet to determine how it will subdivide and market its remaining parcels of land.
Cr Fraser said the land sales to Costco and Green Capital would instill confidence in other businesses to invest in the area.
"This is a place where developers will want to come, this is where people will want to live," she said.
"We're so close to the lake, we're close to the beaches - why wouldn't you want to live here? We're close to the train station, close to the M1 - it has everything.
"Having someone like Costco come here, the only store in regional NSW ... it will spur on other developers to come to our city."
Greg Piper has been an independent voice for the people of Lake Macquarie for more than 30 years, as a Member of Parliament, Mayor and councillor. He was elected to Lake Macquarie council in 1991, served as Mayor from 2004 until 2012 and has been the State MP for Lake Macquarie since 2007.