DE SOTO, Kan. -- The four-billion dollar Panasonic EV Battery Plant in De Soto, Kansas is nearly ready to start production after more than two years of rapid construction. Leaders say the site has already maxed out with roughly 3,800 construction workers on site putting the 300-acre building together. It takes up a relatively small piece in the corner of the former Sunflower Army Ammunition Plant that made a younger De Soto Mayor Rick Walker curious. "I never came on the plant because at every fence there was a marker that said, 'Federal Property: Do Not Cross," said Walker. "It kept me out but it kept me wondering." Two separate Jackson County votes possible for Chiefs, Royals The plant officially closed in the 1990s, but Walker said it had been losing jobs long before that. It made Walker and other residents wonder if there would ever be a new development on the land that needed significant remediation after years of ammunition production. Two years after the Panasonic plant started construction, Walker says it's bringing nearly $250 million worth of infrastructure upgrades like new roads and sewer lines for much less money to the city and much faster than if De Soto had to do the work itself. "The scope of the project allowed for those community benefits to happen and be covered in the cost of the project," said Walker. He says upgrades to other roads and traffic patterns are trying to mitigate the negative impacts of what will be a massive workforce once the plant hires the 4,000 workers when it's at full capacity. Right now, there are 400 Panasonic employees hired and going through training or installing equipment with that number expected to grow to 1,000 by the summer, and 2,000 by early 2026. KC TikTok creators on potential ban: ‘A big step backwards’ "It's not going to be just the 4,000 jobs that Panasonic will have," said Kansas Governor Laura Kelly. "It is going to be a whole host of other entities that will come here and fill up all this empty land." Panasonic is hiring for hundreds of positions right now. You can find more information about those here.