A house I am potentially buying was built in 1955 (Florida). Given the vintage & location, the house was very likely built with cast iron plumbing. The house is ranch style on a crawl space. Sometime between 2005-2008 there was a brand new septic tank put in & then sometime between 2009-2015 the septic tank was filled, abandoned and the home was connected to city sewer. With these changes to the plumbing systems in the recent years, typically would the original cast iron plumbing system be replaced w/ PVC or a like material? Or do these changes not really have an effect on the cast iron pipes? Having a home inspection but curious of others thoughts! Thanks.