Advice needed - 1950's backsplit house, potential leak at main drain

Hi all, I recently purchased a 1950's backsplit home. I attached a picture that seems to show some moisture and potentially salt build-up around the main drain. It looks like it switches to iron just before it enters the ground, which I assume would be original. Could anyone let me know if this is a major concern / sign of impending failure? Is this something I should pro-actively look into or wait till it fails type of issue? Thanks for any/all advice.
Imgur link to pic as I don't know how to direct add a picture :S

https://imgur.com/4sr8TJ0