3 weeping willows close to each other (and a concrete shed and a gas line near the fence). Should I be concerned?

The old homeowners planted 3 weeping willows like this to soak up water that doesn’t drain much in this area. We noticed that a gas line (yellow lines and flags) runs close by as shown in the picture. There is no water or sewage lines.

I understand that the roots are invasive, but if this is not a threat I’d like to leave it as it will good shade. Not concerned about cleaning the mess.

Should I be worried? How do I approach this situation