Ancient pipelines and ancestors

It is too bad, if old becomes ancient and fathers become ancestors. A report the other day was on the water supply agency's need for replacement of its ancient pipelines which account for a fourth the total network. But if they were ancient, they indicated to about a thousand years' existence of the agency in this part of the human habitation --- quite an old modern civilisation. The word 'ancestor' is also often applied to people who are just fathers of fathers --- grandfathers, they are. Old is old and ancient ancient. So are grandfathers and ancestors.