Sewers

What is the useful life of a sewer pipe and wastewater system components? I am trying to valuate sewer pipes for GASB 34 reporting and can't find enough sources to give a definite answer. I need the useful life for water systems and sewer systems (pipes) Please give me a source for this so I can report with it. Thanks

how might wastewater in the home be recycled instead of being poured into the sewer system?