Comment Maintenance costs are real (Score 2) 64
The number of single family homes has grown about 70% since 1970.
I don't know what the average age of a sewer is before it needs it's first major repairs or upgrades, but 50 years doesn't seem improbable. Of course your running costs are going to be lower in the first 20-40 years. But the ground shifts, capacity needs upgrading, things fail etc. US population keeps growing, so more and more sewers will hit that magic 50 year mark (or whatever year you pick) where true Total Cost of Ownership becomes apparent. Europe is more expensive than the US, but their population began to stabilize in ~1985 and they've been paying the "sustainable" cost for many more years. The US will see the same result ~30 years after when the population begins to plateau.