Wasting drinking water to move sewage

In the usual sanitary sewer system we use drinking water to move waste through pipes towards resource recovery plants (wastewater treatment plants). Across the US the infrastructure is in disrepair and needs a lot of attention, so getting a wasteful system running right is going to take a huge investment. Why don't we take an opportunity to rethink how we move our waste? I would love to hear ideas folks have for a system that could work in cities that would be more efficient than water/gravity driven pipes.