Anaerobic sewer system for producing methane

We use the same tubes as long ago to move our waste when it can have methane harvested at small feeder locations throughout the sewer system. The methane can be fed into natural gas lines. Instead of aerobic digestion in the sewage lines anaerobic digestion can immediately Capitalize on an overgrowing resource.

You might say that this would make sewer lines very dangerous yet that isn't really an issue because natural gas lines have already been installed before.

With the massive culture, a warm and energetic group of species can break down food similar to how it was done in the gut.