It's efficient compared to putting it in the trash to go to a landfill.
We compost 99% of ours, but that option isn't practical in cities.
And in Michiganistan, we've no shortage of water. Mine is free.
Plus, all water going down our drain is filtered before it returns
to the aquifer.
It is not efficient compared to being collected by the council and composted with other green waste which is done over the entire UK including cities. Land fill is an extremely expensive resource, and entirely wasteful. The target in the UK is for 100% recycling.
We are a long way off that yet but making steady progress. this is even more important for city waste than for country waste.
The waste from sewage works has always been reclaimed as compost, and never goes as land fill, but it is an expensive process.
Water discharged from a modern sewage works is totally drinkable.
We do not put domestic trash directly in land fill, we all have four coloured wheelie bins. to separate our waste for recycling. The green one is for food and garden waste.