Makes sewer talk, just that, talk!
So called 'advanced economies' could also learn?
http://www.csmonitor.com/World/Making-a-difference/Change-Agent/2012/0703/Biogas-project-helps-Kenyan-school-save-money-and-trees?cmpid=ema:nws:Change%20Agent%20weekly%2007-09-12&cmpid=ema:nws:NzQ4MDU4NDEwMgS2