It is both software and database issue. OpenLCA (and other softwares such as SimaPro and GaBi) are not specific to model waste management processes. For example, they do not include modelling of waste composition and organic matter degradation. The user would have to proceed these process outside the software and bring these specific results into the LCI of OpenLCA. Further discussion can be found here:
For the ecoinvent, I am still trying to understand how treatment of municipal solid waste (landfill and anaerobic digestion) are set for different waste composition and site locations. I want to adapt the data to Brazil specific conditions (e.g. more than 50% of organic matter from municipal solid waste generation). But when I look on the input/output of the treatment process I can not find any flow for organic matter (or any other flow that is related to it). It is not clear how these compositions are made. Some times, there is five different flows (with different amounts) for graphical paper. Where do they come from? The documentation of ecoinvent is very poor.
The lack of examples make it all more difficult for me, as a user beginner.