that's always angered dionisio brito. he's the head of the neighborhood association in one of san cristobal's poor districts. dionisio: the river is seriously contaminated by the rubbish. and the locals suffer from that. all the rats, the flies, the mosquitoes, they bring disease. we have a lot of kids running around here barefoot. and the truth is, that makes me very sad. reporter: but things are changing in this district, thanks to in large part to dionisio's commitment. he takes me to the local school, which plays an important role in what everyone here just calls the project. education is one of the project's key elements. science teacher juan pablo fabian regularly reminds his class how important it is to separate waste, into organic and non-organic. un-separated rubbish festers and ferments, producing greenhouse gases that damage the climate. juan pablo: so our organic waste comes into this compost, into this wooden container. and thanks to certain insects and certain bacteria, this organic material decomposes. but