The EcoSan fallacy − again!

Unfortunately I couldn’t go to the IRC symposium on Sanitation for the Urban Poor which was held in Delft, The Netherlands, during 19−21 November. One of the papers presented was entitled “Alternatives to waterborne sanitation – a comparative study – limits and potentials” and, yes, it’s EcoSan promotion, but with the common error of comparing EcoSan costs (given as USD 935 per household) only with those of conventional sewerage (USD 1038–1227 per household). I’d guess the cost of condominial sewerage would be no more than ⅔ of that of conventional sewerage, so cheaper than EcoSan! Why is this mistake so often made and why is it tolerated? It certainly doesn’t do EcoSan any favours.