Economy and FCF-SC equipment amortization as a function of
average daily washes is shown in Fig. 5. Considering a car wash
wastewater reclamation system in Porto Alegre, with 35 daily
washes, the equipment amortization is achieved in 24 months. In
São Paulo, due to the higher water prices, a demand of 10 washes
per day is sufficient to amortize the equipment in the same period
of time. More, in São Paulo-Brazil, when the daily demand reaches
33 washes, less than 10 months are necessary to amortize the
equipment investment. Ghisi et al. (2009) have considered a range
of 15–45 daily washes when evaluating the potential for potable
water savings in car washes in Brasília (BR).