ECONOMIC FEASIBILITY OF WATER CONSERVATION STRATEGIES IN LARGE COMMERCIAL BUILDING
Name: Carolina Wassem Galvão
Type: MSc dissertation
Publication date: 10/08/2021
Advisor:
Name |
Role |
|---|---|
| Diogo Costa Buarque | Advisor * |
| Ricardo Franci Gonçalves | Co-advisor * |
Examining board:
| Name |
Role |
|---|---|
| Asher Kiperstok First | External Examiner * |
| Diogo Costa Buarque | Advisor * |
| José Antônio Tosta dos Reis | Internal Examiner * |
| Ricardo Franci Gonçalves | Co advisor * |
Summary: The technical and economic evaluation for the implementation of water conservation
systems that address the use of alternative sources for non-potable purposes is an
essential tool in decision-making to determine the most appropriate configuration for
each building. Thus, this research sought to evaluate the technical and economic
feasibility of reusing sanitary sewage to meet non-potable demands in relation to the
reuse of greywater at Shopping Center Vila Velha. Scenarios for the reuse of sanitary
sewage associated or not with the use of rainwater and condensate water were
established and evaluated, in comparison with the reuse of greywater associated
with the use of rainwater and condensate water. The technical evaluation was carried
out with the aid of the STAN software (subSTance flow ANalysis), through the
preparation of three hypothetical water balances for the building. The economic
evaluation was carried out through budgets for the implementation of eight settings
for the collection, storage, treatment and distribution of the four alternative sources of
non-potable water. The results obtained in the technical feasibility assessment
indicated that the reuse of sanitary sewage offers better performance in meeting the
demands for non-potable water, when compared to the reuse of greywater. In
addition, the scenario in which only sanitary sewage is used as an alternative source
is the one that guarantees greater water security for the building, so that all the
demand for non-potable water could be met only with the supply of sanitary sewage.
The results obtained in the economic viability assessment indicated that all the
scenarios evaluated have economic viability, with NPVs between R$ 7,184,956.17
and R$ 11,736,080.62, IRR between 52% and 182% and payback period between
seven months and two years and two months. In addition, despite presenting higher
initial investment and operation and maintenance costs, systems that consider the
reuse of sanitary sewage have NPV, IRR and Pay Back discounted better than that
of the system with reuse of greywater, when considering similar treatment solutions.
Thus, for the Shopping Center Vila Velha, the reuse of sanitary sewage showed
better technical and economic feasibility than the reuse of greywater.
