Promoting Water Efficiency in a Municipal Market Building: A Case Study

Abstract

This study aimed to determine the water demand of a Municipal Market building to propose water use efficiency measures. The flushing cisterns have the highest water consumption (63.15%), followed by washbasins, restaurant and coffee shop taps, and hairdresser’s showerhead (31.64%). Therefore, the implementation of two main categories of solutions: reducing water consumption through the adoption of efficient devices and installing a rainwater harvesting system (RWHS) when drinking water quality is not required, was evaluated. These solutions were organized in four distinct scenarios: (1) Flushing cistern replacement by dual-flush ones; (2) washbasins, restaurant, coffee shop taps, and hairdresser showerhead replacement; (3) scenario 1 combined to a RWHS for recharging the replaced flushing cisterns and (4) combining scenarios 3 and 4. Under scenarios 1, 2, 3, and 4, the expected water consumption reduction was 28.36%, 17.06%, 57.36%, and 74.41%, respectively. As a result, the annual water bill reduction was €3835.81 (scenario 1), €2307.07 (scenario 2), €7757.65 (scenario 3), and €10,064.73 (scenario 4). Furthermore, to ensure the harvested rainwater attains the required standard for recharge flushing cisterns, it is advisable to dispose of the first-flush rainwater collected after a long dry period.

Technical and Financial Feasibility Analysis of Rainwater Harvesting Using Conventional or Green Roofs in an Industrial Building

“…In addition, RWHS reduces the volume of stormwater drained into the drainage system, the flooding risks, and the pressure on natural water resources minimizing the ecological footprint through potable water [15]. Despite the existing research worldwide focusing predominantly on RWHS installation in residential [12][13][14][16][17][18][19][20] and commercial buildings [4,10,[21][22][23][24][25][26][27][28][29][30], implementing RWHS in metalworking industries facilities for cleaning or non-critical cooling processes and for activities when drinking water quality is not required (e.g., recharging flushing cisterns and irrigation of green spaces) can be an important tool, helping to reduce the pressure of this industry on traditional water sources [7].…”

“…Nevertheless, despite the potential benefits of this combination, very few studies have been addressed to evaluate the effectiveness and the interaction between RWHS and GR [15,45,46]. In Portugal, both RWHS with conventional roofs [30] and RWHS combined with GR [15,45,46] have not yet been deeply exploited.…”