Potential use of rainwater as a tool for fire stations and firefighting: Literature review, environmental and cost assessments.

Few studies in the literature integrate rainwater harvesting and firefighting. Thus, the general objective of this paper was to evaluate the potential use of rainwater as a source of water for firefighting. To do so, two approaches were proposed for the assessment. The first approach was the analysis of the existing literature. Two databases were evaluated as references in engineering fields, of which 32 articles mentioned rainwater as an alternative for firefighting. The main result of the review was the scarcity of articles in the area under study, with some of the existing articles focusing on forest fires. In contrast, others analysed the use of rainwater within the scope of buildings or fire stations. The second approach involved a case study that started by analysing the fire statistics provided by the Military Fire Department of the state of Santa Catarina, Brazil. It was observed that, between 2017 and 2020, building fires represented 25 % of the state's fires and 50 % of the water consumption in firefighting, while the rest of the fire occurrences represented the other half of water consumption. Rainwater can be used not only to reduce the total consumption of potable water but also as a logistics tool towards better response time in the event of a fire. With the firefighting water demand obtained, a Life Cycle Assessment (LCA) approach was performed to assess the potential environmental optimisation in a simplified scope. It was performed in a cradle-to-gate approach, leaving the potential optimisations in transport and logistics apart. Also, a cost assessment was carried out, obtaining a much lower cost for firefighting and providing financial savings for fire stations. As a result, rainwater is expected to decrease environmental impacts, help logistics in fire and save money for fire supression.

Impact of residential rainwater harvesting on stormwater runoff.

Population increase, climate change and soil impermeability are factors causing floods in large urban centres. Such places also always have water shortage problems. This research aims to evaluate the influence of rainwater harvesting in residential buildings on stormwater in a basin located in southern Brazil (Rio Cachoeira Basin). Urbanised and non-urbanised areas, soil types, curve numbers and time of concentration of each sub-basin were taken into account. Through the HEC-HMS programme, it was possible to calculate hydrographs for the base scenario (when there is no rainwater harvesting). Then, rainwater tanks for the residential buildings were sized using the computer programme Netuno. In the second scenario, there is rainwater harvesting in all residential buildings. Thus, the hydrographs for the second scenario were also calculated. The peak flow reduction potentials for the sub-basins ranged from 2.7% to 14.3%. The highest percentage (14.3%) did not occur in the sub-basin with the most extensive roof area; such highest peak flow reduction occurred in Bom Retiro sub-basin. In Bom Retiro sub-basin, there are more houses than multi-storey residential buildings. Even when considering the full potential of rainwater harvesting for roof areas of all existing buildings in the Rio Cachoeira Basin, the average potential reduction in peak flow was 7.2%. The conclusion is that rainwater tanks in residential buildings have little influence on stormwater runoff, and the stormwater runoff will be less affected when the area of the hydrographic basin is larger. Thus, the reduction in peak flows is insignificant when considering the flooding in the region.

Influence of rainfall time series indicators on the performance of residential rainwater harvesting systems.

Despite having abundant water sources, some Brazilian regions are likely to face water scarcity within the following decades. In this sense, rainwater harvesting (RWH) systems are considered viable solutions. This study evaluates the influence of rainfall time series indicators on the tank sizes, volumetric reliability and potential for potable water savings in residential buildings in Brazil. The study aimed to determine the most suitable rainfall conditions for RWH systems design. RWH systems were simulated for 27 Brazilian cities considering a daily water balance model. Total water demands and rainfall time series were considered for each city, and RWH-relevant indicators characterised each time series. Generally, cities with higher rainfall availability required smaller tank sizes and yielded greater volumetric reliabilities and potential for potable water savings. Cluster analysis was also used to investigate if similar rainfall patterns generate similar simulation results. Euclidean distance criteria grouped similar time series into ten clustering schemes. Coefficients of variation for tank sizes decreased within each scenario as more clusters were used, i.e. this method is feasible to design rainwater storage tanks. The remaining performance indicators did not show significant variation among the tested clustering scenarios. Similarity analysis resulted in increasingly similar results within each group as the clustering became more refined. As the main conclusion, correlation analysis presented the Seasonality index and indicators related to dry periods as the most influential towards the performance of RWH systems.

Is asbestos still a problem in the world? A current review.

Asbestos has been used by automobile, construction, manufacturing, power, and chemical industries for many years due to its particular properties, i.e. high tensile strength, non-flammable, thermal and electrical resistance and stability, and chemical resistance. However, such a mineral causes harmful effects to human health, including different types of cancer (e.g., mesothelioma). As a result, the use of asbestos has been banned since the 1980s in many countries. Nonetheless, asbestos is still part of the daily life of the population as asbestos-containing materials (ACMs) are still present in many buildings constructed and renovated before the 1990s. This work aims to present a current literature review about asbestos. The literature review was composed mainly of research articles published in international journals from the medical and engineering disciplines to provide an overview of asbestos use effects reported in interdisciplinary areas. The literature review comprised asbestos characteristics and its relationship to the risks of human exposure, countries where asbestos use is permitted or banned, reducing asbestos in the built environment, and environmental impact due to use and disposal of asbestos. The main findings were that ACMs are still responsible for severe human diseases, particularly in areas where there is a lack of coordinated asbestos management plans, reduced awareness about asbestos health risks, or even a delay in the implementation of asbestos-ban. Such issues may be more prevailing in developing countries. The current research in many countries contemplates several methodologies and techniques to process ACMs into inert and recyclable materials. The identification and coordinated management of ACM hazardous waste is a significant challenge to be faced by countries, and its inadequate disposal causes severe risk of exposure to asbestos fibres. Based on this work, it was concluded that banning asbestos is indicated in all countries in the world.

Life cycle assessment of green roofs: A literature review of layers materials and purposes.

Green roofs offer several environmental and social benefits to urban life. However, such roofs require a greater amount of materials than conventional roofs. The life cycle assessment (LCA) is an appropriate tool that has been used to obtain the potential environmental impacts associated with green roofs throughout their life cycle. This paper aims to review the literature related to the LCA of green roofs, responding: which materials and layers were used in green roofs in LCA studies; which processes were considered in each life cycle phase; which types of roofs have already been compared to green roofs through LCA; which measures are taken to reduce the environmental impacts of green roofs; which methods were used to assess the economic feasibility of green roofs over their life cycle and what were the purposes of such analyses; and which LCA studies included public perceptions about the green roofs. Our findings indicate that the materials used in the green roof layers vary among the articles. However, polymeric materials are usually used for all the layers, except for the substrate. Cradle to grave is the most common approach. Within this approach, more than half of the articles considered cooling and heating energy, which may significantly influence the life cycle analysis results. Most studies reviewed agreed that green roofs cause less environmental impacts than conventional and white roofs. The use of byproducts or recycled materials may further improve the performance. In most studies, public perception is not included in the analysis. Regarding the economic approach, both life cycle cost and life cycle cost-benefit are used to compare green roofs economic viability with other roof systems. In addition to discussing studies reported in the literature, this article also recommends future research to improve the performance of green roofs.

Environmental assessment of a permeable pavement system used to harvest stormwater for non-potable water uses in a building.

The objective of this work is to present and to apply a method to environmentally evaluate a permeable pavement system used to harvest stormwater for non-potable water uses in a building. Two pavement systems were compared through life cycle assessment (LCA). The first system consists of a permeable pavement; in this case, the stormwater filtered by the pavement is used for non-potable water purposes in a building. The second system consists of a flexible pavement (impermeable), with no stormwater harvesting, and with conventional water supply in the building. The method was applied in a case study in a public building in southern Brazil. Water consumption surveys were made and the potential for potable water and electricity savings in the building were estimated. In the inventory, input and output data related to each stage of the life cycle of the systems were gathered and quantified. In the impact assessment, it was found that, for both pavement systems, the most significant damages were related to the implementation and end-of-life stages. The permeable pavement system presented a lower potential for environmental impacts in most midpoint categories evaluated, and also lower overall potential impact in the endpoint approach. The results also showed that the categories with the greatest environmental impact for both systems were fine particulate matter formation and global warming. The method proposed can be used as a basis for guiding planning and decision-making to improve water infrastructure management through stormwater harvesting in urban centres.

Life cycle energy assessment and economic feasibility of stormwater harvested from pervious pavements.

Pervious pavements are one of the most used construction techniques among the Sustainable Urban Drainage Systems (SUDS). The objective of this article is to analyse the energy life cycle and the life cycle cost of stormwater harvesting systems using pervious pavements models in order to compare and evaluate the differences and verify what influences the profitability and sustainability. The method proposed started with the definition of pervious pavement models based on literature review. The main characteristic of the models analysed was the use of porous asphalt with different underlying layers, i.e. thickness and material. The hydrological-hydraulic design of the pavements was also assessed. The potential for potable water savings due to harvesting stormwater from a parking lot was estimated for a public building in Florianópolis, southern Brazil. The models were compared to identify what most influences the potable water savings, the profitability and the sustainability of the systems. The maximum potable water savings found were 42%. It was also observed that the overall consumption of the building has been decreasing over the years, and the yearly rainfall has increased, which leads to a higher potential. In the current water consumption pattern, none of the systems evaluated was profitable or presented sustainability, evaluated herein as negative energy balance. However, it was verified that if analysed comparatively with non-pervious pavement, it was profitable to use stormwater harvested from the pervious pavement. Thus, it can be concluded that stormwater harvesting systems in combination with pervious pavements are promising, serving as SUDS and saving money for users. It is also noticeable that the use of porous asphalt is not recommended when aiming for systems with low embedded energy.

Application of stormwater collected from porous asphalt pavements for non-potable uses in buildings.

This study assessed the potential for potable water savings in a building by using stormwater filtered by a porous asphalt pavement located in a parking lot. Stormwater is meant to be used for non-potable purposes (flushing toilets and urinals). Two models of porous pavement systems were constructed, both with porous asphalt mixture over a different combination of porous granular layers. The models were assessed for their filtering capacity; samples of stormwater runoff were collected in a parking lot located near the building where filtered stormwater is meant to be used. The models showed to be capable of filtering some pollutants. However, additional water treatment would be necessary to obtain the quality required for non-potable uses. Then one model was selected for a theoretical analysis on using it in a parking lot. The potential for potable water savings was analysed considering four scenarios as a function of daily local rainfall data. The thickness of the temporary stormwater reservoir layer was calculated in order to meet the design rainfall adopted, and the stormwater tank capacity was estimated using the Netuno computer programme. As a result, using a 45,000-litre stormwater tank, potable water savings of at least 53% would be obtained if filtered stormwater were used to flush toilets and urinals. This indicates that porous pavements show a great potential for filtering stormwater runoff to be used in buildings.

Environmental benefit analysis of strategies for potable water savings in residential buildings.

The objective of this study is to assess the environmental benefit of using rainwater, greywater, water-efficient appliances and their combinations in low-income houses. The study was conducted surveying twenty households located in southern Brazil, which resulted in water end-uses estimation. Then, embodied energy, potential for potable water savings and sewage reduction when using the different strategies were estimated. The environmental benefit analysis of these strategies was performed using an indicator that includes embodied energy, potable water savings, reduction of sewage and energy consumption in the water utility, and sewage production during the life cycle of the system. The results indicated that the strategy with the greatest environmental benefit is the use of water-efficient appliances, which resulted in substantial water savings and reduction of sewage, causing low environmental impact due to lower embodied energy over the life cycle.

Urban rainwater harvesting systems: Research, implementation and future perspectives.

While the practice of rainwater harvesting (RWH) can be traced back millennia, the degree of its modern implementation varies greatly across the world, often with systems that do not maximize potential benefits. With a global focus, the pertinent practical, theoretical and social aspects of RWH are reviewed in order to ascertain the state of the art. Avenues for future research are also identified. A major finding is that the degree of RWH systems implementation and the technology selection are strongly influenced by economic constraints and local regulations. Moreover, despite design protocols having been set up in many countries, recommendations are still often organized only with the objective of conserving water without considering other potential benefits associated with the multiple-purpose nature of RWH. It is suggested that future work on RWH addresses three priority challenges. Firstly, more empirical data on system operation is needed to allow improved modelling by taking into account multiple objectives of RWH systems. Secondly, maintenance aspects and how they may impact the quality of collected rainwater should be explored in the future as a way to increase confidence on rainwater use. Finally, research should be devoted to the understanding of how institutional and socio-political support can be best targeted to improve system efficacy and community acceptance.

Uncertainty analysis of daily potable water demand on the performance evaluation of rainwater harvesting systems in residential buildings.

The objective of this paper is to perform a sensitivity analysis of design variables and an uncertainty analysis of daily potable water demand to evaluate the performance of rainwater harvesting systems in residential buildings. Eight cities in Brazil with different rainfall patterns were analysed. A numeric experiment was performed by means of computer simulation of rainwater harvesting. A sensitivity analysis was performed using variance-based indices for identifying the most important design parameters for rainwater harvesting systems when assessing the potential for potable water savings and underground tank capacity sizing. The uncertainty analysis was performed for different scenarios of potable water demand with stochastic variations in a normal distribution with different coefficients of variation throughout the simulated period. The results have shown that different design variables, such as potable water demand, number of occupants, rainwater demand, and roof area are important for obtaining the ideal underground tank capacity and estimating the potential for potable water savings. The stochastic variations on the potable water demand caused amplitudes of up to 4.8% on the potential for potable water savings and 9.4% on the ideal underground tank capacity. Average amplitudes were quite low for all cities. However, some combinations of parameters resulted in large amplitude of uncertainty and difference from uniform distribution for tank capacities and potential for potable water savings. Stochastic potable water demand generated low uncertainties in the performance evaluation of rainwater harvesting systems; therefore, uniform distribution could be used in computer simulation.

Short-term versus long-term rainfall time series in the assessment of potable water savings by using rainwater in houses.

The main objective of this article is to assess the possibility of using short-term instead of long-term rainfall time series to evaluate the potential for potable water savings by using rainwater in houses. The analysis was performed considering rainfall data from 1960 to 1995 for the city of Santa Bárbara do Oeste, located in the state of São Paulo, southeastern Brazil. The influence of the rainfall time series, roof area, potable water demand and percentage rainwater demand on the potential for potable water savings was evaluated. The potential for potable water savings was estimated using computer simulations considering a set of long-term rainfall time series and different sets of short-term rainfall time series. The ideal rainwater tank capacity was also assessed for some cases. It was observed that the higher the percentage rainwater demand and the shorter the rainfall time series, the larger the difference between the potential for potable water savings and the greater the variation in the ideal rainwater tank size. The sets of short-term rainfall time series considered adequate for different scenarios ranged from 1 to 13 years depending on the roof area, percentage rainwater demand and potable water demand. The main finding of the research is that sets of short-term rainfall time series can be used to assess the potential for potable water savings by using rainwater, as the results obtained are similar to those obtained from the long-term rainfall time series.