Water Balance Assessment in Schools and Households of Rural Areas of Coquimbo Region, North-Central Chile: Potential for Greywater Reuse

Abstract

Population growth, global warming, and increased demand for water have caused global concern about increasing water scarcity. Chile has an unequal geographical distribution of water resources. The north-central area where more than half of the country’s population lives has an availability of less than 1000 m3/hab/year. Particularly, the Coquimbo Region has been one of the most affected by drought due to the great agricultural activity in the area. In this study, surveys were carried out in rural schools and households to determine water consumption habits. The results in the schools showed that between 42% and 72% of the wastewater generated comes from the washbasin, which represents light greywater, that is, with low organic matter content. According to the data obtained, the amount of greywater generated on average reached 12 L per capita per day. These waters have the potential to be treated and reused effectively for the flow of toilets or garden irrigation. In the case of households, the generation of greywater was 84% of the total water consumed, of which, more than 86% correspond to light greywater from the shower and washbasin. On average, the light greywater generated daily reached 204 L per person per day. Due to the heterogeneity of drinking water sources in rural areas of the Coquimbo Region, the high rate of greywater generation in both schools and homes indicates the great potential for water treatment and reuse in this area. These results contribute to a better understanding of water consumption habits in rural areas affected by water scarcity and the potential of implementing greywater treatment systems to generate a decrease in demand for drinking water.

From mathematical models to policy design: Predicting greywater reuse scheme effectiveness and water reclamation benefits based on individuals’ preferences

“…Not all greywater produced by a household is suitable for treatment, and available raw greywater before treatment is limited to that from handwashing, tooth brushing, taking a shower/bath, and laundry. Consistent with other studies (Lefebvre, 2018;Silva et al, 2019;Vuppaladadiyam et al, 2019) and information from Chile (Rodríguez et al, 2020), we assumed a 70% recovery rate of water for these uses. This provides the "average volume of GW available per month (L)"…”

Reclamation of Treated Wastewater for Irrigation in Chile: Perspectives of the Current State and Challenges

“…The selection of these water quality parameters should be locally defined, considering the kind of plants that are to be irrigated. Recent interest in this new water source in Chile has motivated several research articles and the implementation of small projects in the country [87][88][89][90][91]. In addition, recently, the obligation to include greywater reuse systems in edifices of more than 5000 m 2 has been included in Chilean regulations [92], showing the interest of the country in employing this new water source and the challenge in implementing it.…”

Light or Dark Greywater for Water Reuse? Economic Assessment of On-Site Greywater Treatment Systems in Rural Areas

“…In the latter case, it was considered that the irrigation was carried out in recreational or ornamental areas, since current Chilean legislation does not allow the use of treated greywater for the irrigation of crops for edible purposes [44]. However, the benefits of these systems could be greater when considering the current scenario of water scarcity that exists in the area [46][47][48][49]. In addition, green areas could bring many other benefits not quantified in this study, such as the effect of thermal regulation [50][51][52][53][54][55], benefits in mental health [40], and academic benefits manifested as the greater comfort and well-being of students and teachers in schools [56][57][58].…”