The water crisis is a challenge that threatens the development of countries, especially dry areas, which requires managing water consumption and creating new water resources. Uncontaminated household wastewater is one of these valuable water resources. The purpose of this research is to identify the potential of this water source for use in agriculture and environmental improvement. To conduct this research, twin dishwashers were installed in the kitchen. The outlet pipe of one of them was connected to the sewer, and the other pipe was connected to a water storage tank outside the kitchen, and a water meter was also connected to it. A one-inch pipe was also connected to the sink, where no detergent was used, to direct water to a 20-liter graduated tank outside. Graduated containers were also placed in the bathroom to collect uncontaminated water. To plant seedlings, 18 holes were dug with a depth and diameter of 70 and 60 cm, respectively, and seedlings were planted. The treatments in this study included the type of plant (berry, olive, and pomegranate) and the type of water consumed (uncontaminated water and drinking water). Water and soil samples were also tested. The results showed that during the research period (282 days), 34,024 liters of water were extracted, which was higher in quality than the standards of the Environmental Organization.. Also, vegetation data showed that there was no difference between the growth characteristics of plants with the two water used for irrigating seedlings. It is concluded that the water tested in this study is a valuable resource for household economy, environmental improvement, and water stress reduction.

EXTENDED ABSTRACT
Introduction
The threat of water scarcity is one of the fundamental problems confronting the development of human societies, including Iran. These threats go beyond water supply for agriculture and industry and have also limited the supply of drinking water. Despite the increase in irrigation efficiency and the change in cultivation patterns and the use of low-water-consuming crops in some parts of the world, such as developed countries, there is a need to exploit other water resources, including wastewater free of pollution for household consumption, due to the limited freshwater resources in some areas. (Mishra et al, 2023; Szaja et al, 2022; Jahantigh and Jahantigh, 2024). Using uncontaminated household water for various applications is considered one of these sustainable water resources. So that a large part of household water consumption is used for non-potable purposes and a small part is used for drinking (Menin, 2024; Belmeziti et al, 2025). The use of wastewater in the agricultural sector has a long history in the world (Okut et al, 2025; ؛ Liu and Zhang, 2025). The use of recycled wastewater for irrigation of agricultural lands in Asian countries, including Iran, India, and especially China, has a history of about 2000 years. However, it has a shorter history in European countries. Currently, water stress and water shortages in many arid parts of the world have prompted many governments, even those with more favorable rainfall conditions than Iran, to plan for wastewater reuse. In this regard, for example, in the United States, Jordan, Lebanon, the occupied Palestinian territories, India, the Emirates, etc., recycled wastewater has been increasingly used in recent years to improve the situation of drinking water consumption. In this regard, Parwin and Karar Paul (2020) evaluated the quality of kitchen wastewater for irrigation in India in a study. Their results showed that about 30.77% of the water used in the kitchen was safe for direct irrigation of agricultural crops. The results of the study by Albalawneh et al. (2015) entitled "Investigation of gray water recycling and proposal for reuse in agricultural irrigation" showed that gray water constitutes between 50 and 80 percent of the volume of wastewater produced by households, and its treatment and reuse in agricultural irrigation plays an effective role in reducing water stress.

Materials and methods
This research was conducted at the Agricultural Education and Natural Resources Research Center in the city of Zabol in the north of Sistan and Baluchestan province.To conduct this research, twin dishwashers were installed in the kitchen. The outlet pipe of one of them was connected to the sewer, and the other pipe was connected to a water storage tank outside the kitchen, and a water meter was also connected to it. A one-inch pipe was also connected to the sink, where no detergent was used, to direct water to a 20-liter graduated tank outside. Graduated containers were also placed in the bathroom to collect uncontaminated water. To plant seedlings, 18 holes were dug with a depth and diameter of 70 and 60 cm, respectively, and seedlings were planted. The treatments in this study included the type of plant (berry, olive, and pomegranate) and the type of water consumed (uncontaminated water and drinking water). Water and soil samples were also tested. In spring and summer, 20 liters of water were provided to the seedlings every 15 days, and in autumn and winter, 20 liters of water was provided every 30 days. Plant survival and growth characteristics (branch height, number of branches, vigor, diameter, and canopy cover) were measured during the growing seasons. Soil moisture was also measured monthly at a depth of 50 cm using a gravimetric method.

Results and discussion
The results of soil testing in the studied area showed that the soil in the area is derived from sediments transported from the highlands of Afghanistan by the Helmand River, and lacks proper drainage and is of low quality. Daily measurement of uncontaminated water flowing from the dishwasher into the water storage tank outside the kitchen, based on a meter installed at the outlet of this tank, collected 25,000 liters of water for a family of three over a period of 283 days. Also, 7614 liters of water were extracted from the washbasin (ablution water, etc.) during the mentioned period. In addition, 1410 liters of water were also collected from the bathroom during the research period, although the potential for water extraction in this location is greater than this amount. A total of 34,024 liters of water were saved as a result of this research. Therefore, the data showed that considering the daily consumption of 450 liters of water by a three-person urban household in Iran, about 120.6 liters of it is uncontaminated daily and can be directly used in agriculture. Water used in the kitchen, washbasin water (ablution water, etc.), and water extracted in the bathroom account for 73.5, 22.4, and 4.1 percent of the water obtained, respectively. An examination of the growth of the seedlings under study showed that despite the unfavorable soil depth in the study area and the harsh climatic conditions of the region, the planted seedlings had appropriate growth.

Conclusion
In this study, the amount of uncontaminated kitchen water extraction was investigated in order to identify potential for improving the environment and producing agricultural products in the city of Zabol. The results showed that this water source has a high capacity to meet part of the water needs of dry areas. Due to the rapid population growth and increasing global health levels in all parts of the world, household water consumption is also increasing, which in turn causes an increase in wastewater production and, as a result, an increase in diseases. Increased water consumption, including in arid regions due to water shortages, is accompanied by a water crisis, which requires the replacement of this water through other sources. Wastewater treatment using various methods is currently associated with high costs, and in addition, the quality of the treated wastewater is also limited. However, uncontaminated household wastewater does not require treatment. Therefore, using uncontaminated household wastewater not only saves a portion of the available freshwater resources that are usually used for agriculture and green spaces, but also reduces environmental pollution by reducing the amount of wastewater entering sewage wells and urban sewage systems. Uncontaminated household wastewater is a valuable water resource that is easily accessible. Laboratory analysis of this water samples showed that it is of high quality and the quality of its elements is higher than the standards of the Environmental Protection Agency of the country and has no restrictions for use in agriculture and environmental improvement. It is concluded that using this water source for agricultural production and green space development will not only reduce water stress in population centers, but will also be able to meet some of the needs of households. Therefore, efficient management of domestic wastewater is essential to reduce its environmental impacts and protect water resources