Hazards assessment of water resources to pollution caused by landfill’s Yasouj

Introduction
Contaminated drinking water significantly affects the health of consumers and the environment [1]. Numerous scientific reports have shown that the consumption of contaminated drinking water endangers human health and may lead to diseases such as cholera, diarrhea, typhoid, dysentery, polio, guinea worm and skin infections [3]. Various factors threaten the quality of water resources and cause its pollution, including the growing population, followed by increased production of waste, municipal and industrial wastewater and uncontrolled fertilizers in the agricultural sector. Waste management issues in many developing countries often reflect the main environmental problems that arise due to limited urban budget, poor understanding and lack of data and information. One of the serious problems resulting from waste disposal operations is waste leachate, which has significant negative effects on the environment [4, 5]. In general, the nature and content of leachate pollution varies considerably from landfill to landfill and depends on various factors including waste composition, seasons, area hydrology, compaction grade, waste age, landfill technology and sampling process. In order to assess the environmental impact of waste management, the impact of leachate from waste disposal sites on groundwater quality around each landfill must be carefully monitored [2]. Therefore, the study of spatial and temporal changes in groundwater quality parameters is of particular importance in understanding the aquifer quality status, pollutant sources and determining the most appropriate management strategy. Since the landfill of Yasuj city is located in a higher place than the drinking water supply wells of Yasuj city, surface and groundwater sources are always at risk of pollution. Therefore, the aim of this study was to evaluate the probable contamination of surface and groundwater resources around the landfill of Yasouj city over a period of 12 months.
Materials and Methods
After explaining the morphology and field surveying of the area, drinking water wells, east and west stream of landfill, Shah-Qasem dam reservoir and two springs (Sarabtaveh and Parikadan) were sampled monthly for one year. Samples for measuring hydrochemical properties include turbidity, pH, electrical conductivity, cations (sodium, magnesium, potassium, calcium), anions (chlorine, bicarbonate, sulfate, nitrate, phosphate), heavy metals (arsenic, iron, copper, zinc, mercury, chromium, cadmium, nickel, lead), dissolved oxygen, BOD and TDS and its comparison with the limits allowed in the National Drinking Water Standard of Iran and the World Health Organization were transferred to the laboratory.
Discussion and Results
The results showed that despite the desirability of many physicochemical properties of pumping drinking water from the karst aquifer of the Tangeh-Kenarah, some very dangerous properties of wells have been more than allowed during several months of the year. The results of analysis of surface water sources also showed that leachate from waste from Yasouj landfill had a significant effect on the flow of water in the landfill route, so that the amounts of phosphate, iron, turbidity, dissolved oxygen, BOD, arsenic, cadmium, lead and mercury in the surface water flow in the stream of the landfill route, in some months and sometimes the whole year, have been more than allowed. Also, the results of the spring water samples analysis showed that Sarabtaveh spring was more than the allowable in cadmium, lead and mercury pollution in the rainy months, and the amount of lead and mercury in the Perikdan spring also increased during the rainy season. In general, surface and groundwater resources around the landfill of Yasouj city are affected by leachate, so that it is more intense in the rainy season.
Conclusion
One of the main sources of drinking water supply in Yasuj city is eight wells drilled in a karst aquifer. Due to the nature of its fractures, this aquifer is inherently very sensitive to any kind of contaminant and may be easily contaminated with the least amount of chemicals. Disposal conditions and waste management in this place are such that the term landfill cannot be used for it. In fact, the landfill refers to a standard landfill in compliance with all scientific standards and principles, while the principles of engineering and standard design are not observed in this landfill. So that all kinds of wastes are discharged in different parts of the area without proper planning to prevent water and soil pollution caused by leakage and infiltration. On the other hand, this place, however, has been selected in one of the highest points of the study area. So, the most disadvantage of this landfill is its high altitude compared to other surrounding areas. Therefore, surface and groundwater resources around this landfill, especially in the rainy season, can be severely affected by contaminants in the waste. What is certain is that the landfill requires special management that must be implemented as soon as possible to prevent contamination of water resources.