بررسی کیفیت آب زیرزمینی با استفاده از شاخص‌های کیفیت آب جهت مصارف شرب، کشاورزی و صنعت (مطالعه موردی: دشت شیراز)

Document Type: Research Paper
Investigating groundwater quality using water quality indicators for drinking, agriculture and industry (Case study: Shiraz plain)
Marjan Salari
Department of Civil Engineering, Sirjan University of Technology, Sirjan, Iran

Introduction
The study aimed at investigating the groundwater quality for drinking, agricultural and industrial uses by Wilcox and Schuller diagrams using Chemistry Software, Langelier Saturation Index (Is) and evaluating hazards caused by physical-chemical compounds using the health hazard parameters such as chronic daily intake (CDI) and hazard quotient (HQ) in EPA formulas in some parts of the Shiraz Plain, Central Fars Province. First, the data of 10 quality parameters affecting above-mentioned uses, including EC, Ca2+, K+, PH, SO42-, Cl-, Na+, TH, Mg2+ and TDS were collected corresponding to the study area’s 22 wells and their normal distribution was ensured. Regarding Wilcox and Schuller quality indices, the groundwater is classified as average for agricultural uses and as acceptable for drinking use. According to the Langelier Saturation Index, the existing water resources were reported corrosive to scale forming. During the sampling period, the average HQ index values for Ca2+, Mg2+, K+, Na+, Cl-, HCO32-, SO42- were 0.005, 0.011, 0.002, 0.11, 1.765, 0.111, 0.207, respectively. Thus, the programs such as water resources management and announcement of banned situation for the plain should be applied to improve the water quality over time.
This study is a cross-sectional descriptive study. The studied area is a part of the Shiraz plain with an area of 278 hectares, where the wells supplying the city's water are located. There are 22 active drinking water wells in this area, which are mostly located in the urban context. In this study, the parameters of sodium, chloride, nitrate, sulfate, hardness, total dissolved solids and pH were investigated as parameters of resource quality indicators listed in the guidelines book of the World Health Organization. These parameters can affect the taste, smell, and appearance and generally acceptability of water.

Document Type: Research Paper
Investigating groundwater quality using water quality indicators for drinking, agriculture and industry (Case study: Shiraz plain)
Marjan Salari
Department of Civil Engineering, Sirjan University of Technology, Sirjan, Iran

Introduction
The study aimed at investigating the groundwater quality for drinking, agricultural and industrial uses by Wilcox and Schuller diagrams using Chemistry Software, Langelier Saturation Index (Is) and evaluating hazards caused by physical-chemical compounds using the health hazard parameters such as chronic daily intake (CDI) and hazard quotient (HQ) in EPA formulas in some parts of the Shiraz Plain, Central Fars Province. First, the data of 10 quality parameters affecting above-mentioned uses, including EC, Ca2+, K+, PH, SO42-, Cl-, Na+, TH, Mg2+ and TDS were collected corresponding to the study area’s 22 wells and their normal distribution was ensured. Regarding Wilcox and Schuller quality indices, the groundwater is classified as average for agricultural uses and as acceptable for drinking use. According to the Langelier Saturation Index, the existing water resources were reported corrosive to scale forming. During the sampling period, the average HQ index values for Ca2+, Mg2+, K+, Na+, Cl-, HCO32-, SO42- were 0.005, 0.011, 0.002, 0.11, 1.765, 0.111, 0.207, respectively. Thus, the programs such as water resources management and announcement of banned situation for the plain should be applied to improve the water quality over time.
This study is a cross-sectional descriptive study. The studied area is a part of the Shiraz plain with an area of 278 hectares, where the wells supplying the city's water are located. There are 22 active drinking water wells in this area, which are mostly located in the urban context. In this study, the parameters of sodium, chloride, nitrate, sulfate, hardness, total dissolved solids and pH were investigated as parameters of resource quality indicators listed in the guidelines book of the World Health Organization. These parameters can affect the taste, smell, and appearance and generally acceptability of water.

Methodology
During the sampling period, the average HQ index values for Ca2+, Mg2+, K+, Na+, Cl-, HCO32-, SO42- were 0.005, 0.011, 0.002, 0.11, 1.765, 0.111, 0.207, respectively. To investigate the spatial variations of groundwater quality in respect of drinking, agricultural and industrial water uses, various studies have been done across Iran based on the Schuller and the Wilcox diagrams and the Langelier Saturation Index. The results of the present study were in good agreement with the studies carried out by Jafari and Bakhshandehro (2014) in Isfahan Province, Rostamzadeh et al. (2015) in the Hastijan Plain, Mohammadyari and Basiri (2017) in the arid areas of Mehran and Dehloran, and Rafi Sharif et al. (2017) in the Yazd-Ardakan Plain. Therefore, considering the low quality of the groundwater, especially in the around wells, it is suggested that, in addition to prohibition of drilling new wells, the amount of water discharge from the aquifers is managed. Regarding the reduction of surface water input to the region in the recent years and the increase of pressure on the plain’s aquifer, the farming type must be changed based on detailed studies and the salt resistant crops needing less water should be developed. To manage the water resources, the qualitative and quantitative maps of the region’s water should be prepared and analyzed using the modern and precise geo-statistical methods once every couple of years. The capability of increasing the efficiency of water use in agriculture was not fully implemented. It is recommended to carry out applied and basic studies for producing aridity-tolerant and salt resistant crops and inventing irrigation methods and technics compatible with the region’s current conditions. It must be cared that the application of new irrigation technologies is consistent with the climatic and agricultural conditions. The data of this study showed that one of the issues of the available water resources in Shiraz plain was the high amount of their salt and soluble materials indicating the significant impact of the geological formations (evaporates, shales, carbonates) and the salt domes on the groundwater resources and reduction of their quality. Thus, the ongoing programs such as announcement of banned plains must be continued to improve the water quality over time.
Conclusion
The results of the study indicated that the water resources of the study area were within the range of waters with completely hard origin. Generally, the increase of salts and soluble materials in water results in the reduction of groundwater quality. The chemical quality type of the aquifer’s water samples was of bicarbonate and sulfate type and their facies was calcic.
According to the Schuller diagram, 11 wells of the region (37%) classified as good and acceptable in respect of drinking and were potable. Only two wells (7%) classified in the average group and the remaining 16 wells (55%) were in inappropriate, completely inappropriate and non-potable groups. Considering agriculture, the Wilcox diagram showed that 24% of the Plain’s wells classified as good to permissible and 14% were in the permissible to doubtful group (farming salt resistant crops).
Meanwhile, most of the region’s wells (62%) classified as unsuitable for agriculture. Considering the Langelier Saturation Index, 76% of the aquifer’s wells were in the scale-forming category and the remaining ones were in the corrosive category in the industrial respect. Although, the government has made some efforts to constrain groundwater level drop in the context of various projects, but they were not sufficient. Most of the works carried out in the banned plains, were physical, structural and supply management actions, while it might be addressed by the demand management. Since the available water resources are limited and the final cost of water discharge increases, it is necessary to encourage the users to allocate water to the plans with the maximum efficiency per one unit of water. Analysis of the all-over cost of the user’s plans is critical for their comparison and prioritization. Considering the above discussions, some recommendations are given in the following sections to reduce excessive discharge of groundwater.
Keywords: Water quality, Groundwater, Risk assessment, Shiraz Plain.