Assessing the impacts of petrochemical industrial facilities on groundwater in Zubair district Open Access

Industrial activities have a significant impact on the environment, where industrial processes primarily involve converting raw materials into manufactured or semi-manufactured goods. Because the conversion process can never completely exhaust the essential inputs, it produces by-products either in energy or matter. These secondary materials, if not exploited, are transformed into waste, and are discharged into the surrounding environment causing pollution. The degree to which pollutants can affect the natural environment depends on their quantitative and qualitative characteristics. Some of these pollutants are biodegradable, others require a long period to degrade, others are not degradable, and there are social impacts and negative effects of industrial processes on the environment and natural resources.

The process of environmental impact assessment appeared at the beginning of the 1970s in developed countries and has undergone many changes and modifications since then with the aim of reaching the highest level of effectiveness in forecasting and determining the environmental impacts of industrial projects. Environmental impact is any changes in the characteristics of the environment due to a specific and clear activity or group of activities. The study of evaluating the environmental impacts of industrial projects is a predictive study of projects or activities that have a potential impact on the elements of the environment in order to reach the integrated environmental management of these projects.

The environmental impact assessment process is a procedure designed to identify and predict the impact of a project on the biophysical environment, human health and life, and to provide information about and interpret this impact. It is also a process conducted to provide decision-makers and planners with an understanding of the environmental consequences of an industrial project and an assessment of the severity of these consequences on the environment. An environmental impact assessment identifies ways to improve project selection, location, planning, design, and implementation.

One of the most important tools for environmental impact assessment is to find an environmental management system that enables us to reach sustainable development. Therefore, ArcGIS is one of the most important tools that can be used to assess the environmental impacts actually resulting from existing productive industries and provide information on the impact of these industries and its interpretation. In practical terms, it enables us to study the environmental feasibility and the negative effects of the existing project that may affect the safety of the environment and its natural resources or human health, or both, and thus it is considered a procedural means to reach the desired goal for continuous development.

The petrochemical complex in the Al-Zubair region of southern Iraq has environmental impacts on the groundwater of wells located in the areas surrounding the complex. There are three types of environmental waste dumped into the environment surrounding the petrochemical complex: the first type in the form of liquid waste is thrown in the Shatt al-Arab; the second in the form of gas residue being released into the air, and the third type in the form of solid and liquid waste buried in the soil in the surrounding areas. All of these types of waste result in contamination of the groundwater of the wells in the area as a result of deposition. This study will focus on solid and liquid pollutants from factories; the types of liquid and solid pollutants presented by the petrochemical complex to the soil in the study area and its vicinity were reviewed according to the amount of daily production from each factory, its drainage sites, and the extent of its spread in soil.

The objectives of the study were achieved through conducting field surveys with accurate surveying devices (GPS – Leica Viva GS15), in addition to taking laboratory samples from polluted water resulting from industrial processes and comparing them with environmental standards. Then, conducting spatial analysis of the surveys and samples taken using the ArcGIS program to determine the factories that emit the largest percentage of pollutants (which have a priority in maintenance) and the extent of its environmental impact on the wells and the surrounding environment.

Most of the environmental impact assessment studies for industries depend on taking samples at different depths of the soil, which requires digging the soil to reach the polluted layers and taking samples from them, and this requires effort, time, and high cost. Therefore, the main objective of this study is to detect the negative effects of solid and liquid waste produced by the petrochemical industries complex on the local groundwater of the complex without digging the soil layers and reaching the deepest point in the well for sampling. It will be based on surface location data in building a digital model in the GIS program capable of interpreting and analyzing the environmental impacts of the petrochemical complex. This model will depend on digital elevation models to determine the type of pollutant, its spread and concentration in soil layers, and when it reaches and pollutes wells and various layers of soil.

Industrial activities have significant impacts on the environment, especially the resulting pollution and damage to the environment from the industrial zones. Industrial activities occupy large areas of land. These activities have been prominent in the pollution of the basic elements of the biosphere, namely air, water, and soil (Ministry of Planning Regional Planning Authority 2016). The main pollutants resulting from industrial activities represent about one-third of the total pollutants present in the air. Liquid industrial waste is also the most important and dangerous soil and water source contaminant in any country in the world. It was found from a survey conducted in 2012, that the vast majority of toxic pollutants present in water and soil originate from industrial activities (Ministry of Municipalities and Public Works 2012). A later survey was conducted in 2018 by the Ministry of Municipalities and Public Works, Directorate of Urban Planning in light of the development of strategies for the development of Al-Zubair (Ministry of Municipalities and Public Works 2018).

It is not possible to limit polluting substances from industrial production processes (El-Henawy 2006). Each industry produces different types of pollutants, either in the form of gas, solid materials, spray or liquids. The most polluting industry is heavy industries because of their direct handling with often contaminated materials (El-Henawy 2006). The process of dumping these polluting materials may begin from the first stages of industrial activity, which are the different stages of extraction and transport of raw materials to the factory, up to the process of delivery of products to the consumer. In other words, pollution occurs in any industrial production process. Industrial pollution is emitted in stages before it spreads in the environment and causes damage to its components. It has four main stages: the production stage, the emission stage, the transformation stage, and the receiving stage (Ernaout 1997).

Wastes are thrown into the atmosphere if they are gaseous or into water if they are liquid or into the soil in the form of solids (Abed 2019). Note that these wastes cause damage in all cases, not limited to the factory's premises, but extend further depending on the enabling factors. Therefore, the type of industry can determine the type of pollution resulting from it, the extent of the damage caused by it, and thus the siting of the industry in a suitable location of the city (Abdul Majeed 2008).

Soil is one of the most vulnerable elements to environmental pollution within the industrial environment because most industries use it to get rid of their solid and liquid pollutants. The environmental pollution of the soil can be defined as a defect of a physiological, chemical, or biological nature, resulting from a human activity that leads to breaking the state of balance between the soil components. This imbalance negatively affects the total properties of the soil fertility and the type and quantity of its production. It weakens the soil's role as a live filter to digest and decompose the residues of biological activity and reuse the elements of its composition in the biogeochemical cycle. Nevertheless, generally, it can be defined as any physiological or chemical changes in the soil, which cause changes in use or renders the soil unusable without treatment (Al-Sarawi 2009).

As for the nature of soil pollutants, they include several patterns of land contamination (Al-Abbas 2015):

• 1.

  Change the pH due to the leakage of those acidic or alkaline compounds to pollute the groundwater.

• 2.

  Increase the percentage of nutrients in the soil because of the excessive use of fertilizers of various types.

• 3.

  Pollution by heavy metals such as lead and copper, which cause great damage to humans and other organisms.

Soil is contaminated if it contains material or substances in quantities or concentrations exceeding the permissible standards for these substances. Suppose the concentration of the substance exceeds the permissible limit. In that case, it will cause a danger to human, animal, and plant health, or to surface water or groundwater in the soil environment. The impact of these sources of industrial pollution depends on the type and concentration of pollutants (Al-Saraawee 2012).

Water sources in the soil are also affected by pollution from industrial waste. Water sources can absorb a certain amount of pollutants before reaching the state of pollution, so, generally, the water source is labeled as contaminated if it contains excessive amounts of contaminants or certain pollutants (Abed & Sumayah 2021). It is clear from Table 1 that some elements in the soil can become contaminants that go into the groundwater. To date there are an estimated 70,000 chemicals in industrial wastewater, of which more than 40,000 are considered to be harmful to the environment, including highly toxic ones, those dangerous to children and pregnant women, or causing cancer (Al-Sarawi 2009). Therefore, water pollution is a change in water quality, chemical, physical and biotic characteristics, and suitability for different uses. Pollution is caused by the addition of organic and inorganic compounds at concentrations and quantities that exceed the safe limits, resulting in health and economic damage if contaminated water is used, and negative impacts on the organisms living in these waters (Al-Ansari 2016).

Zubair district has large areas that help in the establishment of industrial and agricultural projects, especially in the western part of the province which represents the study area, with a population of 237,681 people, according to the field survey of the city of Zubair in 2018 (Rasool 2017).

The basic industries in Zubair district are ranked first, constituting 56.5% of the total industries in the country. There are 13 factories constituting 0.8% of the total industries in Zubair, as shown in Table 2, which shows the numbers of factories for the transformative and extractive industries in Basrah and county for the year 2020 (Ministry of Municipalities and Public Works 2020).

Despite the differences in these industries in their products and outputs and the number of factories, they are all polluting industries that affect the air and soil at varying rates by industry type (Ministry of Industry 2018). The chemical and metallurgical industries are among the most important sources of soil and air pollution, through the pollutants released during combustion or the various gases, vapors, and smoke that rise from the chimneys of these factories, in addition to the chemicals that are buried underground (Ministry of Environment 2017).

Therefore, this research attempts to study the environmental impacts of the industrial factories located in the Al-Zubair district (especially the petrochemical industrial complex, which is considered a limitation and an area of study) on the surrounding environment and natural resources located in the region.

Due to the ownership of natural gas by the Zubair district, it was planned to build the petrochemical complex at 28 km south of Basrah and 40 km northwest of the district of Um Qasr. The contract for the implementation of the complex was signed with Loms Tessen company in 1976 in the amount of US$1.1 billion. It was implemented to produce the following raw materials (Al-Sharifi 2013):

• 150,000 tonnes of ethylene/year

• 160,000 tonnes of low-density polyethylene/year

• 30,000 tonnes of high-density polyethylene/year

• 10,000 tonnes of polyvinyl chloride/year

• 43,000 tonnes of caustic soda/year

• granules coloring and composition/year

This amount of raw materials is sufficient to produce 145,000 tonnes of plastic products as planned (Al-Sharifi 2013).

The petrochemical complex in Al-Zubair is adjacent to the Highway road (Basrah-Safwan) linking Basrah to Kuwait. The complex consists of eight factories. The complex extends over a wide area of 7990 m², equivalent to 20% of the area of basic industries in Zubair, which is currently the largest in the country. There are 4,260 workers and employees in the complex and the residential complex that surrounds it on the east side and is inhabited by 300 families working in the factories. From the west side of the complex, there is a large amount of informal housing (slums) adjacent to the complex, in addition to the presence of many farms (tomato farms) scattered around the complex, which are irrigated with groundwater in the area (Al-Abbas 2015).

Petrochemicals factories produce many gases at high concentrations under normal operating conditions, such as ethylene, methane, hydrogen sulfide, and nitrogen oxides, as well as many gaseous pollutants such as carbon dioxide (CO₂), sulfur dioxide (SO₂), and amounts of hydrocarbon gases that are discharged from the incinerator. Factories also produce quantities of polluted water. These waters contain high concentrations of chlorine, forming a small lake, which leads to pollution of the air and soil, and leakage into the groundwater to pollute it, then the residues volatolize after the waters dry up (Barbara 2016).

The pollution from varying sources in the petrochemical factories complex have caused significant damage to the soil. They, therefore, have affected the groundwater in the wells of Zubair, which is used for drinking and watering the farms in the area. Where groundwater was damaged and polluted by the pollutants emitted from the complex, this affected the quality and uses of water. In this study, the impact of factories’ waste on the groundwater on which the wells depend for their daily needs will be determined, in order to identify the most polluted wells, identify the type and concentration of the pollutant, and the type of factories that produce the greatest amount of pollutants.

When groundwater is contaminated by soil pollution, concentrations of pollutants vary from one region to another depending on the amount and depth of the pollutants discharged by the factory into the soil (Abed 2020). Therefore, the concentration of pollutants in the water must not exceed the maximum allowed limits for the type of use. Table 5 shows the maximum limits for water quality in soil layers for it to be suitable for agricultural use and to sustain aquatic life.

The water resulting from the industrial processes of the complex of petrochemical factories is usually discharged to the Shatt Al-Basrah channel located north of the city. However, water consumed is drained into the area adjacent to the complex due to the failure or maintenance of the treatment plant. Noting that during the period prior to the maintenance of the treatment plant, industrial waste was discharged to the Shatt Al-Basrah Canal without treatment.

Factories’ units discharge their contaminated water into the final aggregation basin while the flare (vertical flame) continues to burn. It should be noted that the aggregation basin is not lined with asphalt and its base is clay, which causes the absorption of contaminated water and its penetration into the soil layers.

Table 6 shows the results of physical, chemical, and biological tests of samples taken from the petrochemical complex at the last discharge point. The results of the tests were compared with Iraqi and WHO standards for each pollution source to determine whether they exceeded the standard and the permissible limit or not. And it was found that most of the test results exceeded the standards, for the following reasons:

• 1.

  The concentration of the (pH) hydrogen ion did not exceed the standards, but the alkaline function is high for industrial water due to the basic nature of discharges left by the production factories. There is an increase of chlorine factory waste from alkaline substances such as soda, chlorine, and caustic materials directly.

• 2.

  The standard for total suspended solids (TSS) and total dissolved solids (TDS) concentrations were exceeded due to corrosion of old pipes which did not undergo any maintenance or replacement. Exceeding the standard is also attributed to the chemical processes that occur in the units, the chemical additives added in the stages of filtration, and because of the residues from the units, especially chlorine and sulfate. In addition, increasing the temperature in chemical processes, especially in heat exchangers, leads to evaporation of water. The evaporation will increase the concentration of salinity ratios and increase the proportion of salts in the current natural water. This means a certain risk to aquatic life in particular.

• 3.

  Increasing the biochemical oxygen demand (BOD) above the value of the standards is indicative of the presence of microscopic microorganisms that lead to a high BOD concentration. The sewage from the complex is also disposed of in the final aggregation basin, with the presence of hydrocarbons and oil that raise the proportion of BOD.

• 4.

  Chemical oxygen demand (COD) concentration increased above the value of the limits allowed by the standard due to the increase in chemical residues used as auxiliary factors in the production process.

• 5.

  Dissolved oxygen concentrations (DO) were within the value of the permissible standard limit.

• 6.

  The increase in the proportion of oils due to high rates of heavy castings for the production factories which are high- and low-density cholesterol (HDC & LDC). Leakage of the production lines of machinery and equipment, and high rates of oil impurities in the natural gas from the source are major reasons for the high proportion of oils.

• 7.

  NO₃ concentrations were within the permissible limits.

• 8.

  Increasing concentrations of heavy hazardous elements (Zn, Cr, Cu, Ni) due to corrosion of boiler alloys, corrosion of pipes and bolts due to extreme heat, and steam exposed to them. These boilers have not been replaced from the date of the establishment of the complex. Also, the increase in concentrations is due to a technical defect in the production process inside the factory or specific damage in the operating systems. Heavy elements are very dangerous to the life of organisms inside and outside the water medium.

• 9.

  The increased concentration of chloride (Cl) and sulfur (SO₄) ions over the value of the standard. This confirms the presence of salt as a result of the desalination process because the complex uses water free of salt. Residues from the desalination process from the saline-containing water are disposed of in the final aggregation basin. In addition to salts obtained as a result of the passage of the water within the production process units, the salts are discharged as waste from production with water to the aggregation basin.

• 10.

  CL₂ concentrations were within the permissible limit values.

• 11.

  The iron (Fe) concentrations exceeded the value of the standard. The reason depends entirely on the system of transport lines of industrial water, which are old and eroded, leading to an increase in the proportion of iron in industrial water.

• 12.

  The lead (Pb) concentrations exceeded the value of the standard due to the high ratio of lead residues in the atmosphere. The lead is produced from car exhausts due to the proximity of the complex to the main highway and the smoke from factories and wind-borne pollution, which contribute to the arrival of lead compounds in the final aggregation basin of the complex.

GIS (ArcMap 10.4.1) was used to conduct the spatial analysis of the complex of petrochemical factories to determine the range of environmental impact of the pollutants emitted from these factories in the study area. The spatial analysis was carried out in the GIS program based on the sites and drainage points used by each factory, through which solid and liquid wastes are discharged into the soil. Each of these sites and points discharges polluted water through a channel or groove etched with a certain depth into the soil. When factories discharge these pollutants into the soil, they spread in the soil layers according to the absorption and permeability properties. Each material has a range spread through it to a certain extent and depth to accumulate in specific areas within the soil. Since the area adjacent to the factories is rich in wells containing groundwater, these pollutants when penetrated into the soil, reach the water of some wells to pollute and affect the quality of water.

Thus, the contaminated wells were identified and excluded to reduce pollution in groundwater existing in the study area.

When comparing the results of this study with a previous study conducted in the same study area in 2015 to measure the environmental impacts of the industrial complex (Al-Abbas 2015), it turned out that the level of pollution in the wells has increased significantly from the previous survey due to the deterioration of the conditions of factories and treatment methods and the increasing concentrations of pollutants in the soil. The study conducted in 2015 was carried out using traditional methods that required going to the site and measuring the extent of pollution in the soil and wells through samples taken at different depths of soil and wells for long periods of time, and despite that, the study did not determine the extent and limits of pollution accurately and was unable to identify all wells affected by pollution. Whereas the use of GIS in this study gave accurate results on pollution and the limits of its spread through analytical and statistical tools owned by the program, and the following results were obtained:

• 1.

  The highest concentrations of pollutant materials for the soil and groundwater were recorded by chlorine liquid, industrial salts and ethylene, respectively.

• 2.

  The factories that pollute the most are chlorine and soda factories, low-density polyethylene granules, and the PVC factory, which must be given priority from maintenance to reduce environmental pollution in the Zubair region.

• 3.

  The last point of discharge of the complex's wastes is very high in pollutants concentration, which affects the Shatt al-Arab channel and pollutes its waters with the residues of the petrochemical complex.

• 4.

  The pollutants of the petrochemical complex factories and their vapors have led to the desertification of the lands surrounding the wells, despite the continuous irrigation from the well water.

• 5.

  The negative impacts of solid and liquid waste generated from the complex were detected and analyzed based on surface location data without drilling the soil layers and reaching the deepest point in the well for sampling.

• 6.

  GIS was effective and highly accurate in interpreting spatial information and identifying the locations of polluted wells and factories that emit the largest percentage of pollution. In addition, simulation through two and three-dimensional models showed the depths of wells, types, and concentrations of pollutants.

• 7.

  GIS was effective in identifying suitable agricultural areas that contain the lowest percentage of pollution from factories. In addition, the optimal locations for laying out industries away from population centers or areas that do not affect human health and the environment were determined in accordance with the criteria that are defined in the program.

The authors would like to thank Mustansiriyah University (www.uomustansiriyah.edu.iq) Baghdad, Iraq for its support in the present work.

All relevant data are included in the paper or its Supplementary Information.

The authors declare there is no conflict.