The coastal waters of Kuwait Bay have been extensively used for the disposal of domestic wastewater, increasing the level of pollution. Recent studies indicated that the amount of waste discharged into Kuwait Bay is expected to grow further, from raw sewage, illegal disposal of partially treated sewage, and industrial waste. These sources play significant roles in heavy metal, hydrocarbon, and fecal coliform bacteria inputs to Kuwait's coastal waters, which impact the marine environment and lower water quality. This article introduces information relating to pollution levels in Kuwait's marine environment from land-based sources, and compares the level of pollutants in marine waters with water quality standards. This study also recommends an environmental waste management procedure to control waste discharges to the marine environment with a view to future aspects of sustainable development.
Urban waste management is a serious environmental problem in Kuwait. Wastewater generation from industrial sources continue to increase due to industrial development. Waste generation per person has nearly doubled over the past 10 years due to the increase in population and living standards. Non point sources, including storm runoff, street discharges, agriculture activities, infiltration from aquifers, and landfill leachate, discharge directly into the sea, contaminating the marine environment with high loads of nutrients, nonorganic pollutants, and toxic compounds. Treated and untreated sewage wastewater from municipal treatment plants, industrial wastewaters, and power plant effluents discharge directly into the sea, contaminating the beaches and sediments. Such discharges pollute the sea in several ways such as increasing the concentration of inorganic and organic solids, nutrients, and increasing the potential presence of pathogenic microorganisms in receiving waters and sediments. Therefore, the environmental quality of Kuwait's marine environment is threatened by land-based pollution sources. Degradation of the environmental quality of coastal ecosystems is especially concerning due to the important role they play in ecosystem productivity. For example, Holligan and de Boois (1993) showed that ecosystems of the coastal zone occupy just 8% of the global surface area, but are responsible for more than 26% of all biological production.
Past studies have demonstrated that pollutants in the marine environment can harm humans at elevated ambient concentrations (Mustafa and Lee, 1979). Therefore, vigorous efforts are needed to identify and understand health hazards from marine pollution. For example, an integrated approach is required to reduce land-based sources of pollution by implementing a waste management plan, which begins with waste minimization at source, targeted pollution controls, and enhancing public awareness through formal and non-formal education. This article describes land-based sources of discharge in Kuwait, and their corresponding effects on Kuwait's marine environment. A waste management plan is suggested in order to reduce pollution and conserve the marine environment for future generations.
Land-based sources pollution
Sewage treatment plants receive 85% of sewage wastewater from the Kuwaiti population, and an additional 15% of wastewater from light industrial sources. Presently, there are three wastewater treatment plants operated by Kuwait's Ministry of Public Works (MPW), including Jahra, Rekka, and Um Al-Hayman. The Sulibiya wastewater treatment plant is operated by the private sector.
The Jahra wastewater treatment plant commenced operations in 1982 and collects sewage wastewater from north and south Jahra city. The Jahra plant can treat 70,000 m3 d−1, while the Rekka treatment plant treats 180,000 m3 d−1 of sewage from the south coastal areas and from areas in Al-Salem in the north to Al-Ahmadi and Fahaheel in the south. The Rekka plant also began operating in 1982. The Um Al-Hayman plant was constructed in 1999 and commenced operations in 2001 with capacity of 5000 m3 d−1. It collects sewage wastewater from coastal and southern Kuwaiti cities. However, Sulibiya treatment plant came into operation in 2003 and collects sewage wastewater from south and north Kuwait city. The Sulibiya treatment plant is designed to treat 450,000 m3 d−1 (MPW, 2003). Table 1 presents the characteristics and sewage flow for the local treatment plants in Kuwait. The temperature levels in the raw sewage were between 22 and 26C. However for tertiary effluent the temperature ranges from 19 and 24°C. The pH values were in the range of 6.5 and 8.8. However, for tertiary effluents the pH values were in the range of 5.3 and 7.4. The Total Suspended Solids (TSS) values were in the range of 93 and 129 mg l−1 but for tertiary effluents, the TSS values ranged between 2 and 8 mg l−1. Levels of COD in raw sewage ranged between 241 and 297 mg l−1; however, COD in the tertiary effluents ranged between 10 and 20 mg l−1, respectively. The levels of BOD, and TDS in raw sewage ranged from 130 to 209 mg l−1 and 466 to 1531 mg l−1, respectively. However, for tertiary effluent, the levels of BOD and TDS ranged from 3 to 8 mg l−1 and 452 to 771 mg l−1, respectively. Other parameter values were generally close to or lower than raw sewage values. Furthermore, tertiary treatment treated effluents from four plants are directed to the Data Monitoring Centre (DMC) to be used for irrigation. While excess effluents either treated or untreated are directly discharged to the bay area through the sea outfalls (Figure 1). In addition, a storm water network leading directly to coastal outlets serves Kuwait's urban population. There are approximately 28 storm outlets distributed along Kuwait's coast from north to south. Most of these outlets are found to be polluted with fecal coliform bacteria (Salem and Slama, 1981). Figure 1 presents the location of outlets along Kuwait bay. Furthermore, Shatti et al. (1999) showed that bacterial population concentrations decreased with distance from the opening of the emergency outfalls. However, observed differences in the concentration of the indicators and pathogenic bacterial population at sites situated on the right and left sides of the emergency outfall outlets may be due to sea current movement or wind direction. Due to these factors fecal coliforms population may decrease or increase by 10,000 counts 100 ml−1 (Bell, 1991). Al-Muzaini et al. (1991) showed that the percentage of antibiotic resistant bacteria was higher in areas opposite hospitals and was lower in the outfalls than along nearby seashores due to a longer survival for the former in ambient seawater. In general, the sewage wastewater in Kuwait is of high-strength and often septic. This is because of low flows of wastewater through the network and accumulation of sand in the sewage network. It has the highest content of organic and heavy metals relate to all Kuwait (Al-Muzaini et al., 1991). A study conducted by Al-Sarawi et al. (2002) shows that sewage discharges are compared to standard the main source of Zn pollutants in Kuwait's coastal zone. It could be related to the petroleum (Al-Muzaini, 2002). However, the mean concentration of dissolved trace metals were Cu 4.23; Fe 100.0; Ni 0.8; Pb 2.02; Cr 1.16 and Mn 2.6 ug l−1 (Al-Sarawi et al., 2002). Sewage discharges may contain toxic constituents due to the presence of oil and grease, heavy metals, polychlorinated biphenyls, and chlorinated pesticides due to petroleum sources (Al-Muzaini et al., 1991). The percentage removal efficiency for these wastewater treatment plants (Table 1), for TSS range between 94% and 99%, for COD between 92% and 98% and for BOD between 94% and 98%. However, the removal efficiency for oil and grease was 99%.
Table 2 summarizes the sewage water characteristics in Kuwait. It also includes a comparison of wastewater characteristics in Kuwait with those in the Gulf region. The results show that sewage wastewater in Kuwait has the highest total organic matter levels of all sewage water flows in the Arabian Gulf countries due to the inputs of car-service stations and light industries in Shuwaikh into the sewage network (UNEP, 1980). It may also contain toxic constituents as evidenced by the present oil and grease. Furthermore, the tertiary effluents from the sewage treatment plants seemed to comply with the quality standard set by the Kuwait’s ministry of public works.
Industrial and power plant discharges
A majority of the industries in Kuwait are located in the Shuaiba Industrial Area (SIA) complex (Al-Muzaini, 2002). The SIA consists of three refineries, two petrochemical companies, a liquefied petroleum gas plant, two power plants, and many small plants. Most of the industries in the SIA are located near the sea-shore so they can discharge their wastewater directly into the sea after partial treatment or without treatment at all through 13 outlets (Figure 2). Presently, the SIA generates approximately 31,000 m3 d−1 of industrial wastewater. With future expansion, the wastewater in SIA will reach 56,000 m3 d−1 (Al-Muzaini, 2002). The various wastewater sources in the SIA (sanitary and industrial) and their daily flow are summarized in Table 3 (Literathy et al., 1992). The main pollutants discharged by the existing industries in the SIA include high concentrations of ammonia, heavy metals, oil and grease, urea, hydrogen sulfide, and phenol. Sanitary wastewater from the SIA is collected in holding tanks after it undergoes primary treatment, and is then discharged directly to the sea. It was observed from the data collected that even after the physical and chemical parameters of sewage discharge were not high compared to the standard. More information on seawater movement and physiochemical changes of sewage seawater are needed to explain the level of physiochemical parameters in the sea.
Along Kuwait's coastline from Subiya to Al-Zoor, there are six power plants. These plants collectively degrade the seawater quality with discharges of high temperature water, salt, ammonia and organic compounds, resulting in low dissolved oxygen and thermal shock. Furthermore, the latter has caused alterations in fish and coastal ecosystems, (Khan et al., 2002). For example, previously published data show that power plants discharge at 5°C higher temperature than the ambient water temperature (Al-Ghadban et al., 2002). Results of another study (Saeed et al., 1999) showed volatile liquid hydrocarbons (VLH) in the coastal vicinity of power plants with detected concentrations ranging from 307 to 7882 ng l−1 in Kuwait Bay and from 331 to 5017 ng l−1 in the south bay. However, the levels of VLH were low at the intake of power plants located in the Kuwait bay (677 ng l−1) while slightly higher levels were recorded at the intake south of Kuwait Bay (700 ng l−1) due to the location of the SIA.
Impact of land source discharges on the marine environment
The impact of discharge of either raw or partially treated sewage wastewater on marine environmental quality is most noticeable in the nearby intertidal zone sediments. Asfari (2001) indicated that due to aging of some treatment plants and over loading of sewage plants, raw sewage discharges can occur from some of these outfalls. This situation has resulted in serious negative impact on both marine biota and general marine environmental quality. As a result, intertidal sediment always appears dark and there was black color on the surface of the sediments due to bacteria concentrations. Similar impact is observed on the other part of bay where the clay and silt of intertidal zone was contaminated and found to have higher TOC, nitrogen and phosphorus contents than uncontaminated sediments in the south. Level of pollutants (Hg, Pb, Cd, Oil, and TOC) in the top 50 cm of nearby sediments was higher than sediments in deeper parts (Ghobrial and Kasseim, 1986). Observed pollution is due to the discharges of raw sewage, storm water and runoff of nonpoint sources. Total organic carbon (TOC) levels in the clay-silt fraction of the near shore environment of the Kuwait bay were also higher than those in other coastal and off-shore locations (Al-Ghadban et al., 1982). This is due to sewage inputs from different sources. Levels of nutrients, ammonia, TOC, phosphates were found to be generally higher along Kuwait Bay sediments than those offshore indicating greater inputs of sewage to the marine environment (Samhan, 1989). A study by Salem and Salama (1981) indicated that the coastline between Sulaibikhat and Fahaheel was polluted with fecal coliform and bacteria. This can be atttributed to illegal disposal of raw and partially treated sewage. Additional sewage discharges had led to depleted oxygen concentrations, and bioaccumulation of persistent organic compounds. In a study conducted by Bu-Olayan and Thomas in 2001 on the marine ecosystem, the maximum mean concentration of arsenic in samples collected from five stations located between Khadma, north and Salimya south, off the Kuwait coast were as follows; fish 0.5–0.7 ug g−1, mollusk 0.26 ug g−1, shrimp 0.23 ug g−1, particulate matter 0.03 ug g−1, water and phytoplankton 0.02 ug g−1. The main sources of arsenic in the Kuwait marine environment were from the effluent discharge of power plants and sewage outfalls. Even though, the concentrations of arsenic are low, increasing trends in arsenic concentrations are anticipated due to high level of industrial discharges (Bu-Olayan and Thomas, 2001). Hayat (2001) conducted a three year study by collecting samples of mud, benthic organisms, sole, crab, shrimp, and fish at a distance of 30 m away from raw sewer outlets in Kuwait Bay at two locations, covering the northern and middle coasts of Kuwait. Mineral distribution in the stations indicated high levels of Ni and V from oil relative to the values reported by Anderlini et al. (1982). Marmoush (2001) measured levels of toxic compounds (mercury, lead, cadmium and copper) in power and desalination plants and storm water outfalls and found these contaminants to be present in high concentrations. Moreover, marine species exposed to power plant effluents are stressed by the presence of chlorine and high temperatures. Contribution from land reclamation has affected the marine ecology and fisheries, plant productivity was found to have reduced to low level because of light transmission due to an increase in TSS from laud reclamation erosion. Al-Muzaini et al. (1991), and Shunbo et al. (1983), investigated the presence of volatile organic compounds in the SIA. They found that organic compounds such as benzene, methylbenzene, and toluene were present in the wastewater discharge in significant amounts. However, it was interesting to note that organic compounds mostly accumulated in the areas near oil production and petrochemical industrial zones, and their levels decreased in areas further away from industrial petroleum activities. Al-Muzaini et al (1997) concluded that effluents released in the SIA were repeatedly found to contaminate the seawater quality; thus causing acute toxicity in the Microtox Assay. Sediment samples from Shuaiba coastal area (15 × 1.5 km) were collected and analyzed for contamination with total petroleum hydrocarbons, TPH, (Beg et al., 2003). This suggests that the pollution of the sediment along Kuwait's shoreline and of the seawater appear to arise from intermittent discharges of crude oil, land-based wastewater into the sea, and the level of contamination is dependent on the distance from the sources of contamination.
Environmental waste management program
Kuwait's marine environment is being threatened by many land-source discharges, as evidenced by consistently high pollutant levels and concomitant reduced water quality. Therefore, it is imperative to apply environmental policies that reduce pollution sources. One approach is to attempt to apply an environmental waste management program that will effectively reduce the sources of pollution. The program has to be flexible and easy to apply. While the major purpose of such programs is to identify the pollution sources, appropriate environmental waste programs address reducing the toxicity and waste volume at production sites as well as at discharge points. Usually, this involves reuse of the input materials through source reduction, and concomitant reduction of the wastewater discharges. The source reduction can readily be accomplished through product change lines and modifying design processes. Correspondingly, knowledge of design configurations, and operation steps, and a full understanding of the status of the receiving environment are required (Said, 2006). Table 4 shows several categories of pollution prevention. Usually, reducing pollution at the source leads to a major reduction of pollution in the marine environment and aids in meeting marine quality standard setting for pollutants. Presently, the industry in SIA is increasing attention toward the proper handling of wastes and modifying their processes to reduce the quantities of pollution generated as well as reducing wastewater discharges to the marine environment.
Knowledge of ambient quality standards must be considered when planning for new establishments. Reducing production of wastes benefits the receiving environments because it reduces ecological damage due to reduced volume and toxicity of waste discharge. This requires an action from the SIA authority to reduce pollutant accumulation in identified depositional areas on the Shuaiba coast and restricting pollutant discharge at source. Since the end of pipe treatment are much more costly than recycling of waste for reuse, it is preferable from a cost-benefit perspective to reduce wastes at the source (Allen, 1994; USEPA, 1992). The approach to reduce the waste volume during implementation of a waste management program (Allen, 1994) can be described in the following steps:
Set goals and timescales
Establish the assessment and evaluation team
Obtain and interpret facts
Identify significant waste generation practices
Rank practical waste minimization options
evaluate highly ranked options technically and economically
Report on assessment and evaluation
Implement waste minimization projects
Review and audit waste minimization
Implement lower priority projects
Clearly, efforts devoted to pollution prevention often have a positive impact on the environment. For example, Table 5 presents benefits from enforcement of pollution control on land sources.
Therefore, implementation of a flexible waste management program on a wide scale improves the marine environment and results in positive health benefits for both human population and ecosystems (Table 5). Marine quality such as seawater, sediment, fish samples should be collected and analyzed on a regular basis to determine the level of nutrients, heavy metals, chlorinated compounds, hydrocarbons, pesticides, and organic matter. The paramount question is whether the data obtained would be sufficient to judge the magnitude of the impacts that land sources may have on the marine environment. Once the impact is known, specific actions to minimize or mitigate pollution of the marine environment from land sources should be put in action.
Even though the SIA has already developed its own codes for practice and environmental guidelines for water reuse, effluent reuse management should be implemented in the SIA. The management of the reuse program will expand the plantation in the SIA and will help achieve the ultimate goal of preventing any wastewater from being discarded along the coastal areas. As a part of the environmental waste management program, mentoring programs combined with corrective actions may help bring the level of contaminants under control.
Additionally, the presence of the sewage outfalls along the coastline of Kuwait is environmentally and aesthetically unacceptable. This source of pollution causes the marine water quality to deteriorate and results in the release of an offensive odor and increased turbidity, (Marmoush, 2001; Al-Muzaini, 1998). Therefore, action should be taken to stop the practice of discharging sewage and industrial wastes on a regular basis at these storm water outfalls as well as for industrial discharges. Perhaps, all the wastewater generated in SIA needs to be treated to avoid many of these observed coastal pollution problems.
Conclusions and Recommendations
The coastal waters of the State of Kuwait have been polluted and will continue to be polluted by land based sources. The industrial effluents and domestic sewage outfalls are located along the coastline extending from the north to the south, and result in increased levels of pollutants such as nutrients, oil and grease, ammonia, organic compounds and fecal coli, which form bacterial populations associated with degraded marine environmental conditions, among other adverse impacts. The elevated pollutant levels observed have degraded the quality of the marine environment ranging from fish kills and localized smothering of benthic organisms and microbial pollution with a wider impact on overall marine productivity (Al-Muzaini et al., 1991). Power plants and trans-boundary movement of emerging pollutants have affected and damaged marine quality. Management of land-base sources could reduce pollution levels in the marine environment.
The SIA has taken steps to reduce the quantities of discharges and minimize their harmful effects on marine environmental by implementing new technologies and upgrading the performance of the industry operations. However, these steps are not sufficient to reduce pollutant levels in Kuwait’s marine environment.
A comprehensive waste management program is useful to reduce the pollution sources. Recycling, reuse, process modification, and treatment programs are recognized as essential steps toward pollution control and excellent industrial practices and they are part and parcel to effective waste management. Long-term improvement in environmental quality of the marine environment can be achieved by encouraging implementation of waste management programs. Water quality numerical models can be utilized to study the behavior and fate of water quality parameters such as nutrients, heavy metals, algae, and organic matter in the coastal waters of Kuwait. Further, it needs to be studied whether the extension (and/or relocation) of the discharge outfalls in the open sea reduces pollution levels to acceptable levels. Continued vigorous effort is needed to identify and understand water pollution behavior. In addition, toxicity, which is of particular concern in light of observed fish kills, requires further studies. Physical and chemical behavior of pollutants in living organisms needs to be better understood. Long-term studies are required to understand the link between short-term effect and long-term damage. Monitoring of heavy metals especially those derived from the Kuwait Oil sector in SIA should be a continuous process in order to determine the need for process changes, which reduce contaminant discharges. Finally, guideline plans to protect the coastal areas from land-based pollution, especially the economically important areas should be prepared and research organizations could provide help in identifying and understanding the pollution sources.