English abstract
Waste disposal sites in Oman are increasingly becoming important issue because of their adverse effects on the environment; especially, soil and groundwater. Properly designed landfills that contain protection measures against environmental impacts such as liners, leachate and gas collection systems, a location away from residential areas and groundwater resources are absent. A preliminary survey carried out in 2001 by the Ministry of Health in one village near a dumping site in Bowsher indicated increased allergic and respiratory problems in the population due to air pollution. Moreover, no detailed environmental study has so far been conducted for assessing and monitoring the level of water, air, and soil contamination in and near these dumping sites.
This study focuses on two dumping sites from Batinah region and Muscat: Barka landfill and Bowsher landfill. An integrated approach for assessing the potential environmental risks from Barka landfill was conducted. This approach includes: regional groundwater sampling (111 samples), geophysical survey on the landfill, soil and solid and liquid waste sampling from the landfill. The collected samples were analyzed for many physical, chemical, and biological parameters to determine the type and level of contamination. Spatial distribution maps of groundwater quality parameters (using GIS) indicated high contamination spots with NO3 (119 mg/l), Total and Fecal coliform bacteria counts (>2420/100 ml), COD (3347 mg/l), and trace elements along the coastal line and with less extent near the landfill. Anthropogenic activities, mainly septic tanks, OUTCE extensive application of fertilizers, and the landfill, are believed to be the sources of these types of groundwater pollution. Soil and waste analysis data show very high concentrations of some trace elements especially Zn, Cu, and Cr. In the case of Bowsher landfill, twelve soil and waste samples have been collected from different compartments.
The analysis of these samples revealed that there are metallic contamination hotspots. The incineration area of this landfill was the most contaminated spot with Zn, Cu, Pb, are and Ni. This extent of metallic contamination is very threatening to the people living in the nearby (<700 m, away) village.
All contaminated soils must be removed or cleaned. We cannot leave them as is because they are now considered a source of contamination. From another angel, groundwater in the entire town of Barka is far contaminated with coliform bacteria, which applies for other cities in Oman. Therefore, decision makers should make appropriate acts to clean the groundwater and people should be advised not to use their groundwater for any purpose without testing and disinfection if contamination is found.
