Estate Service Asset - PDO

Petroleum Development Oman
Estate Services Asset
Environmental Assessment
2002 Review and Update
Mountains to the sea. It consists of sandy and gravel beaches, coastal marshes and
rocky mountain headlands. The composition of the coastal plain is mainly
sedimentary limestone of Mesozoic origin.
The soils on the coastline are sandy and away from the coast soils are sandy gravel.
No site-specific data are available on the soil quality. Generally, the soils in the asset
are classified as unsuitable for agricultural purposes, as per the Ministry of
Agriculture and Fisheries “General Soil Map of Oman". The soil map of PDO’s
concession area is shown in Figure 5.1.
5.4 Hydrogeology and Groundwater Quality
The tertiary formations contain exploitable groundwater resources in Oman. In the
north, the tertiary aquifer systems are recharged from the flow from the Oman
mountains. The shallow aquifer systems consists of the Fars formations (0-150 m
depth), Dammam formations (150-200 m depth), Rus formations (200-300 m depth)
and Umm er Raduma (UeR) formations (300-600 m depth).
Near the coast, the hydrogeology is influenced by seawater. The shallow ground water
is highly saline and not potable. Potable groundwater for MAF and RAH areas is
sourced from sustainable aquifer in Al Khoud, about 37 km from MAF. The Al
Khoudh well field is located across the alluvial plain often referred to the Al Khoudh
fan in the lower part of the Wadi Samail catchment. Water is extracted from Fars
formations. A recharge dam was constructed surrounding the well field to enhance
recharge during periods of heavy rainfall.
Water levels measured in one of the supply wells in Al Khoud since 1989 show a
wide fluctuation, apparently depending on rainfall in the catchment area. For the
period of 1989-2001, the mean annual average of depth to water level varied from a
minimum of 7.7 m (1998) to a maximum 34.3 m (1994). The weekly averages during
these years showed relatively low fluctuation between 19.4 m (March / May) and 22.6
m (October / November). The details are presented in Appendix 2. Groundwater levels
in boreholes near the dam show fast response to wadi flow events, reflecting the
relatively high permeability (34-149 m/d) of the well field. The quality of
groundwater in Al Khoud field is very good and the groundwater does not require any
treatment for domestic use.
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