Oman Wastewater Services Company is setting up a modern wastewater system in Muscat Governorate with an investment of RO1.2 billion. Akshay Bhatnagar takes a look at the progress made so far on the project, which is expected to be completed by 2017


The gruesome sight of an overflowing septic tank or a tanker sucking out waste from sewage lines at regular intervals in Muscat is expected to be a thing of the past in coming years. Thanks to the efforts of the state-owned Oman Wastewater Services Company (OWSC) that is spearheading the ‘Muscat Wastewater Project’ to build and operate a modern wastewater system in all the wilayats of Muscat Governorate. With a combined investment of RO 1.2 billion (at current prices), the project will cover 30,000 plots spread across the Governorate to reach 90 per cent of the population by 2017.

Project Scope
The Muscat Wastewater Project involves building wastewater networks, pumping stations and sewage treatment plants. The treated water may not be fit for consumption but it will be good enough for irrigation and industrial applications. The treated effluents produced by OWSC will be used for irrigation. OWSC is also planning to produce fertilizers using the waste churned out by the sewage treatment plants (STP). The company is currently in the process of implementing the Bausher wastewater project that consists of an STP in Al-Ansab. Based on the membrane Reactor System, the STP will produce 53,000 m3 of treated water per day. Galfar Engineering & Contracting Co. has undertaken construction work for the STP. Simultaneously, OWSC is constructing sewage networks in Bausher covering areas from Al-Hamriya roundabout to Al Azaiba. The total length of the network will be 300-km and will connect 18,000 plots. The Chinese company Sinohydro has been assigned the construction of the sewage networks in Al-Ghubra and Al Azaiba. The same company is also buildinq g the central pumping station in Al Azaiba.

In the Seeb wastewater project, the company is building a sewage treatment plant with a capacity of 80,000 m3 treated water per day. Three pumping stations will also be constructed to push the wastewater coming from different parts of Al-Seeb to the main collector sewer. A 25-km long main collector sewer will be constructed that will run parallel to Sultan Qaboos highway from the Airport Height road to the STP at Al-Seeb. A 270-km long sewage collection network will be constructed in the coastal strip north of Sultan Qaboos highway. Ten vacuum stations will also be built to suck out the wastewater and transfer it to the main treatment plant.


OWSC is also busy planning sewage networks in Al-Mabella (170-km long) and Al-Khoud (270-km long) using the gravity system. The company recently awarded two related contracts – Al Maabela Gravity Drainage Network to Arab Contractors, and Al Seeb Costal Strip Vacuum Sewers Networks to Galfar – with a combined value of over RO145 million.

New Tenders
Speaking to OER, OWSC’s CEO, Omar bin Khalfan Al-Wahaibi said, “We’re planning to float at least five more tenders this year. The combined construction value of these tenders is expected to be around RO250 million”. On the Bausher sewage network, OWSC will float three tenders for the main assembly line coming out of Al-Ghubra up to Wadi Adai, the sewage networks in Al-Khuwair, Al Qurum and Madinat Al-Aalam.

No mean feat
Creating a wastewater system for a city that is growing at a rapid pace is not an easy task. The non-availability of updated sub-surface information from a centralised source is another issue that the officials of OWSC and its contractors are grappling with. “On the existing underground networks, we collect information from all the relevant authorities to ensure that while digging we don’t damage infrastructure related to telephone cables, oil pipelines, water network, electricity cables etc. But often we find elements that are not provided by the relevant authorities. That leads to alteration in the original plan and unwarranted delay in the execution of the project,” said Samir Abo Humaid, project manager, OWSC.

In order to ensure that digging of the surface doesn’t affect the networks of other companies, OWSC has deployed ‘micro tunneling’ technology. “We are using a remotely controlled Microtunnel Boring Machine (MTBM) combined with the pipe jacking technique to directly install pipelines underground in a single pass. This process avoids the need to have long stretches of open trench for pipe laying, which causes extreme disruption to the community. It is currently the most accurate pipeline installation method. Line and grade tolerances of one inch are the micro tunneling industry standard. This can be extremely important when trying to install a new pipeline in an area where a maze of underground utility lines already exists,” Humaid said.

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