Responsibility for Oman’s wastewater is split between five entities covering different regions in the sultanate. Hundreds of smaller plants are owned by the private sector.

The five main groups are Haya Water, which oversees wastewater services in the Muscat governorate, the most populous of the sultanate’s regions; Salalah Sanitary Drainage Services Company, which looks after Salalah city, in Dhofar province; Dhofar Municipality, which is responsible for the rest of the Dhofar region; Sohar Development Office within Muscat Municipality, which looks after the Sohar province; and the Regional Municipalities & Water Resources Ministry, which is responsible for the rest of Oman.

The sultanate had 105,990 cubic metres a day (cm/d) of wastewater treatment capacity at the end of 2008, with an estimated 230,000 cm/d of new capacity to be built by 2015.

Networking project

Much of the current activity in Oman’s wastewater sector centres around the $4bn Muscat wastewater project, which is being developed by Haya Water.

As part of a 30-year concession, the project aims to connect 80 per cent of the population of Muscat governorate to the wastewater network by 2014, and 90 per cent by 2025.

In November 2008, Haya announced plans to issue tenders in 2009 for four treatment plants as part of the project. The plants are expected to provide a total of 67,500 cm/d of additional wastewater capacity.

Bids for the largest of the four plants were entered on 26 October, covering the construction of a plant in Darsait, in the north of the governorate, which will be able to treat 50,000 cm/d of wastewater. This is expected to begin operating in December 2011.

A smaller plant in Quriyat, in the southeast of the governorate, will be tendered by the end of 2009, with a capacity of 6,500 cm/d. A further two wastewater treatment plant projects are also expected to be tendered before the end of the year in Al-Amerat and Al-Hajir, in the central region of Muscat governorate. The Al-Amerat facility will have a capacity of 10,000 cm/d, while the Al-Hajir plant will treat 1,000 cm/d of effluent.

An additional wastewater treatment plant project will follow in September 2011 when Haya expects to issue a tender for the expansion of the Al-Ansab facility, in the north of the governorate. The scheme will add 25,000 cm/d of capacity at the site.

The Muscat wastewater project also includes construction of 2,164 kilometres of sewers and three treated-effluent reservoirs and distribution networks. These are the Seeb, Al-Ansab and Greater Mutrah centralised and looped network, the Al-Amerat/Al-Hajir network and the Quriyat network. The total length of the treated effluent distribution network will be about 308km.

Due to the mountainous terrain, it is not possible to connect the rest of the governorate to the wastewater network. As of early 2009, only 14 per cent of Muscat governorate was connected to the network. The remaining area is served by septic tanks. 

“As of early 2009, only 14 per cent of the Muscat governorate was connected to the wastewater network”

Haya currently operates 12 treatment plants, which process 50,000 cm/d of wastewater from nearly 80,000 residents. Designed to treat 46,100 cm/d of wastewater, the plants are operating at 8.5 per cent above capacity. Haya estimates that an additional 190,000 cm/d of new wastewater treatment capacity will be required in Muscat up to 2015.

A wastewater treatment plant is being built in the Al-Seeb catchment in the northwest of the governorate. South Korea’s Hyundai Rotem was awarded the OR88m ($229m) contract for the scheme in June 2008. The plant will be able to process 80,000 cm/d of sewage.

Once the new wastewater system is set up and the company is generating sufficient operating revenues, the government plans to privatise Haya. When this will happen and what form the privatisation will take have yet to be decided.

Public wastewater treatment plants outside Muscat, Salalah and Sohar are owned by the Regional Municipalities & Water Resources Ministry, which is responsible for the provision of wastewater services in the Batinah, Musandam, Al-Buraimi, Al-Dhahira, Al-Dakhliya, Al-Sharqiyah and Al-Wusta governorates.

The treatment plants operating in the rest of Oman have a total capacity of 36,890 cm/d. A further 14,350 cm/d of new capacity is due to come on line in 2009 and 2010. Only one plant, at Samail in the Al-Dakhliya region, is operating at above design capacity.