Oman Wastewater Services Company (Haya Water) has awarded the US’ Aecom a $1.6m contract to design phase two of the Al-Ansab sewage treatment plant (STP) and the Azaiba central pump station in Muscat, Oman.

The project is expected to take nine months to complete.

Aecom designed the original Al-Ansab STP in 2002. The plant was built by the local Galfar Engineering & Contracting. The capacity of the Al-Ansab STP is currently 55,000 cubic metres a day (cm/d), and the expansion will increase this by 25,000 cm/d.

In April, Haya invited contractors to submit bids for the contract to build a sea outfall for the Azaibah central pumping station. Bids are due in on 22 July.

Haya Water is planning to invest RO1bn ($2.6bn) on new water projects in the sultanate until 2018. The company has the mandate to build, own and operate the Muscat wastewater project under a 30-year concession, which started on 1 January 2006. Its responsibilities involve wastewater collection, treatment and TSE distribution across the governorate’s six provinces – Muttrah, Bausher, Seeb, Al-Amerat, Quriyat and Muscat.

In December 2011, Haya awarded a joint venture of Egypt’s Arab Contractors and the local National United Engineering Contracting Company an RO28.9m ($75m) contract for sewerage works in the Al-Amerat western area.

The work will involve building 23 kilometres of sewers, 140km of laterals and riders, 7km of treated sewage effluent (TSE) line and 43km of residence connectors, which will service 2,900 properties.