A’Seeb Wastewater Project – Muscat, Oman

Project Details
  • Haya Water (Oman Wastewater Services Company, SAOC)
Project Value

USD 1 billion

Project Duration


Services Provided

Design, project management, design review, construction supervision

Sustainable Water Management

Enclosing the Seeb AWTP protects it from the elements and facilitates odor management

The A’Seeb wastewater project is Muscat’s first wastewater management system. Covering 189 mi2 (490 km2) of established urban environment, the system was designed for more than municipal sanitation—it also supplements the region’s water resources by treating 100% of wastewater to the high-quality level required for beneficial reuse and distributes the recycled water.

Parsons was the engineering consultant responsible for front-end engineering design, project management, and construction supervision of six separate construction contracts. The wastewater management system includes numerous features:

  • 700 mi (1,100 km) of gravity collector sewer lines
  • 14 mi (22 km) of main collector sewer by microtunneling
  • 170 km of high-density polyethylene pressure line for distribution of recycled water
  • 2 large treated-effluent storage and pumping facilities
  • 3 sewage lift stations with pump sizes up to 180 horsepower
  • Largest vacuum sewage system in the world, with 11 vacuum stations, 140 mi (225 km) of vacuum lines, and 4,500 vacuum interface valves
  • 26,500 sewer house connections
  • Seeb Advanced Wastewater Treatment Plant, designed to conduct tertiary treatment on 21.1 million gallons (81 million liters) per day
  • Emergency ocean outfall

Design measures for the project included flood protection for the riverine-like geography with wadis (dry rivers that flood during rain), a vacuum system for areas with a high water table, and enclosure of the Seeb wastewater treatment plant plus odor control solutions to meet the requirement of no odor at the facility’s boundary.

Our project management approach delivered uniform quality assurance and quality control among the six contractors executing the project. We helped the local and international contractors upgrade and implement quality plans and conducted audits to ensure full implementation of the quality systems throughout the project.

Featured Oct 2011/Updated Jul 2017

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