Design of Wastewater Treatment Plant in Ar-Rass (Phase II)

Project Description

The existing Ar-Rass Wastewater Treatment Plant is located in the northern west of Ar-Rass town in Al-Qassim province; one of the 13 regions of Saudi Arabia. The town is almost 400 km north of Riyadh and about 80 km
southwest of Buraydah, the regional capital of Al-Qassim Province. The project aims to design the second phase of Ar-Rass Wastewater Treatment Plant with a total capacity of 25,000 m3 /day.

The number of process and non-process facilities are expected to be 25 buildings on an area of approximately 100,000 m2.

The plant is designed to achieve carbon and nutrients removal. The treatment facilities involve preliminary, primary, secondary and tertiary treatment processes.

Ar-Rass treatment system works as follows:

  • The biological treatment is based on Anaerobic/ Anoxic/Oxic (A2O) systems.
  • Rapid sand filter is used for tertiary treatment.
  • Chlorine gas is used for treated sewage effluent disinfection.
  • Gravity thickener and sludge centrifugal systems are used for sludge treatment.


  • Architectural
  • Civil Works
  • Communications and security systems
  • Electrical
  • HVAC
  • Instrumentation
  • Landscaping
  • Mechanical
  • Roads
  • Structural


  • Conceptual design
  • Data collection
  • Detailed design
  • Preliminary design
  • Tender documents
  • Treatment alternatives study


Saudi Ministry of Electricity & Water








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