Nelson Environmental - Lagoon Aeration - Nitrification - Wastewater Treatment - Canada - United States

Project Information

Project Name: Wadi Hanifah Restoration Project

Location: Riyadh, Saudi Arabia

Project Type: Water Quality Improvement - Bioremediation System (BRS)

Completion: May 2009

Wadi Hanifah Restoration Project

Wadi Hanifah Restoration Project

Project Background

The Wadi Hanifah Restoration Project (WHRP) is a unique natural and geographical feature in the dry central highlands of Saudi Arabia. With a catchment area of 4,500 and a 120 km long main water course, the Wadi offers landscapes that are diverse and extreme. Part of the desert watershed traverses the western portion of Metropolitan Riyadh, one of the fastest growing cities in the world. Beyond the high-rise towers of urban Riyadh, the wadi region includes large industrialized farms, date palm plantations, two (2) significant archaeological sites, and bedouin villages.

In recent years, the rapid expansion and urbanization of the Saudi capital turned parts of the Wadi into a wasteland. Some areas were quarried and mined for construction materials to build the growing city. Others are dumping grounds for rubbish. Residential subdivisions, infrastructure, and expressways encroach upon the Wadi. Pollution, poor water quality, and water related diseases proliferate due to inadequate infrastructure and lack of development controls. Due to this contiuous degradation of the natural biological and aesthetic value of Wadi, the Arriyadh Development Authority (ADA) came up to a decision to protect and improve the current condition of Wadi Hanifah.


Nelson Environmental Inc. has had extensive involvement in developing, designing and implementing the river water quality improvement system (bioremediation process). Objectives of the process were as follows:

  • Natural biological system
  • Eliminate odors from polluted water
  • Reduce organic pollution
  • Channel nutrients to aquatic life
  • Reduce pathogenic bacteria in water
  • Create an aesthetically pleasing facility
  • Create water quality that is suitable and safe for irrigation of plants
  • Utilize the facility to educate people on sustainable natural water pollution control             

NEI's Solution

The Bioremediation Facility is the integral part of the Wadi Hanifah Restoration Project. The main treatment process of the water will take place in this area by enhanced biological treatment process.

The three main goals of the system are:

  • Reduction of fecal & Total Coliform
  • Elimination of foul odors
  • Prevent cumulative negative impacts of nutrient load through the Wadi 

The main components of the BRS are as follows:

  • Facility physical structure (head pools, group cells, bio cells & outlet pools)
  • Submerged aeration system
  • Artificial Periphyton Benthic Substrates (APBS) attached growth media
  • Fish
  • Water Jet Fountain

The system is designed to treat the water biologically and to assimilate the excess nutrients in to higher level of food chain. The process is being enhanced by the aeration system which supplies the system with high level of dissolved oxygen (DO), which is needed by microbes, fish and other aquatic organisms. Artificial Periphyton Benthic Substrate provides efficient substrate for beneficial bacteria essential biofilm micro community (algae, zoo plankton,ect.) which serve as food for fish communities.

Upgraded System Performance

The bio facility is effectively achieving the system goals since commissioning in May 2009. The system performance data as follows:

  • Fecal & Total Coliform: (95%) & (85%)
  • Nutrient load reduction: Carbon (75%), Nitrogen (70%) and Phosphorour (70%)
  • BOD Reduction: (70%) 
  • TSS Reduction: (96%)
  • Odor Control: No Odor
  • Establishment of Aquatic life (fish, birds, invertebrates, mollusk)



View Project Gallery

  • Wadi Hanifah Restoration Project - Jet Fountain
  • Wadi Hanifah - Aerial view of the bioremediation system
  • Wadi Hanifah with a submerged aeration system
  • Nelson Environmental
  • Nelson Environmental