SoharUniversity– Landscape Irrigation and Waste Water Treatment

Landscape Middle East Magazine recently covered a Verdaus project with a focus on integrated water resource management. The article, “SoharUniversity– Landscape Irrigation and Waste Water Treatment” is an interesting cover of how foresight, collaboration and innovation can offer environmental benefits and cost savings.


In 2007, Sohar University appointed a consultant team to prepare a new master plan.  Verdaus Landscape Architects LLC was part of the consultant team.  Later, during the detailed design stage, Sohar University commissioned Mizan Consult to prepare a Feasibility Study and then a design for a “Reed Bed” system for waste water treatment.  This design offers considerable advantages over the present system of removing waste water by tanker.  Intensive collaboration between Verdaus and Mizan identified ways to integrate the landscape irrigation and waste water treatment systems to provide further advantages.

The project site:  Sohar University, Sohar, Sultanate of Oman

In November 2010, the United Nations Development Programme (UNDP) listed Oman, from among 135 countries worldwide, as the nation most-improved during the preceding 40 years.  In spite of its outstanding achievements, Oman is an arid country and faces significant environmental challenges.

Drought and limited rainfall contribute to shortages in the nation’s water supply, so maintaining an adequate supply of water for agricultural and domestic use is one of Oman’s most pressing environmental problems.   The soil in coastal plains, such as Salalah and Batinah (where Sohar is located), have shown increased levels of salinity, due to exploitation of ground water and encroachment by seawater in the water table.

Sohar is the most developed city in the Sultanate of Oman outside the capital Muscat. It is located about 200 kilometers north of Muscat, in the fertile coastal plain of the Batinah Coast.  Sohar was traditionally a fishing town, but is more recently known as Oman’s industrial hub due to the massive developments in the Sohar Industrial Port.

Photo of Sohar University with agricultural fields in the foreground.

Sohar University, a privately funded institution, is affiliated in most of its programmes with the University of Queensland in Australia.  Currently around 3,000 students, men and women, attend courses in Business, Computing and Information Technology, Engineering, and Humanities and Social Sciences. A planned extension aims to increase capacity to accommodate 12,000 students.

The project:  A new Master Plan for Sohar University

In August 2007, Sohar University appointed a team of consultants to prepare a new Master Plan.  This team included Design Inc (now The Green Architecture Company LLC), Cowi & Partners LLC, and Verdaus Landscape Architects LLC.  This team executed the design for the Master Plan, Concept, and Schematic Design Stages.  Verdaus were then appointed directly by Sohar University for the Detailed Design, Tender Services, and Post Contract Supervision stages.

Aerial perspective of the Sohar University campus with proposed extension.

The Landscape and Waste Water Treatment Consultants:  Verdaus and Mizan

Verdaus Landscape Architects LLC was established in 2004 and is one of the longest established landscape consultancy practices the GCC, with extensive project experience in the region.  Verdaus’ projects range from large scale landscape master plans to luxury private residences.  Verdaus partner and director, Laith Wark, received his degree from Queensland University of Technology (QUT) in Australia and designs external environments that are aesthetically pleasing and also play an integral part in water management. 

Mizan Consult FZE was founded in 2008 by Principal Wolfram Sievert, an Environmental Engineer trained in Germany, to deliver qualified independent consultancy for sustainable and environmental solutions.  Amongst other services, Mizan Consult offers expertise in the design of waste water treatment by conventional STPs and/or phytoremediation. An initial feasible study is used to determine the most suitable approach for each individual situation.

Example of waste water treatment reed bed at Seefa, Oman designed by Mizan Consult

Phytoremediation: Wastewater treatment using “Reed Beds”

Phytoremediation (from the Ancient Greek (phyto, plant), and Latin remedium (restoring balance or remediation) describes the treatment of environmental problems through the use of plants.  A particular example of phytoremediation is the use of “reed beds” (also known as “constructed wetlands” or “living systems”) to treat waste water (grey water and black water) from residential use.

The principle of the treatment of sewage by Reed Beds is relatively simple. Reeds have the ability to transfer oxygen from their leaves, down through their stems, and out into the root system.  As a result of this action, a very high population of micro-organisms occurs in the root system.  Therefore with the wastewater moving very slowly and carefully through the mass of reed roots, wastewater can be successfully treated, in a manner somewhat similar to conventional biological filter bed systems of sewage treatment.

Construction drawings showing a typical section through a reed bed.

In Europe these natural systems have been successfully harnessed to treat sewage and many other pollutants in waste waters over the past 30 years.  In the Middle East, and in particular the Gulf region, this technology is also being adopted in a number of countries.

Environmental Foresight:  Sohar University commissions a feasibility study and design for a Reed Bed system

At present, Sohar University’s wastewater is collected in holding tanks and removed by tankers on a daily basis.

During the Detailed Design phase, Verdaus recognized the opportunity for treatment of the university’s waste water using Reed Bed technology.  While there have been several successful implementations of Reed Bed technology in Oman to treat waste water from oil drilling, Sohar University is unique in being the first university in Oman to demonstrate environmental foresight by commissioning a pilot study to consider the feasibility of a waste water treatment system using Reed Bed technology and then a design for the Reed Bed system. Sohar University appointed Mizan Consult to undertake the feasibility study, and then the Reed Bed design.

The study demonstrated the feasibility of the Reed Bed technology for treating the grey and black waste water at Sohar University, with a number of advantages over a conventional STP.  These advantages included economic, aesthetic, technical, and other potential advantages.

Advantages:   Phytoremediation (“Reed Beds”) over conventional STP

Economic advantages

  • The feasibility study showed that Sohar University would need to acquire some additional land adjacent to the university to construct the Reed Beds.  Even taking into account the cost of leasing the additional land, after seven years it was estimated that the overall cost of the Reed Bed would system would be lower than a conventional STP.
  • Lower operation and maintenance cost compared to a conventional mechanical STP
  • Lower skill requirements for operators when compared to a conventional mechanical STP

Aesthetic advantages

  • The reeds grow to a height of approximately five meters and provide a significant green area in the landscape.  The agricultural character of the reed beds will enhance the agricultural character of the Sohar region.
  • The Reed Beds will attract birds.  The landscape consultant can design walking trails and bird watching “hides” to be integrated into the Reed Beds.
  • The Reed Beds provide shelter from wind and dust
  • Reed Beds process less odor than a mechanical STP.  Odor production is virtually zero.


  • Waste water is no longer removed from the Sohar University site, but is recycled into the landscape irrigation system.
  • The Reed Beds remove carbon from the atmosphere and it is estimated that they will produce 60 tonnes of biomass per year.


  • The phytoremediation process accommodates fluctuations in wastewater supply much better than a mechanical chemical process.  This is particularly important for a university as wastewater production drops substantially during vacation periods.

Other potential benefits

  • An opportunity is created for the faculty and students of Sohar University to monitor a unique implementation of Reed Bed technology in the Sultanate of Oman.  Opportunities exist fort Sohar University to lead in research and courses in phytoremediation technology
  • The biomass produced by the Reed Beds which must be periodically removed offer the opportunity for a small spin-off industry.  (In Europe, this biomass has been used to make light-weight brick for housing construction)
Reed beds produce bio-mass which is a useful resource with many applications.

Collaboration and Innovation:  Integration of landscape irrigation and wastewater systems offers additional benefits 

After the choice of a wastewater treatment system, this system and the landscape irrigation network are usually designed as two largely independent systems.  Close collaboration between Verdaus and Mizan Consult identified number of possible measures that would integrate these two systems more closely to give additional benefits. These measures include:

  • Using the final stage reed beds to store the treated sewerage effluent (TSE) instead of using dedicated irrigation storage tanks.  Benefit:  Cost saving  of the irrigation storage tank
  • Using the irrigation mainline to periodically flush the sewerage.  Benefit:  Improved operation of the sewer line, reduced maintenance, and the elimination of anaerobic condition in the sewer lines which contributes to offensive odors.
  • Collapsing two control systems into one and using the same automatic control system for the waste water treatment and the irrigation system.
  • Using the irrigation pumps directly to draw the water out of the final reed bed chamber. This would eliminate one pump set, the discharge pumps from the reed bed.  Benefit:  Cost saving of one pump set and its maintenance.
  • Collapsing two maintenance systems into one.  The skills required to operate and maintain the phytoremediation process are similar to those required for landscape maintenance, so collapsing the two contracts into one would be feasible.  Benefit:  Cost saving of one maintenance contract.


During the project, Sohar University, Verdaus, and Mizan have found that a willingness amongst Client and Consultants to collaborate, to explore, and to innovate across professional boundaries can bring many tangible environmental, aesthetic,  and cost benefits in water management.

This article appeared in Landscape Middle East Nov 2011 Issue.