Dubai is the only place in the GCC to have achieved a 100 per cent treated sewage effluent reuse rate. Others have yet to put infrastructure in place and incentivise industrial users to switch from potable water
The announcement by Dubai Municipality at MEEDs Arabian World Construction Summit (AWCS) in May that soaring demand for treated sewage effluent (TSE) may lead to summer shortages is evidence the GCC is beginning to make progress with water reuse.
Recycling wastewater carries many advantages, including preserving freshwater and groundwater resources for higher quality purposes such as drinking or household usage, and reducing demand for more expensive supply systems such as desalination plants.
If you are using desalinated water, it will cost you a dollar-plus [a cubic metre] to produce, and it has a significant carbon footprint associated with it, says a Dubai-based engineer at a major international water and wastewater firm. Whereas, if you are treating your effluent already, but dont know what to do with it, then all you need to pay for is the cost of getting it to where it is used and disposing of it its almost free.
Until recently, progress with TSE reuse initiatives has been slow in the GCC due to a combination of social resistance, inadequate legislation and insufficient infrastructure. However, with estimates that desalination capacity in the region will need to grow 63 per cent by 2020 to meet demand, governments are now promoting water conservation projects and several have set targets of achieving 100 per cent TSE reuse.
TSE currently has three main uses in the Gulf: as irrigation water for green areas and water features such as ponds; in industrial processes; and as feedwater for district cooling systems. To a lesser extent, it is also used in agriculture and for recharging water aquifers.
Any industry that needs water should have no real objection to the use of non-potable water, particularly given that we treat the TSE to a very high standard by default anyway, says the engineer. In addition to irrigation, TSE can be used for district cooling, cement making and gravel cleaning. Any industrial application you can think of is suitable for TSE reuse.
The lack of surplus TSE in Dubai shows the emirate has not only been successful in delivering the required infrastructure, but also that economic incentives are in place for customers. Dubai Municipality, the body responsible for wastewater treatment in the emirate, introduced a commercialisation programme to sell TSE at just 15 per cent of the cost of potable water provided by Dubai Electricity & Water Authority (Dewa). The price of TSE is set at about AED1.1 ($0.30) a cubic metre, compared with AED7.7 a cubic metre charged by Dewa. This price difference has driven demand for TSE from the district cooling industry. District cooling is an energy-efficient means of chilling buildings, but is also a highly water-intensive process.
The municipality has also set a target of treating 80 per cent of Dubais green areas with TSE by 2030.
While Dubai has achieved a 100 per cent reuse rate, others in the region have faced
technical, economic and political challenges. Abu Dhabi is lagging behind its neighbour in its utilisation of TSE, with a current reuse rate of about 60 per cent. While the UAE capital has sewage treatment plants capable of processing 500,000 cubic metres a day (cm/d) of wastewater to a suitable reuse standard, it is forced to dispose of 40 per cent of its TSE into the sea via the Mussafah channel due to constraints in its transmission and distribution networks.
[The Qatari authorities] dont know what to do with the TSE. So they are left with vast lagoons of treated effluent
Contractor for water company active in Qatar
Abu Dhabi is hoping to maximise the use of TSE and has set a target of 100 per cent reuse by 2018. To meet this goal, Abu Dhabi Sewerage Services Company (ADSSC) is investing heavily in upgrading infrastructure. Its planned projects include the ambitious $1.6bn Strategic Tunnel Enhancement Programme (STEP), which involves building a 41-kilometre deep sewer tunnel, due to be commissioned in 2015.
Qatar also has wastewater treatment plants technically capable of producing high-quality TSE, but has been unable to use the resource to its full potential. Like ADSSC, the Public Works Authority (Ashghal) is proceeding with a multibillion-dollar programme to upgrade its sewerage networks, set for completion in 2019. A key part of the $2.7bn Inner Doha Resewerage Implementation Strategy involves the construction of a 70km TSE return system, able to transport up to 500,000 cm/d.
Lack of coordination
However, while this network will facilitate the transmission of TSE, companies active in Qatars water sector point to a lack of planning for end-uses as a potential stalling point. Qatar has high-level tertiary treatment that should meet any reused effluent standard, yet [the authorities] dont know what to do with the TSE, says a contractor for a water company active in the local market. So they are left with vast lagoons of treated effluent.
I think the problem is, where will the network go? For one [real estate] project I am aware of, the authorities in Qatar had said TSE must be used for the air-conditioning system, but the sewage authority was being difficult about accepting the wastewater back into the system as it was too salty. So you have to jump through a lot of hoops just to implement government targets on TSE.
When setting targets for reuse, it is vital that governments also plan what the TSE will be used for and that decision-makers have the full support of utility providers to ensure a cohesive approach.
But the biggest challenge to meeting TSE reuse targets is undoubtedly the significant water subsidies that exist in most GCC countries. While Dubai has been able to offer TSE at attractive rates to industrial customers, other markets have so far yet to follow suit.
Lack of investment
Unsurprisingly, Saudi Arabia, the worlds largest producer of desalinated water, has the most ambitious plans to expand its TSE market, with an aim of increasing output to 6.3 million cm/d by 2032, almost three times the amount recorded in the latest figures available. Due to a lack of investment over the past 20 years, only 50 per cent of the kingdoms population is connected to a sewage network, with rates as low as 22 per cent in Jeddah. Treatment rates are equally as disappointing, only reaching 50 per cent in some areas.
As a result, National Water Company (NWC) is planning SR89.1bn ($23.8bn) of capital expenditure in its wastewater sector in 2012-20. The company currently has treatment plants with a total capacity of 2.3 million cm/d a day of TSE in operation, and another 2.9 million cm/d in the planning and construction stages.
Saudi Arabia definitely has the most potential for TSE [reuse], due to its growing population and demand for industrial water, says a water consultant based in Dubai. If it is able to invest in infrastructure, the demand for effluent will be there.
NWC already has agreements with 13 companies to supply TSE and has signed a memorandum of understanding with an additional six firms. It is in discussion with at least another 10 private companies to supply recycled water for irrigation and industrial use.
However, doubts remain over the success of these agreements, with NWC having priced TSE at market levels rather than the heavily subsidised value of potable water in the kingdom. Saudi Arabia currently charges among the cheapest rates for water in the world, at less than $0.03 a cubic metre.
In some countries, they want to give away potable water through heavy subsidies, says the Dubai-based consultant. If you are a consumer of water and are presented with the option of almost free desalinated water and almost free TSE,what are you going to choose? Of course, youd take the brand new water.
With desalinated water heavily subsidised in Abu Dhabi, Kuwait and Bahrain, many feel the incentive to buy TSE is not there. Governments know that electricity and water subsidies are a cause of the high consumption and are not sustainable in the long term, says a source at a UAE-based utility company. However, they also know the high social resistance to tariff reform and,
following the Arab Uprisings, are not going to risk upsetting their people.
Abu Dhabi is forced to dispose of 40 per cent of its TSE due to transmission and distribution constraints
TSE=Treated sewage effluent. Source: MEED