Established in 1985, Eagle Electromechanical Company (EECO) is one of the leading players in water and wastewater treatment works in the UAE. The company specialises in turnkey projects involving custom-design, supply, construction, operation and maintenance of water treatment works, wastewater treatment works, sewage treatment plants, chlorination systems and odour control systems. Majd Hamdallah, Operations Manager, EECO spoke to Anoop K Menon, on the key trends in the UAE sewage treatment market
What is the dominant trend in Sewage Treatment Plant (STP) contracts in UAE and how has EECO adapted to that?
The dominant trend in STP contracts is Design, Build, and Operate. But we are always prepared to adapt to market needs, whether it is EPC today or financing in the future. What has distinguished us from competition is our approach to doing everything ourselves, right from design to sourcing/ installing the best equipment to running and maintaining the plant. Today, we are managing more than 40 STPs all over Dubai for developers of the likes of Emaar, Nakheel and Dubai Properties. Our competitive advantage is our long term commitment to the local market. Overseas companies don't have the capability to run STPs for a long period because they are averse to long-term involvement in this area. Moreover, Operations and Maintenance (O&M) is one of our core strengths. Our O&M division, staffed with 20 engineers, boasts of a very successful track record. For example, we have an O&M contract with Le Meridien since 1997, with the Sheraton since 1999. We operate plants for a number of properties of the Jumeirah International Group, including Bab Al Shams and Burj Al Arab. Customers lay down performance and quality specifications very clearly in their contracts and we take it upon ourselves to meet those specifications. Moreover, we are more careful than the customer in selecting the right technology and equipment for the plant; otherwise, we will be saddled with problems of equipment failure and wear and tear.
As a technology trend, Membrane Bioreactor (MBR) seems to be right at the top. How is this technology benefiting Dubai?
The way MBR technology is being implemented, I fear it may end up as another fad. But at EECO, we are careful in that we work closely with clients to understand their actual needs and advise them on the direction they need to take. Like any technology, MBR has its advantages and disadvantages. On the positive side, MBR has a relatively small foot print, a major advantage given the high cost of land in Dubai. For example, we were awarded the Dubai Sports City contract against stiff local and international competition because we convinced them that we could set up a 25,000 m3/day STP with a footprint of only 100m x 40m, which by itself is a huge achievement in our business. The Sports City authorities had envisaged a much larger area for the STP. We saved them Dh 14 million in land costs alone.
Also, the quality of the treated sewage effluent (TSE) from MBR is much higher compared to conventional STPs, making it suitable for industrial applications like district cooling and water features. With additional treatment, it can be made potable. At our projects for Dubai Properties, TSE will be used for district cooling.
However, conventional STPs, with their lower running costs, chemicals and power included, will continue to play an important role, especially in centralised sewage networks.
Singapore is the only country in the world where waste water is completely recycled and re-used, not only for industrial applications but for human consumption too, albeit in a limited way. Can we replicate that in Dubai?
Yes, it can be replicated because in Dubai because we too use the latest technology and equipment for wastewater treatment. For example, at Dubai Sports City, we are treating and transforming sewage into potable water as per DEWA specifications. I don't see too many problems using TSE for industrial applications. We have a large quantity of produced TSE from the Dubai Municipality and the private sector. Even after using that for landscaping, there is a huge quantity left over. Why not treat and use it for industrial applications that require huge quantities of water like water features, lakes, district cooling? Customers only need direction.
However, human consumption is a different story, and the reasons are more psychological than religious. People living in Dubai continue to consume bottled water even though tap water, distilled from the sea and made potable using the most advanced technologies, is good enough. The reason is the source of that water. The same applies for treated wastewater too. We have a lot of ground to cover to reach where Singapore is today.
But industrial users have questioned the suitability and quality of TSE for the applications you mentioned. How can their fears be addressed?
It is a matter of cycles. If you intend to use TSE from a conventional STP for district cooling, the number of cycles will increase; if you use TSE from MBR, the number of cycles would reduce because its quality is much better. You can remove all the hardness and total suspended solids (TTS) using Reverse Osmosis (RO), reduce the odour and it will still be cheaper than using drinking water. And regulations are moving in this direction. For instance, in Dubai, new regulations are on anvil to curb the use of drinking water for district cooling. Hence, there is a need to develop alternative resources, like TSE.
What would be your wish list for Dubai, from a sewage treatment perspective?
Like any other fast growing city, Dubai needs infrastructure that supports its growth, and that includes a well defined sewage network. It is important to understand that everything is interlinked. For example, if traffic jams have increased on Dubai roads, a major reason is the increase in the number of tankers transporting sewage. How did this happen? Most of the new developments are neither connected to the municipality sewerage network nor do they have their own STPs. Dubai Municipality's Al Aweer STP receives around 4,000 tankers daily from all over Dubai, and the waiting time to discharge the sewage can be as long as eight hours. This could have been avoided if there were local STPs in different locations or if the sewage network was ready or if the private STPs received these tankers.
In fact, we receive close to 200 tankers daily at the plants we are operating for certain clients. They have a huge requirement of TSE for irrigation, but the local inflow is very less. Therefore, we have an arrangement to bring sewage into their plants by tankers. On the one hand, this reduces tanker congestion in Dubai, while on the other, free-of-cost supply of TSE is assured for the clients. For Nakheel and Emaar, we are receiving their tankers in their own plants and producing TSE for irrigation. All together, we are receiving 500 tankers at the STPs we are operating in different locations.
What are the new trends in STP design?
Today, STPs are being designed in a way that they blend into the surroundings because nobody wants to see, smell or even know it is there. The Dubai Sports City STP doesn't look like one at all because it is housed inside a building. Developers are becoming careful about the visual impact - given the trend of high rises in Dubai, nobody wants their views marred by STPs. They also want odour-less plants. For example, the Garden Sewage Treatment plant behind Ibn Batutta Mall is located a mere 30 metres from the Mall, but nobody knows of its existence because there is no smell. At EECO, we have developed a three stage process to remove odour completely. Technically, odour cannot be eliminated in entirety as there will always be small traces. What we guarantee is its absence at the boundary.
How does this three stage process work?
Odour is a design issue, and can be traced to two factors. One, all the sewage coming out of new developments is fresh, so to speak, taking only two to three hours to reach the STP rather than 24 to 48 hours. Second, the source of odour in any STP - conventional or MBR - is the inlet work and the sludge treatment.
Based on a study we conducted at Dubai Municipality's STP at The Gardens, during the height of summer, measuring H2S levels continuously for two months, we found that the maximum level H2S can reach is 15 mg/l. While many contractors over-design for H2S levels of 200-300 mg/l, this may not always work. As part of our three stage process of odour removal, we keep the inlet work and the sludge treatment areas sealed and under negative pressure all the time. We extract the air from inside by exhaust fans, treat it by chemical scrubber or impregnated activated carbon and remove H2S completely.
If the STP is in a closed building, we utilise the huge capacity of the blower, designing the plant in such a way to keep the building itself, above the tanks and the rooms, under negative pressure. The blower capacity is huge for the membrane and the process. Even if you have problem of air from any tank, it will not go outside. It will be taken and discharged inside the process inside the aeration tanks. We also have a second stage of treatment for odour control or Plan B to eliminate any source of odour. We monitor H2S measurement online before and after treatment through warning lights and horns. For example, if H2S level is above 10 mg/l, immediately, we will start dosing chemicals to increase the pH value at inlet sewage. If the pH value is 8.5, you eliminate 99% of emissions of H2S gas. Of course, chemicals are expensive and you only use it during emergency. We use chemical dosing at the inlet for two reasons - one, to eliminate high H2S concentrations; second, the desalinated water supplied in Dubai is devoid of alkalinity. Therefore, if the pH value is low or alkalinity is less, we dose soda ash or any alkaline chemical at the inlet to increase pH value.
What are your plans to take EECO overseas?
We do get inquiries from other countries in the Middle East like Qatar, Oman and Iran. In the past, we did more than 10 plant packages in Sudan and also projects in Azerbaijan. However, I don't see us entering overseas markets at least for the next two years because we are overloaded here. For the time being, we intend to focus on the UAE market.
© H2O 2008
