A renewable resource

Treated wastewater could be put to use in the region?s agriculture, while by-products from the treatment process can be used as fertiliser.
[More Images]

How can utilities in the GCC benefit from treating sewage effluent? Nadim Batri, principal, and Johnny Ayoub, senior associate from Booz & Co explain.

The GCC faces the dual challenge of declining water supplies and rising demand. With the region’s countries below the water scarcity threshold of 1,000 cubic meters per capita, all member states have embraced the large-scale desalination of seawater.

While desalination technology has proven to be adequate, it remains expensive and carries significant environmental costs from high energy use and the disposal of brine.

Story continues below

Advertisement

FEATURED COMMENT Please click here to comment on this article

What the GCC needs is an alternative to fresh groundwater and desalination that is less costly, draws from existing water sources, and has less of an impact on the environment.

They need not look far. Right now, GCC nations regularly treat millions of gallons of wastewater before returning it to the sea. Although treated sewage effluent (TSE) is generally not viewed as safe for consumption and is often used in the GCC for landscaping, it is a potential source of water for a variety of critical agricultural, industrial, and other uses.

By turning to TSE as a source, the sunk costs associated with current treatment and disposal could be considered an investment in new water sources. And, perhaps most important, producing and distributing TSE would greatly reduce the stress on current fresh water supplies.

To be sure, this transition will not be effortless. Producing TSE is not inexpensive – groundwater is still cheaper by far, at least on a cost-to-user basis. In the US, agricultural users paid roughly US$0.70-0.90 per 1,000 gallons for reclaimed water; water pumped directly from an aquifer cost approximately
$0.10 – 0.15.

Yet with supplies of water so short and with greater urbanisation causing a strain on resources, GCC water utilities need to explore wastewater treatment technologies fully.

From 2010 to 2016, capacity for reusable water is expected to enjoy annual growth rates of 13 percent, compared with expected growth of four percent for contracted desalination capacity. Thus TSE will play a growing role in curbing water supply levels from non-
renewable groundwater.

This is particularly true because some of the biggest users of water do not necessarily need potable water.

Agricultural users comprise more than 80 percent of total water demand, and TSE has been proven to be effective in irrigating fodder crops eaten only by livestock.

In addition, district cooling providers could easily use TSE as a substitute for desalinated water, which they currently use at a very high expense.

The cost of treated effluent is approximately $0.66 per cubic meter (depending on its quality and on how much it costs to transport to end users) while water from desalination costs an estimated $2.27 per cubic meter.