Dubai Creek: A third line of defence

A third line of treatment at the sewage treatment plant in Ras Al Khor would restore the health of Dubai Creek, a private study by a ranking Roads and Transport Authority (RTA) official has suggested.

The study by Khalid Al Zahed, Director of Maritime Projects Department at the RTA, is part of his doctoral thesis on the marine environment.

Al Zahed’s work revealed that of 29 outflows into the Dubai Creek, the sewage treatment plant at Ras Al Khor was spewing large amounts of nitrates into the water.

Compared to internationally accepted levels of 0.4 milligrammes of nitrates per litre of effluent water, the sewage plant is releasing effluent with 22 mg of nitrates per litre.

With an estimated 100,000 cubic metres of treated grey water being released daily, the nitrate deposit is contributing to a drastic drop in oxygen on the Creek bed, Al Zahed said.

"Dissolved oxygen can cause fish kill," he warned.

Every year, there are reports of dead fish washing up ashore, he added.

To restore plankton life, Al Zahed’s study recommends that the municipality should implement a third line of tertiary treatment which would add more chlorine as well as friendly bacteria to waste water before they are released into the Creek.

Dredging the Creek would also help restore the marine life in less than a year, computer modelling by Al Zahed revealed.