A new focus for Oman as treated produced water research gathers pace

Dr. Alexandros Stefanakis, Bauer Nimr’s constructed wetlands expert, explains why finding alternative resources to groundwater is so important for this water-scarce country.
 
With Oman’s annual water deficit at nearly 2 billion bbls, and agriculture accounting for around 83% of groundwater resource use, it is easy to see why there is interest in using treated produced water to supplement or substitute groundwater supplies. The country produces as much as 8 million bbl/d of water, representing a significant potential resource.
 
Several research groups are conducting studies aligned with these needs. Bauer Nimr LLC, a subsidiary of Germany’s Bauer Resources GmbH, is looking at the feasibility of using produced water treated through its constructed wetlands system for agriculture and aquaculture.
 
The Nimr reed beds treatment facility was constructed in 2010 by Bauer for its client Petroleum Development Oman (PDO) to treat an initial 45,000 m3/d, or about 283,000 bbl/d of produced water from the Nimr field. The project’s success has allowed for three expansions, the most recent of which raised treatment capacity to 175,000 m3/d. By the end of the treatment process, more than 115,000 m3/d of water flows into evaporation ponds downstream of the reed beds.
 
“We are in the middle of the desert in a water-scarce country, so this particular volume can be an alternative water resource in the region,” Dr. Alexandros Stefanakis, a constructed wetlands expert at Bauer Nimr, told Water in Oil. “We are running several research projects to find the best option to reuse this water, not just in terms of market value, but also to do this in a safe way.”
 
The company is currently conducting a market analysis on a four-year biosaline agriculture pilot for which PDO contributed 50% of the funds. During the project, 15 different species of salt-tolerant plants were irrigated with water treated through the wetland system. Bauer Nimr will also begin a fodder production trial using the water, and the company has also completed a feasibility study for aquaculture which Stefanakis hopes will move into the trial phase by next year.
 
“Three or four years ago, I would have said that I don’t see [beneficial reuse projects for produced water] coming, not just because of technical challenges, but mostly because of the perception that it is still an industrial wastewater,” Stefanakis said. “The perception was that it cannot be used for anything that we introduce into the food chain, but in the last one or two years I have seen a shift in how authorities understand and perceive this.”
 
During his presentation at the Produced Water Middle East 2019 event, Hilal Al Qassabi, head of the Soil & Water Pollution Control Section at the Ministry of Environment and Climate Affairs, Oman, told attendees that, while regulations exist for industrial wastewater treatment and reuse in Oman, standards specific to produced water are lacking.
 
Stefanakis believes those standards may still be adequate for produced water, but that the classification of different reuse applications is necessary. “[That] may require some parameters to be lower or higher respectively. In any case, I do not see that specific standards will be developed in the near future,” he said.
 
While stating that more research and information was needed, ministry representatives attending the Produced Water Middle East 2019 conference did not propose next steps toward gathering this information. But setting the appropriate standards for reuse, with help from the proper authorities and experts, would go a long way towards supplementing the country’s need for water.
 

WASTEWATER MAXIMUM QUALITY LIMITS IN OMAN FOR SELECTED CONSTITUENTS

 

Parameter Standard A (mg/l) Standard B (mg/l)

Total dissolved solids

1,500

2,000

Boron

0.5

1

Chloride

650

650

Iron

1

5

Sodium

200

300

Oil and grease

0.5

0.5

Source: MECA, MD 145/93