Probe finds staff ignored manual as Oman desalination plant went down

Lack of staff emergency skills and failure to follow operating manual instructions were among the reasons for a catastrophic loss of power and water production at Oman’s Sohar 1 power and desalination plant in May according to a report issued by the Oman Authority for Electricity Regulation.

The report followed a formal investigation into the breakdown at the Sohar Power Company’s (SPC’s) power and desalination facility which led to loss of water supplies in North Al Batinah on 5 and 19 May this year.

“The Sohar incident caused extensive water shortage in North Al Batinah governorate and caused much distress to the public. The authority conducted a formal investigation into the incident and is making the report available for public inspection,” executive director of the regulator, Qais Saud Al Zakwani, told a recent press conference.

Local media reported that the investigation found that the SPC did not have enough personnel onsite with the skills to troubleshoot the problems being encountered. It had to recruit personnel from other plants to assist. Staff failed even to following the operation manual instructions the report said.

The investigation found that prolonged flooding of a switchgear and control room for the SPC seawater supply pumps followed a rupture to a seawater supply pipe at the Oman Oil Refineries and Petroleum Industries Company (Orpic) facilities on 3 May.

The seawater remained for three days which probably breached cable insulation the report said. Short circuits caused by this breach in all likelihood caused the observed repeated and sporadic fault signals that led to shutdown of field instrument communication interface modules.

The delay in starting to remove the flood water would certainly have contributed to the degradation of any instrumentation cables with damaged outer sheaths the report said. The SPC was dependent on Orpic and Majis Industrial Supply Company (MISC) to clear the flood water.

The plant remained operational while flood water removal was in progress but the power plant tripped on May 5 resulting in loss of power and desalination.

The Authority for Electricity Regulation, contracted Worley Parsons Oman Engineering to explain the causes of the plant outage and to provide recommendations to avoid a recurrence. The authority said that it would act to ensure that all of the recommendations/actions were implemented by the SPC.