Nitrogen oxide emissions from BWSC plant exceeding limits – Auditor General

Nitrogen oxide (NOx) emitted from Delimara's BWSC  power plant extension exceeds the limits set by MEPA and the situation does not seem to be improving, a report by the Auditor General said.

The project shrouded in controversy since its inception, was at the centre of political controversy at the end of 2012, during the commissioning phase, when extensive faults in the plant were alleged by the than Labour Opposition and subsequently reported in sections of the media.

The delay in the commissioning of the €158 million plant had led to Marsa power plant turbines to be switched on again, which cost the government €3.6 million per month.

In view of these technical shortcomings, the National Audit Office (NAO) engaged the services of an expert adviser to assist in its investigation. The report concluded that despite the fact that not all shortcomings have been resolved, "all have or are being dealt with."

The Auditor General pointed out that it thoroughly investigated and reported on every fault which was brought to its attention, or that emerged during the investigation.

Among the shortcomings investigated by NAO, the report highlights the plant's emissions, which have not been completely resolved.

While the report makes it clear that there were no problems with emission levels of dust, Sulpher Dioxide (SO2 ) andCarbon Monoxide (CO), there is a problem with NOx.

The Auditor General explains that "NOx values exceeded the limit on several occasions, particularly for stack B, and the situation does not seem to be improving. There also seems to be a discrepancy between the diurnal and monthly values for NOx."

The report also explains that Enemalta, which commissioned the pland from the Danish company BWSC, was not in a position to explain these discrepancies and had contacted BWSC to clarify the matter.

Atmospheric NOx eventually forms nitric acid, which contributes to acid rain and Inhalation of such particles may cause or worsen respiratory diseases.

The report added: "Moreover, contrary to the conditions of the Integrated Pollution Prevention Control (IPPC) permit, emission data was not being published on-line. Following interventions by NAO, data as from December 2012 was made available on EMC's website. Although outside the scope of this investigation, NAO questions why MEPA failed to monitor requirements that it itself had established when issuing the IPPC permit."

Moreover, the report said that neighbouring local councils, who initially were vociferous about a plant running on heavy fuel oil, "were also conspicuously missing in their non-insistence of having emission data made available to the public."

Other faults and defects investigated by the NAO include the leakages, which the report says was never wholly resolved.

"Although BWSC and the original equipment manufacturer Wartsila took several measures to identify the source of, and address the problem of leakages, this was never wholly resolved. The latest reports available at the closing-off of this investigation suggest that the problem might be due to manufacturing defects," the report noted.

Other problems such as the damage to the steam turbine due to failure of the strainer that caused most damage to the plant have been resolved as the steam turbine was re-built and re- commissioned and no other problems have since ensued.

Ruptured filter bags in the abatement system led to the redesign of the system and the problem seemed to have been addressed until a rise in emissions was observed and a number of torn filter bags was discovered.

"To solve this problem BWSC decided to cap these bags, in effect making them redundant. This did not appear to affect emission levels since data for the months of January, February and March 2013 indicated that emissions of dust were well within limits."

The replacement for the dump condenser which developed cracks in its internal paintwork with clear signs of corrosion quite early on is expected to be delivered in June 2013.

The Auditor General said the considerable delay in the replacement of the damaged dump condenser "seems unwarranted."

Failure of the Limit Switch on Silo The failure of the limit switch on one of the silos containing sodium bicarbonate caused the spillage of a considerable quantity of this substance which, being in powder form, ended up covering a large area around the silo. However, no real damage was caused by the spillage. The limit switch was since reset in a lower position to prevent similar occurrences.

Last year, the Labour Opposition had alleged that the damages to various components of the plant, resulting from faults and failures during the testing phase, would have a long-lasting effect in that these impinged negatively on the expected life of the plant

However, the NAO report concluded that on the basis of the technical advice obtained, the claim of a compromised plant lifetime cannot be substantiated.

The report added that due to the dynamic environment in which the investigation was conducted, other issues emerged.

For this reason, NAO widened the scope of the investigation and in addition to the Labour Opposition's allegations, it investigated the issue of partial taking over, claims and counter-claims for delay and liability charges by Enemalta and BWSC, the status of the maintenance agreement and the appointment of Enemalta consultants DNV KEMA.

"Despite the various shortcomings encountered, the major concern remains whether or not the BWSC plant has serious faults that will impinge on its lifetime. On the basis of the technical advice obtained, NAO concludes that despite the fact that not all defects have been resolved, all have or are being dealt with. Moreover, there does not appear to be enough evidence to suggest that Enemalta was hasty in the taking over process," the report concluded.