Government is working with Belco to address a range of complaints about the energy plant, it was revealed yesterday.

Geoff Smith, an environmental engineer with the Department of Environment and Natural Resources, wrote in the latest edition of the Envirotalk newsletter that problems caused by the new North Power Station had to be resolved.

Mr Smith said: “It is clear that Belco has some significant operational and environmental issues to address as a direct or indirect result of the new NPS engines.

“DENR – the regulator – the Environmental Authority and the Department of Health are also being challenged to ensure the air we breathe and the water we drink is safe.

“Once we have the answers to these questions in addition to monitoring data, the regulator will be able to provide clear instruction to Belco to ensure that the public’s air and water are of an acceptable standard.”

Mr Smith said a flood of complaints about air pollution and soot deposits had been sent to Belco since the company began operation of the new power plant in February.

He added that some of the first complaints may have been sparked by the commissioning process, where the new engines operated at 100 per cent capacity and others operated at a fraction of their normal load.

Mr Smith explained: “Engines operated well below their stated nameplate maximum load will lead to inefficient combustion of the fuel and increased exhaust smoke.

“As a result of the complaints, the Environmental Authority instructed Belco to ensure without delay that all engines are operated at 80 per cent or above of their nameplate load during the rest of the commissioning phase, as would be normal practice outside of commissioning protocols.”

Mr Smith said residents on the north side of Langton Hill had raised fears over air quality, particularly when winds blew from the south-southwest.

He added that DENR staff confirmed the smell of engine exhaust in the area, but a nearby monitoring station found air quality was inside acceptable standards.

Mr Smith said: “The fact that these exhaust emissions are present down the back of Langton Hill suggests that the wind direction and topography are causing the exhaust fumes to downdraft and bring any entrained exhaust emissions towards the ground surface between the north side of Langton Hill and North Shore.

“Air flow modelling of emissions from the proposed NPS was carried out during the design of the new power station, but the downdrafting phenomenon was not apparent.

“Recent remodelling of the area using the latest meteorological and topographical data has confirmed the potential for downdrafting to occur, though the expected concentrations at ground level were still predicted by the model to be within the limits provided in the regulations.”

Mr Smith said the DENR had since instructed Belco to carry out additional air and water quality monitoring, with a state-of-the-art sensor system to be placed where the downdraft has been reported.

He added the energy firm was also told to check if one of its older stacks had contributed to the poor air quality in the downdraft area.

Mr Smith said Belco turned off its new NPS engines for ten days in June and ran its older E5, E6, E7 and E8 engines in the East Power Station instead.

He added: “As air quality complaints continued during this time, it can be concluded that the NPS engines are not the sole cause for poor air quality in the area.”

Mr Smith said it was not known why the complaints “increased significantly” since February as the East Power Station engines were installed between 2000 and 2005, but it was possible that the problems only happened when all four of the engines were in use.

He added: “Further investigation and air quality measurement will be required to confirm the theory above and to determine if pollutants are present in higher concentrations than the air quality standards allow.”

Mr Smith said the ten-day shutdown of the new engines in June also likely contributed to a notable release of soot in the area.

He said: “Upon start-up of the NPS engines, soot was ejected from the stack and onto many nearby properties which is evident by black soot particles, followed a few days later by orange stains that appear to be iron rust emanating from the soot particles.

“DENR has instructed Belco to perform a specific test to determine what pollutants could leach out of the soot by water.

“It is further noted that Belco is working with the NPS engine manufacturer to address the excessive soot emissions that have been occurring.

“The Environmental Authority will soon instruct BELCO on how these soot emissions are to be addressed going forward.”