Leeds Crown Court heard that, on 20 July 2015, Michael Jennings was working in the bottom of a dry well, a designated confined space, at the Tadcaster sewage treatment works.
Mr Jennings and a colleague had been tasked with changing the stop valve on the end of the disused drain pipe that emerged into the bottom of the dry well. Mr Jennings was using an angle grinder to cut through corroded bolts when sparks from the grinding wheel impinged onto his overalls, bursting into flames. He suffered whole body burns and died in hospital two days later.
An investigation by the Health & Safety Executive (HSE) found that the drain valve was half-opened and the atmosphere within the dry well was oxygen-enriched, greatly increasing the risk of fire.
It also found that a near miss report had been recorded at the same location in September 2014 but this warning had not been acted upon.
The HSE investigation showed that the company’s risk assessment and permit to work procedures had been inadequate. There were no site-specific procedures in place and the generic risk assessment template form did not include oxygen enrichment as a possible hazard. The employees working on the day of the incident were not familiar with the site and they were not aware of the September 2014 near miss. This meant that they did not have the knowledge or experience to recognise that oxygen-enrichment of the dry well was a potential hazard when the valve was taken off or opened.
Yorkshire Water Services Ltd of Western House, Bradford, pleaded guilty to breaching Section 2(1) of the Health and Safety at Work etc. Act 1974 and was fined £733,000 and costs of £18,818.