URGENT WARNINGS highlighting the dangers of gases seeping into trenches dug near old mine workings must be issued to the construction industry immediately, a Sheffield coroner ordered last week.
Deputy coroner Professor Robert Forrest instructed the Health & Safety Executive after recording a verdict of accidental death of a man killed while working in a sewer trench last October. He died from carbon dioxide poisoning while digging in a backfilled opencast coal site at Rockingham, near Barnsley.
Professor Forrest claimed there was widespread knowledge in the mining industry of the dangers of black damp gas - the carbon dioxide-rich product of decaying coal - in or near mine workings and the likelihood of it entering excavations. But that information, he said, was not being effectively communicated to the industry.
Christopher Noonan, aged 22, died after he entered the 5m deep trench to rescue his father who had fainted while inspecting a newly laid sewer pipe.
Noonan senior, who had slumped with his head higher up the trench side than his son, survived. Contractor Duffy Construction had gas detection equipment but only used it for checking manholes.
Barnsley metropolitan district council acted as agent for the sewer contract for Yorkshire Water. The HSE is considering prosecutions.
Senior gas engineer with consultant International Mining, Robin Burrell, told the inquest that it was quite common for black damp to seep into the bottom of such trenches. This, he said, could come from either surrounding opencast backfill or, more likely in this case, from earlier mine workings 80m below.
Later measurements recorded a 20 percent concentration of carbon dioxide in lower sections of the trench - over 70 times higher than in normal air.
Speaking after the inquest, Burrell said: 'We need a code of practice recommending that such trenches are regularly checked for gas.'