FRENCH CHEMICAL manufacturer Rhne-Poulenc has halted production and sales of its Rhoca-Gil grout following serious groundwater pollution incidents on two tunnelling projects in Scandinavia.
Tunnelling was brought to a standstill on the twin 8.6km long tunnels under the Hallandss ridge on the delay-hit (SEK930M) £77M Malm-Gothenburg railway line on the west coast of southern Sweden last autumn, after potentially carcinogenic poisons leached into the groundwater.
And just one month later, news emerged that Rhoca-Gil used on the Romeriksporten tunnel, part of the high-speed railway to the Norwegian capital Oslo's new airport at Gardermoen, had also failed to cure correctly and threatened to contaminate groundwater. Work stopped for a week at the beginning of October while the contractor battled to control the situation.
One part of the Rhoca-Gil mix contains the chemical acrylamide which is highly soluble in water and toxic if inhaled and absorbed through unbroken skin. It is known to attack the central nervous system, causing temporary paralysis and is also suspected of being carcinogenic.
Commenting on both incidents, Rhne-Poulenc spokeswoman Crozier Patoux said the problems may have been the result of something 'abnormal' happening on site. These were the first such incidents involving the grout, she said, adding: 'It had been used without problems for over 20 years.'