As the consequence of a defective valve joint on a new pipe, 13 m³ of hydrochloric acid (for regenerating resins used during the dyeing process) were released into the night at a 23-m³ reservoir. A previous temporary repair on the installation piping system (for seepage found on a pipe elbow), before calling for full-scale intervention, had not been notified to the site operator. The retention basin, built one year prior and lined with an epoxy resin layer, did not withstand the acid. Several cracks formed and the acid flowed into the public wastewater network. The product could be neutralised with lime and sodium carbonate. The sewer network experienced deterioration. Nearby vegetation (lawns, tree leaves) was adversely affected to varying degrees, yet pollution did not reach the water table. Site activity was suspended for a half day.