incident Shortly after 16:00 on a weekday in late spring 2013 the munici-pal water company in Bornheim started receiving complaints fromcustomers about the water. It had an odd consistency althoughthere was no unusual smell. The complaints all came from the lowerlying area of the town. One of the first complaints was from a manwho reported that his skin and scalp had turned red, and he felt painand a burning sensation wherever he had been in contact with thewater (Figs. 1–3).The water company called in its standby duty team andincreased the flow of water through the pipes. At first the water
company suspected allergic reactions as a result of the cleaning ofthe municipal water pipes earlier in the day. Then the standby dutyteam realised the water had a soapy consistency and they detecteda pH value of 11.96. They identified the source as a sodium hydrox-ide (NaOH) solution. They cut off the supply of this solution andfurther increased the flow of water through the pipes. In the mean-time the company had arranged for the inhabitants of the streetswhere the complaints had come from to be warned. The police andfire service went door to door advising the residents not to use thewater until the all clear. At 22:00 the flushing of the pipes was com-plete and the pH value was back to normal levels. The all clear wasgiven.The authors were commissioned by town B to investigate thehealth aspects and the management of this incident