USE OF PART-TIME UNMANNED OPERATION AT A LARGE WASTE-WATER TREATMENT-PLANT

The use of part-time unmanned operation at the Goteborg Regional Sewage Works, Goteborg, Sweden (average flow 325 000 m3/d) is described. Outside normal working hours, a two-man standby crew is responsible for the operation of the plant. The plant's SCADA system and special equipment used by the standby crews (e.g. pagers, cellular telephones, Notebook PC) inform the crews when an alarm has been generated. The standby crew can then react to the alarm, often by logging into the SCADA system and taking appropriate actions. More serious disturbances require visiting the plant. Use of the standby system has only a marginal effect on effluent quality and has not affected effluent compliance. A cost comparison of the standby system with a traditional full-time manned system indicates annual savings of about 1 350 000 SEK.