AWWA WQTC52817

In the United Kingdom, the Drinking Water Inspectorate (DWI)has introduced a regulatory standard for Cryptosporidium in water supplies of 1 oocyst in 10 liters. Failure to comply with this standard can lead to prosecution of water companies. One of the main issues in relation to plant operation is the variability of turbidity in the final water. Recent recommendations from an expert group have specified that plant operators need to be able to identify higher than "normal" turbidity, and take appropriate action. In response to this, statistical process control (SPC) techniques have been developed to provide a basis for turbidity alarm setting, using historical data on a site-specific basis. This paper discusses the use of SPC and risk assessment to optimize water treatment for the removal of Cryptosporidium in the United Kingdom. Includes 6 references, table, figures.