John Gray spent 22 years working in UK Water Companies on all aspects of water treatment, supply and analysis. This was followed by 13 years as a regulator before retirement in 2007 from his position as Deputy Chief Inspector (Operations) with the Drinking Water Inspectorate. He has been involved in improving the safety and security of drinking water supplies and has established links with other Government Departments, academia and research organizations involved in "homeland defence" issues both in the UK and internationally. He was closely involved in the development of the specialized analytical capability for the water industry. Actively involved with the Royal Society of Chemistry, John Gray was for six years a member of the Applications Committee followed by seven years with the Ethical Practices Committee. He chaired of the organizing committee of the three Water Contamination Emergencies conferences. Professor Thompson has 37 years experience in the management of environmental laboratories including those at Severn Trent and Yorkshire Water. He is currently Chief Scientist of ALcontrol UK, one of the largest contract water, soil, air and food analysis organizations in Europe. Since its inception in 1995, he has chaired the UK Water Laboratory Mutual Aid Group and been closely involved with the three associated sub-groups on emergency organic and radioactivity analysis and the LEAP emergency incident proficiency scheme. He was Secretary of the organizing committee of the three Water Contamination Emergencies conferences.