Information Report January 1997 Regulation of Dioxin releases from the Runcorn operations of ICI and EVC En viro n m en t Ag e n c y REGULATION OF DIOXIN RELEASES FROM THE RUNCORN OPERATIONS OF ICI AND EVC Executive Summary ICI and EVC at Runcorn operate processes for the production of the chemicals Vinyl Chloride, Perchloroethylene, Trichloroethylene, CTF and chlorine. All these processes form very small quantities of dioxins as unwanted by-products. At present, the site’s largest dioxin arising (some 500 grams Toxic Equivalent (TEQ)/year) is in heavy organic residues which are sent to the Holford brine cavities for secure containment. There are relatively minor releases to the air and water environments. Dioxins may also have been released to the local environment from historical operations. Major environmental improvements are being made on the site through the installation of three incinerators. Local air quality, the ozone layer and global warming will all benefit from a 90% reduction in the emission of chlorinated hydrocarbons to air. Discharges to water will be cut by 80% and this will enable the Weston Canal to comply with water quality standards. The incinerators will also provide for the discontinuation of waste disposal at Weston Marsh Lagoons and Holford brine cavities. These significant environmental improvements are balanced against a small release of dioxins to atmosphere (an estimated maximum of 0.244 grams TEQ/year). However, future dioxin releases are not considered to have any major environmental impact. The Environment Agency considers that there will be a net environmental benefit from the incinerators and supports their installation. The levels of dioxin in local air and soil are typical of an urban environment and do not give cause for concern. Sediments in the Weston Canal show elevated dioxin levels due to site releases, but these sediments are periodically dredged for disposal in Frodsham Marsh Lagoon where they are effectively isolated from the environment. Dioxins found in River Weaver sediments and local soils do not appear to have a significant contribution from process releases. The Ministry of Agriculture Fisheries and Food have been made aware of dioxin releases from the Runcorn site and have concluded that there are unlikely to be any unacceptable effects on the human food chain. This has been supported by a recent survey of local farms which found dioxin levels in cow's milk to be well within acceptable limits. The Environment Agency is satisfied that there is sufficient regulatory control on dioxin releases to protect the local environment Cover photograph reproduced courtesy of ICI Chemicals & Polymers Limited Map extracts are reproduced from Odnance Survey Maps with the permission of the controller of Her Majesty's Stationery Office, © Crown Copyright. Environment Agency Licence CD031 77C0003 Environment Agency Information Centre ENVIRONMENT AGENCY CONTENTS 1. INTRODUCTION...................................................................................................................................1 2. WHAT ARE DIOXINS ?........................................................................................................................2 2.1 Chemistry of Dioxins................................................................................................................ 2 2.2 Reporting Units........................................................................................................................ 2 2.3 Sampling and Analysis..............................................................................................................3 2.4 The Relative Toxicity of Dioxins................................................................................................3 2.5 Properties of Dioxins.................................................................................................................4 2.6 Sources of Dioxins.................................................................................................................... 4 2.7 Health Effects............................................................................................................................5 3. WHY ARE DIOXINS PRODUCED ON THE RUNCORN SITE ?........................................................... 6 3.1 Vinyl Chloride (VC) Process...................................................................................................... 7 3.2 Perchloroethylene-Trichloroethylene (Per-Tri) Process..............................................................8 3.3 CTF Process............................................................................................................................ 10 3.4 Chlorine Process.....................................................................................................................10 3.5 Environmental Improvement Project (EIP).............................................................................10 3.6 Fluorochemicals Vents Treatment Unit (VTU).........................................................................12 3.7 Historical Sources................................................................................................................... 12 4. HOW MUCH DIOXIN IS RELEASED INTO THE ENVIRONMENT ?................................................. 1 3 4.1 Holford Brine Cavities.............................................................................................................1 3 4.2 Weston Marsh Lagoons..........................................................................................................14 4.3 Randle Island Landfill..............................................................................................................15 4.4 Dredging Lagoons..................................................................................................................15 4.5 Gaseous Emissions..................................................................................................................1 5 4.6 Use of Site Products................................................................................................................16 4.7 Site Releases in the UK Context..............................................................................................16 5. HOW ARE DIOXIN RELEASES REGULATED ?.................................................................................19 5.1 Integrated Pollution Control (IPC)......................................................................................... 19 5.2 Water Resources Act 1991 .(WRA 1991)................................................................................. 21 5.3 Environmental Protection Act 1990, Part II............................................................................21 5.4 Self Regulation........................................................................................................................22 6. ARE THE RELEASES HARMFUL ?......................................................................................................23 6.1 Air Quality...............................................................................................................................23 6.2 Water Quality......................................................................................................................... 23 6.3 Soil Quality............................................................................................................................. 25 6.4 Dioxin Origin..........................................................................................................................26 6.5 Food Chain Effects..................................................................................................................26 7. CONCLUSIONS................................................................................................................................... 29 8. FUTURE ACTIONS..............................................................................................................................31 Glossary of Terms....................................................................................................................................... 32 References...................................................................................................................................................33 APPENDICES.............................................................................................................................................34 Appendix A : Dioxin monitoring under the Environmental Protection Act 1990 - Part I (Integrated Pollution Control) Appendix B : Dioxin in soils around Runcorn 1. INTRODUCTION ICI Chemicals & Polymers Limited (ICI) and, provide a clear overview of dioxin releases to a lesser extent, European Vinyls from the Runcorn site. This document Corporation (UK) Limited (EVC) operate a represents the Information Report. The large manufacturing site in Runcorn, Report strikes a balance between technical Cheshire which produces chlorine, detail and readability by a wide audience. chlorinated Organics and a number of other Diagrams and tables have been used to aid chemicals. explanation, and scientific details have been simplified wherever possible. The Glossary In March 1994, Her Majesty’s Inspectorate near the end of this report gives simple of Pollution (HMIP) issued an Integrated descriptions of some of the key terms used Pollution Control (IPC) Authorisation to ICI in the text. for operation of the vinyl chloride process