(BAT) Reference Document for the Production of Chlor-alkali ...

Chapter 4
Recovery of mercury; treatment and disposal of material derived from general clean-up;
plant demolition; demolition of buildings, pipes, etc
Planning for transport and demolition activities
Health and safety monitoring: monitoring of mercury emissions to air and water and also
health checks for personnel involved
Follow-up after plant is stopped: survey on possible contamination of the whole site and
surroundings, including soil, old waste dumps and sediments in nearby waterways. In
addition to mercury the soil/sediment samples should be analysed for PCDD/Fs if
graphite anodes have been used on the site.
Guidelines for the shut-down and decommissioning of mercury cell plants are presented in
[Euro Chlor Env. Prot.3, 1999] and [Italian report, 1997].
{It is proposed to completely revise the description in order to 1) give more details, 2) focus on
the techniques, 3) remove text referring to site remediation, and 4) adapt the style (e.g. avoid
the use of 'should', 'should not').}
1. Elaboration of the decommissioning plan
The decommissioning plan is usually elaborated by a team containing staff from the
management of the chlor-alkali plant. The inclusion of external contractors in the team from the
beginning has proven beneficial. The plan may be shared with the permitting authorities prior to
sending a formal application. The plan usually addresses [ 94, Euro Chlor 2009 ]:
provision of procedures and instructions for all stages of implementation including
health and safety aspects;
provision of a detailed training and supervision programme for personnel without
experience in mercury handling;
provision of a suitable working area;
provision of equipment for mercury handling (e.g. containers, cranes, forklift trucks,
devices to fill containers);
determination of the quantity of metallic mercury to be recovered;
estimation of the quantity of waste to be disposed of and of the mercury contamination
therein;
monitoring of mercury in air, water and waste;
health checks and biological mercury monitoring for staff;
planning of transport and storage.
2. Setting-up of a working area
The working area for dismantling, demolition and decontamination of equipment could be the
basement of the existing cell room or a decontamination pad erected for the decommissioning.
Suitable working areas are [ 94, Euro Chlor 2009 ]:
WORKING DRAFT IN PROGRESS
well defined, if necessary surrounded by kerbing;
covered with a roof to exclude rainwater;
equipped with a smooth, sloped, impervious floor to direct mercury spills to a collection
sump;
well-lit to enable easy identification and clean-up of spills;
free of obstructions and debris that may absorb mercury and/or hinder the clean-up of
spills (e.g. wooden pallets);
equipped with a water supply for washing;
equipped with aspiration equipment with activated carbon filters to rapidly clean up
spills;
connected to a waste water treatment system.
162 December 2011 TB/EIPPCB/CAK_Draft_1