Action in the Event of an Outbreak

(Continued)

5(d).To co-operate fully in an investigation of any plant that may be suspected of being involved in the cause of the outbreak. This may involve, for example:
(i).Tracing of all pipe work runs;
(ii).Detailed scrutiny of all operational records;
(iii).Statements from plant operatives and managers;
(iv).Taking statements from water treatment contractors or consultants.

6.Any infringements of relevant legislation may be subject to a formal investigation by the appropriate enforcing authority.

Emergency cleaning and disinfection procedure for cooling towers

7.If a cooling water system has been implicated in an outbreak of Legionnaires' disease emergency cleaning of that system has to take place as soon as possible. The following actions should be taken, where appropriate:
(a).Switch off the fan immediately;
(b).Take samples for laboratory investigation before any further action;
(c).Switch off the circulation pump as soon as is practicable and the system decommissioned;
(d).Consult the enforcing authority before proceeding further;
(e).Keep all personnel clear of the tower area, when cleared by the enforcing authority, add sodium hypochlorite to the system water to obtain a measured concentration of 50 mg/l of free chlorine;
(g).Circulate the system water with the fans off for a period of at least six hours,
(h).Maintain the free chlorine level at an absolute minimum of 20 mg/l at all times; use a suitable biodispersant; after six hours, de-chlorinate and drain the system;
(k).Undertake manual cleaning of the tower, sump, and distribution system with cleaning staff wearing fully pressurised respirators; refill with fresh water, add sodium hypochlorite; recirculate without using the fan, at 20 mg/1 of free available chlorine for six hours;
(n).De-chlorinate and drain the system;
(o).Refill, recirculate and take samples for testing: re-commission system when test results detect no legionella and/or permission is granted by the enforcing authority.

8.If a water system other than a cooling system is implicated in an outbreak of Legionnaires' disease, emergency treatment of that system should be carried out as soon as possible.