We received confirmation of a set of high level Legionella failures, resulting in the domestic water services needing to be chlorinated, in accordance with the guidance set out in ACOP L8.
A site visit was required immediately, to ascertain the full extent of the works involved and inconvenience anticipated.
The building is an 8 storey office block which incorporates a call centre which is manned 7 days a week. All of the water supply (including drinking water) for the building is supplied via the basement water tanks.
We were required to set up a temporary water supply to the toilets in the basement area, to provide welfare facilities for the 60 or so staff working in the call centre. These were ready and available before the staff arrived for work at 8 am. In addition temporary chemical toilets were also sourced.
A supply of bottled drinking water was sourced for the staff

A full walk around the building was required before work commenced to isolate and disconnect vending machines. During this walk warning notices were placed at every outlet in the building. The water tanks were then isolated from service for initial dosing of disinfectant chemicals, the disinfectant was then drawn through to every outlet in the building.
As all of the tanks were believed to supply drinking water, each tank in turn had to be drained and flushed to ensure no residual disinfectant was present. The system was then flushed through with fresh water to remove all detectable traces of disinfectant.
Upon completion of the works, all warning notices were removed from the outlets and the temporary water supply to the toilets disconnected and reinstated to the original system.
All works were completed without disruption to the buildings operation, with minimal inconvenience to the 60 or so staff working in the building.