The Tower was the venue for a Watermatic-hosted industry conference on water sustainability last Wednesday. Watermatic has completed a feasibility study into the use of harvested water in the visitor toilets at the east London landmark, which is Britain's most popular paid-for attraction with more than two million visitors every year.
Ribak said: "Grey-water harvesting in south-east England is an exciting proposition. The technology isn't ours; we source what's best."
He added that the inclusion of green roofs on Battersea Power Station in the latest proposals for the London site was "promising".