The discovery of the bacteria that causes legionnaires' disease in the apartments used by Canadian diplomats in London is expected to cost taxpayers about $500,000 to fix.

Canadian staff were forced to leave the three apartments near Hampstead Heath in June 2016, when the bacteria were found in the building's plumbing.

The 128 flats in the Eyre Court apartment complex were built in 1935, and Canada bought three of the units in 1976.

The three apartments have been vacant for a year, after Global Affairs Canada moved affected staff into temporary rental lodging. The department says none of the employees got sick.

The Queen is saluted in 2015 after a visit to reopen Canada House, following extensive restorations. The work did not include refurbishing the aging apartments owned by Canada for its diplomatic staff. (Kirsty Wigglesworth/Pool/Associated Press) Officials plan to hire contractors next month to replace the 82-year-old plumbing and do other upgrades, with work expected to be complete in October.

"The goal of the renovations is to eliminate the legionella bacteria by updating the plumbing, and to update the electrical and heating systems to meet minimum and appropriate livable standards," department spokesperson Austin Jean said in Ottawa.

"The internal layouts of three flats have only undergone minor changes since 1935."

Some 45 cases in London

Britain's public health agency reported about 500 cases of the legionella bacteria throughout England and Wales in 2016, with some 45 such cases in London. The bacteria are often associated with older water systems, and can cause severe, life-threatening pneumonia.

Global Affairs Canada has issued a tender for "renewal of plumbing and electrical systems, replacement of all plumbing fixtures, new kitchens and bathrooms, floor and wall refinishing," but has not yet signed a contract. The tender estimates the total cost at about a half-million Canadian dollars.

The department owns most of the apartments, called Staff Quarters, for Canadians working at the high commission known as Canada House, in London's Trafalgar Square.

The department in recent years renovated and consolidated its London diplomatic real estate in a project that cost about $255 million, though Staff Quarters were not included. The Queen attended the official opening of a renewed Canada House in 2015.

The project was paid for through the sale of Canada's leasehold interest in Macdonald House in London, for about $562 million, with the balance going to the federal government's general revenues.

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