Thirteen per cent of household water tests conducted in Toronto over the past six years showed unsafe levels of lead, according to city data obtained by the Torstar News Service.

The data, drawn from the 15,000 samples, was collected by Torontonians from their water taps and submitted to the city for analysis between 2008 and 2014.

This first ever detailed analysis of the test results by neighborhood places the vast majority of failures in aging residential areas of the city where infrastructure is old and real estate values are typically high.