Chicago used water department employees’ homes to test for lead

Exclusive: Testing regime in US's third most populous city raises significant concerns about conflict of interest in producing data to confirm tap water's safety

New evidence suggests that the way US water is tested for lead is vulnerable to conflicts of interest that raise questions about data confirming tap water's safety. The new evidence could cast further doubt on already controversial testing methods highlighted following the ongoing water crisis in Flint, Michigan.

A Guardian investigation has discovered that in the US's third most populous city the testing regime for lead involves using its own employees' homes.