&quot;And switching back to Detroit water doesn&#x27;t solve the lead problem in the mains, although it may be less acute.&quot;<p>It does solve it. The Detroit water has lower chloride levels than the Flint River sourced water, so the lead in the service lines and solder won&#x27;t leach above acceptable limits. There&#x27;s lead in old mains and service lines <i>everywhere</i> in the country, particularly in lines put in place before the mid 20th century. And the cost to remove them in places like Flint is high because the frost line is so deep.