The advisory was put in place after the massive scrapyard fire in Joliet on Friday.
Crest Hill officials said firefighters used their fire hydrants, which caused the city to suffer a pressure drop.
The pressure drop mainly affected residences south of Caton Farm, from the east and west boundaries of the city.
The city said only homes in the mentioned area are under the boil water order.
Residents must boil water for five minutes before drinking or cooking with it.
The city will alert residents once the order is lifted,
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