CNN  — 

A boil water advisory has been issued after E. coli bacteria were found in the water supply near Phantom Ranch at Grand Canyon National Park, officials warned Friday. 

“These bacteria can make you sick and are a particular concern for people with weakened immune systems,” said a park news release.  

The bacteria were found Friday, said the National Park Service. “As of right now, the only affected area is Phantom Ranch and the immediate vicinity,” said the news release.  

E.coli bacteria. Coloured scanning electron micrograph of the rod-shaped, Gram-negative bacteria Escherichia coli, commonly known as E. coli. These bacteria are normal inhabitants of the human intestine (also animal intestines) and are usually harmless. Under certain conditions E. coli may increase in number and cause infection. Serotypes of E. coli are responsible for gastroenteritis in children, particularly in tropical countries. In adults it is the cause of 'traveller's diarrhoea'; and of 80% of all urinary tract infections. E.coli 0157:H7 can cause additional complications in children and the elderly; renal failure, anaemia, and dehydration especially for children and spontaneous bleeding, organ failure, and mental changes in the elderly. Some of these patients develop permanent disabilities or die. Magnification: x4000 when printed at 10 centimetres wide

Phantom Ranch is a popular lodge within Grand Canyon National Park run by the park system.

Officials urged individuals in the affected area to boil water before consuming it until further notice.  

“Bacterial contamination can occur when increased run-off enters the drinking water source,” said the news release. “It can also happen due to a break in the distribution system or a failure in the water treatment process,” officials said.