They woke up on Sunday morning to read a notice posted on their doors from the local Health Affairs Department warning of possible water contamination, Al-Riyadh daily reported on Monday.

The department circular urged the residents in the district’s 8/56 area to immediately contact their nearby primary health center to ensure that they were not infected.

So far, no cases of bacterial infection have been reported from residents in the area.

Consultant physician Dr. Khaled Al-Madani said the discovery of bacteria such as E. coli in the area’s water network was proof that it had been contaminated with sewage.

“E. coli and other fecal coliforms are usually found in the large intestine. If these bacteria moved on to other parts of the body, it could cause health problems,” he said.

High levels of these bacteria could lead to severe food poisoning, he added.

According to experts, large quantities of E. coli and other fecal coliforms in the water are not harmful but may indicate the presence of potentially dangerous pathogens in the water.

Diseases residents could contract due to the contamination of their water supply include ear infections, dysentery, typhoid fever, viral and bacterial gastroenteritis and hepatitis A.

The presence of fecal coliforms tends to affect humans more than it does aquatic creatures, they pointed out.