The Centers for Disease Control and Prevention recommends consuming a maximum of 1,000 milliliters of water a day for people with diarrhea and 1,200 millilitres for those who are dehydrated.
The U.S. Department of Health and Human Services recommends consuming 1,400 millilitre a day.
But if you do not drink enough water to avoid a waterborne illness, you may need to seek medical help, according to the CDC.
Symptoms include fever, sore throat, runny nose and cough.
In some cases, dehydration can lead to pneumonia, diarrhea and other symptoms, according the CDC website.
Symptom severity is determined by the severity of symptoms, the number of times the person has symptoms, and the amount of time elapsed since symptoms started, according Health Canada.
For people who are severely dehydrated, symptoms can last from two hours to two days, according Toews.
In the past, there have been outbreaks of infections that were traced to the ingestion of food or drinks contaminated with fecal matter, which can lead people to drink more water, Toews said.
The federal government said it is investigating how the water supply could have contaminated the water in the past.
Toews said the outbreak of food-borne illnesses in Canada has occurred because Canadians are not following the health guidelines set by the World Health Organization.
To see what the CDC recommends for drinking water, go to www.cdc.gov/diseases-and-disorders/water.
Symposium attendees said the water supplies in some communities are contaminated, which could have resulted in an outbreak of the bacteria that causes waterborne illnesses.
To hear the full conversation with Dr. Toews, click on the audio link above.