Sodium - Elevated readings in municipal water supplies

Under the new Ontario Drinking Water Protection Regulation elevated sodium levels (greater than 20 mg/L) are to be reported to the local Medical Officer of Health so that this information can be communicated to local physicians for their use with patients on sodium restricted diets.

Sodium in drinking water

In drinking water, a sodium level of greater than 20 milligrams per liter (mg/L) is not harmful to the average person's health. However, if you suffer from high blood pressure, heart disease or kidney disease, and the sodium level of your water sample is higher than 20 mg/L, the Simcoe Muskoka District Health Unit recommends that you contact your doctor for advice.

In the meantime, you can take steps to lower the sodium level in your drinking water. If you own a water softener make sure your drinking water is taken from a tap not connected to the system. Otherwise, switch to a source of drinking water that you know is low in sodium.

NOTE: Boiling does not remove sodium from water and in fact may increase the sodium concentration.

The sodium in drinking water contributes very little to average adult's sodium intake of 4000 mg to 6000 mg daily. Processed foods - e.g. popular snacks, fast food items, canned goods and other prepared foods - are the major sources of sodium in the Canadian diet. A hamburger (double patty) with condiments provides about 800 mg sodium; one dill pickle, over 800 mg; a cup of chicken noodle soup (made from canned concentrate), almost 1200 mg; a sub made with cold cuts, 1650 mg; one ounce of potato chips, over 210 mg. By comparison, 1.5L of drinking water at a sodium concentration of 50 mg/L would contribute 75mg of sodium to a person's overall daily intake.

Individuals suffering from hypertension or congestive heart disease may require a sodium restricted diet, in which case the concentration of sodium in drinking water may become significant. Drinking water concentrations of sodium that exceed 20mg/L may need to be taken into consideration in dietary planning for individuals prescribed a regime that significantly restricts sodium intake. This is most likely to be the case when a patient requires a diet with a very strict level of sodium restriction, e.g. a diet that provides a total sodium intake of no more than 500mg/day.

Notifications received from waterwork operators and/or the Ministry of Environment have been grouped by local municipality. To review elevated sodium notifications click on the municipality below.

** Chart Under Revision. Please check back again at a later time. **