Sodium is a nutrient found in table salt and many other foods. Your body needs some sodium to function, but too much may lead to high blood pressure (a major risk factor for stroke, heart disease and kidney disease). Most Canadians take in more than twice the amount of sodium they need in a day.
In Oxford County, natural sodium levels in drinking water are high enough that people on a sodium-restricted diet should be aware of how much sodium they are taking in through their water.
For a healthy adult, the level of sodium in the water supply does not pose a risk to health. However, if you or members of your family have kidney disease, heart disease, high blood pressure or liver disease, and need to restrict your salt intake because of these illnesses, please ask your physician or health care professional how sodium in the water may affect your health.
Sodium is a mineral that occurs naturally in raw water sources. At the Elgin Area Primary Water Supply System (EAPWSS), naturally occurring sodium in Lake Erie can contribute as much as three quarters of the sodium in the drinking water. The lake water’s naturally occurring sodium levels range between 8 mg/L and 14 mg/L, with the remainder of the sodium in the treated drinking water coming from the water treatment process.
In addition, people using a water softening system in their home may have higher levels of sodium in their drinking water as most softeners use a calcium-sodium exchange system. This may add significant amounts of sodium to drinking water in the home. There are some treatment systems that may reduce the amount of sodium from softened water, including reverse osmosis, ion exchange or distillation units. Alternatively, a separate water line which bypasses the water softener can be used for drinking and cooking.
The Guidelines for Canadian Drinking Water Quality and Ontario Drinking Water Quality Standards set an aesthetic objective for sodium in drinking water at 200 mg/L, at which point it can be detected by a salty taste by the average person. A maximum acceptable concentration for sodium in drinking water has not been specified.
The Safe Drinking Water Act, the Ontario Drinking Water Systems Regulation (Ontario Regulation 170/03), requires that a report be made to the local Medical Officer of Health if a sodium result is higher than 20 mg/L in a sample of drinking water so that local physicians and other health professionals can be advised of this to help those on sodium restricted diets control their sodium intake.
Healthy adults (14-50 years old) should consume between 1500 and 2300 mg of sodium each day; however, for individuals on sodium restricted diets, the amount of sodium in the water may be significant. When sodium levels in drinking water are at 20 mg/L, drinking 2 litres per day would contribute 40 mg of sodium to a person’s diet.
For healthy adults, this level of sodium in drinking water does not pose a health risk; however, for people on a very strict sodium restricted diet of 500 mg per day, this would contribute about 8% of their daily sodium allowance.
When sodium levels are higher than 20 mg/L, the Medical Officer of Health is required to inform the public, through health professionals, in order to help people on sodium-restricted diets control their sodium intake.
The bacteriological safety of municipal drinking water is not affected by sodium levels, meaning that the water is safe to drink.
Oxford County tests for sodium in drinking water every five years. To find out what the sodium levels are in within Oxford County, visit the online annual drinking water reports on this website: Drinking Water | Annual Reports.
Oxford County municipal water containing sodium levels under 20 mg/L is considered safe for drinking.
If you have questions about the safety of your drinking water, please consult your health care professional, or call Southwestern Public Health at 1-800-922-0096.