The Maximum Acceptable Concentration (MAC) for nitrate in drinking water in British Columbia is 45 mg/L. In a laboratory test the MAC for nitrate - nitrogen is 10 mg/L

Nitrates are naturally occurring during the decay of organic materials. However the presence of nitrate in groundwater higher than 3 mg/L usually indicates leachate from animal manure, chemical fertilizers, and/or groundwater contamination from septic systems.

High levels of nitrates can be a health concern, particularly to babies and young farm animals, and water with high levels of nitrates should not be comsumed by pregnant women or infants under eighteen months.