The following graph describes the average acidity of precipitation for selected British Columbia locations in 1988. Precipitation is considered acidic if its pH is below 5.6. Many locations in British Columbia have precipitation that is below this level. However, the cause of this acidic precipitation is a result of both human and natural sources. In British Columbia, the major human related sources of acid forming pollutants are natural gas processing plants, pulp mills, smelters, oil refineries, power plants, and vehicles. The production of natural sulphates over the Pacific ocean probably adds to the acidity of precipitation falling over coastal sites in British Columbia.
Source: British Columbia Ministry of the Environment. 1990. Summary Information Package on Acid Rain Effects on Forests and Lakes of BC. Ministry of the Environment, Air Management Branch, Victoria, British Columbia.