Provincial laws outline how the oil and gas industry must ensure water resources are protected during drilling and production operations. A number of measures are required to protect the water supply such as setbacks to maintain distance between water wells and drilling operations. Pressure-tested steel casings are cemented in place to prevent hydraulic fracturing fluids from migrating into freshwater aquifers, and the integrity of the casing can be evaluated to ensure it is maintaining an impermeable barrier. There has never been an instance of groundwater contamination due to hydraulic fracturing in British Columbia.
The water table is in most cases thousands of metres above unconventional gas target zones. Potable water is found between 18 and 150 metres down while unconventional gas target zones are typically at a depth of 2,000 to 3,200 metres.
When the well is no longer being used it is plugged with dense impermeable cement. The casing is cut off below ground and the well is capped.