A large diameter, 1067 mm (42 in) and 914 mm (36 in), high pressure gas mainline, and four (4) smaller diameter lateral pipelines, between 406 mm (16 in) and 610 mm (24 in), were constructed in Alberta, Canada, between 1999 and 2000. At the time of construction, the pipelines were built in proximity to several high voltage alternating current (HVAC) transmission lines. In subsequent years, additional transmission lines were built near the pipeline system, bringing the total number of lines with significant proximity to eight (8).