The WestTX gathering system has approximately 4,400 miles of natural gas gathering pipelines located across nine counties within the Permian Basin in West Texas. We have an approximate 72.8% ownership in the WestTX system. Pioneer, the largest active driller in the Spraberry and Wolfberry Trends and a major producer in the Permian Basin, owns the remaining interest in the WestTX system.
The WestTX system has access to natural gas take-away pipelines owned by Atmos; El Paso Natural Gas Company; Kinder Morgan; Oneok West Texas, Enterprise Interstate, LLC; and Northern. On January 1, 2016, we began selling our NGL production at WestTX to our Logistics and Marketing segment.
The following table lists the West Texas Gathering & Processing plants and related volumes for the year ended December 31, 2016
(1) Gross processing capacity represents 100% of ownership interests and may differ from nameplate processing capacity due to multiple factors including items such as compression limitations, and quality and composition of the gas being processed.