As one of the largest owner/operators of underground natural gas and natural gas liquid (NGL) pipelines, Williams (NYSE:WMB) is joining pipeline operators across North America in recognizing April as National Safe Digging Month and encouraging all excavators to call 811 to have underground utility lines marked before digging. When calling 811, callers are connected to a local one call center, which notifies the appropriate utility or pipeline company of the intent to dig. Professional locators are sent to the requested digging site to mark the approximate locations of underground lines with flags or spray paint at no cost to the homeowner. Once lines have been properly marked, digging can begin around the marked lines. “Pipelines are public infrastructure that benefits each of us. By taking the time to call 811, we can help keep our neighbors safe and make sure pipelines continue to provide a vital service to our community,” said Randy Barnard, president of Williams’ natural gas pipeline business and a Common Ground Alliance board member. The Common Ground Alliance is an industry association dedicated to reducing damages to underground facilities. Williams and its affiliates, including Williams Partners L.P. (NYSE:WPZ), own, operate or have an interest in approximately 25,000 miles of underground natural gas transmission, natural gas gathering and NGL pipelines. One call is a free service, but digging without calling 811 can potentially disrupt service to an entire neighborhood, harm you and those around you and result in fines and repair costs. Failure to call 811 before digging results in more than 200,000 unintentional hits annually across the country. Visit www.call811.com for more state information about 811 and the call-before-you-dig process. About Williams (NYSE: WMB) Williams is one of the leading energy infrastructure companies in North America. It owns interests in or operates 15,000 miles of interstate gas pipelines, 1,000 miles of NGL transportation pipelines, and more than 10,000 miles of oil and gas gathering pipelines. The company’s facilities have daily gas processing capacity of 6.6 billion cubic feet of natural gas and NGL production of more than 200,000 barrels per day. Williams owns a 72-percent ownership interest in Williams Partners L.P. (NYSE: WPZ), one of the largest diversified energy master limited partnerships. Williams Partners owns most of Williams’ interstate gas pipeline and domestic midstream assets. The company’s headquarters is in Tulsa, Okla.