Common Ground Alliance,

Stacy Cummings, “Do You Know What’s Below? Call 811 Before You Dig!”, U.S. Department of Transportation “Fast Lane” blog, Aug. 6, 2015, bulletins/1132ec1

National Transportation Safety Board, pipeline accident brief,

Washington State Department of Labor & Industries,http://www.lni.wa. gov/safety/research/face/files/711362015laborerelectrocuted.pdf

Cynthia Quarterman, “An Easy Call to 811 Could Prevent a Call to 911,” U.S.Department of Transportation “Fsne” blog,

Common Ground Alliance, 2017 DIRT Report

U.S. Department of Transportation, Pipeline and Hazardous Materials Safety Administration, “Safe Digging Testimonial: A Call to 811 Could Prevent a Call to 911,”April 21, 2014,

OSHA “Trenching and Excavation” Web page, SLTC/trenchingexcavation/

OSHA, “Trenching and Excavation Safety” guide, 2015, https://www.

U.S. Bureau of Labor Statistics, “Nonfatal Occupational Injuries and Illnesses Requiring Days Away from Work, 2014,”