Enbridge's plan to relocate a portion of its Line 5 pipeline in northern Wisconsin could involve a drilling method even the company admits will likely release toxic chemicals into surrounding waters. Horizontal Directional Drilling (HDD) is a common method for building pipelines under bodies of water, and it sometimes leads to "frac-outs," or drilling-fluid leaks. Bobbi Rongstad, who lives in northern Wisconsin, said she has serious concerns about the plans to use HDD on Line 5. ...