Several environmental groups in Maine, New Hampshire and Vermont are asking federal regulators for a moratorium on new tar sands oil pipelines until new standards are created. The environmental activists contend current safety rules aren’t adequate to the region from “dirty” tar sands oil from Alberta, Canada. So far, none of that oil is flowing through the region. But the Portland Montreal Pipeline Company says it would welcome the opportunity to use the pipeline that crosses Vermont, New Hampshire and Maine to transport the tar sands oil to tankers in Portland Harbor. Critics say states like North Dakota, Minnesota, Wisconsin and Michigan with a history of moving tar sands oil through pipelines have spilled nearly three times the national average of crude oil per mile of pipeline.