A new report from the Council of Canadians says the Energy East Pipeline would cross and endanger 961 waterways that are important for drinking water, First Nations cultures and treaty rights, fish and wildlife habitat and tourism.
That includes 300 waterways in New Brunswick.
TransCanada Corporation's proposal would see the conversion of roughly 3,000 kilometres of natural gas pipeline on the company's Canadian Mainline route and the construction of 1,400 kilometres of new pipeline, to carry crude oil from Alberta to Saint John.
"The sheer volume of substance proposed to be pushed through the Energy East pipeline would mean that when the pipeline spills (and it will spill), it would seriously endanger our water sources," according to the report entitled Energy East: Where Oil Meets Water.
The council compiled the report with information from Fundy Baykeeper Matthew Abbott and the Conservation Council of New Brunswick, among others. It also used TransCanada's filings to the National Energy Board.
The rivers and streams it found in the pipeline's path are in the Restigouche River Basin, the St. John River Basin and a number of sub-basins.
The council noted the proposed pipeline route crosses at least six of the St. John River's major tributaries - the Madawaska, Rivière-Verte, Tobique, Salmon, Canaan, and Kennebecasis.
Residents of Edmundston and Grand Falls rely on wells downstream of the pipeline route, the council said in the report.
The pipeline crosses the Salmon River near Chipman and Coal Creek, where the council said a spill would be disastrous to those who enjoy Grand Lake.
It also crosses the southwest branch of the Miramichi River near Juniper and, according to the company's pre-application, the Tobique River sub-basin.
The council said the pipeline would significantly increase tanker traffic in the already busy Bay of Fundy, thereby increasing the risk of spills and marine noise.
In reacting to the report, the Conservation Council's executive director Lois Corbett highlighted the potential of a diluted bitumen spill to seep into groundwater, and flow into waterways.
She cited new research by federal government scientists that found spilled bitumen will sink and form tar balls in marine conditions such as the Bay of Fundy.
The report also encourages municipal and provincial governments along the route to commission independent scientific analysis to evaluate the threat of a spill.
CBC contacted the pipeline proponent TransCanada, but has not yet received its comments in response to the council's report.