A letter distributed to residents near the company's Westridge marine terminal in Burnaby blamed city council for blocking its survey crews from Burnaby Mountain, home to Simon Fraser University and a expansive conservation area.
Kinder Morgan's preferred route through the mountain would avoid residential neighbourhoods, the company told residents.
"The ability to route through Burnaby Mountain would avoid several private homeowners and minimize community disruptions," the letter said.
If the company is unable to complete those studies soon, "we may have to pursue our alternate route through city streets."
Crews will conduct survey work in the residential neighbourhood over the next week, it said.
"As we have not yet been able to fully explore the Burnaby Mountain route, we need to continue our planning and work for the neighbourhood route as well," the letter said.
"I cannot emphasize strongly enough this is not our preferred option, and we would much prefer to work together with residents in order to minimize impacts."
Kinder Morgan and the city have been in an escalating battle over the $5.4-billion Trans Mountain expansion between the Alberta oilsands and a tanker terminal in Metro Vancouver.
The expansion would almost triple the pipeline's capacity, from 300,000 barrels a day to about 900,000 barrels.
Vancouver city council is also opposed to the project but it is particularly controversial in Burnaby, where Kinder Morgan was fined for a 2007 construction accident along the pipeline that rained 230,000 litres of oil down on a neighbourhood.
For its part, Burnaby council tried and failed this week to win the support of convention delegates at the Union of B.C. Municipalities annual meeting on a motion to oppose the pipeline.
It was a narrow loss. The resolution was defeated by a margin of 50.7 per cent against and 49.3 per cent in favour, following a debate that touched on issues including the likelihood of an oil tanker spill to the increase in oil-by-rail through the province's Interior region.
Municipal leaders did vote in favour of a Burnaby resolution calling for change to the regulatory hearing process.
Under new rules, the National Energy Board has opted against allowing interveners to directly question the company. All comment must be submitted in writing.
The dispute has already set the regulatory review for the pipeline back seven months. A final report from the energy board panel to cabinet is now due Jan. 25, 2016.
The report could be further delayed, after the NEB dismissed a Kinder Morgan request for the federal regulator to bar the City of Burnaby from blocking survey work on the mountain.
Earlier this month Burnaby halted survey crews on the mountain, saying they were cutting down trees and boring large holes in the ground in violation of city bylaws.
The city unsuccessfully sought a court injunction but Trans Mountain said it would not resume work until the issue was resolved. It then filed the motion with the regulator.
In a decision released Thursday, a board panel found Kinder Morgan was essentially asking them to override the city bylaws.
"In the board's view, this clearly raises a constitutional question," the panel wrote.
The company will have to inform the federal and provincial attorneys general and raise specifically that constitutional question about the regulator's legal authority, the board said
On Friday, Kinder Morgan said it had filed the required notice.
"We have no intention of resuming invasive work in Burnaby Mountain Conversation Area," said Trans Mountain spokeswoman Lizette Parsons Bell.
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