The responses were originally to be made public by Feb. 28. That original deadline was extended to March 31.
In a March 30 letter, Imperial Oil informed the National Energy Board that it won't have the information processed until April 11.
The volume of requests from the National Energy Board (NEB), Joint Review Panel (JRP) and intervenors and the logistics of filing responses are named by Imperial Oil as the reasons for the delay.
"You do everything you can to meet those deadlines," said spokesperson Hart Searle. "At a certain point, both NEB and JRP will be satisfied and start talking about scheduling hearings."
Dehgah Alliance Society consultant Joe Acorn said the failure to meet the second deadline outlines how the pipeline review process is biased in favour of the companies. Dehgah represents Dehcho First Nations on pipeline issues.
"The company gets to take as much time as it likes to prepare its submissions and conversely, it opposes us when we ask for more time," he said. "The communities have to abide by whatever unreasonable schedule the NEB decides for them."
Because of the delay, NEB spokesperson Denis Tremblay said intervenors deadlines will be extended 11 days.Using the energy board's timeline, that could give intervenors until May 2 to file final information requests to the applicant, which will likely have until May 16 to respond. The deadline for intervenors to file written evidence to the NEB could be pushed back to May 30.