Washington's Department of Ecology wants the Canadian government to fix what it calls "deficiencies in critical areas" of its spill response plan for a spur of the Trans Mountain pipeline that runs through the state.

When Canada purchased the Trans Mountain pipeline and assets for $4.5 billion, it also bought the Puget Sound line, which carries Alberta oil to four Washington refineries.

The state's Ecology Department says in a news release that the Canadian government, as the owner of the 100-kilometre pipeline, is required by law to have an approved spill response plan.

It says the pipeline operator submitted a plan to the department for review and approval, and it's now given the operator 60 days to add more details in several areas.

Crown corp will respond within 60 days

It wants to know more about how it would respond to a spill of heavy oils that may sink to the seafloor, how it would protect endangered killer whales, salmon, and other natural resources from a spill, and the initial steps it would take after a spill is discovered.

The Trans Mountain Corp., a newly formed Crown corporation, says it's reviewing the department's conditions and will respond within the allowed 60-day period.

"Our top priority is the safety of the communities where we operate and Trans Mountain understands the most critical and responsible emergency management strategy is to prevent an incident from occurring at all," it says in a statement.

"In the unlikely case of an emergency, we have detailed emergency response procedures and trained professionals who are prepared to quickly respond to any type of incident anywhere along the pipeline system."

Canada's Department of Finance and Environment and Climate Change Canada did not immediately respond to requests for comment.

14,000 public comments received

Washington's Ecology Department says it received 14,000 public comments after a public review of the proposed response plan. The comments opposed the plan's ability to address a response to heavy oils that are difficult to clean up once spilled, as well as the lack of details in the plan on species at risk from potential spills, such as declining populations of southern resident killer whales, it says.

"We expect Canada to adhere to the high standards Washington has worked so hard to achieve that protect our environment, economy, and the health of our communities," says Dale Jensen, manager of the department's spill prevention, preparedness and response program.

The spill response plan only covers the existing operation of the Puget Sound line that has been transporting oil in Washington since the 1950s. In 2017, it carried more than 9.8 billion litres of crude oil to refineries in Ferndale and Anacortes, the department says.

While it wasn't part of the review's scope, many comments expressed concerns about the planned expansion of the pipeline on the Canadian side of the border, the department says.