Trans Mountain says an estimated 150-190 cubic metres (150,000 to 190,000 litres) of sweet crude oil spilled from its Sumas Pump station this weekend.
B.C.’s Ministry of Environment had earlier said the initial amount reported was estimated at 1,500 litres.
The pipeline was shut down early Saturday and restarted around 7 p.m. on Sunday.
“Clean-up is well underway with trucks and crews working around the clock. The free-standing oil has been recovered and is being transported to an approved facility for disposal,” said Trans Mountain in a statement Sunday afternoon.
“The site has permanent groundwater monitoring in place and air monitoring continues. Monitoring has not identified any risk to the public or community.”
The company said an investigation had found that the spill was related to a fitting on a 2.5-centimetre piece of pipe connected to the mainline.
It said there was no pipeline expansion construction taking place nearby at the time.
The company says that a control centre alarm alerted it to the spill in the “early morning hours” of Saturday.
According to provincial regulators, the spill occurred around 11:20 p.m. Friday night.
“The spilled material has not migrated offsite due to the incident site having perimeter berms,” said B.C. Spill Response Saturday afternoon.
Trans Mountain said the spill had been fully “contained” and that there was no risk to the public.
The Union of BC Indian Chiefs said Sunday that spilled oil escaped into a field adjacent to the pump station, which is also owned by Trans Mountain, but leased for agricultural uses.
“It’s in a place where we’re very concerned about the aquifer that we draw from for our drinking water for the community,” Sumas First Nation Chief Dalton Silver told Global News.
“In the past 15 years, this is the fourth spill right in the vicinity of our community.”
Silver said the Sumas First Nation was still trying to get its own monitors onto the spill site.
Amita Kuttner, federal Green Party leadership candidate and the party’s 2019 candidate in Burnaby-North Seymour — where the pipeline terminus lies — also raised concerns Sunday.
“We’re assured constantly that there are really good safety measures in place,” they said.
“I’m concerned the spill got to that size. And also, in terms of the aftermath of such a thing — you can contain it, you can work on getting rid of the excess oil, but there are impacts that last a lot longer.”
Kuttner said they also had questions about how the spill got so large considering how small the damaged coupling was.
B.C. Spill Response said Trans Mountain’s Oil Spill Containment and Recovery (OSCAR) trailers, vacuum trucks and emergency response contractors had been deployed to the site.
An environmental emergency response officer (EERO) from the Ministry of Environment and Climate Change Strategy was also deployed to the site.