B.C.'s Ministry of Environment is reviewing claims that CN Rail improperly sprayed pesticides directly adjacent to the Skeena River between Terrace and Prince Rupert.

Photographs taken along the river near CN tracks show what appears to be a line of dead vegetation that crosses creeks and waterways, according to the environmentalists who documented the more than 100 kilometre stretch of treated area.

"You can see the dead vegetation, it goes right onto the rubble that goes down into the Skeena," said Luanne Roth, a spokesperson with the T. Buck Suzuki Environmental Foundation.

Roth and her husband spotted the dead plants while travelling from Prince Rupert to Terrace to visit the farmer's market in early September.

"If this was a herbicide, and I can't imagine that it's anything else, and they sprayed it this close over waterways, I just think it's totally unacceptable and I think they should be held to account for this," she said.

CN Rail says it is conducting its own review of vegetation control that was done along rail lines near the Skeena River. (T. Buck Suzuki Environmental Foundation)

Provincial inspection

B.C. Ministry of Environment officials say staff are aware of herbicide spraying in the area.

"And were onsite this week conducting an inspection following complaints on significant pesticide overspray," wrote an official from the Ministry of Environment.

Under the B.C. Weed Control Act, CN is required to remove noxious weeds and invasive plant species along tracks and in rail yards.

It is also required to maintain minimum sight lines, set by Transport Canada, at railroad crossings.

CN's most recent pest management plan (PMP) available to the public was approved by the Ministry of Environment in May, 2012 and expired in May, 2017.

PMP's are required for pesticide application on public land and private land used for transportation under the Integrated Pest Management Act.

The company is also required to keep accurate daily records of pesticide applications.

CN conducting review

CN told CBC News on Friday that it could not say what kind of chemicals were used or how the vegetation control was applied, but was conducting its own review.

"The only restriction on what herbicide can be used is whether or not it is approved for use by Health Canada for that purpose," wrote the Ministry of Environment.

The expired PMP lists nine chemicals that can be applied to rights-of-way to remove vegetation.

Under that plan, CN was required to leave a buffer of five metres between non-selective pesticide applications and fish bearing bodies of water.

Selective methods were permitted to be applied within one metre of such waterways.

'Very close' to the river

Reviewing the images provided by the T. Buck Suzuki Environmental Foundation, Vicki Marlatt, an assistant professor in environmental toxicology at Simon Fraser University said chemicals appear to be applied very close to waterways and the images did give her cause for concern.

"It is very close. The last picture I'm looking at looks like the swath of dead plants is just a few feet from the river so there would have to be some pesticide entering the water if you were doing some sort of foliar spray method."

With files from George Baker and CBC's Daybreak North