And they suggest that decisions on whether federal or provincial charges will be laid against Plains Midstream for the 2012 leak into the Red Deer River will reveal how serious governments are about the industry's environmental safety.
"The government needs to acknowledge what this report shows, which is that their own monitoring and compliance system failed," Rachel Notley, environment critic for the Alberta New Democrats, said Wednesday.
"The government needs to be explaining what they're going to do to assure Albertans that there aren't 20 other companies out there that have been in non-compliance with safety standards."
On Tuesday, the Alberta Energy Regulator released results from its investigation into the leak of about 470,000 litres of oil into the river just downstream of the community of Sundre.
The oil tainted a long stretch of the river and flowed into Gleniffer Lake, a reservoir used for boating, fishing and swimming.
Drinking water had to be trucked in for the residents of 750 permanent and recreational homes at the lake. The marina was closed. Rafting, fishing and guiding businesses were affected.
Notley points out that the regulator's report concludes the U.S.-based company knew as early as 2008 that the affected section of pipe, which crosses the river, was exposed and in danger of cracking. That information came from consultants hired by Plains and the company's own internal assessment, the report says.
"Plains did not apply any additional measures to reduce the likelihood or consequence of failure," it reads.
It found Plains didn't inspect the line once between November 2008 and September 2011, despite company policies requiring annual examination.
That's what happens when you leave safety up to industry, said Notley.
"Here you had a company whose internal professionals were repeatedly telling it to do something different, which it just ignored," she said. "They were also failing to meet government standards around the inspection frequency and nobody noticed — for four years."
The province has until June to lay charges or impose fines.
"It is still too early to speculate about charges as the investigation is still ongoing," said Alberta Environment spokeswoman Nikki Booth.
"We continue to monitor the biodiversity of the watershed," she said. "There has also been water sampling that has taken place."
That data is not yet public.
The case would seem strong, said environmental lawyer Barry Robinson. Federal legislation forbids introducing a "deleterious substance" into fish-bearing waters.
"It seems you have a deleterious substance," said Robinson. "Definitely you've got fish-bearing waters.
"It would be difficult for Plains Midstream to say they've done everything that's required to prevent this from happening. All the pieces are there for a charge. If there wasn't a charge, you would have to ask why."
Robinson said his firm, Ecojustice, will be writing federal Environment Minister Leona Aglukkaq to ask about the department's intentions.
Federal officials were not immediately able to say if charges are being considered.
Meanwhile, fishing guide Garry Pierce said oil was still visible along riverbanks late last summer, when he was last on the river.
"There was a lot of oil on those shorelines in the upper Red Deer," he said. "The damage in the ecosystem — in the forest and the banks — was, to me, pretty thick."
Still, mature fish seemed healthy, although he didn't see many juveniles, Pierce said.
Catch-and-release fishing restrictions are in place to help rebuild fish stocks, said Booth. Samples of fish from an adjacent trout pond haven't shown any human health threats.