Richard Deane, the manager of environmental health and safety at Teck's Trail operations, said the five-year plan calls for a treatment plant to remove heavy metals that have tainted the groundwater under the smelter.
The public will have to take his word for it, as Environment Canada will not release the company's plan to deal with the arsenic, ammonia, lead and other heavy metals that have leached from historic tailings ponds and trenches.
"Teck Metals Ltd. is the author of the plan in question. It would therefore be inappropriate for Environment Canada to distribute it," Mark Johnson, spokesman for the federal department, said in an email response.
"For further queries about the plan, please contact Teck Metals Ltd."
Teck declined to release the plan, which is under review by the federal agency, but they did offer an interview with Deane. Environment Canada declined a request for an interview.
The remediation plan was originally due March 31, but that deadline was extended to Oct. 31 to allow for further testing.
Deane said the contamination comes from ponds and trenches used at the smelter in the 1980s and earlier.
"The smelting and refining operations have existed on this site since 1896, well over 100 years of operation at this site," he said.
The contamination was discovered in 2001, as part of an ecosystem risk assessment being conducted by the company. They have since discovered the tainted water runs under the Columbia River into an aquifer in east Trail.
Testing has shown that contamination is not detectable in the river itself, Deane said.
"There is some upwelling along the river bottom in some localized spots, and then into the east Trail aquifer," Deane said.
"The purpose of the remediation plan is to intercept the groundwater as it leaves the Trail operations site before it gets to the area under the Columbia River or to the east Trail aquifer, and also to prevent any upwelling of the affected ground water into the Columbia River."
Studies conducted to date suggest fish populations in the river are not affected, and the aquifer is not used for drinking water, he said.
The remediation involves a series of wells that will capture the water for the treatment plant.
"The plan itself is going to take about five years to fully implement, but fairly quickly the installation of those wells will basically reverse the flow of groundwater immediately in the area and bring it into the wells and bring it up to the surface," Deane said.
"So fairly quickly the intention is they will prevent any upwelling of this groundwater into the Columbia River."
Over the past few decades, Teck has invested more than a billion dollars into environmental improvements at the Trail smelter, and in 1996 stopped dumping slag into the Columbia. Just last year, the company said it would invest another $210 million to increase capacity of an electronic waste recycling operation at its zinc smelter and hydroelectric plant in Trail.
But a century of operations has left a heavy environmental footprint in B.C. and beyond.
In September, Teck admitted in a U.S. court that slag from the smelter has polluted the Columbia River in Washington state for more than a century.
The civil court lawsuit claims the metals have contaminated the surface water, ground waters and sediments of the upper Columbia River and Lake Roosevelt, the reservoir created by the Grand Coulee Dam. The clean-up costs have been estimated as high as $1 billion.
Company officials have said their admission does not address whether U.S. authorities have jurisdiction over a company operating fully in Canada in compliance with Canadian regulations in place at the time.
Environment Canada said technical experts are reviewing the remediation plan.
"The Company has already met with officials from Environment Canada enforcement and has started on some of the remediation work identified," Johnson said in an email.
"Environment Canada continues to conduct inspections at the facility to monitor compliance with the Fisheries Act and (Canadian Environmental Protection Act)."
Environment Canada said they are unable to provide copies of the last three inspection reports at this time.