Toxic PCBs have been flowing into Hamilton Harbour for years from an east end sewer outlet, new documents reveal, and now the Ministry of Environment has issued a draft order to four companies for cleanup and remediation.

As with many of Hamilton's environmental blights, it's a complicated issue with a tangled history of ownership. Three of the four companies involved say a company that left Hamilton decades ago is the source of the PCBs – but the MOE still wants the property owners it has deemed with some responsibility to work together to come up with solutions.

The Ministry first became aware of contaminants in the groundwater, sediment, soil and soil vapour near three east Hamilton properties in 1995. In 2008, tests by Environment Canada and the Ministry started pointing to an "ongoing source" of PCBs discharging into the harbour, according to a draft Director's Order.

This is a contaminant that is harmful to living organisms and sticks around for a long time. - Lynda Lukasik, Environment Hamilton

"In particular, monitoring results from the Strathearne Avenue slip demonstrated anomalously high concentrations of PCBs in both water and passive sampling devices," the report reads. In 2013, those elevated levels were traced to storm water sewers from commercial properties near Strathearne Avenue.

The "slip" is a shipping inlet at the far east end of the harbour near the Windermere Basin.

According to the ministry, the PCBs are making their way into the harbour from a combined sewer overflow.

4 companies named in order

The MOE has named four companies that own or have owned property near the foot of the slip in its order: Union Gas, Coca-Cola, Rosart Properties and AVX Corporation.

"During an October 2013 meeting, representatives of the properties agreed to voluntarily develop proposals to assess and curtail off-site impacts from their sites," the order reads. "The representatives also urged the Ministry to pursue AVX Corporation as the person responsible for the contamination occurring on their properties."

Three addresses have been named in the order: 1565 Barton St. E, 1575 Barton St. E and 360 Strathearne Ave. N.

From the late 1940's until 1972, Aerovox Canada operated an electrical capacitor manufacturing facility at the 1565 Barton address (the ministry names Aerovox as the "successor" company to AVX). The Ministry says this facility used PCBs, which were legal at the time. Rosart then bought the property in the early 70s.

Commercial production of PCBs started in 1929, but they have been banned or restricted in many countries since the 1970s because of risks to human health and the environment. They were used in the manufacturing and operation of electrical equipment, heat exchangers and hydraulic systems.

PCBs illegal since the 70s

The import, manufacture, and sale of PCBs was made illegal in Canada in 1977. Releasing PCBs into the environment has been illegal since 1985 – though Canadian legislation allows owners of PCB equipment to keep using it until the "end of its service life," Environment Canada says.

Environment Hamilton Executive Director Lynda Lukasik questioned how the Ministry could know about this issue since the 90s, and yet the public hadn't been informed, "That's a long time, and I don't understand why it has taken so long," she said. "Why did the government not take some steps back in the 90s on this?"

"This is a contaminant that is harmful to living organisms and sticks around for a long time."

The ministry says it is proposing to this order to require AVX and the owners of the three properties to hire a company to figure out how the contaminants are seeping out of the three properties and develop ways to stop it. Spokesperson Jennifer Hall told CBC News in a statement that the ministry is "working on a long term strategy" to address PCBs in the harbour.

"The ministry has been actively working to stop the movement of the PCBs from the properties and the companies involved have done further sampling and developed proposed work plans," Hall said. She did not immediately answer questions on why it has taken 20 years to issue an order.

Companies say workers not affected

In a statement, Coca-Cola Canada said the company is taking this situation seriously.

"Testing confirms that there is no contamination risk at surface level to our employees, our products or our consumers," said Shannon Denny, the soda giant's director of brand and business communications. She also noted that the Hamilton property operates as a sales, distribution and warehouse facility that doesn't handle drink production.

"The information available indicates this situation originated at a neighbouring property at 1565 Barton Street decades before we acquired our site in 1950," the statement reads. "Only a portion of our property is affected, and since we became aware of this in 1995 we have been working continuously with the Ministry and the other affected property owners to address it. These efforts include monitoring, and air and soil testing."

In a Facebook post, Union Gas said that it did not cause or contribute to any of the contamination, which is in the soil "well below" their parking lot. The company says it was "caused by migration of contaminants from a neighbouring property."

"We have a longstanding commitment to environmental responsibility and have taken proactive steps to address this issue," the statement reads.

The companies will have the opportunity to respond and comment on the proposal. CBC News is also seeking comment from the other two companies, but representatives were not immediately made available.

This aerial shot shows the Strathearne Avenue slip, which is the area the Ministry says has a PCB contamination problem. (Google)

adam.carter@cbc.ca