MAC: Mines and Communities

Contaminated slag sparks debate in Canada

Published by MAC on 2004-04-09

Contaminated slag sparks debate

By Rob O'Flanagan, The Sudbury Star

Friday, April 09, 2004

Dave Petryna says he unwittingly used contaminated slag as fill on his property

Local News - Is industrial slag a safe product to use as a fill in residential construction, particularly those near watercourses and lakes? It's a question Dave Petryna wants answered after the Ministry of the Environment ordered a massive cleanup of slag and slag-related water contamination on his Nepahwin Lake property.

Petryna, a Sudbury businessman and former city councillor, began construction on a new home last summer on Eden Point Drive in the city's south end. The excavation/blasting contractor, Canadian Mining and Development, used several tons of slag as a foundation for the house.

The slag came from Fisher-Wavy, a local concrete block company. Petryna said he and the contractor assumed it was a suitable alternative to sand, gravel or rock.

For several decades, slag, a pebble-like byproduct of nickel smelting, has been widely used as a road, driveway and rail-line construction material in the region.

But a local environmental expert says there should be restrictions on its use near lakes and watercourses, and an Inco spokesman said it is not a suitable field bed material.

Petryna said that, after the lot was prepared, heavy rains and ground water accumulated on the compacted slag. A large pond of water formed and stayed on the property, which is on the lakeshore. A toxic, greenish film soon formed over the water.

"A neighbour saw this green water that was sitting in this pond, and was apparently concerned about the environment," said Petryna. "He went on to the property, took a sample of the water and sent it to a lab for analysis."

The results of the lab test showed high concentrations of nickel and copper, and the environment ministry (MOE) was called in. Petryna said the ministry took a sample of its own and ordered a costly clean up.

"All the water on the property - something like 85,000 gallons of water - had to be removed by special waste removal trucks, which I had to pay for," Petryna said. "And every piece of slag that caused this problem had to be removed. That was a huge cost. The total bill was somewhere around $70,000."

The water and slag were returned to Fisher-Wavy's slag operation on Big Nickel Mine Drive, said Petryna, adding that the company has a tailings pond that can handle contaminated water. A lawsuit followed, whereby Canadian Mining and Development refused to pay for the product, Fisher-Wavy launched a claim for payment, and Petryna and the contractor launched a suit seeking clean-up and legal costs.

Fisher-Wavy counter-sued, stating in its defence that, had it known that Canadian Mining and Development was going to use the slag as foundation material near a lake, it would not have sold the product to the contractor.

Fisher-Wavy is a trade name of Alexander Centre Industries Ltd. President Mark McGoey said there are no regulations governing the use of slag, but "you have to be careful that it doesn't go near watercourses."

Inco, he said, owns the slag and Fisher-Wavy processes it for sale. The nickel giant conducted studies in the past, McGoey added, which showed that small amounts of metal material is leached (washed off) slag and released into the environment.

"The paradoxical thing, the thing I have a problem with is, the MOE allows Fisher-Wavy to sell this product. But when it gets put on my property, they make me remove it," he said. "Supposedly, it was a legal product that they sold to me. How can it be a legal product if the ministry requires me to remove it?"

The Sudbury Star posed a number of questions to an MOE spokesman, who said he would investigate and respond. By the end of business hours Thursday, he had not responded.

Corey McPhee, Inco spokesman, said slag is classified by the MOE as a "non-hazardous, industrial solid waste."

McPhee said the product is used extensively and safely in applications such as roadbeds and rail ballasts.

"But it's really application specific," he added. "It has to meet certain specifications for the application. When Inco has someone approaching us for a large order, we ask what they plan to use it for. If we were approached for a residential application, such as a field bed, we would say no. We wouldn't recommend it for that application because we haven't tested it under those conditions."

Allen Bonnis, director of operations for the Nickel District Conservation Authority, said there are no specific regulations governing the use of slag as a fill material. If it is used near a watercourse and a problem arises, "we'll deal with it," he said. A vague guideline states that fill materials used in areas near lakes and watercourses must be "clean fill" and can not contain garbage or toxic materials.

Al McCann, a plants examiner with the City of Greater Sudbury, said slag is commonly used as fill, but because it is not an "original" material - a natural soil, sand or gravel - an engineer must inspect operations where slag is used to ensure it is properly compacted and capable of holding the load that will be placed on it.

David Pearson, an Environmental Earth Sciences professor at Laurentian University, and an expert on environmental issues, said slag, especially fresh slag, is known to release some heavy metal materials, such as nickel, copper, lead and zinc.

"I believe that slag should not be used within 300 to 500 metres of a lake," he said. "My inclination is to have a rule which says that you can not use slag within a certain distance of a lake, whether it is for residential use or as a road bed, because of the potential for heavy metals to leach out of the slag."

Those heavy metals are known to be hazardous to certain forms of aquatic life, he added.


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