QUESTION
We recently purchased a cabin and love every aspect of it except the retaining wall. It is made of creosote-treated railway ties and stands about 1.2 metres high. We would love to replace it with something more environmentally friendly, as we are concerned about creosote leaching into the lake, but are at a loss as to the alternative. The cabin sits only about a metre back from the wall, so removing the wall altogether is not an option. The wall is just back from the shore, and in high years the water would probably reach it. 

ANSWER

Taking down and replacing that wall is a huge, expensive job requiring the services of a professional (so that you don’t take down the cottage at the same time!) and, if you’re replacing material that is below the high waterline, you’ll need approval from Fisheries and Oceans Canada, Alberta Environment, and Alberta Sustainable Resource Development.

Although having creosote-treated wood near the water isn’t ideal and should be avoided in a new installation, the disruption caused by taking it out and replacing it will do more environmental damage than leaving it in place.

According to Tony Fernandes, senior engineering specialist in the Environmental Policy Branch at Alberta Environment, the chemicals will have penetrated deep into the wood cells and won’t leach out into the soil or water to any appreciable degree. He adds that, unlike creosote itself, creosote-treated wood doesn’t pose a risk to humans as long as frequent direct physical contact is avoided (so don’t sit on the wall, for example). However, we should note that the health hazards associated with the use of creosote in wood are currently under review by Health Canada.

Elaine Vida, a landscape designer with Brackenrig Landscaping in Port Carling, Ont., suggests you plant a native grass or vine to disguise your retaining wall and discourage kids and pets from making direct contact.

Christine Langlois

* Published in the November/December 2007 issue of Cottage Life