Biology Question #3553

Sharon Johnson, a 38 year old female from Tobermory asks on August 6, 2006,

Can decomposing cedar wood chips or household compost cause environmental problems in surrounding soil and/or water tables? Long story-short: my in-laws have been having bad water samples when they test their well. Never had problems before so I'm trying to track down what has changed that may be impacting the results. Their neighbour filled an adjoining driveway with cedar wood chips 2' high, over an area of about 20' by 8'. She covered them with topsoil, grass seed and fertilizer. There's 3 large compost piles right there too. All this is only a few feet from where my in-law's well head is. I read online that decomposing wood, paper and food can produce methane gas and liquid pollutants. I'm just wondering if that's true and if that would contaminate well water?

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The answer

Murray Strome answered on August 15, 2006

It depends. First, cedar chips take a very long time to decompose, and will affect the soil and water, but not significantly differently than the decomposition of cedar in the forests which occurs naturally. However, I suggest that you avoid trying to decompose them with other materials such as garden waste or household vegetable matter.

I assume by "Household Compost" you are talking about vegetable/fruit waste from inside the home. In this case, the important thing is to ensure that the composting is done in a container that is fully protected from rats in particular. Some things, like red worms, significantly improve the efficiency of composting these wastes.

It is best that you have good drainage to ensure the composted material dries out fairly well. It is a good idea to turn it once in a while, i.e. mix it up. There is a neat tool which makes this quit easy. Done properly, this will not adversly affect the water or soil.

The one thing that I would NOT include in my compost pile is evergreen clippings, needles or cones. These don't compost very well, and will make the soil too acidic.

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