Asphalt roofing falling into garden. - Ask Extension
I work in a community garden behind our apartment complex. Over the past two weeks the management has had contractors removing the old asphalt shingle...
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Asphalt roofing falling into garden. #160547
Asked November 15, 2013, 5:17 PM EST
I work in a community garden behind our apartment complex. Over the past two weeks the management has had contractors removing the old asphalt shingles and laying new. Many shingles have fallen into our garden spaces and while we've picked out as much as we can, their are micro-pieces, like the size of sand grains, remaining. Will many toxic chemicals leach? Should we remove our topsoil to remove most of the micro pieces? Is a little contamination okay?
Multnomah County Oregon
Expert Response
Thank you for your question to Ask an Expert.
The debris from the shingles contains particulates (sand/gravel) and asphalt, which is a heavy organic compound that does not readily leach into the soil and likely will not cause any contamination to the plants since the plants are unlikely to absorb any petroleum compounds from the asphalt. The addition of compost to the soil will also help to bind any potential contaminants and keep them fixed in the soil.
To be extra safe, you might choose tall and upright crops like tomato and peppers in the beds most affected and not grow root crops (carrots, beets, radishes) that are in contact with the soil and greens where the leaves come in contact with the soil.
Please let me know if you have any further questions.
Weston
The debris from the shingles contains particulates (sand/gravel) and asphalt, which is a heavy organic compound that does not readily leach into the soil and likely will not cause any contamination to the plants since the plants are unlikely to absorb any petroleum compounds from the asphalt. The addition of compost to the soil will also help to bind any potential contaminants and keep them fixed in the soil.
To be extra safe, you might choose tall and upright crops like tomato and peppers in the beds most affected and not grow root crops (carrots, beets, radishes) that are in contact with the soil and greens where the leaves come in contact with the soil.
Please let me know if you have any further questions.
Weston
