Saturday, October 20, 2012

Compost Berms for Erosion and Sediment Management

Traditionally erosion and sediment control seems to have started and stopped with using a silt fence.
Experience in the tropics often seems to indicate that silt fences may not be the solution that is best suited to these conditions.  They often are poorly constructed, commonly with poor insertion of the tail into the ground.  The intensity of rain commonly dislodges soil particles and along with a lot of water these fines clog the fence.  Common result is a failed fence.  Not to mention the need for a lot of maintenance.  They have a place – but there are smarter options.
Mulch and compost berms are gaining a lot more credibility in many seasonally wet tropical regions as a superior option to provide erosion and sediment management.  If you have tried them out………they are worth considering.

That is particularly true in north Australia where copious volumes of green waste are dumped at local landfill sites and then ground up at many of the regional towns and cities, to produce mulch.  This material is commonly then given at least a partial pasteurisation in a stacked row, and reused for garden mulch.  As well as garden mulch – it is ideal for building small mulch / compost berms that can provide excellent erosion and sediment management on construction sites.
The berms can be built with readily available machinery, or if available a mulch blower.

There are a range of on line resources available to help you gain more understanding, and the concept is strongly recommended by the US EPA as well as many other organisations.

This link is to the US EPA site with many links to a range of construction site tools of which compost filter berms are but one………albeit very useful.

The next link is to an article where berms are compared to silt fences in the USA.  The article is over 10 years old, but mostly still relevant.  There are many advocates for the use of mulches but read about it yourself.
The article is a good overview of using berms.
And the trees or vegetation often removed for construction can also be utilised to reduce sediment and erosion – even laid in a simple matrix on the ground, with plenty of leaves and small branches inter mixed with larger branches.  It is a smart idea, a simple easy option to reduce erosion problems.  

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