Woodchip corrals, straw-bedded corrals and stand-off pads are unroofed outside enclosures. They are used for over-wintering cattle and occasionally sheep.
The enclosures can be unlined if they are over a free-draining soil.
Woodchip corrals are bedded with woodchip. They are usually permanent structures that need annual maintenance.
If the woodchip corral is lined, it is known as a stand-off pad. It will have a system for collecting effluent.
Straw-bedded corrals are bedded with straw. More straw is added throughout the over-wintering period as the bed becomes wet or unclean. The straw is kept to a depth sufficient to prevent faeces, urine and rainfall leaking into the ground.
Straw-bedded corrals are usually unlined, temporary structures with the farm yard manure removed each year. The next winter's straw-bedded corral is sited on a new parcel of land. If permanent, it is normally lined with systems to collect effluent with the farm yard manure removed each year.
What you must do
Unlined woodchip corrals and permanent straw-bedded corrals have a potential to pollute groundwater. You must not use an unlined woodchip corral, unless you can prove that it is unlikely to cause groundwater or surface water pollution.
You may be able to use a temporary straw-bedded corral if the risk to groundwater is low and you maintain a sufficient depth of straw when stocked.
In most instances, where the underlying soil is not impermeable, you will need to install a liner. This is to allow effluent to be collected, treated and recycled to land.
You must not allow the drainage from a woodchip corral to enter groundwater or surface waters. This normally means that you must collect the effluent from the corral and spread it onto land.
Collection systems for the drainage must comply with rules for storing slurry.
Disposing of waste woodchips
If you dispose of waste woodchips by landspreading or composting you must have registered an exemption with your environmental regulator.
Areas at risk from nitrate pollution
In Northern Ireland all farmers must comply with rules under the Nutrient Action Programme Regulations.
In Scotland you should find out whether you are within a nitrate vulnerable zone (NVZ). If you are within an NVZ you will need to follow certain rules, such as limiting the amount of organic and inorganic nitrogen fertiliser you use and keeping records.
You should always contact your environmental regulator before building a new woodchip corral or stand-off pad, or altering an existing one.
The Scottish Agricultural College (SAC) and the Department of Agriculture and Food (Ireland) have published technical guidance on the design, construction and use of woodchip corrals and stand-off pads.