Fencing around slurry pits and stores is a vital safety measure that is often overlooked.
Here is some useful information from the HSE’s ‘Managing Slurry’ guidance, to provide you with a helpful guide on securing your slurry storage.
Perimeter protection
Drowning in slurry lagoons and other similar areas has resulted in many fatal incidents. You can prevent this by:
- surrounding your store with a perimeter wall or fence. This will help to prevent access by unauthorised people, such as children, and livestock.
- access points such as gates or apertures for suction pipes should be protected to the same standard as the remainder of the fence or wall. You may wish to completely cover below-ground stores such as reception tanks or sheep dips when they are not in use.
Check that fences:
- have been designed to deter access and are properly erected and maintained.
- are constructed of suitable material, such as small mesh wire fencing or sheet material which do not offer hand or footholds, particularly for children.
- have an overall minimum height of at least 1.3 m (see Figure 1), including at least two strands of barbed wire spaced 100 to 150 mm apart at the top.
- will not be pushed up from the bottom by stock. Two strands of barbed wire at the bottom will help prevent this.
- provide a standard of deterrence equal to that provided by the fence if erected to the standard described above. For gates, this may be achieved by fitting metal sheeting or cladding to the outside, so it is virtually impossible for children to climb them.
- are topped by two strands of barbed wire.
- are designed to prevent unauthorised opening. This could involve using a chain and padlocks, fitting latches designed so that children will be unable to open them, e.g., placed on the inside of the gate, or otherwise protecting against opening to an equivalent standard.
If your store includes a scraping ramp, consider whether it is best in your circumstances to:
- extend the fencing to the bottom of the ramp and provide a sheeted gate across the ramp at that point; or
- provide swinging flaps attached to the tractor stop rail. These provide good protection if they are properly designed, constructed, and maintained.
Below-ground stores
If you decide to use a cover to protect your below-ground store, check that:
- the cover can withstand any foreseeable traffic loads, e.g., cattle, humans, or a tractor.
- there are not any gaps greater than 75 mm, e.g., between slats or mesh or alongside pumps.
- extraction pipes cannot fall into the pit. Consider securing them in position.
- there are suitable ‘no access for unauthorised persons’ prohibitory signs on, or close to, covers. If covers have removable sections, check that they are large enough to allow access for rescue purposes – bear in mind that this may need to accommodate a person wearing breathing apparatus.
- hinged or otherwise attached so that they will not fall into the store.
- closed or replaced when access is not needed.
- heavy enough to prevent children from opening them or fitted with a padlock or other locking device.
Maintenance of slurry storage towers
Slurry and digestate stores can collapse if not suitably maintained. Indications that your slurry tower needs replacement or repairs include:
- leaks.
- bowing or cracking to the outer skin.
- deterioration around joints.
- spalling or flaking of the concrete layer of a tower, caused by corrosion of the metal reinforcing bars. This may also show as rust staining on the concrete surface.
- corrosion on either the surface or the underside of concrete slats and concrete covers to pits. These are symptoms of a tower or slurry system in need of specialist attention.
- Wherever possible, routine maintenance work should be undertaken when the plant is empty of slurry. All work, including emergency work, must be planned carefully using the correct equipment, including appropriate RPE and trained, experienced workers. If you cannot ensure a high level of training, supervision of workers and a robust emergency plan, you should leave this work to specialist contractors.
- Never work alone on the maintenance of slurry systems. Work on valves and pipework could lead to slurry spillages which could result in exposure to extremely dangerous slurry gases including hydrogen sulphide.
