Farm safety: avoiding slurry pit accidents

There are two main dangers when it comes to slurry pits: drowning and exposure to poisonous gases.

Reducing the risk of drowning

We advise our Members that simple provisions, such as putting up fences, gates and covers to deter people or livestock from entering the store, can make a big difference in preventing accidents. There is also a potential environmental risk should slurry contaminate water courses.

There are a number of safety considerations and steps that farmers can take to minimise risks. Farmers must ensure that they are complying with the Health and Safety at Work Act 1974 and the provisions of the Workplace (Health, Safety and Welfare) Regulations 1992 by reducing the risk of anyone accidentally accessing slurry pits.

The HSE recommends that fences should be properly erected and maintained, with a minimum height of 1.3 metres and at least two strands of barbed wire on the top. If there is no barbed wire, consideration should be given as to whether the fence should be raised to two metres in height.

For below-ground stores, it’s important to ensure that covers are able to withstand the weight of vehicles, humans and animals. There should be no gaps and suitable signage is recommended to deter against unauthorised access. It’s advised that farmers should make sure a cover is hinged so that it doesn’t fall into the pit and remains closed when access is not needed. It’s also recommended to add a lock device to avoid other people opening and accessing the store.

Exposure to poisonous gases

When manure and water are mixed, they produce dangerous gases including hydrogen sulphide, ammonia, methane and carbon dioxide. The gases are odourless and all displace oxygen. Hydrogen sulphide is the most hazardous as even a small concentration could be fatal. The gas can affect the nervous system, cause discomfort, disorientation and loss of consciousness, and in some cases it can lead to sudden death.

The first half an hour in a slurry pit store is the most dangerous. That is why farmers should leave the store when mixing starts and not return for at least 30 minutes. It’s advised to wear breathing apparatus with its own air supply when entering a slurry tank, as well as being connected by a harness and lifeline to two people outside.

Some farmers are now investing in slurry-separation systems, which separate the solids from the liquid to reduce slurry volume and the potential for pollution. These systems are becoming more popular, particularly for farms in nitrate vulnerable zones, but they can be expensive to run and some require more labour input than others.

We advise only entering a slurry pit when absolutely necessary, ensuring adequate ventilation and testing for gases before entry and planning for emergency. Children and animals should always be kept away from slurry tanks and there should always be at least two people on site when slurry is being mixed.

Most farm accidents are preventable and incidents involving slurry pits are no exception. Following these precautions is the best way to keep you, your workers and the public as safe as possible.