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Find out why fire water run-off management is and why it is important.

Why Should I Consider Fire Water Run-Off?

Despite the best preventative measures, the risks of emergencies are present for all businesses and procedures should be in place to manage the impacts of an emergency. One possible emergency is a fire and a big environmental issue associated with fire is the water run-off from tackling it. Why you should consider fire water run-off when preparing and planning for emergency response?

What is fire water run-off?

Water is the most widely used medium when fighting fires as it is cheap, usually plentiful and easily accessible and very effective at fighting fire. Although some of the water will evaporate in the heat of the fire, most of it will fall to the ground and drain away. Typically, this water is non-hazardous and does not pose a threat to the environment. However, it can easily become contaminated with the materials you store on site, combustion by-products or firefighting foam. These contaminants can cause significant environmental damage and must be managed.

What are the risks of fire water run-off?

Run-off can enter the environment through a variety of pathways, including surface water drains, foul drainage systems, run-off directly into water bodies or absorption by the ground, leading to groundwater. Depending upon the contaminants, the resulting pollution can cause significant environmental harm and threaten local water supplies and public health. The resulting environmental damage could be long term, particularly if groundwater is contaminated and rivers and other water bodies can carry the contaminants far away from your site, expanding the impacted area.

Why does fire water run-off need to be managed?

Having the necessary controls, policies and procedures in place can help to reduce the potential impact of any unplanned events that occur, including fire. All businesses should have robust emergency plans, including a (PIRP) Pollution Incident Response Plan (for more information, read here). More high-risk sites, like COMAH (Control of Major Accident Hazards) sites are legally required to have more comprehensive and detailed plans. Regardless of business size and activity, you should have robust, reviewed and tested procedures in place and they should consider fire water management. If you do not manage fire water run-off, you could face prosecution, the costs of environmental clean-up and/ or be liable for the costs of clean-up by the Environment Agency. Under normal insurance policies, these costs are not covered so the impact of fire water run-off could end up being very expensive.

You should have policies and procedures in place to prevent emergencies and to manage the impacts if they should happen. One of the impacts that you should consider is fire water run-off management, which has the potential to cause significant environmental damage and could lead to prosecutions and fines. Having a clear plan to manage fire water run-off and including the strategy in your emergency procedures could help you to reduce the risks to the environment and public health. Our next blog will discuss the options you can consider for fire water management.


How Can I Manage Fire Water Run-Off?

Risk Assess

Contaminated fire water can cause environmental pollution and could potentially lead to prosecution or fines, so it is essential that you have a strategy to manage the risk and include it in your emergency plans and procedures. When considering your strategy, you should carry out a risk assessment that should be comprehensive and include factors like:

  • The volume of water that might be used to tackle a fire
  • The substances you store on site and what the fire water could become contaminated with
  • Pathways of how fire water could enter the environment e.g. surface water drains, foul drains, direct run-off into watercourses or absorption through the ground
  • The sensitivity of the environment that would be affected by contaminated fire water
  • Current site arrangements that could deal with fire water run-off

After these assessing these considerations, it is important to determine whether additional measures are required to sufficiently manage fire water run-off.

Fire Water Containment

To prevent fire water from causing pollution, containment is the best method. There are various methods of containment, permanent or temporary, including:

  • Containment lagoons e.g. earth banked containment basins
  • Purpose built or portable tanks, overdrums and tankers, where contaminated water can be contained
  • Shut-off valves and penstocks where the whole or part of the drainage network can be isolated to contain contaminated water (read our next blog for more information on this)
  • Sacrificial area that can be used for other purposes like a car park or sports ground when there is not an emergency
  • Bunding of vehicle car parks and other hard standing areas
  • Pits and trenches, where no other option is available around the site

In all cases, fire water must be fully contained. This may mean installing an impermeable membrane or a method of isolating the drainage network in a particular area. In addition, some of these methods may allow the recycling of fire water if a risk assessment determines it is possible.

Other methods of fire water management

It is not always possible to provide containment for fire water, but the options should always be assessed and considered. The main concern is ensuring that fire water does not enter drains. This can be avoided by using suitable spill kits or drainage covers to protect them. If this method is used, be sure to dispose of the waste correctly.

As part of your emergency procedure preparation, you must consider fire water management. When you have a suitable strategy, you should ensure this is included in your PIRP and other procedures. You should make sure the necessary equipment is available and that everyone is aware of your procedures. You should ensure any waste and contaminated water is disposed of legally and that you fully check all drains and interceptors for contamination before opening drainage systems after the event.