This news article featured in issue no.18 in CHSP’s November 2022 newsletter


In this article you will learn of a confined space fatality, how hazardous working in water tanks can be and what is a confined space.


What took place

In December 2013, Robert Geach 54, died by drowning after he fell into a water tank. He had been attempting to fulfil his workplace duties.

The accident took place in a sand filtration tank at a water treatment plant in Falmouth Cornwall. He was working for South West Water at the time. He was attempting to fix a fault by unblocking a filter on the inside of the tank.  Robert had to lean in to reach the filter and leaned in too far. He fell through the hole and drowned. He was eventually found face down in over six feet of water.



Robert was working at height with no fall protection in place to prevent a fall into the tank of water.

The lone working alarm system had been set off but there was a slow response rate. Responders didn’t find Mr Geach for four and a half hours.

South West Water had apparently been warned on a number of occasions of the fall from height hazard. They were also informed control measures needed putting in place. The warnings had not been acted upon up until this incident.

The risk assessment was also found not to be sufficient for the job.



Judge Robert Linford of Truro Crown Court, found South West Water guilty of breaching the Health and Safety At Work Act 1974. This was for failure to provide a safe place to work. South West Water was fined a whopping £1.8 million, excluding costs.



South West Water were reported to have rectified their health and safety systems within a week after the incident. They had reduced the size of the access point installed to prevent falls, introduced 2 man working policy and a revised lone working device designed to detect a man down with GPS tracker. Prevention is better then a cure.


What is a confined space?

A confined space is an enclosed  or substantially enclosed space that has a foreseeable risk to workers including fire, explosion, fumes etc.


What makes a water tank a confined space?

Water tanks are confined spaces because they have limited access combined with the possibility of oxygen depletion. Oxygen depletion could be due to chlorine fumes above the water level (if the water hasn’t been drained), the water itself as a worker is at risk of being submerged and drowning. Fumes sitting at the bottom of the tank if the water has been drained from chlorine. With water in the tank fumes can accumulate just above water level. Rust from the metal inside the tank also uses up oxygen. This is why it is important to have effective control measures in place and an effective rescue plan in place.

Risk assessments need to be prepared that are specific to the hazards present at each particular site. These are commonly referred to as site specific risk assessments. Each site will have differences to consider. There are other hazards associated with water tanks, these include:

  • Falls from height – as tanks very often do not have guardrails or anchorage points to prevent a fall,
  • Lone working – consider the likely delayed response time in the event of an emergency,
  • The access egress method can pose a hazard for example in built ladders or self supplied are available or MEWPs,
  • If power tools are planned to be used in a tank with atmospheric risks then this would increase the risk. Explosions can be caused from a combination of airborne dust particles, oxygen and heat, sparks generated from the use of the power tool,
  • Insufficient rescue plan – It has been estimated that 60% of confined space fatalities involve the rescuer.

Risk Assessment – Factors to consider

Around 15 people are killed in confined space accidents in the UK each year. The hierarchy of controls must be used as a method to eliminate the risks where possible and if not then to put measures in place to reduce the risk of an accident taking place.


Confined spaces and access

The first thing to consider is, is entry into a tank necessary. If it isn’t maybe work can be planned remote from the tank using an access platform such as an aluminium tower, scaffold or a MEWP. Otherwise, restrict access for partial entry. Where there is an alternative safer means to complete the work required use it.

If there isn’t then consider how can the hazard within a confined space be removed and assessed prior to a necessary entry. Consider atmospheric testing using purpose built devices to measure the fumes and oxygen levels in the tank down to the level where the worker will be required prior to entry.

Another to thing to think about is what would you do about the fumes if they are detected to be to high for entry or work to take place? Consider time allowance for ventilation, periodic monitoring, respiratory protective equipment or if worse comes to worse rescheduling.

Can the water be drained prior to entry to prevent drowning?


Lone working

If you haven’t been able to eliminate the atmospheric hazards and others, how will a rescue plan be performed if worse comes to worse, without a look out / watchman? A rescue plan in confined spaces and work at height situations needs to be in place without any reliance on the emergency services to complete some or all of a rescue. So consider if lone working is safe and legal. If you can justify it is, which can only be assured if the definition of a confined space is not satisfied, what lone working procedures are in place?


Falls from height

Again think is work at height absolutely necessary, if so can the time be minimised?, how can a fall from height be prevented? This often requires a combination of safety measures such as working from working platforms guardrails, fall restraint and arrest harness lanyard systems and anchor points.


Use of power tools

Can safer alternatives be used that reduce the chances of heat generation such as hand tools.


Rescue Plan

What is the safest way to perform a rescue? Consider different scenarios such as the method of rescue when they are conscious, the rescuee is unconscious and / or injured.


Next Steps

CHSP offer Working in Confined Spaces Training, click on the following link to access your Free Trial.

For further advice and support make your enquiries to:


Tel: 07908 174408