Safety Precautions When Working in Confined Space
Many workers are injured and killed each year while working in confined spaces. An estimated 60 percent of the deaths have been among the would-be rescuers
Many workers are injured and killed each year while working in confined spaces. An estimated 60% of the fatalities have been among the would-be rescuers.
In a July 2021 incident that occurred in Kamulu, Nairobi County, two people died inside a 50ft septic tank as they were reportedly working to pump out waste water.
In another case in September 2020, three middle-aged men died after they slipped into a 90-feet deep underground water reservoir at Ngoingwa estate, Thika town. According to witnesses, one of the victims, a water vendor, was repairing an underground pump to facilitate water flow in a six-storeyed Nyathira Square apartment. Two of his colleagues met their death as they tried to save him out of the slippery well where they also slid and fell.
The Daily Nation on April 19, 2019 reported yet another unfortunate incident in Kisii, Western Kenya where two men died inside a well. According to the reports, a 32 year old man suffocated and died inside the well that he had been engaged to deepen. The second man is said to have slipped and fallen into the well as he attempted to rescue the well digger leading to his death.
There have been many other similar cases where many people working in water wells or other confined spaces die or are seriously injured for failing to use appropriate safety precautions.
Generally speaking, a confined space is a fully or partially enclosed space that:
- Is not primarily designed or intended for continuous human occupancy
- Has limited or restricted entrance or exit, or a configuration that can complicate first aid, rescue, evacuation, or other emergency response activities
- Can represent a risk for the for the health and safety of anyone who enters, due to one or more of the following factors:
- its design, construction, location or atmosphere
- the materials or substances in it
- work activities being carried out in it, or the
- mechanical, process and safety hazards present
Confined spaces can be below or above ground. Confined spaces can be found in almost any workplace. A confined space, despite its name, is not necessarily small. Examples of confined spaces include silos, vats, hoppers, utility vaults, tanks, water supply towers, sewers, pipes, access shafts, truck or rail tank cars, aircraft wings, boilers, manholes, pump stations, digesters, manure pits and storage bins. Ditches and trenches may also be a confined space when access or egress is limited. Barges, shipping containers and fish holds are also considered as possible confined spaces.
In this article we look at some safety precautions to avoid such incidents in hand dug wells. The advice is adapted from The Hand Dug Well [instruction manual, by Henk Holtslag & John deWolf, Foundation Connect International.
Safety Precautions for Hand Dug wells
- Never work alone. The excavator in the bottom of the well should have a buddy at ground level above, on guard to assist if needed. While someone is working down the well there must always be someone in attendance at the top. Never leave someone unattended at the bottom of the well.
- Signaling between well excavator and people at ground level: A system may need to be developed for signaling between people at the bottom and top of the well for lowering and raising equipment and people. Make sure everyone understands these signals and there is no miscommunication.
- Check all ropes and hand-dug-well digging equipment every day at the start of work
- Rope knots: When using a rope to lower or lift something from the well, knots should be made along the rope at metre intervals to stop the rope slipping through your hands;
- Earth lifting buckets: Ensure that the handle of the bucket is firmly fixed and cannot slip off;
- Lowering worker into the Dug well: If possible, always use a windlass to lift and lower materials. Use a windlass with two handles and therefore two people if a digger is lowered or lifted. If one of the people loses the control of his handle, the digger will not fall back in the well because the other still controls his side.
- Protect edges of the top of the well opening during construction: Put a plank across the edge of the opening to the shaft, so that people and buckets can be lowered over the edge without wearing away the ground at the side and causing it to cave in;
- Steps in well shaft sides? Cut steps into the side of the shaft to make it easier for people going up and down the well. This is only possible if the soil is strong enough to hold the weight of a person. When you doubt: do not make them!
- Well digger head protection: Always wear a helmet in case something falls down in the well;
- Well digger foot protection: Be careful while loosing the soil in the well with the long chisel. Don't cute off your toes! If possible wear shoes with a metal nose protection.
- Safety of air supply at the bottom of a hand dug well: In narrow wells more than 15 metres deep, there may be a problem having fresh air at the bottom of the well. This is very dangerous and even poison gasses may appear. Air circulation can be helped by raising and lowering leafy branches in the shaft to "stir up" the air. The best way is to use a ventilator to get fresh air in the well. This ventilator can easily be made by a local workshop and exists of local available materials.
- Handling soil & rocks dug out of the well: Heap excavated soil more than one metre from the edge of the shaft so that as the pile grows, it will not fall back down the well;
- Hand dug well site safety: Put a fence or some sort of barrier around the digging site to stop people and animals falling in; when the well is completed it should have a child-proof surrounding fence and cover.
Other Safety Aspects to consider for the completed well;
- Provide an above-ground wall around the completed well to prevent children and animals from falling into the well - a drowning hazard.
- Provide a safety screen over the above-ground wall to prevent children from falling in to the well
- Provide a child-safe heavy, secure cover at ground level for dug wells with no above-ground wall or for any below-ground well pit.
- Direct surface runoff away from the well and test the water frequently for potability and for other surface-borne water contaminants.
- Beware of hand dug well collapse hazards - do not ever enter a hand dug well unless you are properly trained and do not work there alone.
- Test hand dug well water regularly for potability - since these wells commonly have sanitation issues.
- Abandoning a hand-dug well - requires that the well be protected from someone falling into the well; a smart abandonment will also protect the dug well from being used as a refuse or chemical dump - doing so risks contaminating the aquifer and is illegal in most jurisdictions.
Source: The Hand Dug Well [instruction manual, by Henk Holtslag & John deWolf