Nancy Pearce

Fatality in a water tank reminds us about importance of confined space safety procedures

Blog Post created by Nancy Pearce Employee on Dec 19, 2016

The recent death of a worker in a water tank in Braintree, Massachusetts this past week provides a grim reminder of the importance of following safe entry procedures for all confined spaces.

Water tanks are confined spaces because they are not normally occupied and their design and configuration offer limited means for entry and exit. When they are entered for the purpose of periodic inspection and maintenance it is essential for workers to be familiar with the characteristic hazards of such spaces and to have a plan for safe entry, work, and exit. Typically these tanks are entered through a hatch in the top of the tank, requiring workers to climb to the top of the tank, where there might not be guardrails around the top to prevent falls and often there are no appropriate anchorage points for the connection of fall protection devices.   Atmospheres inside the tank can be unsafe due to rusting or decomposition of residual debris which can lead to unsafe levels of oxygen or other atmospheric hazards.   Water tanks may also be covered with snow or ice, leading to slip hazards. Rescue from these spaces is also a challenge because of the elevation and the possibility for the rescuers falling.  

In this recent incident, reports indicate there were two workers on the top of the tank. The tank did not appear to have guardrails on top and it is unclear if there were anchorage points in the vicinity of the hatch. The victim (the entrant) was inside the water tank wearing diving equipment to inspect the tank while a “spotter” was outside the tank. The spotter in this case acted like the “attendant” in a confined space entry. When it became apparent that the diver’s equipment was compromised, the spotter “heroically” jumped into the space in an attempt to rescue his coworker. Ultimately, the spotter had to be rescued by fire department and technical rescue personnel.

There are on average 100 deaths per year caused by confined spaces. It is estimated that 60% of fatalities that occur in confined spaces involve the “would be” rescuers. The spotter who dove into the tank was rescued but could have become the second victim in this incident for a myriad of reasons including a hazardous atmosphere above the water level due to oxygen deficiency, a condition that frequently occurs when a metal tank rusts and uses up oxygen. Entering a space without testing is risky, which is why NFPA 350, Guide for Safe Confined Space Entry and Work, recommends atmospheric testing all confined spaces prior to entry to ensure there is no hazardous atmosphere.

Safe confined space entry procedures that include identification, evaluation and control of hazards in and adjacent to confined spaces are addressed in the guide.   The document provides guidance beyond OSHA regulations and explains “How To” comply with requirements in OSHA regulations, including best practices for entering into and providing rescue from confined spaces.   Prevention through Design (PtD) information is also addressed and covers safe design practices such as designing guardrails, anchorage points or other means of fall protection in or adjacent to confined spaces.

You can view NFPA 350 free of charge on line at the document information page found at   If you are unsure whether you have a confined space in your workplace check out this a free 5 minute video available.

An online training program is also available and site specific training is also available on request. Click on the training tab for further information. Additional questions on confined spaces and the new NFPA 350 Guide for Safe Confined Space Entry or work can be directed to me at