September 21, 2026
This week’s photo is courtesy of- K.P. Ventures Drilling and Pump - Camp Verde, AZ, USA.
Safety Focus
Part 1 of 4: Confined Space Entry: Why It Matters
From 2011 to 2018, 1,030 workers in the United States died in incidents involving a confined space. That is the Bureau of Labor Statistics (BLS) count from its Census of Fatal Occupational Injuries. The annual figures ran from a low of 88 in 2012 to a high of 166 in 2017. Eight years, and no downward trend.
Read the breakdown and the job starts looking familiar. BLS could identify the type of space in 643 of those cases. Sewers, manholes and storm drains accounted for 61 deaths. Septic tank and water tank interiors, 19. Wells and cisterns, 10. Pits, vaults, lift stations and manholes are not somebody else's problem.
Here is what makes this hazard different from every other one we cover. A large share of the dead are the people who went in after somebody else. NIOSH's surveillance system counted about 89 confined space deaths a year from 1980 to 1989, and roughly 20 of them each year, about 22 percent, happened during rescue attempts. Its FACE investigators reviewed 68 confined space incidents from 1982 to 1992 that killed 104 workers, and 36 of those, 35 percent, died trying to get somebody else out. One man goes down. A second man goes in after him. Sometimes a third.
That happens because whatever drops the first man is usually invisible. Of those 1,030 deaths, 126 involved inhaling a harmful substance in a single episode. The most common gases were hydrogen sulfide, at 38 cases, and carbon monoxide, at 23. Another 39 deaths came from plain depletion of oxygen. No smoke. No noise. Nothing to see from the top of the hole.
This week we work the problem in order. Tuesday, how to recognize a confined space and a permit-required confined space, and which OSHA standard actually applies to the work you are doing. Wednesday, atmospheric testing, ventilation and the attendant. Thursday, the written program and the rescue plan that keeps the second man out of the hole.
The takeaway for Monday: a confined space does not always look dangerous. That is the entire problem.
Key Takeaways
• BLS recorded 1,030 confined space fatalities from 2011 to 2018, with no downward trend over those eight years.
• Sewers, manholes, storm drains, water tanks, septic tanks, wells and cisterns all appear in the count.
• NIOSH surveillance puts 22 to 35 percent of confined space deaths among workers attempting a rescue.
• Atmospheric hazards give you nothing to see from outside the space.
Sources:
• U.S. Bureau of Labor Statistics: Fatal Occupational Injuries Involving Confined Spaces
• CDC, Morbidity and Mortality Weekly Report: Fatalities Attributed to Entering Manure Waste Pits, Minnesota, 1992, with NIOSH confined space surveillance data
Knowledge Share
Part 1 of 4: Pump Test Interpretation: Why It Matters
Last week we solved for transmissivity and storativity from time-drawdown data using Theis and Cooper-Jacob. The math works. This week we deal with the part that decides whether the math means anything, which is the test that produced the numbers.
A pumping test, also called an aquifer test, is a controlled experiment. You stress the aquifer by pumping a well at a known rate, and you measure how water levels respond in that well and in nearby wells. Everything you get out of it, transmissivity, storativity, boundary conditions, well performance, comes from that record of rate and response.
Three terms, in plain words. The pumping well is the well you pump. An observation well is a separate well where you measure the water level but do not pump. Drawdown is the drop in water level from the static, pre-pumping level, measured in feet.
Here is why design decides everything. Every analytical method you will use makes assumptions about the test: that the rate was constant, that you know the distance from the pumping well to the point where drawdown was measured, that you know what the water level was doing before you started, and that the test ran long enough for the aquifer to answer. If the test does not deliver those conditions, the equations still produce a number. It just will not be the aquifer's number.
That is the trap. A bad test does not fail loudly. It does not throw a code or blow a hose. It hands you a clean-looking transmissivity that somebody then uses to size a pump, space a well field, or write a yield guarantee, and nobody downstream has any way to know the number was never good.
This week: Tuesday, step tests versus constant-rate tests and where the observation wells go. Wednesday, the field setup. Thursday, the design errors that quietly ruin a test.
What this means for your next design: Before you agree to a test schedule, ask what the data is going to be used for. A test designed to size a pump is not the same test as one designed to defend an aquifer yield estimate to a regulator. Decide the question first, then design backward from it.
Sources:
• S. Geological Survey: Aquifer-Test Design, Observation, and Data Analysis (TWRI 3-B1)
Recommended Print References:
• Hydraulics of Wells: American Society of Civil Engineers
• Handbook of Ground Water Development- Roscoe Moss Company
• Groundwater & Wells, Third Edition- Edited by Robert J. Sterrett, Johnson Screens
Vendor Directory
Premium Vendors-
Become a Premium or Plus vendor and increase your exposure. Claim your company and upgrade or list your company at https://waterwellresource.com/become-a-listed-vendor/
Basic Vendors-
Work Hard. Work Smart. Stay Safe!
