Featured Video: The Science Behind Exploding Manhole Covers

Every season has its challenges for public works departments, and now that spring is just around the corner, it is pretty obvious that this past winter came with more than its fair share. Yet we are not in the clear quite yet, as this news story about two manhole explosions just a few weeks ago demonstrates. In fact, as winter winds down, accumulated road salt compounds corrode through underground electrical cables, causing sparks to ignite gases that can build up in confined spaces. With over 2,000 annual incidents in New York City alone, exploding manholes are not a joke: they can be dangerous, destructive and downright difficult to predict.

And while large cities like New York City are especially prone to these incidents due to aging infrastructure and the sheer amount of underground electrical cables present, small towns are definitely not immune. For example, in 2014 the tiny town of Sauget, Illinois (pop. 150) experienced an explosion so powerful manhold covers damaged overhead power lines.  

 Find out more about how road salt compounds contribute to this problem in this week's featured video.  

While explosions are the most dramatic hazard associated with manholes, research suggests that manholes are in general one of the most dangerous work locations for water system staff. In fact, according to AFSCME, fully one-third of all injuries/deaths of workers occur in or around manholes. Check out this safety presentation hosted by Michigan WEA for more information on the types of hazards presented by manholes and how to protect yourself from them. 

And if you have any lingering doubts about the force, and destructive power, of an expoding manhole, take a look at this video. 

Featured Video: An Inflow and Infiltration Reduction Program in Missouri

Inflow and infiltration (I/I) can be very costly for small communities, especially those communities with outdated combined wastewater/stormwater systems or collection systems in poor repair. According to this classic National Small Flows Clearinghouse article, I/I problems place additional burdens on these older and/or fragile systems because the extra water that seeps or flows into them can be very damaging, and, in some cases, even cause contamination issues.

This week's featured video describes how the City of Columbia, Missouri is attempting to locate, identify, and correct improper connections and defects that cause these inflow and infiltration problems so that their system capacity improves, and sanitary sewer overflows and basement backups are eliminated.