Our UK associates were delighted to see a pair of Priorclave research autoclaves featured in a recent episode of Blue Planet UK on BBC One:
The noble task of those autoclaves? Helping scientist breakdown and analyze a massive “fatberg” found clogging the sewers of Sidmouth (an otherwise lovely fishing village in South West England).
Blue Planet‘s televised fatberg autopsy revealed that this particular sewer clog—composed of fat, oil, grease, wet-wipes, hair, shame, regret, and other not-exactly-flushables—was the size of six double-decker buses, heavier than a pair of humpback whales, hard as concrete.
— BBC Breakfast (@BBCBreakfast) March 27, 2019
Kudos to BBC for choosing to air this item as part of BBC Breakfast.
Fatberg Autopsy & the Science of Fatberg Accumulation
Headlines usually focus on the content of a fatberg—fat, oil, grease, baby wipes, and furiously reproducing bacteria colonies. But research has shown that your average fatberg is just as much a result of fluid dynamics as human filthiness:
Fatbergs usually only form on the inside of rough-surfaced sewer channels. This may be because the sewer line itself is particularly craggy (like the older rough-hewn brick and concrete sewer systems beneath cities like London). Or the line may have begun to degrade or been compromised by plant roots.
When a pipe is smooth, fluid flows through it fairly uniformly, carrying away debris, fat, oil, and other don’t-flushables. But if the fluid flow becomes turbulent—for example, in a rough-hewn brick tunnel—the water swirls, collecting and compressing denser debris. From there, you have a classic snowball (“fatball”?) effect:
As the fatberg grows, it further constructs the pipe, increasing turbulence, and thus increasing its ability to pull in and compact ever more fat, oil, grease, and filth.
Fatbergs are most often associated with the London (and its aging Victorian Sewer system). The Museum of London even went so far as to mount extremely popular exhibit dedicated to the great Whitechapel Fatberg. (FUN FACT: Most of that fatbergs was ultimately converted into biodiesel.) But the U.S. is hardly immune to fatbergs. Here in the U.S., almost half of all sewer blockages are caused by congealed grease—i.e., either established fatbergs, or their embryonic buddings—despite our generally newer and more robust sanitary sewer systems.