https://en.wikipedia.org/wiki/List_of_largest_wastewater_treatment_plants
https://www.mswmag.com/bytes/2025/03/the-most-complex-sewer-systems-in-the-world
https://www.zoomdrain.com/blog/2022/september/the-worlds-largest-sewer-is-in-tokyo-and-its-unb/
https://www.slate.com/blogs/atlas_obscura/2013/05/17/g_gans_the_world_s_largest_drain_sits_below_saitama_japan.html , https://www.youtube.com/watch?v=b7jIqru1Nzo
While its very unlikely that there are monsters in the NYC sewers like in the movie C.H.U.D., there are still some dangerous things down there.
https://en.wikipedia.org/wiki/C.H.U.D.#Plot
Entertainment and excrement, WTF?
The monster in the sewer theme has been around for quite a while.
https://en.wikipedia.org/wiki/It_(1986 novel)
There’s no threat to the public, and officers have scoured the sewer system to make sure “nothing nefarious had been left behind,” a law enforcement source said. https://www.nbcnews.com/news/us-news/police-investigate-videos-men-mysteriously-emerging-new-york-city-sewe-rcna347914
When some men are seen mysteriously emerging from the sewer, it must be investigated immediately. Sometimes drills are conducted by various agencies, that local law enforcement might not always be aware of. Thus, its important that good interagency communication is maintained.
https://www.cbsnews.com/newyork/news/brooklyn-sewer-manhole-video-urban-explorers/
Whether its some urban explorers, robbers, or someone wanting to plant something dangerous, every manhole cover should have some kind of a sensor tag, or security seal.
https://www.cbsnews.com/newyork/news/manhole-brooklyn-sewer-system-break-in-video/
https://people.com/cause-of-death-revealed-grandma-died-after-falling-into-uncovered-manhole-nyc-11979445 The tragic incident of a woman-who-fell-into-NYC-manhole-and-died-of-scald-burns-and-other-injuries shouldn't have happened.
https://www.reddit.com/r/nyc/comments/1tu29o6/police_investigate_videos_of_men_mysteriously/
Any manhole cover should never be left unattended, not just because a person can fall in, but if someone wants to use it for access to plant a device to cause harm.
https://thedigitallabyrinth.blogspot.com/search?q=New+York+City+sewers
While urban explorers and treasurer hunters might be of no bad intent, there is always the potential for someone to go there to cause trouble.
https://thedigitallabyrinth.blogspot.com/search?q=New+York+City+sewers
