How do sewers work near sea level

As a sewing machine operator I was quite confused with your question for longer than I care to admit.

Wouldn't pumps be used?

Thanks for the question, we shall all go down the rabbit hole together, hahahaha

Still looking... talks about gravity at 4min mark...

Practical Engineering - How Swewes Work (feat. Fake Poop): https://www.youtube.com/watch?v=UpHOkHxpTvQ

a lot of the time, nothing is done – it’s just dumped straight into the ocean

Giant pumps.

"Watewster pump stations" being the industry term.

Don’t have the link handy, but there’s a video out there about Chicagos approach to this and it’s absolutely nuts. The amount of infrastructure they’ve put in place, and sewage still ends up in the lake.

The answer is that it is there you just don't see it. Like for example NYC has Tallman Island and an underground one on the West Side. It also depends on what exactly are you dealing with. For ground water (that little stream you might see by the beach) there might be a tiny treatment plant that dumps what is processed into the ocean. Bradley Beach NJ has one of those.

As others have pointed out pumps are a thing. In some situations you can do a degree of preprocessing before it hits the mainlines.

In most seaside towns, sewage is taken directly to the sea, through a long pipe

I'm no expert but I wonder if where there's limited space for traditional sewage treatment plants, wastewater is just transported through a network of sewer lines to centralized treatment facilities? 🤔

This would allow the treatment plants to be located further inland.

Alternaively I guess they could employ on-site treatment technologies that can be incorporated into the building's infrastructure 🤔

But like I said I ain't no expert and just speculating 😅