https://techcrunch.com/2021/06/24/nixies-drone-based-water-sampling-could-save-cities-time-and-money/

Regularly testing waterways and reservoirs is a never-ending responsibility for utility companies and municipal safety authorities, and generally — as you might expect — involves either a boat or at least a pair of waders. Nixie does the job with a drone instead, making the process faster, cheaper, and a lot less wet.

The most common methods of testing water quality haven’t changed in a long time, partly because they’re effective and straightforward, and partly because really, what else are you going to do? No software or web platform out there is going to reach into the middle of the river and pull out a liter of water.